- Chapter 2 Adequate Nutrients Within Calorie Needs
- KEY RECOMMENDATIONS
- Meeting Recommended Intakes Within Energy Needs
- Variety Among and Within Food Groups
- Nutrient-Dense Foods
- Nutrients of Concern
- Considerations for Specific Population Groups
- People Over 50 and Vitamin B12
- Women and Iron
- Women and Folic Acid
- Special Groups and Vitamin D
- Flexibility of Food Patterns for Varied Food Preferences
- Vegetarian Choices
- Substitutions for Milk and Milk Products
- TABLE 1. Sample USDA Food Guide and the DASH Eating Plan at the 2,000-Calorie Levela
- TABLE 2. Comparison of Selected Nutrients in the Dietary Approaches to Stop Hypertension (DASH) Eating Plana, the USDA Food Guideb, and Nutrient Intakes Recommended Per Day by the Institute of Medicine (IOM)c
- TABLE 3. Estimated Calorie Requirements (in Kilocalories) for Each Gender and Age Group at Three Levels of Physical Activitya
- Can you gain weight from eating too little? No, but here’s why it’s so easy to think you can.
- “How can I be eating so little, and still gaining weight?”
- Truth: Thermodynamics don’t lie.
- Measuring metabolism is tricky.
- Not only that, but the idea of “eating too little” is subjective.
- Most times, the problem is perception.
- Even more, the dynamic nature of metabolism can be confusing.
- Plus, humans are incredibly diverse.
- And yes, water retention is a thing.
- OK, but what if I track my intake and expenditure meticulously?
- What about legitimate medical problems?
- So what can you do?
- If you’re a coach or professional, here’s how to help people with this.
- A final note on body composition.
- If you’re a coach, or you want to be…
- Interested? Add your name to the presale list. You’ll save up to 30% and secure your spot 24 hours before everyone else.
- Low-Calorie Diets Mean High-Quality Lives, Research Shows
- What Is a Low-Calorie Diet?
- Good Reasons to Try a Low-Calorie Diet
- What Happens When People Restrict Calories?
- Is a Low-Calorie Diet Right for You?
- Appendix 2. Estimated Calorie Needs per Day, by Age, Sex, and Physical Activity Level
- Calories: How to Know if You Go Too Low
- Other Issues
Chapter 2 Adequate Nutrients Within Calorie Needs
Many Americans consume more calories than they need without meeting recommended intakes for a number of nutrients. This circumstance means that most people need to choose meals and snacks that are high in nutrients but low to moderate in energy content; that is, meeting nutrient recommendations must go hand in hand with keeping calories under control. Doing so offers important benefitsnormal growth and development of children, health promotion for people of all ages, and reduction of risk for a number of chronic diseases that are major public health problems.
Based on dietary intake data or evidence of public health problems, intake levels of the following nutrients may be of concern for:
At the same time, in general, Americans consume too many calories and too much saturated and trans fats, cholesterol, added sugars, and salt.
- Consume a variety of nutrient-dense foods and beverages within and among the basic food groups while choosing foods that limit the intake of saturated and trans fats, cholesterol, added sugars, salt, and alcohol.
- Meet recommended intakes within energy needs by adopting a balanced eating pattern, such as the USDA Food Guide or the DASH Eating Plan.
Key Recommendations for Specific Population Groups
- People over age 50. Consume vitamin B12 in its crystalline form (i.e., fortified foods or supplements).
- Women of childbearing age who may become pregnant. Eat foods high in heme-iron and/or consume iron-rich plant foods or iron-fortified foods with an enhancer of iron absorption, such as vitamin C-rich foods.
- Women of childbearing age who may become pregnant and those in the first trimester of pregnancy. Consume adequate synthetic folic acid daily (from fortified foods or supplements) in addition to food forms of folate from a varied diet.
- Older adults, people with dark skin, and people exposed to insufficient ultraviolet band radiation (i.e., sunlight). Consume extra vitamin D from vitamin D-fortified foods and/or supplements.
Meeting Recommended Intakes Within Energy Needs
A basic premise of the Dietary Guidelines is that food guidance should recommend diets that will provide all the nutrients needed for growth and health. To this end, food guidance should encourage individuals to achieve the most recent nutrient intake recommendations of the Institute of Medicine, referred to collectively as the Dietary Reference Intakes (DRIs). Tables of the DRIs are provided at http://www.iom.edu/Object.File/Master/21/372/0.pdf.
An additional premise of the Dietary Guidelines is that the nutrients consumed should come primarily from foods. Foods contain not only the vitamins and minerals that are often found in supplements, but also hundreds of naturally occurring substances, including carotenoids, flavonoids and isoflavones, and protease inhibitors that may protect against chronic health conditions. There are instances when fortified foods may be advantageous, as identified in this chapter. These include providing additional sources of certain nutrients that might otherwise be present only in low amounts in some food sources, providing nutrients in highly bioavailable forms, and where the fortification addresses a documented public health need.
Two examples of eating patterns that exemplify the Dietary Guidelines are the DASH Eating Plan and the USDA Food Guide. These two similar eating patterns are designed to integrate dietary recommendations into a healthy way to eat and are used in the Dietary Guidelines to provide examples of how nutrient-focused recommendations can be expressed in terms of food choices. Both the USDA Food Guide and the DASH Eating Plan differ in important ways from common food consumption patterns in the United States. In general, they include:
- More dark green vegetables, orange vegetables, legumes, fruits, whole grains, and low-fat milk and milk products.
- Less refined grains, total fats (especially cholesterol, and saturated and trans fats), added sugars, and calories.
Both the USDA Food Guide and the DASH Eating Plan are constructed across a range of calorie levels to meet the nutrient needs of various age and gender groups. Table 1 provides food intake recommendations, and table 2 provides nutrient profiles for both the DASH Eating Plan and the USDA Food Guide at the 2,000-calorie level. These tables illustrate the many similarities between the two eating patterns. Additional calorie levels are shown in appendixes A-1 and A-2 for the USDA Food Guide and the DASH Eating Plan. The exact amounts of foods in these plans do not need to be achieved every day, but on average, over time. Table 3 can aid in identification of an individual’s caloric requirement based on gender, age, and physical activity level.
Variety Among and Within Food Groups
Each basic food group5 is the major contributor of at least one nutrient while making substantial contributions of many other nutrients. Because each food group provides a wide array of nutrients in substantial amounts, it is important to include all food groups in the daily diet.
Both illustrative eating patterns include a variety of nutrient-dense foods within the major food groups. Selecting a variety of foods within the gran, vegetable, fruit, and meat groups may help to ensure that an adequate amount of nutrients and other potentially beneficial substances are consumed. For example, fish contains varying amounts of fatty acids that may be beneficial in reducing cardiovascular disease risk (see ch. 6).
Nutrient-dense foods are those foods that provide substantial amounts of vitamins and minerals (micronutrients) and relatively few calories. Foods that are low in nutrient density are foods that supply calories but relatively small amounts of micronutrients, sometimes none at all. The greater the consumption of foods or beverages that are low in nutrient density, the more difficult it is to consume enough nutrients without gaining weight, especially for sedentary individuals. The consumption of added sugars, saturated and trans fats, and alcohol provides calories while providing little, if any, of the essential nutrients. (See ch. 7 for additional information on added sugars, ch. 6 for information on fats, and ch. 9 for information on alcohol.)
