Thyroid medication weight loss

Is it Possible to Lose Weight with an Underactive Thyroid?

If you are being treated for an underactive thyroid, medically known as hypothyroidism, and are struggling to lose body fat, you are not alone. Of the estimated 4.6 percent in the U.S. who have hypothyroidism, many find themselves with undesirable weight gain.

Even after diagnosis and treatment, it may be extremely difficult to lose weight. You may even find yourself gaining weight, so attaining your personal body composition goals seems impossible.

This article provides information about thyroid function and its role in obesity, discusses the possible barriers to improving body composition even with treatment, and gives you specific steps you can take to lose weight.

The small but mighty thyroid gland

The thyroid gland is a small butterfly-shaped gland located low on the front of your neck. It secretes several hormones, primarily T3 (triiodothyronine) and T4 (thyroxine), that act on every cell throughout the body to regulate metabolism, growth and development, and body temperature. These hormones also affect breathing, heart and nervous system functions, muscle strength, menstrual cycles, weight and cholesterol levels.

The thyroid functions by receiving information from the hypothalamus and pituitary gland located in the brain. The pituitary gland, which is like a thermostat for your body, stimulates the thyroid by secreting Thyroid Stimulating Hormone (TSH). When the pituitary senses a low concentration of thyroid hormone in your blood, it produces more TSH to signal to increase production of T4 or T3. If thyroid hormone levels are high, the pituitary produces only tiny amounts of TSH.

Thyroid dysfunction

Millions of people in the U.S., mostly women, have thyroid diseases – ranging from a harmless goiter (enlarged gland) to life-threatening cancer. An abnormal production of thyroid hormones is the most common thyroid condition.

If your thyroid makes too much thyroid hormone, you have hyperthyroidism. Common symptoms include uncontrolled weight loss, rapid heart rate, and heat sensitivity.

With hypothyroidism, insufficient thyroid hormone is secreted to meet the body’s needs, and body functions slow.

Common causes of underactive thyroid include autoimmune disease, such as Hashimoto’s disease, inflammation (thyroiditis), surgical removal of part or all of the gland, radiation treatments, treatments for hyperthyroidism, and certain medications.

If you have hypothyroidism, you may gain weight, feel tired, have dry hair and skin, be constipated, and have an intolerance to cold.

Hypothyroidism is treated with daily thyroid hormone pills to replace the amount of hormone your body is no longer producing.

The link between hypothyroidism and weight gain

Weight gain or the inability to lose weight is a common concern for people with hypothyroidism. Even when on treatment, there is usually only a modest loss in weight.

The way the thyroid functions to affect weight and body composition is quite complex. Research has found interactions between thyroid hormones and factors directly affecting energy expenditure, such as fat tissue, other hormones, and the brain.

Although clinicians are not certain whether hypothyroidism causes obesity or vice versa, there is undoubtedly .

Barriers to weight loss

It is frustrating to struggle to lose weight or continue to gain weight, even while taking your daily medication. There are five potential barriers that may be making weight loss difficult for you:

  • Suboptimal Thyroid Treatment

Most people with hypothyroidism are treated with thyroid hormone replacement medication to restore TSH levels to what is known as “reference range.” A reference range is a set of values that includes an upper and lower limit of a lab test that are considered normal for a defined healthy population.

When you fall within the TSH reference range, you are euthyroid, which means your thyroid function is considered clinically “normal”.; however, this may not mean it is optimal for you. Many people experience symptoms while in the “normal” range.

There are a few factors that can affect how well your treatment is working.

The timing of your medication is a key factor, since a number of foods, supplements and drugs interfere with the absorption or action of levothyroxine in the body.

Also, researchers have found that TSH levels in the upper end of the reference range are linked to increased weight and higher rates of obesity. In fact, even small increases in TSH within the normal range are associated with weight gain.

  • A Decreased Metabolic Set Point

Why is it that that your friend eats more than you do, doesn’t exercise nearly as much, but easily maintains a lower weight? It may be that you have a lower metabolism than she does.

Metabolism is the process by which your body converts the food you eat into energy. It is essential to ensuring your body has sufficient energy to function while protecting you from starvation. Your metabolism works like a thermostat (remember the pituitary?) to maintain your body fat percentage – slowing down or speeding up to maintain a certain set point range.

