Anyone diagnosed with hypothyroidism (or under functioning or under-active thyroid gland) understands the frustration of watching their body change without permission. Weight gain occurs despite reduced appetite along with fatigue, dry hair and skin, constipation, cold temperature sensitivity, and depression. Hypothyroidism is most common in women and the chances of developing hypothyroidism increases with age and family history of thyroid or autoimmune disease. For the 20 million Americans diagnosed with hypothyroidism there is nothing that they have done to cause this disease and there is nothing they could have done to prevent it. It just happens.

What do thyroid hormones do?

Thyroid hormone is a requirement for a healthy normally functioning body because thyroid hormones have so many essential functions. These potent chemicals are released from a butterfly shaped organ located in the middle of the neck called the thyroid gland and have functions that span from brain and nerve maturation, temperature regulation, mood, memory, and metabolism.

Hypothyroid Symptoms

  • Gеnеrаl mаlаіѕе оr not feeling well
  • Fatigue
  • Cold Intolerance 
  • Constipation
  • Poor appetite
  • Dерrеѕѕіоn
  • Irritability
  • Brittle and dry or coarse hair
  • Weak and easily cracked or broken nails
  • Dry skin
  • Slow heart beat
  • Mental “Fogginess” and difficulty with memory


Hypothyroid and weight gain

Despite the assumption that all weight gain is due to overeating and sedentary behavior, patients with hypothyroidism rarely gain weight due to eating too many calories or foods high in sugar. Individuals with hypothyroidism tend to eat less due to a reduced appetite. On the contrary, individuals with hyperthyroidism – or an over functioning thyroid (the opposite of hypothyroidism) lose weight despite eating more calories due to constant hunger and increases in appetite. So how does weight gain occur in hypothyroidism? One cause is slow metabolism. Metabolism is the workhorse of the body. It is a huge part of how the body goes about doing its daily business. Metabolic actions range from converting cellular building blocks into a full product, breaking down substances, and converting calories and food (or fat stores) into fuel and energy. Because thyroid hormones aid in directing overall metabolism even the basal metabolic rate or metabolism at rest is lowered. Therefore the number of calories burned in a day is lower for someone with hypothyroidism in comparison to someone with normal thyroid function. A lower metabolism coupled with lack of energy, brain fog, feeling sluggish, and depressed makes weight gain inevitable. To counteract the unpleasant weight gain, sufferers of hypothyroidism often work harder to lose weight and this serves to only cause more weight gain. Continuing to fail at weight loss leads to more frustration and feelings of defeat. To add, attempts to cut caloric intake further reduce metabolic rate, exercise results in even lower energy and more fatigue, and any weight that is lost just leads to even lower metabolism. As weight continues to pile on it is most dramatic for individuals who were already overweight or obese prior to hypothyroidism.  The average amount of weight gain varies but it is common to see as much as a 20 pounds in only 1 to 2 months. Many medical blogs, articles, and even doctors will erroneously diminish the weight gained from hypothyroidism as only a few vanity pounds but that is not always true. Hypothyroidism not only causes weight gain but can make it extremely difficult to lose weight. It is not an excuse or crutch, it’s just a fact. So now what ?

Losing weight with hypothyroidism

The first steps toward weight loss are knowledge, understanding, and patience. Hypothyroidism causes weight gain and it is no one’s fault, it is unfortunately a normal physiological response to the absence of key metabolic hormones. The next step is to work with a physician to restore thyroid hormone. This is extremely important as it is impossible to live without thyroid hormone. The complete lack of thyroid hormone leads to coma, breathing issues, and ultimately death. The most common treatment for hypothyroidism is synthetic thyroxine or T4. A doctor will measure the level of these hormones along with thyroid stimulating hormone (TSH), a hormone from the brain that tells the thyroid gland to produce and release thyroid hormone. Once these hormones are restored symptoms of hypothyroidism will slowly start to fade, constipation is cured, slow heart rate normalizes, mental fogginess, and fatigue go away. Understand that some hypothyroid symptoms may linger despite normal hormone levels, such as fatigue, but over time all symptoms should continue to improve. Weight gain will unfortunately not go away overnight but it will make weight loss easier to obtain once thyroid hormones normalize.

What NOT to do to lose weight with hypothyroidism

During the time that thyroid levels are still abnormally low it is important to avoid strict dieting and caloric restriction because this will not work and will only make matters worse. It is also important to avoid rigorous exercise as this will not significantly impact basal metabolic rate and will only lead to more fatigue and frustration. The quality of exercise will be poor until other symptoms are optimized. While avoiding rigorous exercise, it is okay to work on building consistency with daily walking, light jogging, swimming, or biking. Strict dieting is not recommended, however, since gaining weight will be easier during this period, it is important to avoid large portions, excess calories, unnecessary calories from sugary beverages and alcohol, and foods with excess sugar and carbohydrates. Also avoid skipping meals. Meals should be well balanced, high in protein, low in sugar, and portion controlled. This will be a good time to use a calorie and macronutrient counter such as MyFitnessPal to keep track of food intake.

Will weight loss medication aid in weight loss for hypothyroidism ?

The answer is that it depends. It depends on the severity of thyroid disease, thyroid hormone levels, the weight loss medication utilized, and of course the patient. Weight loss medications can be effective by counteracting low metabolism and poor energy. However, weight loss medication is not a substitute for correcting thyroid hormone and should be considered secondary to proper thyroid management. It is important to work work with a weight loss doctor early in the process of hypothyroidism because the longer excess weight stays on the body the more difficult it will be to lose.