Selecting low-fat forms of foods in each group and forms free of added sugarsin other words nutrient-dense versions of foodsprovides individuals a way to meet their nutrient needs while avoiding the overconsumption of calories and of food components such as saturated fats. However, Americans generally do not eat nutrient-dense forms of foods. Most people will exceed calorie recommendations if they consistently choose higher fat foods within the food groupseven if they do not have dessert, sweetened beverages, or alcoholic beverages.
If only nutrient-dense foods are selected from each food group in the amounts proposed, a small amount of calories can be consumed as added fats or sugars, alcohol, or other foodsthe discretionary calorie allowance. Appendixes A-2 and A-3 show the maximum discretionary calorie allowance that can be accommodated at each calorie level in the USDA Food Guide. Eating in accordance with the USDA Food Guide or the DASH Eating Plan will also keep intakes of saturated fat, total fat, and cholesterol within the limits recommended in chapter 6.
Nutrients of Concern
The actual prevalence of inadequacy for a nutrient can be determined only if an Estimated Average Requirement (EAR) has been established and the distribution of usual dietary intake can be obtained. If such data are not available for a nutrient but there is evidence for a public health problem associated with low intakes, a nutrient might still be considered to be of concern.
Based on these considerations, dietary intakes of the following nutrients may be low enough to be of concern for:
Efforts may be warranted to promote increased dietary intakes of potassium, fiber, and possibly vitamin E, regardless of age; increased intakes of calcium and possibly vitamins A (as carotenoids) and C and magnesium by adults; efforts are warranted to increase intakes of calcium and possibly magnesium by children age 9 years or older. Efforts may be especially warranted to improve the dietary intakes of adolescent females in general. Food sources of these nutrients are shown in appendix B.
Low intakes of fiber tend to reflect low intakes of whole grains, fruits, and vegetables. Low intakes of calcium tend to reflect low intakes of milk and milk products. Low intakes of vitamins A (as carotenoids) and C and magnesium tend to reflect low intakes of fruits and vegetables. Selecting fruits, vegetables, whole grains, and low-fat and fat-free milk and milk products in the amounts suggested by the USDA Food Guide and the DASH Eating Plan will provide adequate amounts of these nutrients.
Most Americans of all ages also need to increase their potassium intake. To meet the recommended potassium intake levels, potassium-rich foods from the fruit, vegetable, and dairy groups must be selected in both the USDA Food Guide and the DASH Eating Plan. Foods that can help increase potassium intake are listed in table 5 (ch. 5) and appendix B-1.
Most Americans may need to increase their consumption of foods rich in vitamin E (α-tocopherol) while decreasing their intake of foods high in energy but low in nutrients. The vitamin E content in both the USDA Food Guide and the DASH Eating Plan is greater than current consumption, and specific vitamin E-rich foods need to be included in the eating patterns to meet the recommended intake of vitamin E. Foods that can help increase vitamin E intake are listed in appendix B-2, along with their calorie content. Breakfast cereal that is fortified with vitamin E is an option for individuals seeking to increase their vitamin E intake while consuming a low-fat diet.
In addition, most Americans need to decrease sodium intake. The DASH Eating Plan provides guidance on how to keep sodium intakes within recommendations. When using the USDA Food Guide, selecting foods that are lower in sodium than others is especially necessary to meet the recommended intake level at calorie levels of 2,600/day and above. Food choices that are lower in sodium are identified in chapter 8.
Considerations for Specific Population Groups
People Over 50 and Vitamin B12
Although a substantial proportion of individuals over age 50 have reduced ability to absorb naturally occurring vitamin B12, they are able to absorb the crystalline form. Thus, all individuals over the age of 50 should be encouraged to meet their Recommended Dietary Allowance (RDA) (2.4 µg/day) for vitamin B12 by eating foods fortified with vitamin B12 such as fortified cereals, or by taking the crystalline form of vitamin B12 supplements.
Women and Iron
Based on blood values, substantial numbers of adolescent females and women of childbearing age are iron deficient. Thus, these groups should eat foods high in heme-iron (e.g., meats) and/or consume iron-rich plant foods (e.g., spinach) or iron-fortified foods with an enhancer of iron absorption, such as foods rich in vitamin C (e.g., orange juice). Appendix B-3 lists foods that can help increase iron intake and gives their iron and calorie content.
Women and Folic Acid
Since folic acid reduces the risk of the neural tube defects, spina bifida, and anencephaly, a daily intake of 400 µg/day of synthetic folic acid (from fortified foods or supplements in addition to food forms of folate from a varied diet) is recommended for women of childbearing age who may become pregnant. Pregnant women should consume 600 µg/day of synthetic folic acid (from fortified foods or supplements) in addition to food forms of folate from a varied diet. It is not known whether the same level of protection could be achieved by using food that is naturally rich in folate.
Special Groups and Vitamin D
Adequate vitamin D status, which depends on dietary intake and cutaneous synthesis, is important for optimal calcium absorption, and it can reduce the risk for bone loss. Two functionally relevant measures indicate that optimal serum 25-hydroxyvitamin D may be as high as 80 nmol/L. The elderly and individuals with dark skin (because the ability to synthesize vitamin D from exposure to sunlight varies with degree of skin pigmentation) are at a greater risk of low serum 25-hydroxyvitamin D concentrations. Also at risk are those exposed to insufficient ultraviolet radiation (i.e., sunlight) for the cutaneous production of vitamin D (e.g., housebound individuals).
For individuals within the high-risk groups, substantially higher daily intakes of vitamin D (i.e., 25 µg or 1,000 International Units (IU) of vitamin D per day) have been recommended to reach and maintain serum 25-hydroxyvitamin D values at 80 nmol/L. Three cups of vitamin D- fortified milk (7.5 µg or 300 IU), 1 cup of vitamin D-fortified orange juice (2.5 µg or 100 IU), and 15 µg (600 IU) of supplemental vitamin D would provide 25 µg (1,000 IU) of vitamin D daily.
The combination of thirst and normal drinking behavior, especially the consumption of fluids with meals, is usually sufficient to maintain normal hydration. Healthy individuals who have routine access to fluids and who are not exposed to heat stress consume adequate water to meet their needs. Purposeful drinking is warranted for individuals who are exposed to heat stress or perform sustained vigorous activity (see ch. 4).
Flexibility of Food Patterns for Varied Food Preferences
The USDA Food Guide and the DASH Eating Plan are flexible to permit food choices based on individual and cultural food preferences, cost, and availability. Both can also accommodate varied types of cuisines and special needs due to common food allergies. Two adaptations of the USDA Food Guide and the DASH Eating Plan are:
Vegetarians of all types can achieve recommended nutrient intakes through careful selection of foods. These individuals should give special attention to their intakes of protein, iron, and vitamin B12, as well as calcium and vitamin D if avoiding milk products. In addition, vegetarians could select only nuts, seeds, and legumes from the meat and beans group, or they could include eggs if so desired. At the 2,000-calorie level, they could choose about 1.5 ounces of nuts and 2/3 cup legumes instead of 5.5 ounces of meat, poultry, and/or fish. One egg, ½ ounce of nuts, or ¼ cup of legumes is considered equivalent to 1 ounce of meat, poultry, or fish in the USDA Food Guide.