When your body senses you are in a state of “famine”; for example, if you consistently eat too few calories, it adjusts by decreasing your metabolic set point. Similarly, hypothyroidism leads to chronically slower metabolism, and as you take in more calories than you burn, the body establishes a new, lower metabolic set point. This means fewer calories are needed to maintain body weight, making weight loss more difficult.

  • Other Thyroid Hormones

The treatment most commonly used for hypothyroidism is synthetic T4 hormone, called levothyroxine; however, T4 is not the only thyroid hormone that affects your metabolism.

Triiodothyronine (T3) works at the cellular level delivering oxygen and energy. T3 is produced by the thyroid as well as through conversion of T4 to T3. Lower T3 levels are associated with lowered resting metabolic rates. A lower metabolism requires less caloric intake and more physical activity to maintain current body weight or to lose fat. Some people, due to genetics, have an increased need for T3. These people may benefit from a T4/T3 combination therapy, such as levothyroxine plus liothyronine (synthetic T3).

Thyroid Binding Globulin (TBG) is a transportation hormone that carries T3 and T4 through your bloodstream to your cells. If you have too little or too much TBG, your thyroid hormones cannot get to your cells adequately or efficiently.

  • Insulin Resistance

Insulin, another hormone released by your pancreas, increases after you eat sugar or carbohydrates. Insulin stimulates your cells to absorb the excess sugar in the blood, storing it for energy and protecting your body from high glucose levels.

When insulin levels remain chronically elevated, your body becomes resistant to insulin, which means the cells are less responsive, and more insulin is required to maintain normal blood sugar levels. Research has found that people with hypothyroidism are more likely to be insulin resistant.

Elevated levels of insulin not only increase your risk of developing Type 2 diabetes, it causes weight gain, even if you eat fewer calories, by making your cells better at storing fat and increasing cravings for carbohydrate-rich foods.

  • Leptin Resistance

Leptin, a hormone secreted by your fat cells, acts on the hypothalamus in your brain to regulate metabolism and appetite. As you accumulate more fat cells, leptin levels increase and signal to the brain there is adequate energy storage. In response, your pituitary gland increases TSH to stimulate thyroid production and your body burns fat rather than storing it.

Leptin resistance occurs much like insulin resistance. The hypothalamus becomes unresponsive to chronically high levels of leptin, which causes your brain to act as if the body is in a state of starvation. Metabolism slows, appetite increases and you gain weight, which further increases leptin levels. Recent research has shown that leptin resistance contributes to a reduced metabolic set point.

Not only is leptin resistance linked to obesity, recent studies have discovered as well. Leptin resistance makes you chronically hungry and prevents your body from using stored fat, which creates weight gain and can makes weight loss more difficult.

Steps to attaining your ideal body composition

Hope is not lost! Your motivation may be lagging because the weight is not melting off even while taking thyroid hormone replacement. There are proactive steps you can take to address issues keeping you from meeting your goals.

Get your thyroid tested – Discuss the results with your doctor to see if your TSH levels are in the higher end of the reference range, or if your T3 or TBG is low. You may need to adjust your current medication or supplement with T3 in order to find your optimal thyroid levels.

Optimize your thyroid medication – Take levothyroxine on an empty stomach either a half hour before breakfast or before bedtime. Wait at least three to four hours after taking your medication before taking supplements or drinks that contain calcium or iron. Also, discuss any changes in your medications with your doctor.

Get tested for insulin and leptin resistance – If you have these conditions, discuss treatment options with your doctor.

Exercise regularly – Lifestyle changes, such as physical activity, which improve body composition (even without a change on the scale), improve thyroid function. Regular exercise raises your metabolism, curbs your appetite, lowers blood sugar levels, and reduces insulin and leptin resistance.

Change your diet – Work with your doctor to find a diet plan that will provide optimal thyroid health and control your weight while helping to manage or prevent conditions associated with hypothyroidism.

Change your eating patterns – Larger, less frequent (2-3) meals each day with few or no between-meal snacks may be more effective at controlling insulin and leptin levels, which will optimize fat usage. Avoid excess calorie restriction as that may further lower your metabolic set point.

Get your 8 hours of sleep – Getting enough sleep controls insulin and leptin as well as stress hormone levels.


