Not only is belly fat unattractive but it may be a sign of poor health. Even if your overall weight is within the range of normal, an increasing amount of visceral fat — the fat which surrounds your internal organs and causes a widening of the waist — may contribute to very serious health problems, including cardiovascular disease, type 2 diabetes, and colorectal cancer. For women, especially those who are post-menopausal, tummy fat is usually associated with a decreasing level of estrogen.

Yet, many women fear their widening waist line may be caused by a thyroid problem.

What Is The Thyroid?

In the base of the neck, just above the collarbone, is a butterfly-shaped gland. The thyroid is part of the endocrine system of glands, and as such, it secretes hormones directly into the bloodstream instead of into ducts. The hormones secreted by the thyroid regulate the rates of different activities in your body. This gland, then, is your body's metronome and helps set the tempo of the heart beat and how quickly the body burns calories. Both of these activities are central to your metabolism and define not only how you feel physically but also how likely you are to gain weight.

When the thyroid is too active, a condition known as hyperthyroidism, your thyroid produces more hormones than necessary. Hyperthyroidism speeds the heart and raises the metabolism, causing a person to lose weight. An additional issue is sensitivity to heat; people with this disorder often become overheated very quickly.

The exact opposite occurs when the thyroid gland is not active enough. A sluggish thyroid does not create enough hormones, and this is referred to as hypothyroidism. People with this condition gain weight easily, often feel fatigue, and find cold temperatures problematic.

Women, especially those who are post-menopausal, are overwhelmingly more likely to develop hypothyroidism than men; in fact, they are eight times more likely to be diagnosed with the disorder. Although this condition may not cause symptoms in the earliest stages, untreated hypothyroidism and the disruption it causes to the body's chemical processes may contribute, over time, to a number of health problems, such as obesity, joint pain, infertility, and heart disease. Aside from strict health concerns, many who have a hypothyroid condition worry about the weight gain, in particular, belly fat. Yet, is the thyroid really responsible for gain in this area of the body?

One study, though it focuses on thyroid cancer, may provide some evidence.

Adult Weight Changes

Concerned with a dramatic rise in the prevalence of thyroid cancer over the past 30 years, a group of researchers wondered if the similarly increasing rate of obesity during the same period might be perhaps linked to it in some way — if not responsible for thyroid cancer. To determine if some association between the two existed, the researchers compared body fat distribution and weight change with thyroid cancer risk in the NIH-AARP Diet and Health Study. This large prospective study of U.S. men and women was conducted by the National Institutes of Health in collaboration with AARP, an organization for people over the age of 50, in order to better understand the link between diet, health, and death.

Having analyzed the data for 334,907 participants who were between the ages of 50 and 71 and resided in California, Florida, Pennsylvania, New Jersey, North Carolina, Louisiana, and metropolitan Atlanta and Detroit, the researchers found that a waist circumference above 'normal' (greater than 40.2 inches in men and greater than 34.6 inches in women) predicted increased risk of thyroid cancer for both men and women. With men, though, this relationship between belly fat and cancer appeared to be stronger than for women. The researchers also discovered that a weight gain of 22 lbs. or more between the ages of 18 to 35 was related to an increased risk of thyroid cancer when compared to those whose weight remained consistent. Overall, the researchers found a slightly stronger association for waist circumference and weight change with thyroid cancer risk in men compared to women.

Does a cancerous thyroid cause an expanding waistline? The link between the two certainly exists but whether the damaged thyroid brings about belly weight gain or vice versa is unclear.

All doctors agree that hypothyroidism will cause weight gain overall, but proof that a thyroid condition will specifically cause belly fat remains inconclusive.


A doctor diagnoses hypothyroidism based on the results of blood tests that measure the level of thyroid stimulating hormone (TSH) in your blood. Produced by the pituitary gland, TSH signals the thyroid gland to produce and release hormones. Often, a doctor will also measure the level of the thyroid hormone thyroxine and compare that with the level of TSH: A low level of thyroxine and high level of TSH often points to hypothyroidism.

A condition referred to as 'myxedema,' in which fluid accumulates in the tissues and often gives the appearance of excessive fat, is a result of severe thyroid problems. Myxedema, although uncommon, can be life-threatening and needs to be treated immediately. Hashimoto's disease is also a very common cause of hypothyroidism; in the case of Hashimoto's, the immune system creates antibodies that attack the thyroid gland. Again, this is serious and must be treated.

Patients with hypothyroidism are generally prescribed oral medication, the synthetic thyroid hormone levothyroxine, to restore adequate hormone levels as well as to reverse the symptoms. According to Mayo Clinic, when used at an appropriate dosage, levothyroxine causes virtually no side effects. Natural cures may be helpful, but doctors warn that they may not do enough in a case where the thyroid is truly functioning improperly.

Natural Cures

Nevertheless, according to Dr. Oz, eating more of the following foods that are rich in iodine may help you boost your thyroid function:

  • Low-fat cheese
  • Cow's milk
  • Eggs
  • Low-fat ice cream
  • Low-fat yogurt
  • Saltwater fish
  • Seaweed (including kelp, dulce, nori)
  • Shellfish
  • Soy sauce

Source: Kitahara CM, Platz EA, Park Y, Hollenbeck AR, Schatzkin A, de Gonzalez AB. Body fat distribution, weight change during adulthood, and thyroid cancer risk in the NIH-AARP Diet and Health Study. International Journal of Cancer. 2012.