Substitutions for Milk and Milk Products
Since milk and milk products provide more than 70 percent of the calcium consumed by Americans, guidance on other choices of dietary calcium is needed for those who do not consume the recommended amount of milk products. Milk product consumption has been associated with overall diet quality and adequacy of intake of many nutrients, including calcium, potassium, magnesium, zinc, iron, riboflavin, vitamin A, folate, and vitamin D. People may avoid milk products because of allergies, cultural practices, taste, or other reasons. Those who avoid all milk products need to choose rich sources of the nutrients provided by milk, including potassium, vitamin A, and magnesium in addition to calcium and vitamin D (see app. B). Some non-dairy sources of calcium are shown in appendix B-4. The bioavailability of the calcium in these foods varies.
Those who avoid milk because of its lactose content may obtain all the nutrients provided by the milk group by using lactose-reduced or low-lactose milk products, taking small servings of milk several times a day, taking the enzyme lactase before consuming milk products, or eating other calcium-rich foods. For additional information, see appendixes B-4 and B-5 and NIH Publication No. 03-2751.6
TABLE 1. Sample USDA Food Guide and the DASH Eating Plan at the 2,000-Calorie Levela
Amounts of various food groups that are recommended each day or each week in the USDA Food Guide and in the DASH Eating Plan (amounts are daily unless otherwise specified) at the 2,000-calorie level. Also identified are equivalent amounts for different food choices in each group. To follow either eating pattern, food choices over time should provide these amounts of food from each group on average.
Note: Table updated to reflect 2006 DASH Eating Plan.
|Food Groups and Subgroups||USDA Food Guide Amountb||DASH Eating Plan Amount||Equivalent Amounts|
|Fruit Group||2 cups (4 servings)||2 to 2.5 cups
(4 to 5 servings)
| ½ cup equivalent is:
| Vegetable Group
||2.5 cups (5 servings)
|2 to 2.5 cups
(4 to 5 servings)
| ½ cup equivalent is:
| Grain Group
|6 to 8 ounce-equivalents
(6 to 8 servingsc)
|1 ounce-equivalent is:
|Meat and Beans Group||5.5 ounce-equivalents||6 ounces or less meats, poultry, fish||1 ounce-equivalent is:
|4 to 5 servings per week nuts, seeds, and legumesd|
|Milk Group||3 cups||2 to 3 cups||1 cup equivalent is:
|Oils||27 grams (6 tsp)||8 to 12 grams (2 to 3 tsp)||DASH: 1 tsp equivalent is:
| Discretionary Calorie Allowance
|~2 tsp of added sugar (5 Tbsp per week)||DASH: 1 Tbsp added sugar equivalent is:
a All servings are per day unless otherwise noted. USDA vegetable subgroup amounts and amounts of DASH nuts, seeds, and dry beans are per week.
b The 2,000-calorie USDA Food Guide is appropriate for many sedentary males 51 to 70 years of age, sedentary females 19 to 30 years of age, and for some other gender/age groups who are more physically active. See table 3 for information about gender/age/activity levels and appropriate calorie intakes. See appendixes A-2 and A-3 for more information on the food groups, amounts, and food intake patterns at other calorie levels.
c Whole grains are recommended for most grain servings to meet fiber recommendations.
d In the DASH Eating Plan, nuts, seeds, and legumes are a separate food group from meats, poultry, and fish.
e Since eggs are high in cholesterol, limit egg yolk intake to no more than 4 per week; 2 egg whites have the same protein content as 1 oz of meat.
f The oils listed in this table are not considered to be part of discretionary calories because they are a major source of the vitamin E and polyunsaturated fatty acids, including the essential fatty acids, in the food pattern. In contrast, solid fats (i.e., saturated and trans fats) are listed separately as a source of discretionary calories.
TABLE 2. Comparison of Selected Nutrients in the Dietary Approaches to Stop Hypertension (DASH) Eating Plana, the USDA Food Guideb, and Nutrient Intakes Recommended Per Day by the Institute of Medicine (IOM)c
Estimated nutrient levels in the DASH Eating Plan and the USDA Food Guide at the 2,000-calorie level, as well as the nutrient intake levels recommended by the Institute of Medicine for females 19-30 years of age.
Note: Table updated to reflect 2006 DASH Eating Plan.
a DASH nutrient values are based on a 1-week menu of the DASH Eating Plan. Visit www.nhlbi.nih.gov.
b USDA nutrient values are based on population-weighted averages of typical food choices within each food group or subgroup.
c Recommended intakes for adult females 19-30; RDA = Recommended Dietary Allowance; AI = Adequate Intake; AMDR = Acceptable Macronutrient Distribution Range; UL = Upper Limit.
d As Low As Possible while consuming a nutritionally adequate diet.
e Amount listed is based on 14 g dietary fiber/1,000 kcal.
f The DASH Eating Plan also can be used to follow at 1,500 mg sodium per day.
g AT = mg d-α-tocopherol
h RAE = Retinol Activity Equivalents
TABLE 3. Estimated Calorie Requirements (in Kilocalories) for Each Gender and Age Group at Three Levels of Physical Activitya
Estimated amounts of calories needed to maintain energy balance for various gender and age groups at three different levels of physical activity. The estimates are rounded to the nearest 200 calories and were determined using the Institute of Medicine equation.
a These levels are based on Estimated Energy Requirements (EER) from the Institute of Medicine Dietary Reference Intakes macronutrients report, 2002, calculated by gender, age, and activity level for reference-sized individuals. “Reference size,” as determined by IOM, is based on median height and weight for ages up to age 18 years of age and median height and weight for that height to give a BMI of 21.5 for adult females and 22.5 for adult males.
b Sedentary means a lifestyle that includes only the light physical activity associated with typical day-to-day life.
c Moderately active means a lifestyle that includes physical activity equivalent to walking about 1.5 to 3 miles per day at 3 to 4 miles per hour, in addition to the light physical activity associated with typical day-to-day life
d Active means a lifestyle that includes physical activity equivalent to walking more than 3 miles per day at 3 to 4 miles per hour, in addition to the light physical activity associated with typical day-to-day life.
e The calorie ranges shown are to accommodate needs of different ages within the group. For children and adolescents, more calories are needed at older ages. For adults, fewer calories are needed at older ages.
5 The food groups in the USDA Food Guide are grains; vegetables; fruits; milk, yogurt, and cheese; and meat, poultry, fish, dry beans, eggs, and nuts. Food groups in the DASH Eating Plan are grains and grain products; vegetables; fruits; low-fat or fat-free dairy; meat, poultry, and fish; and nuts, seeds, and dry beans.
6 NIH Publication No. 03-2751, U.S. Department of Health and Human Services, National Institutes of Health, National Institute of Diabetes and Digestive and Kidney Diseases, March 2003. http://digestive.niddk.nih.gov/ddiseases/pubs/lactoseintolerance/index.htm.
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Updated Wednesday, July 09, 2008 by ODPHP Web Support
Can you gain weight from eating too little? No, but here’s why it’s so easy to think you can.
You’re tracking your eating and exercise meticulously but not seeing results. Has your metabolism slowed to a crawl? Are your hormones off? Is it really possible to GAIN weight from eating too LITTLE? Here’s what’s really going on—and how to solve it.
- Want to listen instead of read?
“How can I be eating so little, and still gaining weight?”
Have you ever felt this way? (Or had a client who has?)
In my years as a coach, it’s a question that’s come up time and time again—from both clients and fellow coaches.
They’re confused. Frustrated. Maybe even angry. (Or certainly “hangry.”)
Despite doing everything they can, including eating less—maybe a lot less—they’re still not losing weight. In fact, they might even be gaining.
Do a quick Internet search and you’re bound to find lots of explanations.
