Nutrients that provide energy

A Diet for Better Energy

Juggling the responsibilities of work, life, and family can cause too little sleep, too much stress, and too little time.

Yet even when you’re at your busiest, you should never cut corners when it comes to maintaining a healthy diet. Your body needs food to function at its best and to fight the daily stress and fatigue of life.

Energy and Diet: How The Body Turns Food Into Fuel

Our energy comes from the foods we eat and the liquids we drink. The three main nutrients used for energy are carbohydrates, protein, and fats, with carbohydrates being the most important source.

Your body can also use protein and fats for energy when carbs have been depleted. When you eat, your body breaks down nutrients into smaller components and absorbs them to use as fuel. This process is known as metabolism.

Carbohydrates come in two types, simple and complex, and both are converted to sugar (glucose). “The body breaks the sugar down in the blood and the blood cells use the glucose to provide energy,” says Melissa Rifkin, RD, a registered dietitian at the Montefiore Medical Center in the Bronx, N.Y.

Energy and Diet: Best Foods for Sustained Energy

Complex carbohydrates such as high-fiber cereals, whole-grain breads and pastas, dried beans, and starchy vegetables are the best type of foods for prolonged energy because they are digested at a slow, consistent rate. “Complex carbohydrates contain fiber, which takes a longer time to digest in the body as it is absorbed slowly,” says Rifkin. Complex carbs also stabilize your body’s sugar level, which in turn causes the pancreas to produce less insulin. This gives you a feeling of satiety and you are less hungry.”

Also important in a healthy, energy-producing diet is protein (preferably chicken, turkey, pork tenderloin, and fish), legumes (lentils and beans), and a moderate amount of healthy monounsaturated and polyunsaturated fats (avocados, seeds, nuts, and certain oils).

“Adequate fluids are also essential for sustaining energy,” says Suzanne Lugerner, RN, director of clinical nutrition at the Washington Hospital Center in Washington, D.C. “Water is necessary for digestion, absorption, and the transport of nutrients for energy. Dehydration can cause a lack of energy. The average person needs to drink six to eight 8-ounce glasses of water each day.”

Energy and Diet: Foods to Avoid

Simple carbohydrates, on the other hand, should be limited. Ranging from candy and cookies to sugary beverages and juices, simple carbs are broken down and absorbed quickly by the body. They provide an initial burst of energy for 30 to 60 minutes, but are digested so quickly they can result in a slump afterward.

You should also avoid alcohol and caffeine. Alcohol is a depressant and can reduce your energy levels, while caffeine usually provides an initial two-hour energy burst, followed by a crash.

Energy and Diet: Scheduling Meals for Sustained Energy

“I always recommend three meals and three snacks a day and to never go over three to four hours without eating something,” says Tara Harwood, RD, a registered dietitian at the Cleveland Clinic in Ohio. “If you become too hungry, this can cause you to overeat.”

Also, try to include something from each food group at every meal, remembering that foods high in fiber, protein, and fat take a longer time to digest.

Even if life is hectic, it’s important to make wise food choices that provide energy throughout the day. Your body will thank you.

Fuel Sources During Exercise

Professional athletes must eat many calories each day. Consequently, they can be lax with the quality of their diet. They will not gain weight even if they eat burgers and fries and a bunch of sugared energy bars. However, weight gain is not the only factor that must be considered when it comes to an athlete’s diet. If the athlete does not eat enough healthy nutritious foods, his or her performance will suffer and eventually lead to injury and a long, difficult recovery.

At rest and during normal activities, fats contribute 80–90% of our energy; carbohydrates provide 5–18% and protein 2–5%. During exercise there are four major endogenous sources of energy: muscle carbohydrate stores (glycogen), blood sugar, blood fatty acids, and intramuscular triacylglycerols. The extent to which these substrates contribute energy for exercise depends on the intensity and duration of exercise, the level of exercise training, the initial muscle glycogen levels, and supplementation with carbohydrates during exercise.

Protein can be used by the body for fuel or for anabolic processes. Anabolic processes are those that build up the body, whereas catabolic processes are those that break down the body. Please note that not all protein is equal in its ability to be anabolic vs. catabolic within the body. Protein is used as an energy source if calories are insufficient. However, with sufficient calories, the break down of amino acids (the building blocks of protein) contributes only minimally to the total amount of energy used by working muscles. When a person begins a moderate endurance exercise program, they initially lose more protein than they ingest; that corrects itself within 2–3 weeks without dietary intervention.

In order to promote increases in muscle size (hypertrophy) and increase in strength, it is an absolute requirement that athletes be in a positive nitrogen status (ingesting more protein than is lost). Ingesting more protein than needed, however, does not lead to increased protein synthesis over a certain level and too much protein can result in dehydration, loss of urinary calcium, and stress on the kidneys and liver. Recommended protein intake is .8–2 gm protein/kg body weight per day or 12–20% of total energy intake.

Body Weight in lbs and kg 0.8 g/kg RDA 0.9 g/kg Light Exercise 1.0 g/kg Moderate Exercise 1.2 g/kg Moderate/Heavy Exercise 1.4 g/kg Heavgy Exercise
110 lbs (50 kg) 40 gm 45 gm 50 gm 60 gm 70 gm
130 lbs (59 kg) 47 gm 53 gm 59 gm 71 gm 83 gm
150 lbs (68 kg) 54 gm 61 gm 68 gm 82 gm 95 gm
170 lbs (77 kg) 62 gm 70 gm 77 gm 92 gm 108 gm
190 lbs (86 kg) 60 gm 77 gm 86 gm 103 gm 120 gm
210 lbs (95 kg) 76 gm 86 gm 95 gm 114 gm 133 gm
230 lbs (105 kg) 84 gm 94 gm 105 gm 125 gm 146 gm

Fat is the major fuel for light-intensity to moderate-intensity exercise, such as jogging, hiking, dance, cycling, and recreational swimming. Half of the energy for these activities comes from the aerobic (using oxygen) breakdown of muscle sugar stores (glycogen) and the other half comes from circulating blood sugar and fatty acids. It is recommended that athletes consume 20–30% of calories as fat. These fats should include the “good” fats, such as the essential fatty acids EPA, DHA that are found in fish, flax, avocados, and olive oil as well as typical meat/dairy fats. Intake of trans fatty acids (from partially hydrogenated oils) should be avoided entirely and saturated fats should be limited but not completely restricted.

