Thyroid and Weight | American Thyroid Association

Leer en Español

WHAT IS THE THYROID GLAND?

The thyroid gland is a butterfly-shaped endocrine gland that is normally located in the lower front of the neck. The thyroid’s job is to make thyroid hormones, which are secreted into the blood and then carried to every tissue in the body. Thyroid hormones help the body use energy, stay warm and keep the brain, heart, muscles, and other organs working as they should.

WHAT IS THE RELATIONSHIP BETWEEN THYROID AND WEIGHT?

It has been appreciated for a very long time that there is a complex relationship between thyroid disease, body weight and metabolism. Thyroid hormone regulates metabolism in both animals and humans. Metabolism is determined by measuring the amount of oxygen used by the body over a specific amount of time. If the measurement is made at rest, it is known as the basal metabolic rate (BMR). Indeed, measurement of the BMR was one of the earliest tests used to assess a patient’s thyroid status. Patients whose thyroid glands were not working were found to have low BMRs, and those with overactive thyroid glands had high BMRs. Later studies linked these observations with measurements of thyroid hormone levels and showed that low thyroid hormone levels were associated with low BMRs and high thyroid hormone levels were associated with BMRs. Most physicians no longer use BMR due to the complexity in doing the test and because the BMR is subject to many influences other than the thyroid state.

WHAT IS THE RELATIONSHIP BETWEEN BMR AND WEIGHT?

Differences in BMRs are associated with changes in energy balance. Energy balance reflects the difference between the number of calories one eats and the number of calories the body uses. If a high BMR is induced by the administration of drugs, such as amphetamines, animals often have a negative energy balance which leads to weight loss. Based on such studies many people have concluded that changes in thyroid hormone levels, which lead to changes in BMR, should also cause changes in energy balance and similar changes in body weight.

However, BMRs are not the whole story relating weight and thyroid. For example, when metabolic rates are reduced in animals (for example by decreasing the body temperature), they often do not show the expected weight gain. Thus, the relationship between metabolic rates, energy balance, and weight changes is very complex. There are many other hormones (besides thyroid hormone), proteins, and other chemicals that are very important for controlling energy expenditure, food intake, and body weight. Because all of these substances interact with the parts of the brain and body that control energy expenditure and energy intake, we cannot predict the effect of altering only one of these factors (such as thyroid hormone) on body weight as a whole. As a consequence, at this time, we are unable to predict the effect of changing thyroid state on any individual’s body weight

HYPERTHYROIDISM

WHAT IS THE RELATIONSHIP BETWEEN HYPERTHYROIDISM AND WEIGHT?

Since the BMR in patients with hyperthyroidism (see Hyperthyroidism brochure) is elevated, many patients with an overactive thyroid do, indeed, have some weight loss. Furthermore, weight loss is related to the severity of the overactive thyroid. For example, if the thyroid is extremely overactive, the individual’s BMR increases which leads to increased calories needed to maintain the body weight. If the person does not increase the amount of calories eaten to match the excess calories burned, then there will be weight loss. As indicated earlier, the factors that control our appetite, metabolism, and activity are very complex and thyroid hormone is only one factor in this complex system. Nevertheless, on average the more severe the hyperthyroidism, the greater the weight loss observed. Weight loss is also observed in other conditions where thyroid hormones are elevated, such as in the toxic phase of thyroiditis (see Thyroiditis brochure) or if the dose of thyroid hormone pills is too high for a patient. Since hyperthyroidism also increases appetite, some patients may not lose weight, and some may actually gain weight, depending on how much they increase their caloric intake.

WHY DO I GAIN WEIGHT WHEN HYPERTHYROIDISM IS TREATED?

Because hyperthyroidism is an abnormal state, we can predict that any weight loss caused by the abnormal state would go away when the abnormal state is reversed. This is indeed what we find. On average, any weight lost during the hyperthyroid state is regained when the hyperthyroidism is treated. Weight gain can even occur when there was little or no weight loss because patients may have gotten used to eating more calories because of the extra energy expenditure during hyperthyroidism.

HYPOTHYROIDISM AND THYROID HORMONE

WHAT IS THE RELATIONSHIP BETWEEN HYPOTHYROIDISM AND WEIGHT GAIN?