Jennifer Boidy, RN is a freelance healthcare content writer who is always on the lookout for innovative technologies that improve health and the delivery of healthcare. Jennifer resides in Manchester, MD with her husband, two teenagers, dog, cat, and plenty of wildlife.

Losing Weight With an Underactive Thyroid

Hypothyroidism: Control the Condition, Control the Weight

The best way to manage weight gain from hypothyroidism is to control the condition. If you get your metabolism back up to speed, the weight shouldn’t keep adding up. You’ll also have more energy, which can help motivate you to exercise.

Hypothyroidism can be treated with a thyroid hormone supplement, which provides the body with the thyroid hormone it needs to keep metabolism at a healthy level. A common medication to treat hypothyroidism is levothyroxine (Levoxyl, Synthroid), a synthetic form of thyroid hormone.

Hypothyroidism: A Frustrating Condition

Even if you are able to get your hypothyroidism under control through treatment, some people still have problems shedding those extra pounds and preventing more weight from creeping on.

Angie, a Graves’ disease patient in Frankfort, Ky, was diagnosed with a hyperthyroid condition a few years ago. Hyperthyroidism is caused by an overactive thyroid gland. After receiving treatment, she developed hypothyroidism and has struggled with maintaining a healthy weight ever since.

“Since my thyroid was made inactive due to hypothyroidism, it has been a monumental struggle to lose and maintain weight. This is despite having a dedicated exercise program and watching what I eat,” says Angie.

She believes the weight loss process has become even slower for her specifically because of her hypothyroidism. “While it might take a normal person a week to lose two pounds, it may take me a month to do so. It is frustrating, but weight can be controlled through a consistent exercise program and watching what I eat. What works for me is to be consistent with my exercise,” says Angie. She hits the gym at least four to five days a week for 60 to 90 minutes each session, combining strength training with cardiovascular exercise. Angie also watches her calorie and carbohydrate intake, eats plenty of fruits and vegetables, and drinks lots of water to help maintain a healthy weight.

Wolf stresses that people with hypothyroidism should never use the condition as an excuse to let the pounds add up — it is admittedly more difficult to manage your weight with hypothyroidism, but it can be done. If you need to lose weight, Wolf suggests making small changes in your diet to cut calories. Try having fruit instead of an unhealthy snack, or swap your high-calorie desert for a lower-calorie option. Results take time, but if you stick with it and don’t get discouraged, you’ll eventually see them.

Satisfied with her current health and body weight, Angie admits that though it’s still a challenge to stay in control of her weight, “moderation and balance” are the keys to her success.

For people with hypothyroidism, making a commitment to better health and weight loss is necessary to shed those stubborn pounds, but feeling well again is worth the effort.

Does Treatment of Hypothyroidism Lead to Weight Loss

October 16, 2013 — Decreased thyroid function, or hypothyroidism, is commonly associated with weight gain. But contrary to popular belief, effective treatment with levothyroxine (LT4) to restore normal thyroid hormone levels is not associated with clinically significant weight loss in most people. The study that led to this surprising finding will be presented by researchers from Boston University Medical Center at the 83rd Annual Meeting of the American Thyroid Association, October 16-20, 2013, in San Juan, Puerto Rico.

In “Weight Change after Treatment of Hypothyroidism,” SY Lee, LE Braverman, and EN Pearce describe the retrospective review of patients with newly diagnosed primary hypothyroidism over an 8-year period, not caused by thyroid cancer or other forms of disease or associated with pregnancy or use of prescription weight loss medication.

About half (52%) of the patients lost weight up to 24 months after initiation of treatment with LT4. Overall, weight loss was modest, with a mean weight loss of 8.4 + 9.7 lbs.

“Because obesity and hypothyroidism are very common, there are many patients who have both conditions,” says Ronald J. Koenig, M.D., Ph.D, Program Committee Co-Chair, and Professor, Department of Internal Medicine, University of Michigan Medical Center, Ann Arbor. “These patients (and sometimes their physicians) often assume the hypothyroidism is causing the obesity even though this may not be the case. This study is important because it shows, unfortunately, that only about half of hypothyroid patients lose weight after the successful treatment of their hypothyroidism. It will be interesting and important to have follow up data to know whether the patients that lose weight are the ones most in need of weight loss, and to know how significantly their weight loss contributed toward achieving a normal body weight.”