Some folks say that the laws of energy balance apply, and that people aren’t counting calories properly. Others call it “starvation mode”, or some weird metabolic or hormonal problem.
So what’s the deal? Is there something wrong with them? Are their bodies broken? Is it all in their heads?
Or can you actually gain weight from eating too little?
Let’s find out.
Truth: Thermodynamics don’t lie.
You’ve probably heard the phrase—the laws of thermodynamics—before. Or maybe you’ve heard it as energy balance. Or “calories in, calories out.”
Let’s break down what it actually means.
Thermodynamics is a way to express how energy is used and changed. Put simply, we take in energy in the form of food, and we expend energy through activities like:
- basic metabolic functions (breathing, circulating blood, etc.)
- movement (daily-life activity, purposeful exercise, etc.)
- producing heat (also called thermogenesis)
- digestion and excretion
And, the truth is…
Energy balance (calories in, calories out) does determine bodyweight.
- If we absorb more energy than we expend, we gain weight.
- If we absorb less energy than we expend, we lose weight.
This has been tested over and over again by researchers, in many settings.
It’s as close as we can get to scientific fact.
Sure, there are many factors that influence either side of this seemingly simple equation, which can make things feel a little confusing:
However, humans do not defy the laws of thermodynamics.
But what about unexplained weight changes? That time you ate a big dinner and woke up lighter? When you feel like you’re “doing everything right” but you’re not losing weight?
Nope, even if we think we’re defying energy in vs. energy out, we’re not.
And what about that low carb doctor who implies that insulin resistance (or some other hormone) mucks up the equation?
While hormones may influence the proportions of lean mass and fat mass you gain or lose, they still don’t invalidate the energy balance equation.
Yet, as the title of the article suggests, it is easy to understand why folks—even internet-famous gurus and doctors—get confused about this.
One reason why…
Measuring metabolism is tricky.
The fact is, your exact metabolic demands and responses aren’t that easy to measure.
It is possible to approximate your basal metabolic rate—in other words, the energy cost of keeping you alive. But measurements are only as good as the tools we use.
When it comes to metabolic measurement, the best tools are hermetically sealed metabolic chambers, but not many of us hang out in those on the regular.
Which means, while we may have our “metabolism” estimated at the gym, or by our fitness trackers, as with calorie counts on labels, these estimates can be off by 20-30 percent in normal, young, healthy people. They’re probably off by even more in other populations.
Of course, if we could accurately measure how much energy you’re expending every day, and then accurately measure exactly how much energy you’re taking in and absorbing, we could decide whether you were truly “eating too little” for your body’s requirements.
But even if we could know this outside the lab, which we can’t, it wouldn’t be useful. Because energy output is dynamic, meaning that every variable changes whenever any other variable changes (see below).
In other words, unless we can exactly measure energy inputs and outputs from minute to minute, we can’t know for sure what your metabolism is doing and how it matches the food you’re eating.
So, most of the time, we have to guess. And our guesses aren’t very good.
Not only that, but the idea of “eating too little” is subjective.
Think about it. By “eating too little”, do you mean…
- Eating less than normal?
- Eating less than you’ve been told to eat?
- Eating less than feels right?
- Eating less than you need to be healthy?
- Eating less than your estimated metabolic rate?
- Eating less than your actual metabolic rate?
And how often does that apply? Are you…
- Eating too little at one meal?
- Eating too little on one day?
- Eating too little every day?
- Eating too little almost every day but too much on some days?
Without clarity on some of these questions, you can see how easy it is to assume you’re “eating too little” but still not eating less than your actual energy expenditure, even if you did some test to estimate your metabolic rate and it seems like you’re eating less than that number.
Most times, the problem is perception.
As human beings, we’re bad at correctly judging how much we’re eating and expending. We tend to think we eat less and burn more than we do—sometimes by as much as 50 percent.
(Interestingly, lighter folks trying to gain weight often have the opposite problem: They overestimate their food intake and underestimate their expenditure.)
It’s not that we’re lying (though we can sometimes deceive ourselves, and others, about our intake). More than anything, it’s that we struggle to estimate portion sizes and calorie counts.
This is especially difficult today, when plates and portions are bigger than ever. And energy-dense, incredible tasting, and highly brain-rewarding “foods” are ubiquitous, cheap, and socially encouraged.
When folks start paying close attention to their portion sizes using their hands or food scales and measuring cups, they are frequently shocked to discover they are eating significantly more than they imagined.
(I once had a client discover he was using ten tablespoons of olive oil—1200 calories—rather than the two tablespoons—240 calories—he thought he was using in his stir-fry. Oops.)
At other times, we can be doing everything right at most meals, but energy can sneak when we don’t realize it.
Here’s a perfect story to illustrate this.
A few years ago Dr. Berardi (JB, as he’s known around here) went out to eat with some friends at a well-known restaurant chain. He ordered one of their “healthier” meals that emphasized protein, veggies, and “clean” carbs. Then he finished off dinner with cheesecake.
Curious about how much energy he’d consumed, he looked it up.
Five. Thousand. Calories.
Incredibly, he hadn’t even felt that full afterwards.
If the calorie content of that one meal surprised someone with the expertise and experience of JB, how would most “normal” eaters fare? Good luck trying to “eyeball” things.
Also imagine a scenario where you were under-eating almost every meal during the week and maintaining an estimated negative energy balance of about -3,500 calories. Then, during one single meal, a “healthy” menu option plus dessert, you accumulated 5,000 calories.
That one meal would put you in a theoretically positive energy balance for the week (+1,500 calories), leading to weight gain!
Seriously, how would you feel if, after eating 20 “perfect” meals in a row and 1 “not so bad” meal, you gained weight? You’d probably feel like your metabolism was broken.
You’d probably feel like it’s possible to gain weight from eating too little.
But, again, the laws of thermodynamics aren’t broken. Rather, a whole bunch of calories snuck in without you realizing it.
Even more, the dynamic nature of metabolism can be confusing.
Another reason it can be easy to believe you gained weight eating too little (or at least didn’t lose weight when eating less) is because your metabolism isn’t like a computer.
For instance, you might have heard that one pound of fat is worth 3,500 calories, so if you cut 500 calories per day, you’ll lose one pound per week (7 x 500 = 3,500).
(Unless, of course, you downed 5,000 calories in a single meal at the end of the week, in which case you’d be on track to gain weight).
Except this isn’t how human metabolism works. The human body is a complex and dynamic system that responds quickly to changes in its environment.
When you undereat, especially over a longer period (that part is important), this complex system adapts.
Here’s an example of how this might play out:
- You expend less energy in digestion because you’re eating less.
- Resting metabolic rate goes down because you weigh less.
- Calories burned through physical activity go down since you weigh less.
- Non-exercise activity thermogenesis (daily-life fidgeting, movement) goes down and you expend less energy through the day.
- Your digestion slows down, and you absorb more energy from your food.
Your body will also adjust hormonal feedback and signaling loops. For instance:
- Appetite and hunger hormones go up (i.e. we want to eat more, are more stimulated by food cues, may have more cravings).
- Satiety hormones go down (which means it’s harder for us to feel full or satisfied).
- Thyroid hormones and sex hormones (both of which are involved in metabolic rate) go down.
Your planned 500 calorie daily deficit can quickly become 400, 300, or even 200 calories (or fewer), even if you intentionally exercise as much as you had before.
And, speaking of exercise, the body has similar mechanisms when we try to out-exercise an excessive intake.