Since the BMR in the patient with hypothyroidism (see Hypothyroidism brochure) is decreased, an underactive thyroid is generally associated with some weight gain. The weight gain is often greater in those individuals with more severe hypothyroidism. However, the decrease in BMR due to hypothyroidism is usually much less dramatic than the marked increase seen in hyperthyroidism, leading to more modest alterations in weight due to the underactive thyroid. The cause of the weight gain in hypothyroid individuals is also complex, and may not be related to excess fat accumulation. Most of the extra weight gained in hypothyroid individuals is due to excess accumulation of salt and water. Massive weight gain is rarely associated with hypothyroidism. In general, 5-10 pounds of body weight may be attributable to the thyroid, depending on the severity of the hypothyroidism. Finally, if weight gain is the only symptom of hypothyroidism that is present, it is less likely that the weight gain is solely due to the thyroid.

HOW MUCH WEIGHT CAN I EXPECT TO LOSE ONCE THE HYPOTHYROIDISM IS TREATED?

Since much of the weight gain in hypothyroidism is accumulation in salt and water, when the hypothyroidism is treated one can expect a small (usually less than 10% of body weight) weight loss. As in the treatment with hyperthyroidism, treatment of the abnormal state of hypothyroidism with thyroid hormone results in a return of body weight to what it was before the hypothyroidism developed. Since weight gain may have many causes and develops over a long period of time, it is fairly common to find that there is not a large amount of weight loss after successful treatment of hypothyroidism. Again, if all of the symptoms of hypothyroidism other than weight gain resolve with thyroid hormone treatment, it is unlikely that the weight gain was solely due to the thyroid. Once hypothyroidism has been treated and thyroid hormone levels are in the normal range, the ability to gain or lose weight is the same as in individuals who do not have thyroid problems.

CAN THYROID HORMONE BE USED TO HELP ME LOSE WEIGHT?

Thyroid hormones have been used as a weight loss tool in the past. Starting or increasing thyroid hormone to cause thyroid hormone levels to be elevated is unlikely to dramatically change weight. Studies have shown that excess thyroid hormone treatment can help produce more weight loss than can be achieved by dieting alone, but includes the risk of major negative consequences from the use of thyroid hormone to help with weight loss, such as the loss of muscle protein, loss of bone, and/or heart problems. Furthermore, once the excess thyroid hormone is stopped, any weight loss is usually regained.

Losing weight and hypothyroidism: Methods and more

We include products we think are useful for our readers. If you buy through links on this page, we may earn a small commission Here’s our process.

Medical News Today only shows you brands and products that we stand behind.

Our team thoroughly researches and evaluates the recommendations we make on our site. To establish that the product manufacturers addressed safety and efficacy standards, we:

• Evaluate ingredients and composition: Do they have the potential to cause harm?
• Fact-check all health claims: Do they align with the current body of scientific evidence?
• Assess the brand: Does it operate with integrity and adhere to industry best practices?

We do the research so you can find trusted products for your health and wellness.

Read more about our vetting process.

Was this helpful?

People with hypothyroidism can often lose or manage weight through dietary changes, physical activity, and stress reduction.

Hypothyroidism occurs when the thyroid gland does not produce enough hormones.

While a reduction in metabolism can make weight loss difficult, it is not impossible. Steps to managing weight often involve:

• lifestyle changes such as:
  • diet
  • physical activity
  • stress management
• treatment for the underlying cause
• hormone level checks

This article reviews weight and hypothyroidism and the changes people can make to help manage and lose weight with hypothyroidism.

Serious cases of hypothyroidism can lead to an estimated 50% loss in metabolism, leading to weight gain and issues with losing weight.

A person may also gain about 5–10 pounds directly due to hypothyroidism. This weight gain mainly comes from water and salt retention, but it should clear once treatment or lifestyle changes start.

Read on for the ways a person can lose weight with hypothyroidism.

Dietary changes may help with weight management. However, a person with hypothyroidism should consider how certain foods may affect their thyroid and include or exclude them from their diet.

Currently, there is no specialized diet for hypothyroidism. However, the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) suggests that food has the following possible effects on hypothyroidism:

• certain foods may interfere with medications
• foods with certain nutrients may help maintain thyroid function, such as:
  • iodine
  • selenium
  • zinc
• some foods may contribute to a diminished thyroid function

Hypothyroidism may occur due to much or too little iodine intake. The thyroid needs a certain amount of iodine to function properly.