About the ATA

The American Thyroid Association (ATA) is the leading worldwide organization dedicated to the advancement, understanding, prevention, diagnosis and treatment of thyroid disorders and thyroid cancer. ATA is an international individual membership organization with over 1,700 members from 43 countries around the world. Celebrating its 90th anniversary, ATA delivers its mission through several key endeavors: the publication of highly regarded monthly journals, THYROID, Clinical Thyroidology (CT), VideoEndocrinology and CT for Patients; annual scientific meetings; biennial clinical and research symposia; research grant programs for young investigators, support of online professional, public and patient educational programs through; and the development of guidelines for clinical management of thyroid disease. Visit for more information.

Media Contact
Bobbi Smith
Executive Director of the American Thyroid Association
Email: [email protected]

Losing weight and keeping it off can be a struggle.

Especially if you have an underactive thyroid. Your metabolism has slowed down and you’re almost always feeling tired.

But if you break down the process into small steps, and tick each box as you go, weight loss comes much easier.

This guide covers the 6 fundamental steps required to successfully lose weight with an underactive thyroid.

1. Optimise Your Thyroid Medication

I wanted to begin with a nutrition recommendation, but correcting your thyroid medication first priority.

If your medication is not helping to correct TSH and your T3 and T4 thyroid hormone levels, as well as relieve symptoms, then weight loss goes from difficult to impossible.

Work with your health care provider to determine what type of medication is better for you, and also to find the optimal dose required. While Levothyroxine is on average more effective, Armour is reportedly much better tolerated.

There is no difference between taking your thyroid hormone meds in the morning vs evening. Choose whatever is easier for you to have it on a fasting stomach (1, 2).

Summary: It is fundamental to work with your doctor to explore what type and dose of thyroid medication is best for you. Until your thyroid hormone levels are corrected, weight loss is much more difficult.

2. Cut Back on Added Sugars and Refined Starches

I need to begin with this clarification:

Carbohydrates are not inherently bad for you. That is, they do not make you fat or sick on their own (I wrote in detail about it here). It always comes back to total calories consumed.

That said, carbs in the form of added sugars and highly refined starches are unhealthy and unnecessary. They offer almost zero nutritional benefit (known as “empty calories”) and make up a large portion of the excess calories we consume.

In fact, the average American adult’s consumption of added sugar increased by more than 30% in the last 30 years, with children consuming approximately 20% more. This was illustrated below by

Fortunately those numbers have began to reverse; a trend that needs to continue. Nevertheless, cutting back on added sugar is still the most simple and direct way to cut out excess “empty” calories.

This is done by limiting intake of junk foods, flavoured drinks (including juice), alcohol, white bread, most cereals and muesli bars, and a good portion of packaged food in your supermarket’s “health food” aisle. That includes gluten-free junk food… it’s still junk food.

Now it’s unrealistic (and unfair) to expect yourself to completely avoid added sugar every day of the year. But you need to begin taking actionable steps that help you cut back and form healthier habits.

Start by not having junk foods at home, or at least keep them out of sight in a cupboard you never use.

Summary: Added sugar makes up a large portion of the excess calories an average person consumes each day. Cutting down on your intake is critical if you want to successfully lose weight.

3. Base Meals Around Vegetables and Protein

If you want to lose weight with an underactive thyroid, these should be the foundation of almost every meal you make, and plated first when serving.

There are 2 main reasons for this:

1. Protein is paramount for weight loss

The main benefit of protein is that it’s much more satiating than both fat and carbs. That is, it has a unique ability to reduce appetite and therefore your overall caloric intake too.

Studies show high protein diets may also reduce obsessive thoughts about food by 60% and cut desire for late-night snacks by half (3, 4).

Foods high in protein include meat, seafood, eggs, nuts, legumes (beans) and dairy.

Protein is also the muscle-building nutrient, so a high protein diet complements regular exercise.

2. Vegetables provide most vitamins, minerals and other micronutrients

The nutrient-density of meals is even more important for those with hypothyroidism and other autoimmune diseases, where nutrient absorption and deficiency are more common.

Emphasis goes to green leafy vegetables, mushrooms and cruciferous vegetables like broccoli, cauliflower and cabbage.

