We are all aware of the link between weight gain and low thyroid. Hypothyroidism slows metabolism, enhances your appetite and makes you eat the wrong foods at the wrong time, making you gain weight. Studies have shown that the frequency of hypothyroidism among obese patients is slightly higher than among normal weight people. Besides thyroid dysfunction, several hormonal and endocrine disorders are associated with being overweight or obese. Research conducted on a large number of obese patients, prior to their bariatric surgeries, evaluated the function of their thyroid, parathyroid, adrenals, and pituitary gland. The research has shown that nearly half of these obese people had some kind of endocrine gland problem, excluding diabetes mellitus; 18.1% of the obese patients were found to have hypothyroidism. 1.9% were diagnosed with a pituitary dysfunction and nearly 1 out of 100 of the obese patients had cortisol excess from Cushing’s syndrome. 16.3% of them endocrine problems. It would therefore be wise to have an endocrine evaluation that includes thyroid, adrenal, and pituitary gland testing before even considering bariatric surgery. Obese hypothyroid patients who are receiving thyroid hormone treatment seem to require higher doses of thyroid hormone than the general population as a result of gastrointestinal motility disturbances. Moreover, obese people have a higher total blood volume and a higher cardiac output, explaining why they need higher doses of thyroid hormone.