For example, research suggests that increasing physical activity above a certain threshold (by exercising more) can trigger:
- More appetite and more actual calories eaten
- Increased energy absorption
- Lowered resting or basal metabolism
- Less fidgeting and spontaneous movement (aka NEAT)
In this case, here’s what the equation would look like:
These are just two of the many examples we could share.
There are other factors, such as the health of our gastrointestinal microbiota, our thoughts and feelings about eating less (i.e. whether we view eating less as stressful), and so on.
The point is that metabolism is much more complicated (and interdependent) than most people realize.
All of this means that when you eat less, you may lose less weight than you expect. Depending how much less you eat, and for how long, you may even re-gain weight in the long run thanks to these physiological and behavioral factors.
Plus, humans are incredibly diverse.
Our metabolisms are too.
While the “average” responses outlined above are true, our own unique responses, genetics, physiology, and more means that our calorie needs will differ from the needs of others, or the needs predicted by laboratory tools (and the equations they rely on).
Let’s imagine two people of the same sex, age, height, weight, and lean body mass. According to calculations, they should have the exact same energy expenditure, and therefore energy needs.
However, we know this is not the case.
- Your basal metabolic rate—remember, that’s the energy you need just to fuel your organs and biological functions to stay alive—can vary by 15 percent. For your average woman or man, that’s roughly 200-270 calories.
- Genetic differences matter too. A single change in one FTO gene can be an additional 160 calorie difference.
- Sleep deprivation can cause a 5-20 percent change in metabolism, so there’s another 200-500 calories.
- For women, the phase of their menstrual cycle can affect metabolism by another 150 calories or so.
Even in the same individual, metabolism can easily fluctuate by 100 calories from day to day, or even over the course of a day (for instance, depending on circadian rhythms of waking and sleeping).
Those differences can add up quickly, and this isn’t even an exhaustive list.
If you want to dig really deep into the factors that influence our energy balance, check this out:
The multifactorial nature of body weight.
In the end, hopefully you can see how equations used to predict calorie needs for the “average” person might not be accurate for you. And that’s why you could gain weight (or not lose weight) eating a calorie intake that’s below your measured (estimated) expenditure.
It’s also why some experts, who aren’t knowledgeable about the limitations of metabolic measurement, will try to find all sorts of complicated hormonal or environmental causes for what they think is a violation of thermodynamics.
The answer, however, is much simpler than that.
The estimates just weren’t very good.
And yes, water retention is a thing.
Cortisol is one of our “stress hormones”, and it has effects on our fluid levels.
Food and nutrient restriction is a stressor (especially if we’re anxious about it). When we’re stressed, cortisol typically goes up. People today report being more stressed than ever, so it’s easy to tip things over into “seriously stressed”.
When cortisol goes up, our bodies may hold onto more water, which means we feel “softer” and “less lean” than we actually are. This water retention can mask the fat loss that is occurring, making it seem like we aren’t losing fat and weight, when in fact we are.
Here’s an example.
A good friend of mine (and former high school hockey teammate) was struggling to make the NHL. He had played several seasons in the AHL (one step down from the NHL) and had just been called up to the pros.
The NHL club wanted him to stay below 220 lbs (100 kg), which was a challenge for him at 6’2”. He found that eating a lower-carb diet allowed him to maintain a playing weight around 218 lbs.
Yet his nutrition coach told him it was OK to have some occasional higher-carb days.
Unfortunately for him, he had one of these higher-carb days—going out for sushi with his teammates—right before his first NHL practice.
The next day, when reporting to the NHL team, he was called into the GM’s office to get weighed. He was 232 lbs (105 kg).
Thanks, carbs and salt!
My friend was crushed. Even worse, two days later he was back to 218 lbs.
OK, but what if I track my intake and expenditure meticulously?
You might be nodding your head, beginning to realize how complex metabolism is. How inaccurate calorie counts can be. How variable we all are. How much the body seeks to maintain the status quo. And how poor we are at estimating our own intake and expenditure.
But what if you are meticulously tracking intake? Logging your meals? Counting your steps? Even hitting a local research lab to measure your metabolism? And things still aren’t adding up?
Well, it goes back to what we’ve discussed so far:
- The calorie counts of the foods you’ve logged might be higher than expected, either because of erroneous labeling or because of small errors in your own measurement.
- Your energy needs might be lower than calculated (or even measured). This may be because…
- You’re expending less energy through movement than your fitness tracker or exercise machine suggests.
- You have less lean mass as you think, or it may not be as energy-consuming as you expect.
- You’re absorbing more energy in digestion than you realize (for instance, if your gastrointestinal transit time is slow, or your microbiota are really good at extracting nutrients).
Maybe you’re just missing some data.
As mentioned above, while you’re probably not outright lying, it could be that you’re also “forgetting” to account for the few bites of your kids’ chicken nuggets that you didn’t want to go to waste. Or that extra spoonful of peanut butter. Or the large glass of wine you counted as a ‘medium’. Likewise, the calorie counts on those food labels can be (and often are) off.
Maybe you’re counting your workout as high intensity, even though you spent much of it sitting on a bench between low-rep strength sets. Maybe you were so hungry afterwards, you ate more than you intended (but figured it was all going to muscle-building, so no biggie).
It happens; we’re all human.
Measuring and tracking your energy intake carefully can help.
When we measure and track for a while, we become more aware of what we’re eating, get a more realistic idea of our portion sizes, and help ourselves be consistent and accountable.
But measuring and tracking definitely is not a perfect strategy.
It can be stressful and time-consuming. Most people don’t want to do it forever.
And it may misrepresent the “exact” calories we consume versus the “exact” calories we burn, which can lead us to believe we’re eating less than we’re burning, even when we’re not.
What about legitimate medical problems?
Whenever we arrive at this point of the discussion folks usually ask about whether underlying health problems, or medications, can affect their metabolism, weight, and/or appetite.
The answer is yes.
This includes things like polycystic ovarian syndrome (PCOS), certain pharmaceuticals (corticosteroids or birth control), severe thyroid dysfunction, sex hormone disruption, leptin resistance, and more.
However, this is less common than most people think, and even if you do have a health issue, your body still isn’t breaking the laws of thermodynamics.
It’s just—as discussed above—that your calorie expenditure is lower than predicted. And a few extra calories may be sneaking in on the intake side.
The good news: weight loss is still possible (albeit at a slower pace).
If you truly feel that you are accurately estimating intake, exercising consistently at least 5-7 hours a week, managing your sleep and stress, getting expert nutritional coaching, and covering absolutely all the fundamentals, then it may be time to consider further conversations and testing with your doctor.
So what can you do?
If you feel your intake is less than your needs, (in other words, you’re eating what feels like ‘too little’) but you still aren’t losing weight, here are some helpful next steps to try.
Measure your intake.
Use whatever tools you prefer. Your hands, scales and spoons, pictures, food logs, etc. It doesn’t matter.
Track your intake for a few days or a full week, to see if it adds up to what you “thought” you were eating. We are often surprised.
Sometimes, just the act of tracking increases our awareness of our intake, which helps us make better choices.
Be compassionate with yourself.
It may feel like being strict or critical is a good approach, but it isn’t. It just makes you more stressed out.
Conversely, research shows that being kind and gentle with yourself (while still having some grown-up honesty about your decisions) helps you have a healthier body composition, make wise food choices, stick to your fitness goals better, feel less anxious and stressed, and have a better relationship with food overall.
There are going to be meals or days where you don’t eat as you “should”. It’s OK. It happens to everyone. Recognize it, accept it, forgive yourself, and then get back on track.