Carbohydrates are the main source of fuel for athletes, especially those participating in endurance sports. It is more beneficial to eat a low glycemic carbohydrate (oatmeal, yams, brown rice, 100% whole grains) meal 3–4 hours before exercising or athletic competition. A high glycemic carbohydrate meal (refined sugars in soda, candy, cake, muffins, white bread, Gatorade) will result in a rapid release of insulin and ultimately reduced blood sugar, suppressed release of fatty acids from fat stores, and inhibition of liver glycogen breakdown.

Carbohydrate intake during intense exercise should average 25–30 gm/30 minutes of activity. Carbohydrate solution should not exceed 6–8%; otherwise the athlete may experience cramps, nausea, and diarrhea. (To determine the concentration in a sports drink, the grams of carbs in a serving is divided by the weight of the serving of the drink, which is usually 240gm.) Post-exercise, it is important for the individual to restore muscle glycogen or carbohydrate stores by eating a source of carbohydrate mixed with a small amount of protein. (Refined carbohydrates work best at this time—small baked potato, yogurt, or Gatorade.) For the average exerciser this is not a crucial step and is in fact where a lot of people are mistaken when they start an exercise program. They tend to fuel themselves more than they actually need and end up gaining weight.

Water intake is a crucial part of our diet that is often overlooked due to its lack of “substance”. However, if the importance of a nutrient is judged by how long we can do without it, water ranks as the most important. A person can survive only eight to ten days without water, whereas it takes weeks or even months to die from a lack of food. Water circulates through our blood and lymphatic system, transporting oxygen and nutrients to cells and removing wastes through urine and sweat. Water also maintains the natural balance between dissolved salts and water inside and outside of cells. Our joints and soft tissues depend on the cushioning that water provides for them. While water has no caloric value and therefore is not an energy source, without it in our diets we could not digest or absorb the foods we eat or eliminate the body’s digestive waste.

Water absorption is maximized when sugar concentrations range from 1–3 %. Again, to determine this, the number of grams of carbs in a serving is divided by the weight of the serving of the drink, which is usually 240gm. It is also necessary to have sodium for sugar to be absorbed. Rehydration alone in endurance athletes (i.e., those who are active for over 60 minutes) is not as efficient. Too much water dilutes the blood rapidly, increases its volume and stimulates urine output. Blood dilution lowers both sodium and the volume-dependent part of the thirst drive (making one less thirsty). Sufficient amounts of electrolytes need to be ingested with the water in endurance athletes. After one hour of intense exercise, sports drinks (or something similar that contains electrolytes in a good proportion) are highly recommended.

Strenuous exercise can produce free radicals that cause damage to all of our cells. Antioxidants such as beta-carotene, vitamin E, and vitamin C all decrease the free radical damage, improve recovery time, decrease muscle damage and help with immune response. Athletes are at risk for developing some common nutrient deficiencies/health problems including:

  1. The B vitamins (thiamine, riboflavin, niacin, pyridoxine, pantothenic acid, folate, B12)—The increased energy metabolism seen with athletes creates a need for more of the B vitamins that serve as helpers in the energy production cycle.
  2. Iron-deficiency anemia is not frequently seen among athletes, but suboptimal iron stores are common. Athletes at risk are the rapidly growing male adolescent, the female athlete with heavy menstrual losses, the person who restricts energy intake (wrestlers, dancers, young girls in general), the distance runners who have increased GI iron loss, and those training heavily in hot climates with heavy sweating.
  3. Osteoporosis can become a problem in females who exercise strenuously enough. Women with amenorrhea stop having menstrual cycles. Low estrogen associated with this can inhibit calcium absorption from the gut.
  4. Intense and lengthy exercise (thiamine, riboflavin, niacin, pyridoxine, pantothenic acid, folate, B12)—The increased energy metabolism seen with athletes creates a need for more of the B vitamins that serve as helpers in the energy production cycle.
    1. Food allergies and asthma
    2. IBS aka Runners “Trots”
    3. Higher susceptibility to microbial imbalances or dysbiosis
    4. Frequent colds and coughs

All of these can be treated or prevented by simple dietary interventions. Sometimes, however, some athletes may need intravenous nutrients to keep their bodies at optimal performance.

The main point to remember is that exercise is very important for good health. Our bodies are meant to move, and most chronic pain is due to a lack of proper movement of our tissues. When we exercise, our muscles are broken down, and it is the rebuilding process after the fact that is most crucial. You have to break it down to build it up stronger. The quality of food you choose to put in your body should be your highest priority because that is what your body uses to repair itself.

“Dis-moi ce que tu manges, je te dirai ce que tu es” translates to “Tell me what you eat and I shall tell you what you are.” This quote was written by a French doctor, Anthelme Brillat-Savarin, back in 1826. It may also be translated as “You are what you eat.” He knew that the food we eat is what our bodies use to build and repair itself. But, he also believed that the type of food that you choose to consume is a reflection of the kind of person you are. So, next time you eat, take a moment before and decide, “Is this really the person I am?” If it is not, then choose to make the change to be the person you want to become.