Veggies are also our greatest source of fiber, a nutrient that feeds the healthy bacteria in our gut. Studies show that long-term low fibre intake will completely throw out the balance of your gut bacteria; the effects on the gut health of mice was irreversible (5).

Fiber supplements are also an option if you want to be extra sure you are meeting your requirements.

As a general guide, the protein portion of your meal should be the size of your palm, and salad/vegetables the size of your hand. This would leave about 1/4 or less of your plate for carbs (such as rice or potato or pasta).

Summary: Protein foods and vegetables should make up the majority of your plate. They are generally the most filling and/or nutrient-dense foods per calorie.

4. Increase your intake of Selenium and Zinc

Selenium and zinc are two nutrients directly involved in thyroid function.

It’s critical that a diet for hypothyroidism contains adequate quantities in order to optimise thyroid hormone production and metabolism.


Selenium is an essential mineral that helps the body to recycle iodine. That’s the reason the thyroid has the highest selenium content (per gram of tissue) of all our organs (6).

Therefore, it’s thought that low selenium levels contribute to hypothyroidism through alternate mechanisms related to iodine. For this reason it’s fundamental to eat a diet that contains many selenium-rich foods, such as:

  • Brazil nuts
  • Tuna and sardines
  • Beef and chicken
  • Eggs
  • Legumes


Zinc is an essential mineral required to regulate Thyroid Stimulating Hormone (TSH).

In fact, the metabolism of zinc and thyroid hormones are closely interlinked, which is why a deficiency can lead to alopecia (hair loss) (7).

While zinc deficiency is very uncommon in the developed world, it’s still recommended to eat a variety of zinc-rich foods (8). This includes:

  • Oysters and shellfish
  • Beef and chicken
  • Legumes, nuts and seeds
  • Milk and yoghurt.

Iodine is also important for thyroid health, but in reality insufficient iodine levels that can harm the thyroid is extremely rare in developed countries (9).

You’re much better off focusing on selenium and zinc-rich foods, many of which contain iodine anyways.

Summary: Consuming a diet naturally rich in selenium and zinc is critical for maintaining a healthy thyroid and metabolism.

5. Take regular walks or start lifting weights each week

“You can’t out-exercise a bad diet.”

This is true, especially when your metabolism is slower than normal. That’s why this article places so much emphasis on dietary changes.

However, if you want to kick-start your weight loss then regular exercise is the best way to do it.

Weight loss ultimately comes down to expending more energy (calories) than you consume. Although it’s much more complex than “eat less, move more” (there are many biological factors to consider), being active helps to burn additional calories. It also improves aspects of health that even perfect nutrition can’t provide, such as strength and mobility.

You don’t have to put yourself through miserable high-intensity workouts either. Research shows that low-intensity exercise that lasts longer – such as regular long walks – are just as effective for weight loss, especially if you are just starting out (10).

A general guideline is to walk for at least 60 minutes or 10,000 steps on most days.

Unable to do cardio exercise

Regularly lifting weights (or bodyweight exercises) is also highly beneficial, especially if mobility is an issue for you. In fact, it’s equally as important as cardio and we should be doing both where possible.

Known as resistance exercise, it still helps burns additional calories, but with the added benefit of building lean muscle. The more muscle you have, the faster your metabolism and the less likely you are to fall ill (11).

There are numerous resistance exercise programs on Youtube for beginners, and you can do it all at home if you invest in a pair of dumbbells or even one kettle bell.

Summary: Regular exercise helps to kick-start weight loss and speed up the entire process. It also improves your strength, mobility and metabolic health. If mobility is a problem for you, lifting weights or bodyweight exercises are a fantastic alternative.

6. Trial The Autoimmune Protocol Diet (Optional for Hashimoto’s)

This step is only for those with Hashimoto’s or another autoimmune disease, and only recommended if you already consistently follow steps 1 to 5 but are still very overweight.

The Autoimmune Protocol (AIP) is an elimination diet that temporarily cuts out numerous food groups including dairy, grains, nuts and seeds, legumes, nightshade vegetables and more. It is said to have emerged from the Paleo movement (and sometimes referred to as Autoimmune Paleo), but to describe it as Paleo seems too basic.

The AIP goes by the premise that certain food chemicals and compounds cause low-grade inflammation in the gut of individuals with an autoimmune disease (in this case Hashimoto’s disease). Low-grade inflammation appears to be a driving factor behind many modern health conditions, including autoimmune diseases, metabolic disorder and obesity too (12).