Choose mostly less-processed whole foods.
Foods that aren’t hyper-rewarding or hyperpalatable are harder to over-eat. They don’t cause hypothalamic inflammation and leptin resistance.
They have lots of good stuff (vitamins, minerals, water, fiber, phytonutrients, disease-fighting chemicals, etc.) and are usually lower in calories.
And they are usually far better at keeping you full and satisfied.
Choose whole foods that you enjoy and will eat consistently.
Play with macronutrient levels.
Some people respond better to more carbs and fewer fats. Others respond better to higher fats and few carbs.
There’s no single best diet for everyone. We all have different preferences, and even different responses to foods and macronutrients. So play with this a bit, and find what works for you.
Own your decisions.
Let your adult values and deeper principles guide you when you sit down to eat. Make food choices by acknowledging the outcome you would expect.
Avoid playing mental games like “If I’m ‘good’ then I get to be ‘bad”, or “If I pretend I didn’t eat the cookies, then it didn’t happen”.
Face your behavior with open eyes, maturity, and wisdom.
Accept that all choices have consequences.
And appreciate that it’s OK to indulge sometimes.
If you are still having trouble, get coaching.
Behavior change and sustained weight loss are hard. Especially when we try to go it alone.
Seek out a qualified and compassionate coach or professional who can help you navigate these tricky waters.
(Might I suggest Precision Nutrition Coaching?)
If you’re a coach or professional, here’s how to help people with this.
If you’re working with clients or patients as a service provider, be empathetic. Remember, it can be incredibly easy to believe that we’re “doing everything right” and yet not seeing results.
Instead of jumping to conclusions or rushing in with reasons why your client isn’t succeeding, instead, follow these steps:
Step 1: Be compassionate and curious.
Understand that most people in this space are probably frustrated and/or beating themselves up. Don’t dial up some “tough love” and call them liars.
Be empathetic and gently curious.
Step 2: Gather (accurate) data.
Have people show you what they’re doing to the best of their ability. Pictures, food logs, tracking apps… whatever suits their level of ready, willing and able.
While meticulous tracking isn’t usually a good long-term solution, it can help both of you to get some more accurate data.
Step 3: Have a crucial conversation.
If you think this means being Coach Hardass, you are off the mark. Remember:
- You are both working together in an alliance against the problem, not against each other.
- You both want your client or patient to succeed.
Bring facts to the table, not opinions. What you see and what they see are likely different.
Step 4: Help them feel safe.
If someone is hiding from you foods that they ate, that is at least partly your responsibility.
For whatever reason, the individual doesn’t feel comfortable telling you they aren’t doing what they think they should.
This needs to be explored together. Slowly. Gently. With a curious, and non-judgemental mind.
A final note on body composition.
Before wrapping up I wanted to mention something important.
In this article I decided to focus only on the body weight implications of the energy balance equation because that’s all the equation really describes (i.e. net transfers of energy).
Changes in body composition (i.e. your relative proportions of lean tissue and body fat) are, if you can believe it, much more complicated and far less comprehensively studied.
If you’re a coach, or you want to be…
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If you’d like to learn more about both, consider the Precision Nutrition Level 1 Certification. The next group kicks off shortly.
What’s it all about?
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Whether you’re already mid-career, or just starting out, the Level 1 Certification is your springboard to a deeper understanding of nutrition, the authority to coach it, and the ability to turn what you know into results.
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If you’re ready for a deeper understanding of nutrition, the authority to coach it, and the ability to turn what you know into results… this is your chance to see what the world’s top professional nutrition coaching system can do for you.
Low-Calorie Diets Mean High-Quality Lives, Research Shows
For people who’ve tried a low-calorie diet in the past, the thought of cutting calories each day probably brings back bad memories.
Most diets involve reducing calories in some way or another: Some introduce foods that fill you up faster but contain fewer calories, such as fruits and vegetables in place of processed foods. Other diets restrict your options, and eating the same food sources becomes repetitive and less interesting, so you consume fewer items.
Still other diets combine both strategies, such as diets recommending a low-calorie food such as a tomato, or a special shake that you make, for most or all of your meals.
But new research shows that low-calorie diets can help with surprisingly more than your weight.
What Is a Low-Calorie Diet?
A low-calorie diet is one that restricts your intake to 1,200 to 1,600 calories per day for men, and 1,000 to 1,200 calories per day for women. Some people go on a very low-calorie diet for rapid weight loss, often consuming only 800 calories a day. This type of diet usually includes special foods such as shakes, bars, or soups to replace meals and for added vitamins. Very low-calorie diets can help a person achieve weight loss of up to 3 to 5 pounds per week.
For weight loss, most people should consider a low-calorie diet rather than a very low-calorie diet. Less extreme diets are easier to follow, they interrupt normal daily activities less, and are less risky if you’re over 50 or have other health problems. In addition, gallstones have been reported in people who go on very low-calorie diets.
Keep in mind that most diets only work when you make healthy lifestyle choices at the same time, including increasing daily exercise and reducing your sedentary time throughout the day.
Good Reasons to Try a Low-Calorie Diet
The obvious reason to restrict calories is to help with weight loss. Why else give up something that you enjoy? Yet very interesting data from animal studies throughout the animal kingdom shows additional effects of calorie reduction. As reviewed in Molecular Aspects of Medicine in June 2011, studies show that animals subjected to periods of calorie restriction, including primates, have:
- Longer lives
- Higher levels of physical activity
- Lower rates of cancer
- Less age-related degeneration of the brain
- Improved reproductive performance
Some of these findings may seem odd to anyone who’s tried to fast or restrict their calories and then felt the early fatigue, weakness, lack of energy, nausea, and stomach pains associated with their efforts.
Keep in mind that the animal studies and observations involved regular periods of calorie restriction followed by, or within the context of, a healthy diet. In other words, the animals’ bodies had time to adapt in a healthy manner to slightly less caloric intake over a long period of time.
What Happens When People Restrict Calories?
When I talk with patients about cutting calories for heart health, I don’t think I’ve had anybody tell me they want to do it to live longer, feel better, and have a better quality of life. But this is because most people think of exactly how they’re going to feel the first few days or weeks after they start, rather than taking a long-term outlook.
A study published in June 2016 in JAMA Internal Medicine provided unique insight into what happens to people when they restrict their calories. This study included people who were not obese specifically because weight loss in obese people is often used to lower risk of diabetes, high blood pressure, sleep apnea, and coronary artery disease in addition to improving their quality of life.
The investigators in this study followed 218 participants for two years. The average age was 38, and 70 percent were women. At the time of enrollment, they could have a body mass index (BMI) up to 28, but no lower than 22. The groups were randomized to either continue with their normal diet or participate in a calorie-restricted diet. The diet contained approximately 25 percent fewer calories than they had previously eaten.
Why did the researchers choose a 25 percent reduction in calories? They thought this level was the most that could be reduced and sustained for the entire two-year study. Participants met in groups and had web-based resources to assist with their diet. Registered dietitians monitored participants’ weekly food diaries to determine total calories. All participants were encouraged to exercise at least five days a week for 30 minutes at a time.
The authors reported several important findings. First, and not too surprisingly, the people in the group who ate fewer calories lost more weight. On average, people in this group lost 7.6 kg (16.7 lbs) compared to those in the other group, who lost 0.4 kg (0.9 lbs).
What was even more interesting was the impact of calorie restriction on quality of life. Those who restricted calories reported better moods and less daily tension, and they rated their overall health better throughout the study period.