If you or someone you know would like to learn more about nutrition and/or the health, hope, and healing offered at the Riordan Clinic, call 316-682-3100 to make an appointment or contact us here.

Body Fuel – The Difference Between Carbohydrates, Protein and Fats


Photo Credit: floodkoff via Compfight cc

Understanding your body’s fuel system will give your players an edge during game time. They’ll be able to make educated decisions about how their diet affects their play.

Your body has three main types of nutrients (called “macronutrients): carbohydrates, proteins and fats.

I’m not going to go into a ton of detail about each of them.

Why not?

Because you don’t need to know everything. Too much information and you and your players will become confused and forget it all. At least, that’s what happened to me the first couple of times anyway. You need to know the essentials… the things that are most important to athletes.

Here’s the essential things you need to know about each fuel source.

Carbohydrates: Your Body’s Primary Fuel Source

Carbohydrates are your body’s main fuel source.

There are two types of carbohydrates: simple and complex.

Simple carbohydrates are carbs that your body can break down into glucose and burn as energy almost immediately. If you eat a slice of watermelon, it only takes about 20 minutes before the sugar hits your blood stream. High doses of simple sugars can cause sugar spikes and crashes, while small doses can help give an immediate energy boost.

Complex carbohydrates are carbs that your body needs to digest and slowly break down. They’re converted into simple sugars over time as your body metabolizes the carbs. Bread, rice and vegetables are examples of complex carbs.

It’s important to note that not all carbs are created equal. Though a Kit-Kat bar and a banana are both simple carbs, the latter has far more nutrition and causes less of an insulin spike than the Kit-Kat bar. As a rule of thumb, opt for whole foods rather than processed foods and avoid processed sugars.

Fats: A Multi-Purpose Nutrient

Fats serve several important functions in the body. For one, they’re a store of energy. When your body needs more energy than it has glucose, it breaks down fat. Fat also helps your body process vitamins. The body also uses fats as a temporary storage system for toxins, before they can be carried out of the body.

There are many different kinds of fats. The so-called “unhealthy fats” are trans-fats and saturated fats. These tend to be found in fast foods, hydrogenated oils, baked foods, butter and certain kinds of animal meats.

The “healthy fats” are monounsaturated fats and polyunsaturated fats. Nuts, avocados, olives and other natural sources of fats have these kinds of healthy fats.

Proteins: Your Body’s Building Blocks

Proteins are the primary building block for your body’s tissues. The amino acid chains form different patterns to create different kinds of tissues. Think of it like the raw materials that your body uses to form new muscles.

Protein is generally not used as an energy source unless the body has no other option. It uses carbohydrates first, then fats and finally breaks down muscles and uses protein if no other options are present.

These are the three essential building blocks to your body’s fuel system. Make sure you have enough carbs to fuel your workout, enough proteins to build new muscles and enough healthy fats to keep your body running smoothly.

Is there anything you consider important that I left out about each of these fuel sources? Let me know in the comments.

– Coach Mac


Those enviable people who effortlessly drift off to sleep, wake up with the birds and charge through the day full of enthusiasm almost certainly have their daily diets nailed. If all-day energy currently eludes you, your eating habits and food choices may need a shake up…

Complex (not simple) carbohydrates

Not only are they a good source of fibre, can help you manage weight and may reduce the risk of certain health conditions, complex carbohydrates release glucose into the blood gradually, providing the body with a steady supply of energy. A diet rich in foods such as wholegrains, oats, pulses, nuts and seeds will help you stay healthy and full of energy.

Simple carbohydrates come in two forms, natural and refined. Some fruits and vegetables are high in natural sugars, and can provide a healthy boost of energy when needed. Refined carbohydrates are often found in processed foods such as cakes, biscuits and sweets and include white flours and table sugar. These are best enjoyed as an occasional treat as they are quickly digested, releasing sugar rapidly into the blood stream, causing insulin spikes that lead to energy highs and crashing lows.

Swap white pasta and rice for brown or wholewheat varieties, try using wholemeal flour as an alternative to white flour and make the most of cheap, filling legumes.

Recipe ideas
Zingy salmon & brown rice salad
Wholewheat pasta with broccoli & almonds
Brown rice stir-fry with coriander omelette
Malted walnut seed loaf
Walnut & raisin oatcakes
Banana fairy cakes
Red lentil, chickpea & chilli soup

Always eat breakfast

People skip breakfast for reasons varying from not feeling hungry first thing in the morning to believing it will aid their weight loss goals. It is well documented that in fact, eating a healthy breakfast can reduce cravings later in the day and encourage healthier food choices for subsequent snacks and meals.

Eating low-GI, complex carbohydrates alongside a helping of protein at the start of the day will give your body all it needs in terms of energy, will kick-start your metabolism so you start burning more calories earlier in the day and will even help get your brain in gear.

Replace any white breads with wholemeal or wholegrain for a satisfying and healthy breakfast.

Recipe ideas
Spinach & smoked salmon egg muffins
Peanut butter & banana on toast
Cinnamon porridge with banana & berries
Dippy eggs with Marmite soldiers

Eat less, more often

Hands up if you’ve lost an entire afternoon asleep on the sofa post-Sunday lunch. When we over-indulge in foods high in carbohydrates, fats or sugars, a few things happen in the digestion process that can leave us feeling lethargic and drowsy. When you eat, your brain signals to your body to slow down and digest the incoming food – the more you put in, the harder your digestive system has to work – and the less energy you will have.

If your giant portion was full of sugar and simple carbohydrates such as white bread, pasta and flours, then your brain will also be dealing with an increase of insulin and elevated levels of serotonin and melatonin – chemicals associated with drowsiness.

