Hypothyroidism is associated with decreased thermogenesis, decreased metabolic rate, and has also been shown to correlate with a higher body mass index (BMI) and a higher prevalence of obesity.

Can you be overweight with thyroid problems?

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.

Can hyperthyroidism cause obesity?

A common symptom of hyperthyroidism is weight loss without trying. Sometimes this can even happen despite increased appetite. Treatment of hyperthyroidism commonly results in weight gain, but the extent of weight gain is not well known. Patients may regain the weight they had lost or may overshoot and become obese.