However, people with Hashimoto’s thyroiditis, an autoimmune disorder that is a common cause of hypothyroidism, or other autoimmune disorders affecting the thyroid may negatively react to foods and supplements containing large amounts of iodine. This could lead to diminished thyroid function.

To avoid

Other foods to avoid include gluten and processed foods.

Evidence suggests that people with Hashimoto’s thyroiditis have a higher rate of celiac disease. Further research suggests that gluten can negatively affect a person with Hashimoto’s thyroiditis.

To eat

A person should focus on following a balanced diet and consuming foods such as:

• fruits and vegetables
• whole grains
• fiber
• lean protein or alternatives
• healthy fats like olive oil

To help a person lose weight and avoid exacerbating their hypothyroidism symptoms, a person can follow a balanced diet and limit foods that are:

1. processed
2. high fat
3. simple carbohydrates like sugar

Read more about foods to eat and avoid with hypothyroidism.

A food journal may help a person understand the foods they are eating and be more mindful of what they consume each day. This is a form of mindful eating.

The benefits of food journaling can include helping a person:

• determine if they are eating too little or too much each day
• remember what they consumed each day
• see when they get hungry each day and adjust their eating habits
• determine if they are eating due to boredom instead of hunger
• achieve their goal

However, journaling may not be for everyone. A person should discuss this method with a doctor or nutritionist before trialing it.

Increased activity can work in conjunction with improvements to diet. A person needs to be more active to lose weight or maintain it.

Researchers in a 2015 study attributed improvements in thyroid function with decreased weight due to regular exercise. They observed these effects mostly in people with hypothyroidism.

Exercise types

At a minimum, a person should aim to get at least 150 minutes of moderate physical activity every week. A person can break this down into 5 days of 30-minute exercise sessions or moderate intensity activities, which can include:

• tennis
• basketball
• running
• walking
• rowing
• swimming

In addition to cardio workouts, a person should aim to participate in resistance training twice a week. Resistance training can include:

• lifting weights
• using exercise bands
• doing bodyweight exercises, such as pushups or pullups
• using kettlebells

However, before starting any new activity or exercise program, a person should consider talking with a doctor or physical therapist to discuss suitable levels of exercise for them.

Find out more about exercise and fitness from our dedicated hub.

Research from 2018 shows that stress can contribute to weight gain and the development of obesity in individuals.

While the specific links between stress and hypothyroidism are not conclusive, finding ways to manage stress may help a person lose weight and maintain weight loss.

Though people may respond differently to interventions, some ways to reduce stress include:

• psychotherapy (talk therapy) or other therapeutic approaches
• regular exercise
• breathing techniques
• yoga
• practicing mindfulness and meditation
• journaling
• avoiding stressors whenever possible

Learn more about stress-reduction strategies.

To treat hypothyroidism, a doctor will typically prescribe medications to replace the hormones the thyroid should be making.

A doctor may also recommend treatment to address an underlying cause of the condition.

The NIDDK suggests several factors can cause hypothyroidism, such as:

• Hashimoto’s thyroiditis
• surgery
• radiation near the thyroid
• congenital causes
• certain medications

A person should follow all instructions from a doctor regarding when and how to take the medication and adhere to any other treatment methods needed.

By addressing hypothyroidism, a person may lose some weight through treatment. A person can lose a small amount of weight when starting hormone medications, but it is generally less than 10% from medication alone, meaning a person will still need other methods to help lose weight.

As part of treatment, a person should have their hormone levels checked regularly. This can help ensure that treatment is effective for the person.

Typically, a doctor checks a person’s blood work every 6–8 weeks after a person starts medication and after every medication change. If hormone levels appear to be stabilizing, a doctor will likely check a person’s levels every 6–12 months.

Losing weight safely generally involves a combination of lifestyle changes, including increased exercise and changes to diet.

People interested in losing weight may want to check out support programs for further guidance. For example, Weight Watchers, rebranded as WW, provides support, meal plans, and other advice on losing weight.

Learn more about science-backed ways to lose weight.

The following sections answer some frequently asked questions about weight loss and hypothyroidism.

How long will it take to lose weight with hypothyroidism?