Eating smaller meals more regularly will help regulate your blood glucose levels, as well as releasing energy gradually instead of in one big hit. Controlling your portion sizes is key to this approach – you could well be eating more at meal times than a balanced diet requires.

Top tips
A balanced diet for women
A balanced diet for men

When you need a quick boost…

As we all know, exercise is key to staying healthy, but sometimes the energy to lace up those trainers eludes even the best of us. This is the time carbohydrates with simple, quick releasing sugars come into their own. The concentrated carbs in these foods will provide energy to the muscles in the quickest way possible. However, we’re not suggesting you eat a slice of chocolate cake before hitting the gym. Instead, take advantage of high fibre foods containing natural sugars such as fresh or dried fruit, or a homemade smoothie topped with honey to give you a boost without leaving you uncomfortably full.

Recipe ideas
Oaty energy cookies
Exercise shake
Dried fruit energy nuggets
Instant frozen berry yogurt

The importance of B vitamins…

All B vitamins play a role in converting your food into energy that the body can use. Therefore, making sure you get your recommended daily amount will ensure your body has a reliable source of energy to call upon. Avoid deficiencies by eating a diet rich in whole foods such as fruits, vegetables, wholegrains, meat and fish.

Learn more about vitamins and minerals and how to get them naturally…
Vital vitamins
Vital minerals

What are your top tips for keeping your energy up?

Try making our choc-orange energy booster balls.

This article was last reviewed on 16 September 2019 by Kerry Torrens.

Kerry Torrens BSc. (Hons) PgCert MBANT is a Registered Nutritionist with a post graduate diploma in Personalised Nutrition & Nutritional Therapy. She is a member of the British Association for Nutrition and Lifestyle Medicine (BANT) and a member of the Guild of Food Writers. Over the last 15 years she has been a contributing author to a number of nutritional and cookery publications including BBC Good Food.

All health content on is provided for general information only, and should not be treated as a substitute for the medical advice of your own doctor or any other healthcare professional. Any healthy diet plan featured by BBC Good Food is provided as a suggestion of a general balanced diet and should not be relied upon to meet specific dietary requirements. If you have any concerns about your general health, you should contact your local healthcare provider. See our website terms and conditions for more information.

23 Best Foods for Energy

Maybe you had a bad night’s sleep or are approaching the afternoon slump, but the bottom line is that you need an energy kick—stat! Well, skip the Red Bull because there are better and healthier sources of energy that won’t drive you into a sugar coma.

Generally speaking, all food supposedly gives you energy. But some foods are better at providing the energy kick you need to conquer the world. Try noshing on any of these picks—and go from 0 to 10 on the energy scale. And for more inspiration for getting fired up to make big things happen, don’t miss these 20 Foods Successful People Eat.



Packed with more protein than any other grain, plus rich in amino acids, quinoa makes the perfect energy boost mid-day. “It is also high in folate, magnesium, phosphorus and manganese, making it a nutrient-packed source of carbohydrates for long-lasting energy levels,” says Dr. Lindsey Duncan, celebrity nutritionist. For plenty of ideas on how to enjoy quinoa, save this list of 30 Quinoa Recipes for Weight Loss.



Lentils are a food that gives you a bang of nutritional value for barely a buck. Its high fiber content stabilizes blood sugar levels, keeping you energized all day.


Tuna Fish

While it doesn’t have the most pleasant smell, eating tuna fish for lunch can perk you up. Loaded with protein and vitamin B, eating type of fish can provide a great source of energy says Rebecca Scritchfield, R.D.N. A piece of advice: go for the light canned tuna which is one of the 6 Best Fish for Weight Loss. And to really get a better understanding of your most nutritious fish options, take a look at our exclusive report on the 40+ Popular Types of Fish—Ranked for Nutrition.



Not only will beans keep you feeling full and satisfied, but they can also prevent you from feeling sluggish midday. “The protein helps keep blood sugar levels steady to keep you energized, plus the complex carbohydrate provides energy for the brain and body,” says Zied.



They’re the number one breakfast food for a reason! “Eggs provide high-quality protein and heart-healthy monounsaturated and polyunsaturated fatty acids and help stay energized and prevent overeating,” says Elisa Zied, R.D.N., C.D.N., author of Younger Next Week and Food, Fitness & Fiction blogger. (Psst! Find out What Happens to Your Body When You Eat Eggs!)


Whole Grain Cereal

There is nothing bland about whole grain cereal! And eating this in the a.m. is a great way to pump up your energy. “High-fiber whole grain cereals slow the release of glucose into the bloodstream which ultimately translates to more consistent energy levels throughout the day,” says Lisa Moskovitz, R.D., founder of The NY Nutrition Group.


Chia Seeds

Sprinkles these healthy seeds into your yogurt or smoothies and you the energy you need to fuel your day. “Chia seeds give you stable energy because of their great ratio of protein, fats and fiber combined with the fact that they’re low-carb,” says Carolyn Brown, MS, RD at Foodtrainers on Manhattan’s Upper West Side. “They won’t cause spikes and drops in blood sugar or insulin levels, preventing cravings and overeating later.”


Green Tea

More of a tea drinker? Then trade the java for a some green tea; we’re such big fans at Eat This, Not That! that we created The 7-Day Flat-Belly Tea Cleanse. Much like coffee, green tea naturally contains caffeine, but it also has a compound called thymine that keeps you focused and alert without feeling jittery. Meanwhile, its powerful properties help burn more belly fat—which is why test panelists for the cleanse lost up to 10 pounds in a week!



“Yogurt is a great source of high-quality protein to fill you up and provide basic energy for the brain, says Zied.” The best part about this food is it pairs well with pretty much everything. Add some granola, nuts, or fruit to amp up its flavor.