The calorie-restricted group also reported improved sleep duration and quality. Finally, the calorie-restricted group experienced more sexual drive and arousal, and better sexual relationships, than the other group.
Is a Low-Calorie Diet Right for You?
If you’re overweight or obese, the choice may be simple. Weight loss is a critical lifestyle choice to improve your general health and lower your risk of cardiovascular disease, diabetes, sleep apnea, premature joint disease, high blood pressure, and cancer.
But lowering your risk for these diseases is only part of the potential benefit of cutting calories. Many other benefits of calorie restriction can improve your qualify of life and daily functioning. If you’re in the normal weight range, this new study also suggests a potential benefit of calorie restriction if done carefully — as long as your BMI doesn’t drop below 22.
If you chose to cut your calories, consider the expertise of the study investigators in this trial and aim for a 25 percent reduction. This is the level at which there was some benefit and that was at the same time tolerable, so it’s possible to keep it up. Here’s how to get started:
- Keep an accurate diary of your food intake for one to two weeks.
- Use an online calorie counter to help you determine your daily calorie intake.
- Plan to restrict your calorie intake by 25 percent over the next month.
- Write out a menu each week that includes a wide variety of foods that you enjoy.
One of the easiest ways to cut calories is to increase your intake of whole fruits and vegetables, which you’ll find are more filling and less calorie dense. Also consider making these diet changes with other people, who can provide social support and accountability — powerful ways to improve the likelihood that you’ll succeed.
As you begin to experience the improved quality of life, sleep, and other benefits, these will help positively reinforce your goals and make the calorie-restricted diet a daily habit. And as you feel better, become more active, and maintain a healthy diet, you’ll have the added benefit of having to see your local cardiologist less.
Follow Dr. Bunch @TJaredBunch on Twitter. He’s also a frequent guest on The Dr. John Day Show podcast, available on iTunes.
PHOTO: Getty Images
Appendix 2. Estimated Calorie Needs per Day, by Age, Sex, and Physical Activity Level
The total number of calories a person needs each day varies depending on a number of factors, including the person’s age, sex, height, weight, and level of physical activity. In addition, a need to lose, maintain, or gain weight and other factors affect how many calories should be consumed. Estimated amounts of calories needed to maintain calorie balance for various age and sex groups at three different levels of physical activity are provided in Table A2-1. These estimates are based on the Estimated Energy Requirements (EER) equations, using reference heights (average) and reference weights (healthy) for each age-sex group. For children and adolescents, reference height and weight vary. For adults, the reference man is 5 feet 10 inches tall and weighs 154 pounds. The reference woman is 5 feet 4 inches tall and weighs 126 pounds.
Estimates range from 1,600 to 2,400 calories per day for adult women and 2,000 to 3,000 calories per day for adult men. Within each age and sex category, the low end of the range is for sedentary individuals; the high end of the range is for active individuals. Due to reductions in basal metabolic rate that occur with aging, calorie needs generally decrease for adults as they age. Estimated needs for young children range from 1,000 to 2,000 calories per day, and the range for older children and adolescents varies substantially from 1,400 to 3,200 calories per day, with boys generally having higher calorie needs than girls. These are only estimates, and approximations of individual calorie needs can be aided with online tools such as those available at www.supertracker.usda.gov.
Table A2-1. Estimated Calorie Needs per Day, by Age, Sex, and Physical Activity Level
Sedentary means a lifestyle that includes only the physical activity of independent living.
Moderately Active means a lifestyle that includes physical activity equivalent to walking about 1.5 to 3 miles per day at 3 to 4 miles per hour, in addition to the activities of independent living.
Active means a lifestyle that includes physical activity equivalent to walking more than 3 miles per day at 3 to 4 miles per hour, in addition to the activities of independent living.
Estimates for females do not include women who are pregnant or breastfeeding.
Source: Institute of Medicine. Dietary Reference Intakes for Energy, Carbohydrate, Fiber, Fat, Fatty Acids, Cholesterol, Protein, and Amino Acids. Washington (DC): The National Academies Press; 2002.
Calories: How to Know if You Go Too Low
Cutting calories is the approach most dieters must take to meet their weight-loss goals. But every once in a while people take calorie restriction too far, ultimately making weight loss slower and more difficult by slowing your metabolism.
Figuring out the right number of calories for you on a daily basis depends on your age, gender, and activity level. In general, the younger and more active you are, the more calories you can consume. And men are able to eat more calories daily than women. For example, the U.S. Department of Agriculture guidelines says that women 19 to 30 years old should consume 2,000 calories if they have a sedentary lifestyle or 2,400 calories if they have an active one; for men of the same age the range is 2,400 to 3,000 calories.
Defining the Low-Calorie Diet
It seems logical that if calories are the problem, you would want to eat as few of them as possible to speed weight loss. As a general rule, people need a minimum of 1,200 calories daily to stay healthy. People who have a strenuous fitness routine or perform many daily activities need more calories. If you have reduced your calorie intake below 1,200 calories a day, you could be hurting your body in addition to your weight-loss plans.
“The big picture is to consume enough calories with a balance of nutrients and engage in physical activity for good health management to achieve one’s weight goals. Consuming less than 1,200 calories per day may make it difficult to meet vitamin and mineral needs via food,” says nutrition therapist Andrea Spivack, MA, RD, LDN, with Penn Behavioral Health at the University of Pennsylvania in Philadelphia.
Tempting as it may be to continue with your low-calorie weight-loss plan and simply take a supplement, Spivack points out that there are some key nutrients which are only available through your diet.
Occasionally, obese people will go on a very low-calorie diet — 800 to 1,000 calories per day — for a brief period of time in order to achieve a specific weight-loss goal, but then will switch to a diet with more calories to reach and maintain their desired weight. Such a diet is usually supervised by a doctor or nutritionist so that it is nutritionally balanced. Unfortunately, weight regain is common after these restricted calorie diets end.
Why Low-Calorie Diets Slow Your Metabolism
If you are on a very low-calorie diet, you may wonder why the numbers on your scale aren’t budging, but your diet buddy is slimmer by the month.
The reality is that different people respond differently to low-calorie diets. When your body senses that food may not be in plentiful supply, it may slow down your metabolism as protection against the possibility of starvation, even if you are obese and deliberately trying to lose weight.
Everything you do — from sleeping to eating a bowl of chocolate chip ice cream — burns calories. Likewise, every bodily function, like digestion, blood circulation, and breathing, takes effort. The energy, or calories, your body burns just to keep you alive is called your basal metabolic rate (BMR).
For simplicity’s sake: Your BMR expresses many calories you would burn if you did nothing but lie on the floor all day (sans eating, that is!). But your specific calorie needs take into account other factors, such as activities of daily living (otherwise known as ADLs). See below to calculate your energy needs.
How to Calculate Your Basal Metabolic Rate
Women: (10 x weight in kilograms) + (6.25 x centimeters) – (5 x age in years) – 161
Men: (10 x weight in kilograms) + (6.25 x centimeters) – (5 x age in years) + 5
That said, take your “number” with a grain of salt. Your BMR will vary based on genetics, muscle mass, age, and gender, so one single number is rarely accurate. Instead, your energy needs will always vary, so staying within a 200 calorie range of your daily burn rate can help you maintain your current weight.