Weight loss with hypothyroidism will typically take about the same time as it would if the person did not have hypothyroidism.

Once treatment starts, a person can expect to lose some weight associated with hypothyroidism.

How to lose 20 pounds with hypothyroidism?

A person hoping to lose more weight can take some time. With or without hypothyroidism, a person can only lose so much weight at any given period.

People can generally safely lose up to 2 pounds a week with regular exercise and a healthy diet.

A person can speak with a doctor to explore other weight loss measures, particularly if they have hypothyroidism, to avoid any complications.

Can rapid weight loss cause hypothyroidism?

Extreme dieting can have negative health impacts. According to a 2014 study, weight loss can lead to a minimal decrease in thyroid hormone activity levels. The study suggests that drastic dieting and bariatric surgery can lead to potential thyroid issues.

If a person restricts their diet too much, it can lead to a decrease in a necessary nutrient, iodine. An iodine deficiency may lead to hypothyroidism.

To maintain their iodine intake, a person can use iodized table salt and eat iodine-rich foods, such as dairy products, seafood and meat, and eggs. They can also take a multivitamin with iodine.

Note that iodine deficiency in Western countries is relatively rare.

People should speak with a doctor to discuss suitable diet options, with or without hypothyroidism.

Hypothyroidism can cause some weight gain and make it more difficult to lose weight. However, with successful treatment and lifestyle changes, a person can lose weight or maintain a moderate weight.

People should stick with their treatment plan and discuss any issues with a doctor. A doctor can also recommend how much exercise a person should do and dietary changes that may help.

Causes of weight loss: what diseases make you lose weight

While some are dieting and exercising to get rid of extra pounds, others quite unexpectedly discover that their weight has decreased by several kilograms, and without any effort on their part . Reason for joy? Not always, sometimes it can be a symptom of a serious illness.

Tags:

depression

Fight against cancer

weight loss

tuberculosis

Family

Getty Images

Perhaps the first thing that comes to mind when losing weight is cancer. Indeed, many oncological diseases occur without pronounced symptoms, and sudden weight loss is not always associated with the disease. Doctors remind that an unexpected weight loss of 5% of your weight or more without a change in diet and other significant changes is a reason for contacting a specialist and a serious examination.

Do not self-medicate! In our articles, we collect the latest scientific data and the opinions of authoritative health experts. But remember: only a doctor can diagnose and prescribe treatment.

But sudden weight loss does not only accompany cancer. It can also be observed for other reasons, some of which can be quite serious.

Hyperthyroidism

In hyperthyroidism – an overactive thyroid gland – this gland produces too much thyroid hormone. They perform many functions in the body, including affecting metabolism. Against the background of hyperfunction of the thyroid gland, the body may begin to burn too many calories – stored fats will be processed, weight will begin to decrease. Usually, a sharp weight loss in hyperthyroidism is accompanied by increased anxiety, sleep disturbances, severe fatigue, and heart palpitations.

Depression

This is not just a feeling of depression and a constant bad mood, it is a real psychiatric illness, which may require medication and psychotherapy sessions.

ADVERTISING – CONTINUED BELOW

Weight loss can be one of the side effects of depression. The condition itself is often accompanied by a loss of appetite, although in some cases people, on the contrary, begin to eat more.

Other symptoms that accompany depression include constant fatigue, depression, lack of vitality even for habitual activities, sleep problems, insomnia or excessive sleepiness, difficulty concentrating and solving problems at work.

Inflammatory bowel disease

The most common inflammatory bowel diseases are Crohn’s disease and ulcerative colitis. These conditions are accompanied by constant fatigue, diarrhea, severe abdominal pain, bloating and increased gas formation.

Patients with inflammatory bowel disease often have impaired production of ghrelin, the hormone responsible for feeling hungry, and leptin, the satiety hormone. Because of this, they do not feel hungry, and food often does not seem tasty to them. Lack of appetite, as well as the constant discomfort that accompanies the process of digestion, leads to the fact that people eat less, and their weight, as expected, falls.

Tuberculosis

Tuberculosis has ceased to be a disease of the lower social strata, it can be found in quite prosperous office workers and members of their families.