Oranges contain high levels of vitamin C, which can make you less tired two hours after intake. For more smart snacks, try these 40 Healthy Snack Ideas to Keep You Slim.



Most nuts like almonds, peanut butter, and cashews are booming with nutrients, healthy fats, and are an excellent source of protein. Past studies have found that their nutrition content can help sustain energy levels. Plus, they’re easy to take wherever you go.


Wild Salmon

Caroline Attwood/Unsplash

There’s nothing fishy about this! Not only is wild salmon great for muscle de is a rich source of omega-3 fatty acids and protein, which can help you maintain those high energy levels. It’s also one of the 20 Healthy Fats to Make You Thin.


Pumpkin Seeds

“Pumpkin seeds are a good source of protein, healthy fats and fiber, keeping you feeling full and energized longer,” Dr. Duncan says. “They also contain manganese, magnesium, phosphorus and zinc, which provide additional energy support to maximize gym time.” Add them on to your salads or eat them alone during lunch to perk you up for the rest of the day.



With its high abundance of vitamins and minerals, an apple is basically the poster child for healthy food. It’s also made up of simple carbohydrates, which can offer a quick burst of fuel.



One of the easiest and cheapest foods for an instant pick-me-up. Bananas contain glucose which provides a great energy boost to help you crush your workout. Plus noshing on this fruit gives you a load of benefits. Check out 21 Amazing Things That Happen to Your Body When You Eat Bananas.



The all and mighty powerful leafy green just got mightier. Spinach gets its gold star for energy due to its amino acids and tyrosine, a compound that has been known to improve alertness. Not a fan of greens? Toss it in your smoothie. We promise you won’t taste it!



Snacking on these powerful berries can help you beat that post-lunch slump. They’re low in sugar, but high in fiber, a powerful combination to keep your body humming with energy. The best part is that you can throw in anything: salads, yogurt, smoothies, or just enjoy them on their own. Bonus: They’re one of the 15 Most Antioxidant-Packed Fruits & Veggies.


Dark Chocolate

Charisse Kenion/Unsplash

Researchers from Northern Arizona University had participants snack on chocolate with 60 percent cacao and found an increase in alertness and attentiveness. But that doesn’t give you the green light to devour the chocolate bar. A small piece is just enough to get you going but remember to choose a dark chocolate with at least 70 percent cacao.


Trail Mix

This combination of nuts, seeds, and dried food makes this an epic snack when fatigue strikes. The fat found the nuts and seeds are a great source for long-lasting energy while the high fiber content slows down glucose-release so there’s a steady supply says Moskovitz. Just make sure to keep your portion control in check; you really only need a handful or two. Downing an entire bag (like you might find at the airport) is actually a calorie bomb for your belly.



Mike Marquez/Unsplash

We all know that caffeine can provide a much-needed jolt to get through the workday. But a study also found that drinking coffee pre-workout can improve your exercise. Men who drank about 5 milligrams of coffee (about 2-3 cups) and found that they were able to complete more reps of bench presses and leg presses than workout days sans java. Speaking of, here are 35 Things You Didn’t Know About Caffeine.


Lean Beef

Being a meat lover has its perks! Zied says that a piece of beef contains high protein and amino acids to sustain your energy levels and keeps you fuller longer. Pair it with veggies for a well-balanced meal.



Past studies found that dehydration is the culprit to why we’re so tired (or think we’re hungry). So, next time you’re feeling sluggish, guzzle down some H2O for a quick energy boost.


Yerba Mate

Never heard of Yerba Mate? Allow us to explain: it’s an all-natural energy drink derived from the mate plant found in South America. Like coffee and green tea, it has a natural source of caffeine, but its abundance of vitamins and minerals helps sustain your energy without the crash and burn. Need more convincing? Here are 10 Reasons People Swear By Yerba Mate.

Get the New Book!

Want to lose 10, 20, even 30 pounds—all without dieting?! Get your copy of Eat This, Not That: The Best (& Worst) Foods in America!, and learn how to indulge smarter and lose weight fast!

Definitions of Health
Terms: Nutrition

Nutrition is about eating a healthy and balanced diet. Food and drink provide the energy and nutrients you need to be healthy. Understanding these nutrition terms may make it easier for you to make better food choices.

Find more definitions on Fitness | General Health | Minerals | Nutrition | Vitamins

Amino Acids

Amino acids are the building blocks of proteins. The body produces many amino acids and others come from food. The body absorbs amino acids through the small intestine into the blood. Then the blood carries them throughout the body.
Source: NIH MedlinePlus

Blood Glucose

Glucose — also called blood sugar — is the main sugar found in the blood and the main source of energy for your body.
Source: NIH MedlinePlus


A unit of energy in food. Carbohydrates, fats, protein, and alcohol in the foods and drinks we eat provide food energy or “calories.”
Source: National Institute of Diabetes and Digestive and Kidney Diseases


Carbohydrates are one of the main types of nutrients. Your digestive system changes carbohydrates into glucose (blood sugar). Your body uses this sugar for energy for your cells, tissues and organs. It stores any extra sugar in your liver and muscles for when it is needed. There are two types of carbohydrates: simple and complex. Simple carbohydrates include natural and added sugars. Complex carbohydrates include whole grain breads and cereals, starchy vegetables and legumes.
Source: NIH MedlinePlus


Cholesterol is a waxy, fat-like substance that’s found in all cells of the body. Your body needs some cholesterol to make hormones, vitamin D, and substances that help you digest foods. Your body makes all the cholesterol it needs. However, cholesterol also is found in some of the foods you eat. High levels of cholesterol in the blood can increase your risk of heart disease.
Source: National Heart, Lung, and Blood Institute