By removing the everyday trigger foods in your diet, inflammation subsides giving your body the opportunity to recover and “reset”; known medically as remission. This is what occurs in celiac disease patients when they remove gluten from the diet, or most IBS patients following a low FODMAP diet.

Is It Evidence-Based?

I’ll admit I was highly sceptical of this theory at first; researchers in the area of rheumatology/immunology rarely do randomised trials on elimination diets (the only way to prove “cause and effect”). That means we still cannot reliably say what foods influence autoimmune diseases and their symptoms (nor to what extent).

Does it help because you cut out specific trigger food components? Or because such restriction inadvertently forces you to eat healthier consistently? Or is it a combination of both? It’s hard to say, but we cannot ignore the abundance of non-trial and anecdotal evidence (personal testimonial) that indicate AIP helps with a variety of symptoms.

Although only temporary, elimination diets like AIP are highly restrictive and can get complicated if you take medications for other medical conditions or are at risk of nutrient deficiencies. It’s fundamental you speak with your doctor before beginning.

Summary: Trialling the Autoimmune Protocol is an option if you have Hashimoto’s disease and have found steps 1 to 5 are no help. It may help with weight loss given its (theoretical) influence on inflammation and its highly restrictive nature.

Additional Tips to Lose Weight With An Underactive Thyroid

Here are some extra pointers to help you lose weight with an underactive thyroid:

  • Prioritise sleep: Alongside poor diet and exercise, short sleep duration is one of the strongest risk factors for obesity. Good quality sleep is fundamental for weight loss.
  • Thyroid support supplements: Anecdotal reports suggest supplements can give you more energy, at least for the first few months of use. But they’re likely unnecessary if you regularly eat nutritious foods.
  • Use smaller plates and small spoons: Studies show the bigger the plate and the bigger the cutlery, the more calories we consume (13). This proven phenomenon is called the Delbouef illusion.
  • Plate your meals first: Instead of putting all the prepared food at the table (like a buffet), plate your meal first and then sit down. You are much less likely to go for a second (or third) round.
  • Drink lots of water: Keep a water bottle on hand wherever you go. Research suggests the more water we drink before meals, the fewer calories we eat overall (14).
  • Be mindful: Mindful eating is about becoming more aware of your experiences, physical cues and feelings about food. It is based on a form of meditation called mindfulness.

Wish you could go back to how you felt before thyroid symptoms?

Now you can.

Introducing my Thyroid “Time Machine” meal plan. .

How to Manage Your Weight

If you have hypothyroidism and the start of treatment gets your weight where it should be, you may still find a challenge ahead. Even after your thyroid levels go back to the normal range, Harris says, many people still find it hard to stay at a healthy weight.

The best plan for reaching your weight goal is to focus on the things you can control.

Exercise regularly. “Exercise is a great way to boost metabolism, strengthen bones, build muscle, manage stress, and improve health,” Harris says.

If you’re a beginner, she suggests that you start with a daily walk (use a pedometer to track your progress) and gentle yoga.

Curb your stress: If you’re under pressure, it can lead to a cycle of poor eating choices, fatigue, and depression.

When you feel stress, your body releases a hormone called cortisol. Too much of it can interfere with the production of your thyroid hormone. Pay attention to things that cause you stress and try to avoid them.

Get enough sleep. Getting shut-eye can pack a big health punch.

“Sleep is the body’s time to take care of repair and maintenance in the body, and it’s essential for weight loss and overall health,” Harris says.

Thyroid Hormones May Help Predict Successful Weight Loss

With Qi Sun, MD, ScD, and J. Michael Gonzalez-Campoy, MD, PhD

Which individuals will lose or will not lose weight on any given dietary plan has been mostly unknown, but findings from the Prevention of Obesity Using Novel Dietary Strategies (POUNDS) LOST trial demonstrated that certain thyroid hormones appear predictive of a person’s ability to lose weight, as published in the International Journal of Obesity.