How to Calculate Calories to Lose Weight
While there’s a lot of debate on the topic, estimating about one pound of body weight as 3,500 calories can be helpful if you’re looking to lose weight. So, if you need 2,000 calories a day to maintain your weight, subtract 500 from that (about 1,500 calories) and you’ll have the number you should consume each day to still lose a pound in one week. (Try out our 1,500 calorie meal plan!)
How to Calculate Calories to Gain Weight
Likewise, to gain one pound per week, you’ll need to add 500 calories to your diet each day.
How to Improve Your Metabolism
While cardio exercises like running and swimming will raise your heart rate and torch calories, they won’t change the rate at which you burn them. Building lean muscle mass from strength training at least three times a week can give you a slight metabolism boost.
Plus, don’t forget to eat! Skipping meals, especially for prolonged periods, can make your metabolism sluggish, so be sure to eat a meal or snack every three to four hours.
The Bottom Line
Calorie-counting can often do more harm than good. In fact, I’d argue that calorie-counting is passé these days. Instead, focus on how you feel when you eat. Does a meal make you feel stuffed? Satisfied? Full, but not satisfied? The key is to eat meals with whole foods, filling fiber, and lean protein to keep you satiated and your appetite in check. Sounds more delicious than “dieting” doesn’t it?
Jaclyn London, MS, RD, CDN, Good Housekeeping Institute Director, Nutrition Lab A registered dietitian with a Bachelor of Arts degree from Northwestern University and a Master of Science degree in Clinical Nutrition from New York University, Jaclyn “Jackie” London handles all of Good Housekeeping’s nutrition-related content, testing, and evaluation.
Caloric intake is not solely about quantity. The quality of the caloric intake is vital as well. Just because all foods in equal amounts may be isocaloric, this does not mean that they are all isometabolic. When comparing foods, an equal number same amount of calories does not mean that the foods will affect the body in the same way. For example, obtaining one’s daily calories only from fat may numerically equate to the calories one can get from fruits and vegetables, but potential benefits are lost and numerous risks associated with not getting the right balance of nutrients. If one’s diet consists solely of sugars and refined carbohydrates without adequate intake of protein, huge rises in blood sugars will result, leading to increased insulin spikes and increased fat storage.
Studies have also shown that an increase in caloric consumption from fruits, vegetables, and whole grains decreases the risk of certain types of malignancies including (but not limited to) esophageal and esophagogastric junctional adenocarcinoma and that a diet high in animal fats (particularly red meat) actually increases the risk of these cancers.
Daily caloric intake can be calculated and is influenced by various factors, including gender, height, weight, activity level, and age. Children, for example, have different caloric needs than adults, and specific age groups of children have different caloric needs. Infants, for example, require liquids filled with high amounts of fats and nutrients, especially vitamins and minerals. As they grow older, especially past age 5, fiber, healthy fats, protein, and calcium become of great importance for their bones and teeth to grow healthy and strong. From toddler age to adolescent age up until the age of 18, caloric need requirements grow steadily higher.Adult women and men differ in what they need in regards to caloric intake, thus they have different requirements for weight loss. On average, a woman should eat 2000 calories per day to maintain her weight, and she should limit her caloric intake to 1500 or less in order to lose one pound per week. For the average male to maintain his body weight, he should eat 2500 calories per day, or 2000 a day if he wants to lose one pound per week. A more exact calculation to determine the specific calories required to lose weight is to multiply body weight in kilograms by 29 for fat loss or by 40 for muscle gain. For example, if a woman weighs 60 kg, she should eat a maximum of 1740 calories a day to see weight loss. To gain muscle mass, the same 60 kg woman should eat 2400 calories a day.
However, weight loss is not this simple for every person. Counting calories and increasing exercise do indeed have a noticeable effect on weight loss, but it is temporary. To actually maintain this weight loss, it is important to focus on the type of calories that are put into the body. Fat has long been considered the root of the obesity epidemic, but research has shown that the real culprits are processed sugars and carbohydrates. In fact, foods containing a high-fat content are some of the most nutritious foods one can consume; for example, nuts, avocados, and olive oil.The problem with refined sugars is that they make insulin levels surge. When these insulin levels spike, fat cells respond by storing these calories. However, the calories are not filled with nutrients the body needs. Our brains recognize this fact and respond with hunger. This, in turn, makes us want to eat more and causes our metabolisms to slow down, resulting in weight gain. Another false belief is that by exercising excessively, one can eat whatever is desired. However, 80% of our weight is what we put into our bodies and only 20% of the amount we burn by activity.A person’s caloric intake consists of carbohydrates, proteins, fats, and for some, alcohol. Alcohol contains the type of calories that should be limited the most, as it contains calories called “empty calories,” meaning they have nothing the body can actually use for energy. Alcohol simply causes weight gain without adding nutrients to the body. Carbohydrates, proteins, and fats have varying calories per gram. Carbohydrates and proteins, for instance, contain 4 calories per gram, and fat has 9 calories per gram. This is helpful in calculating calorie consumption per day when trying to obtain and maintain a healthy weight.Balance in one’s diet is key to good health. The American diet is filled with excessive amounts of processed sugars and saturated fats, with basically none of the other nutrients the body desires. Fat and glucose are vital to sustaining life, especially brain function, but they cannot be the sole fuel to keep the body energized. This is a major issue in the American diet today and a growing area of concern, not just because of malnutrition but also because of the increase in chronically debilitating yet preventable diseases such as diabetes, heart disease, and various cancers.
Calories provide energy, which we need to survive and perform daily activities. The calories we get from food and beverages allow us to breathe, walk, run, laugh and even pump blood. Calorie needs vary depending on age, sex, height and activity level. Calorie needs are often higher during the teenage years than any other time of life. During this period of rapid growth and development, boys require an average of 2,800 calories a day, while girls require an average of 2,200 calories a day.
Below is a detailed list of calorie needs for teens by age, sex and activity level.
|Age||Not Active||Moderately Active||Active|
- Not Active – Minimal activity, only moving for tasks needed for daily life, such as walking to the mailbox.
- Moderately Active – Engages in activity needed for daily living, plus activity equivalent to walking 1.5 to 3 miles daily, or 30 to 40 minutes.
- Active – Engages in activity needed for daily life, plus activity equivalent to walking 3 or more miles daily, or more than 40 minutes.
A Well-balanced Eating Plan
The amount of calories in food vary depending on how much carbohydrate, protein and fat it contains – both carbohydrates and protein provide four calories per gram, while fat provides nine calories per gram. It is important that teens obtain calories from nutrient-dense sources, which are higher in vitamins, minerals and dietary fiber, and limit added sugars, salt and saturated fats. A well-balanced eating plan includes fruits and vegetables, whole grains, low-fat or fat-free dairy products and lean protein foods.
Body image may be a concern for teens, as they start to form thoughts and feelings about the way they look. Body image can be positive or negative and may have little to do with actual appearance. Parents are the most influential role model in a teen’s life, so it is important to teach healthy body image by being a positive example. Avoid dieting, eat an overall balanced diet and try not to talk negatively about your body around your children. Avoid putting emphasis on people’s physical appearance and engage in discussions with your teen about body image portrayed in media. Encourage your teen to exercise for energy, health and strength rather than for outward appearance.
Just like adults, teens come in all shapes and sizes. A balanced eating plan and regular physical activity will help your teen grow into their healthy weight. While nearly 20 percent of teens have an obese body mass index, nearly 3 percent of adolescent girls meet the criteria for an eating disorder. If you are concerned about your teen’s weight or relationship with food, seek guidance from a registered dietitian nutritionist or physician.