Dehydration is a condition that happens when you do not take in enough liquids to replace those that you lose. You can lose liquids through frequent urinating, sweating, diarrhea, or vomiting. When you are dehydrated, your body does not have enough fluid and electrolytes to work properly.
Source: NIH MedlinePlus


Your diet is made up of what you eat and drink. There are many different types of diets, such as vegetarian diets, weight loss diets, and diets for people with certain health problems.
Source: NIH MedlinePlus

Dietary Supplements

A dietary supplement is a product you take to supplement your diet. It contains one or more dietary ingredients (including vitamins; minerals; herbs or other botanicals; amino acids; and other substances). Supplements do not have to go through the testing that drugs do for effectiveness and safety.
Source: National Institutes of Health, Office of Dietary Supplements


Digestion is the process the body uses to break down food into nutrients. The body uses the nutrients for energy, growth, and cell repair.
Source: National Institute of Diabetes and Digestive and Kidney Diseases


Electrolytes are minerals in body fluids. They include sodium, potassium, magnesium, and chloride. When you are dehydrated, your body does not have enough fluid and electrolytes.
Source: NIH MedlinePlus


Enzymes are substances that speed up chemical reactions in the body.
Source: National Institute of Diabetes and Digestive and Kidney Diseases

Fatty Acid

Fatty acid is a major component of fats that is used by the body for energy and tissue development.
Source: National Cancer Institute


Fiber is a substance in plants. Dietary fiber is the kind you eat. It’s a type of carbohydrate. You may also see it listed on a food label as soluble fiber or insoluble fiber. Both types have important health benefits. Fiber makes you feel full faster, and stay full for a longer time. That can help you control your weight. It helps digestion and helps prevent constipation.
Source: NIH MedlinePlus


Gluten is a protein found in wheat, rye, and barley. It can also be in products such as vitamin and nutrient supplements, lip balms, and certain medicines.
Source: National Institute of Diabetes and Digestive and Kidney Diseases

Glycemic Index

The glycemic index (GI) measures how a carbohydrate-containing food raises blood sugar.
Source: NIH MedlinePlus


HDL stands for high-density lipoproteins. It is also known as “good” cholesterol. HDL is one of the two types of lipoproteins that carry cholesterol throughout your body. It carries the cholesterol from other parts of your body back to your liver. Your liver removes the cholesterol from your body.
Source: National Heart, Lung, and Blood Institute


LDL stands for low-density lipoproteins. It is also known as “bad” cholesterol. LDL is one of the two types of lipoproteins that carry cholesterol throughout your body. A high LDL level leads to a buildup of cholesterol in your arteries.
Source: National Heart, Lung, and Blood Institute


Metabolism is the process your body uses to get or make energy from the food you eat.
Source: NIH MedlinePlus

Monounsaturated Fat

Monounsaturated fat is a type of fat is found in avocados, canola oil, nuts, olives and olive oil, and seeds. Eating food that has more monounsaturated fat (or “healthy fat”) instead of saturated fat (like butter) may help lower cholesterol and reduce heart disease risk. However, monounsaturated fat has the same number of calories as other types of fat and may contribute to weight gain if you eat too much of it.
Source: National Institute of Diabetes and Digestive and Kidney Diseases


Nutrients are chemical compounds in food that are used by the body to function properly and maintain health. Examples include proteins, fats, carbohydrates, vitamins, and minerals.
Source: National Institutes of Health, Office of Dietary Supplements


This field of study focuses on foods and substances in foods that help animals (and plants) to grow and stay healthy. Nutrition science also includes behaviors and social factors related to food choices. The foods we eat provide energy (calories) and nutrients such as protein, fat, carbohydrate, vitamins, minerals, and water. Eating healthy foods in the right amounts gives your body energy to perform daily activities, helps you to maintain a healthy body weight, and can lower your risk for certain diseases such as diabetes and heart disease.
Source: National Institutes of Health, Office of Dietary Supplements

Polyunsaturated Fat

Polyunsaturated fat is a type of fat that is liquid at room temperature. There are two types of polyunsaturated fatty acids (PUFAs): omega-6 and omega-3. Omega-6 fatty acids are found in liquid vegetable oils, such as corn oil, safflower oil, and soybean oil. Omega-3 fatty acids come from plant sources—including canola oil, flaxseed, soybean oil, and walnuts—and from fish and shellfish.
Source: National Institute of Diabetes and Digestive and Kidney Diseases


Protein is in every living cell in the body. Your body needs protein from the foods you eat to build and maintain bones, muscles, and skin. You get proteins in your diet from meat, dairy products, nuts, and certain grains and beans. Proteins from meat and other animal products are complete proteins. This means they supply all of the amino acids the body can’t make on its own. Plant proteins are incomplete. You must combine different types of plant proteins to get all of the amino acids your body needs. You need to eat protein every day, because your body doesn’t store it the way it stores fats or carbohydrates.
Source: NIH MedlinePlus

Saturated Fat

Saturated fat is a type of fat that is solid at room temperature. Saturated fat is found in full-fat dairy products (like butter, cheese, cream, regular ice cream, and whole milk), coconut oil, lard, palm oil, ready-to-eat meats, and the skin and fat of chicken and turkey, among other foods. Saturated fats have the same number of calories as other types of fat, and may contribute to weight gain if eaten in excess. Eating a diet high in saturated fat also raises blood cholesterol and risk of heart disease.
Source: National Institute of Diabetes and Digestive and Kidney Diseases


Table salt is made up of the elements sodium and chlorine – the technical name for salt is sodium chloride. Your body needs some sodium to work properly. It helps with the function of nerves and muscles. It also helps to keep the right balance of fluids in your body.
Source: NIH MedlinePlus