For overweight and obese patients, including those with type 2 diabetes, clinicians now have an effective method of assessing which patients might be encouraged to consider dietary adjustments to reverse their excess body weight, while others may have more confirmation that bariatric surgery offers a better long-term outlook for weight loss.1

Results from this randomized clinical trial provide a strong indication that even in adults with normal thyroid function, these hormones play a role in body weight regulation and may help identify individuals more responsive to a dietary intervention aimed at promoting weight loss,1 according to lead investigator Qi Sun, MD, ScD, an assistant professor of nutrition at the Harvard University School of Public Health in Boston, Massachusetts.

Researchers found that higher baseline free triiodothyronine (T3) and free thyroxine (T4) levels predicted more weight loss among overweight and obese adults with normal thyroid function. Unfortunately, these hormones were unable to offer any clue as to whether these individuals would regain the lost weight, said Dr. Sun.

Linking Thyroid Hormones and Body Weight

“Our study was among the first to investigate the role of thyroid hormones in weight change in a controlled clinical trial rather than an observational study,” Dr. Sun, MD, ScD, told EndocrineWeb.

Higher levels of baseline free T3 and free T4, but not TSH, had a significantly associated to greater weight loss at six and 24 months, induced by weight loss dietary plans However, baseline TSH did not predict weight loss or weight regain. In addition, changes in free T3 and total T3 levels, but not free T4 and total T4 or TSH, were positively associated with changes in body weight and metabolic parameters, including RMR, blood pressure, triglycerides, and leptin.

“Knowing which factors can predict weight loss increases our understanding of the biology of , as well as to identify high-risk patients early on who may need to consider other options, such as bariatric surgery,” Dr. Sun told EndocrineWeb.

“This is a very important analysis,” said J. Michael Gonzalez-Campoy, MD, PhD, medical director and Chief Executive Officer of the Minnesota Center for Obesity, Metabolism and Endocrinology in Eagan, Minnesota, told EndocrineWeb, “It validates that there is a role for thyroid hormones in addressing weight loss and weight maintenance.”

Thyroid Hormone Levels Associated with Metabolic Rate, Too

A similar pattern of associations was observed between baseline thyroid hormones and changes in resting metabolic rate (RMR). There was a significant association between higher baseline free T3 and free T4 levels and a greater decrease in RMR during the weight loss period, but not in the weight regain period, according to the authors.

“We wanted to explore whether any factors could explain why some people lost weight and some do not,” said Dr. Sun. Investigators looked at weight loss between baseline and six months, and weight change between six months and 24 months. The associations between baseline thyroid hormones and changes in body weight, RMR, and body composition at six months and at 24 months were examined using linear regression (weight assessment at only six months and 24 months were used).

At baseline, participants with diabetes treated with medications or with unstable cardiovascular disease, or those using medications that affected body weight or who had insufficient motivation were excluded. In addition, anyone with subclinical thyrotoxicosis or hyperthyroidism based on TSH level was excluded from the analysis.

Study Findings Viewed as Clinically Useful for Treatment

“The use of thyroid hormone supplementation has been considered in the past as an adjunct to weight loss. However, making people hyperthyroid has more of a risk than there is benefit; there may be cardiac arrhythmias, damage to skeletal muscle, bone mineral density loss, and anxiety,” Dr. Gonzalez-Campoy told EndocrineWeb.

“This paper opens the doors for us to consider thyroid hormone supplementation, to move an individual patient’s thyroid hormone level from the low end to the high end of normal as a safe adjunct in a weight loss program. It mandates that we treat subclinical hypothyroidism and hypothyroidism,” he concluded.

POUNDS LOST Trial Methodology

Participants in another 2-year randomized clinical trial2 were assessed for changes in body weight and resting metabolic rate (RMR) during the intervention period, which offered outcomes data for the POUNDS LOST protocol.

In this study, freeT3, free T4, total T3, total T4, and thyroid-stimulating hormone (TSH), as well as anthropometric measurements and biochemical parameters were assessed at baseline, six months, and 24 months.1

The mean age of the 569 participants was 51.6 (± 9.0) years, and their mean BMI was 32.6 (± 3.8). They lost an average of 6.6 kg during the first six months, and subsequently regained an average of 2.7 kg for the remaining 6-24-month period. There were no significant differences in weight loss among the four different diets studied in the POUNDS LOST trial.2

In this analysis,1 study participants provided fasting serum samples at baseline and six months, and 429 of those participants also provided blood samples at two years.