The causative agent of tuberculosis is the bacterium Mycobacterium tuberculosis. When infected, the disease does not always manifest itself, often the bacterium passes into a latent, dormant state. In some cases, the infection becomes active, the patient develops a severe cough (often with blood), chest pains, severe fatigue, hot flashes. Loss of appetite and sudden weight loss are also among the most typical symptoms of tuberculosis.

Addison’s disease

This is an endocrine disease in which the adrenal glands stop producing enough cortisol and aldosterone. Cortisol deficiency leads to a decrease in appetite, and weight, in a completely logical way, goes down.

In addition, patients with Addison’s disease (which, we note, is quite rare) have constant fatigue, low blood pressure, muscle weakness, and a strong craving for salty foods.

Heart failure

In heart failure, tissues and organs may not get enough oxygen simply because the heart is unable to pump blood as efficiently as it used to.

Because of this, a feeling of fullness may be present even when the person actually ate little or no food at all. In addition, the inflammation that occurs when the heart is disrupted can affect the metabolic rate – calories will be burned faster and more efficiently, provoking a sharp weight loss.

Rheumatoid arthritis

This is a common autoimmune disease with no known exact cause. A person feels severe pain, it becomes difficult to perform even the simplest movements.

Rheumatoid arthritis is when the body’s immune system attacks its own joints. This leads to constant inflammation in the body, against which the usual metabolism is accelerated – both calories and stored fat deposits are burned. A person loses weight even if he eats the same amount as usual.

Doctors emphasize that any noticed weight loss, which seems to have happened by itself, should be a reason to see a doctor. People often do not notice cancer, despite seemingly obvious signs, and if the disease proceeds atypically, they tend to ignore any alarming symptoms.

How do hormones affect weight?

Understanding whether hormones can cause excess weight.

Tags:

Question answer

Diets

Excess weight

Hormones

Getty Images

Read more in our material.

Contents of the article

“On the one hand, this statement is not unfounded,” says dietitian Alexander Burlakov. “The endocrine system regulates a huge number of processes in our body, including metabolism.”

“At the same time, realizing that there are no special levers or magic products to speed up metabolism, a person sometimes becomes discouraged (which is not worth doing) and begins to blame his hormonal system for all the troubles. This happens especially often when it comes to overweight.”

Perhaps more often than other conditions, overweight is blamed on hypothyroidism, a condition where the thyroid gland does not produce enough hormones to meet the body’s needs. And these hormones, in addition to a number of other functions, also regulate metabolic processes in the body.

How does hypothyroidism affect body weight?

“Metabolism (or metabolism) is determined by measuring the amount of oxygen used by the body over a period of time. If such measurements are made at rest, then this indicator is called basal metabolism (BMR) and it is measured in the amount of energy expended (kcal),” the expert explains.

ADVERTISING – CONTINUED BELOW

“Everything is again tied to the energy balance. If you spend more than you consume, you lose weight, and vice versa. In a state of hypothyroidism, a person’s BMR decreases. Accordingly, energy expenditure is reduced, a plus can be attributed to a decrease in daily physical activity (NEAT) due to lethargy, frequent feelings of fatigue. All this further reduces energy consumption.

At the same time, human nutrition does not change in any way (this is logical, because a person does not know about it, especially since in mild forms there may be practically no symptoms). And it turns out that a person, even eating in the norm of calories, begins to eat in excess, and if there was an excess before, then overeating will be even greater. And accordingly, weight gain begins,” the expert notes.

( Read also: 5 healthy habits for successful weight loss.)

Thyroid hormones affect body weight interesting, says the doctor.

“The American Thyroid Association notes that weight gain between 2 and 5 kg will be thyroid-related, depending on the severity of the hypothyroidism, with fluid accumulation also contributing.”

But nutrition has the last word

“With all this, we can conclude that the dietary factor will play a rather important role, along with physical activity, especially if a person has previously eaten with a calorie surplus. With hormone replacement therapy, the symptoms of hypothyroidism improve within 2 weeks, and in people with severe forms, within a few months. Therefore, if there is a problem with excess weight against the background of hypothyroidism, it is necessary to simultaneously normalize nutrition.

What conclusions can we draw?

“First conclusion: it is possible to lose weight with hypothyroidism.

Even if the metabolism of a patient with compensated hypothyroidism differs from that of a healthy person, these differences will not be so great.