Sugars are a type of simple carbohydrate. They have a sweet taste. Sugars can be found naturally in fruits, vegetables, milk, and milk products. They are also added to many foods and drinks during preparation or processing. Types of sugar include glucose, fructose, and sucrose. Your digestive system breaks down sugar into glucose. Your cells use the glucose for energy.
Source: NIH MedlinePlus

Total Fat

Fat is a type of nutrient. You need a certain amount of fat in your diet to stay healthy, but not too much. Fats give you energy and help your body absorb vitamins. Dietary fat also plays a major role in your cholesterol levels. Not all fats are the same. You should try to avoid saturated fats and trans fats.
Source: NIH MedlinePlus

Trans Fat

Trans fat is a type of fat that is created when liquid oils are changed into solid fats, like shortening and some margarines. It makes them last longer without going bad. It may also be found in crackers, cookies, and snack foods. Trans fat raises your LDL (bad) cholesterol and lowers your HDL (good) cholesterol.
Source: NIH MedlinePlus


Triglycerides are a type of fat found in your blood. Too much of this type of fat may raise the risk of coronary artery heart disease, especially in women.
Source: National Heart, Lung, and Blood Institute

Water Intake

We all need to drink water. How much you need depends on your size, activity level, and the weather where you live. Keeping track of your water intake helps make sure that you get enough. Your intake includes fluids that you drink, and fluids you get from food.
Source: NIH MedlinePlus

Energy for work and play

Energy from food is what keeps us alive and active. Energy is required for even the smallest of movements. Even when sleeping, our bodies still need energy so that our metabolism, heart and breathing function and our body temperature is maintained.

Energy Supply
Our bodies’ main sources of energy are carbohydrates and fats. We can also use protein and alcohol as sources of energy. The energy content of food is measured in kilocalories (kcal) or kilojoules (kJ). One kilocalorie is equivalent to 4.2 kilojoules. Not all types of food contain the same amount of energy. Of all of the food types, fat provides the most energy. Alcohol is also very high in energy. Carbohydrates and protein, on the other hand, have half as many kilocalories:

  • 1 gram of fat provides approx. 9 kcal
  • 1 gram of alcohol provides approx. 7 kcal
  • 1 gram of carbohydrate provides approx. 4 kcal
  • 1 gram of protein provides approx. 4 kcal

Our Energy Requirement
Energy requirements vary from person to person. The amount of energy we need each day depends on many factors. In addition to our age and gender, body weight and physical activity also play a part. The following overview shows the average amount of energy required across different age groups.

How much Energy (Calories) should we intake daily?
Guideline values for average energy intake. RDA for Energy for Indians, 2010

Age group RDA(Kcal/day)
Adult Sedentary Male 2320
Adult Sedentary Female 1900
Pregnant Female 2250
Lactating Mother (0-6 months) 2500
(6-9 months) 2420
Infant (0-6 months) 496
(6-12 months) 672
Children 1-3 years 1060
4-6 years 1350
7-9 years 1690
Boys 10-12 years 2190
13-15 years 2750
16-17 years 3020
Girls 10-12 years 2010
13-15 years 2330
16-17 years 2440

Input must equal output
People who consume more energy than their body needs for an extended period will put on weight. It is therefore important to eat in moderation to keep your body weight within a healthy weight range. Are you carrying a few excess pounds? Then a combination of more exercise and reduced calorie intake is the most effective way to get back to your ideal weight.

To maintain energy balance, input must equal the output, which corresponds to a steady state of equilibrium which helps in maintaining good health.

Source Of Energy In Indian Diets:
The main source of energy in Indian diets are carbohydrates, fats and protein. But the main source is carbohydrates derived largely from cereals present in them. These cereals constitute 80 % of our diet, and provide 50-80% of daily energy intake. Most families derive nearly 10-12 % energy from proteins. Energy from fats vary according to family type. Those belonging to low income groups have only 5 % fat in their diet whereas affluent families derive as high as 30 % of their dietary energy from fat

When Our Bodies Become Energy-Savers
A calorie-controlled diet can also be helpful when losing weight. However, not every diet is recommended. Make sure that your meals are varied and balanced and that the diet does not promise significant weight loss over a short period of time. It is especially important not to let a weight-loss diet become a matter of habit. While you are on this temporary diet, your body will adjust to receiving less energy. It becomes an “energy-saver”. As soon as you start eating normally again, the energy stores will fill up quickly to prepare for the next period of hunger. People’s weight is often higher after they have been on a calorie-controlled diet than beforehand.

The Body’s Fuel Sources

The Body’s Fuel Sources

Our ability to run, bicycle, ski, swim, and row hinges on the capacity of the body to extract energy from ingested food. As potential fuel sources, the carbohydrate, fat, and protein in the foods that you eat follow different metabolic paths in the body, but they all ultimately yield water, carbon dioxide, and a chemical energy called adenosine triphosphate (ATP). Think of ATP molecules as high-energy compounds or batteries that store energy. Anytime you need energy—to breathe, to tie your shoes, or to cycle 100 miles (160 km)—your body uses ATP molecules. ATP, in fact, is the only molecule able to provide energy to muscle fibers to power muscle contractions. Creatine phosphate (CP), like ATP, is also stored in small amounts within cells. It’s another high-energy compound that can be rapidly mobilized to help fuel short, explosive efforts. To sustain physical activity, however, cells must constantly replenish both CP and ATP.