View Sources

  1. Liu G, Liang L, Bray GA, et al. Thyroid hormones and changes in body weight and metabolic parameters in response to weight loss diets: the POUNDS LOST trial. Intl J Obesity. 2017;40:878-886.
  2. Sacks FM, Bray GA, Carey VJ, et al. Comparison of weight-loss diets with different compositions of fat, protein, and carbohydrates. N Engl J Med. 2009;360:859-873.

Updated on: 07/08/19 Continue Reading: Bariatric Endocrinology: 2015 Update

Managing Your Weight with Hypothyroidism

There’s a good chance you’ll gain weight if you indulge in a few too many comfort foods or stay away from the gym for too long. But if you have hypothyroidism, the numbers on the scale can creep up, even if you’ve stuck firmly to your diet and exercised religiously.

The hormones your thyroid gland releases help regulate your metabolism, or how efficiently your body burns food for energy. When your thyroid makes less of its hormones — as it does in hypothyroidism — your metabolism slows down. So you won’t burn off calories as quickly and you’ll gain weight. The weight gain usually isn’t extreme, maybe 5 or 10 pounds, but it can be enough to affect your self-esteem.

The more severe your hypothyroidism is, the more weight you’ll gain. Some of the weight gain is fat, but much of it is fluid buildup from the effects of an underactive thyroid on your kidney function.

Stop weight gain

One way to manage weight gain is by taking the thyroid hormone medicine your doctor prescribed. A daily dose of levothyroxine (Levothroid, Levoxyl, Synthroid) will rev up your thyroid hormone production again, and with it, your metabolism. Once you’re on the right dose, your weight should stabilize, and you shouldn’t have any more trouble losing weight than anyone else.

Thyroid hormone might not rid you of any weight you’ve already put on, though. To get back down to your original weight, follow a sensible strategy that combines diet and exercise.

Adopt a new diet

To trim down, start by subtracting calories from your daily count — but do it safely. Don’t go on an extremely strict, low-calorie diet. Your body will only hoard calories, and you’ll end up gaining weight. Instead, you want to find a balance between the calories you take in and the calories you burn off each day.

A safe goal for weight loss is 1 to 2 pounds a week. On average, eat 500 fewer calories each day and you’ll lose about a pound a week. Cut 1,000 calories a day, and you’ll lose 2 pounds a week.

One easy way to trim those calories is to eliminate all the foods you don’t need. Cookies, cake, sodas, and candy are all full of empty calories. They’ll make you gain weight without contributing any nutrients.

Instead of dessert, eat a bowl of fresh fruit sprinkled with no-calorie sweetener. Replace soda with sparkling water and lemon. Switch out foods made with processed white flour, like white bread and crackers, for those made with whole grains.

Another way to trim calories is to eat more energy-dense foods. These foods contain fewer calories per bite. They’ll make you feel full faster and stay full longer.

For example, have a bowl of vegetable soup for lunch instead of pizza. The soup has fewer than 100 calories and is high in water content, so it will fill you up. A slice of pizza has nearly 300 calories and is high in carbs, which your body will burn through quickly and leave you wanting more.

Center your meal around fruits and vegetables, which are low in calories and packed with nutrition. Add in a lean protein source, like fish, poultry, or tofu.

Of course, talk to your doctor before making any significant adjustments to your diet. You’ll want them to help guide and monitor you through the process.

Get moving

Exercise is the other essential component to any weight loss plan. Regular exercise turns your body into a more efficient fat-burning machine. The more you work out, the more calories you’ll burn both with exercise and when you’re at rest.

To lose weight, do 300 minutes a week of aerobic exercise, like jogging, bike riding, or playing tennis. That works out to about 60 minutes a day, five days a week. If you don’t have a full hour at a time to exercise, break up your routine into 10- or 20-minute segments.

Pick an activity you love and that’s convenient for you, so you’ll stick with it. You can walk around your neighborhood each morning, follow a fitness DVD, or take a spin class at your local gym. Any activity that makes your heart beat harder and causes you to break a sweat — even gardening or mopping your floors — counts as exercise.

A daily workout will also give you more energy, counteracting the fatigue hypothyroidism can cause. Because an underactive thyroid can slow your heart rate, talk to your doctor before starting any new fitness routine.

Ease into exercise slowly, and only gradually increase your pace and workout duration when you feel ready. Again, ask your doctor about specific exercises and doing a set routine.

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