Our daily food choices resupply the potential energy, or fuel, that the body requires to continue to function normally. This energy takes three forms: carbohydrate, fat, and protein. (See table 2.1, Estimated Energy Stores in Humans.) The body can store some of these fuels in a form that offers muscles an immediate source of energy. Carbohydrates, such as sugar and starch, for example, are readily broken down into glucose, the body’s principal energy source. Glucose can be used immediately as fuel, or can be sent to the liver and muscles and stored as glycogen. During exercise, muscle glycogen is converted back into glucose, which only the muscle fibers can use as fuel. The liver converts its glycogen back into glucose, too; however, it’s released directly into the bloodstream to maintain your blood sugar (blood glucose) level. During exercise, your muscles pick up some of this glucose and use it in addition to their own private glycogen stores. Blood glucose also serves as the most significant source of energy for the brain, both at rest and during exercise. The body constantly uses and replenishes its glycogen stores. The carbohydrate content of your diet and the type and amount of training that you undertake influence the size of your glycogen stores.

The capacity of your body to store muscle and liver glycogen, however, is limited to approximately 1,800 to 2,000 calories worth of energy, or enough fuel for 90 to 120 minutes of continuous, vigorous activity. If you’ve ever hit the wall while exercising, you know what muscle glycogen depletion feels like. As we exercise, our muscle glycogen reserves continually decease, and blood glucose plays an increasingly greater role in meeting the body’s energy demands. To keep up with this greatly elevated demand for glucose, liver glycogen stores become rapidly depleted. When the liver is out of glycogen, you’ll “bonk” as your blood glucose level dips too low, and the resulting hypoglycemia (low blood sugar) will further slow you down. Foods that you eat or drink during exercise that supply carbohydrate can help delay the depletion of muscle glycogen and prevent hypoglycemia.

Fat is the body’s most concentrated source of energy, providing more than twice as much potential energy as carbohydrate or protein (9 calories per gram versus 4 calories each per gram). During exercise, stored fat in the body (in the form of triglycerides in adipose or fat tissue) is broken down into fatty acids. These fatty acids are transported through the blood to muscles for fuel. This process occurs relatively slowly as compared with the mobilization of carbohydrate for fuel. Fat is also stored within muscle fibers, where it can be more easily accessed during exercise. Unlike your glycogen stores, which are limited, body fat is a virtually unlimited source of energy for athletes. Even those who are lean and mean have enough fat stored in muscle fibers and fat cells to supply up to 100,000 calories—enough for over 100 hours of marathon running!

Fat is a more efficient fuel per unit of weight than carbohydrate. Carbohydrate must be stored along with water. Our weight would double if we stored the same amount of energy as glycogen (plus the water that glycogen holds) that we store as body fat. Most of us have sufficient energy stores of fat (adipose tissue or body fat), plus the body readily converts and stores excess calories from any source (fat, carbohydrate, or protein) as body fat. In order for fat to fuel exercise, however, sufficient oxygen must be simultaneously consumed. The second part of this chapter briefly explains how pace or intensity, as well as the length of time that you exercise, affects the body’s ability to use fat as fuel.

As for protein, our bodies don’t maintain official reserves for use as fuel. Rather, protein is used to build, maintain, and repair body tissues, as well as to synthesize important enzymes and hormones. Under ordinary circumstances, protein meets only 5 percent of the body’s energy needs. In some situations, however, such as when we eat too few calories daily or not enough carbohydrate, as well as during latter stages of endurance exercise, when glycogen reserves are depleted, skeletal muscle is broken down and used as fuel. This sacrifice is necessary to access certain amino acids (the building blocks of protein) that can be converted into glucose. Remember, your brain also needs a constant, steady supply of glucose to function optimally.

Fuel Metabolism and Endurance Exercise

Carbohydrate, protein, and fat each play distinct roles in fueling exercise.


  • Provides a highly efficient source of fuel—Because the body requires less oxygen to burn carbohydrate as compared to protein or fat, carbohydrate is considered the body’s most efficient fuel source. Carbohydrate is increasingly vital during high-intensity exercise when the body cannot process enough oxygen to meet its needs.
  • Keeps the brain and nervous system functioning—When blood glucose runs low, you become irritable, disoriented, and lethargic, and you may be incapable of concentrating or performing even simple tasks.
  • Aids the metabolism of fat—To burn fat effectively, your body must break down a certain amount of carbohydrate. Because carbohydrate stores are limited compared to the body’s fat reserves, consuming a diet inadequate in carbohydrate essentially limits fat metabolism.
  • Preserves lean protein (muscle) mass—Consuming adequate carbohydrate spares the body from using protein (from muscles, internal organs, or one’s diet) as an energy source. Dietary protein is much better utilized to build, maintain, and repair body tissues, as well as to synthesize hormones, enzymes, and neurotransmitters.


  • Provides a concentrated source of energy—Fat provides more than twice the potential energy that protein and carbohydrate do (9 calories per gram of fat versus 4 calories per gram of carbohydrate or protein).
  • Helps fuel low- to moderate-intensity activity—At rest and during exercise performed at or below 65 percent of aerobic capacity, fat contributes 50 percent or more of the fuel that muscles need.
  • Aids endurance by sparing glycogen reserves—Generally, as the duration or time spent exercising increases, intensity decreases (and more oxygen is available to cells), and fat is the more important fuel source. Stored carbohydrate (muscle and liver glycogen) are subsequently used at a slower rate, thereby delaying the onset of fatigue and prolonging the activity.


  • Provides energy in late stages of prolonged exercise—When muscle glycogen stores fall, as commonly occurs in the latter stages of endurance activities, the body breaks down amino acids found in skeletal muscle protein into glucose to supply up to 15 percent of the energy needed.
  • Provides energy when daily diet is inadequate in total calories or carbohydrate—In this situation, the body is forced to rely on protein to meet its energy needs, leading to the breakdown of lean muscle mass.

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