Obesity Causes Hormones

What causes obesity? Obesity statistics and studies have revealed that a small number of cases are due to a hormonal imbalance or disorder. Conversely, obesity may also be a cause of hormonal imbalance, which affects hormones responsible for regulating appetite.

Obesity and Hormones

Leptin Hormones and Appetite

Fat cells in the human body produce leptin, a hormone that controls weight and affects how stored energy is used. This hormone is responsible for communicating with your brain and telling it how much energy is stored. In obese people, there is too much leptin in the bloodstream, but not enough being transmitted to the brain, which causes continued hunger.

Some scientists believe that obese people are somehow resistant to leptin’s appetite suppressant action, similar to how diabetics are resistant to insulin.

Estrogen, Obesity and Hormones

The female hormone estrogen affects how people store fat. While men tend to accumulate fat deposits around the abdomen, women store fat around the lower body during their reproductive years. After menopause and when estrogen levels fall, however, women begin to store fat around the abdomen as well. Obesity statistics show that fat stored in this area is more dangerous than fat stored in the lower body.

Obesity Statistics: Growth Hormones

As scientists try to determine what causes obesity, growth hormones come into play as well. Obesity statistics show that these hormones, produced by the pituitary gland, may also affect obesity. Obese people typically have lower growth hormone levels than people with a healthy weight, suggesting another link between obesity and hormones.

Hormonal Imbalance and Obesity

Obesity statistics provided Mayo Clinic (2010) indicate that less than 2 percent of obesity cases can be traced to hormonal imbalance. When an underlying hormonal disorder is what causes obesity, the most common culprits are the following:

  • Cushing’s syndrome occurs when the adrenal glands produce too much cortisol, a naturally occurring steroid. Cushing’s syndrome causes fat deposits in the upper back, abdomen and face.
  • Hypothyroidism develops when the thyroid gland doesn’t produces enough thyroid hormone. This hormonal imbalance slows metabolism, leading to weight gain and fatigue.
  • Polycystic ovarian syndrome is a cluster of hormonal conditions that affect 5 to 10 percent of women, according to obesity statistics provided by the National Women’s Health Information Center (2010). Women with PCOS have high levels of the male hormone androgen, and are often obese or overweight.

Sleep, Obesity and Hormones

Sleep, or rather a lack of sleep, may cause hormonal imbalances that lead to weight gain. A study published in the Public Library of Science (2004) shows that shorter sleep times result in higher levels of the hormone ghrelin, as well as lower levels of leptin, the appetite suppressant hormone. Ghrelin stimulates the appetite and the production of fat cells.

Hunger and Appetite Hormones - Obesity and Hormones

A hormonal imbalance associated with short or disrupted sleep patterns, combined with low energy levels due to lack of sleep, may be part of what causes obesity in some people.


Better Health Channel Staff. (2008). Obesity and hormones. Retrieved April 8, 2010, from the Better Health Channel Web site: http://www.betterhealth.vic.gov.au/bhcv2/bhcarticles.nsf/pages/Obesity_and_hormones.

Merck Manuals Online Medical Library Staff. (2008). Obesity. Retrieved April 8, 2010, from the Merck Manuals Online Medical Library Web site: http://www.merck.com/mmhe/sec12/ch156/ch156a.html.

National Women’s Health Information Center Staff. (2010). Polycystic ovary syndrome (PCOS): Frequently asked questions. Retrieved April 9, 2010, from the National Women’s Health Information Center Web site: http://www.womenshealth.gov/faq/polycystic-ovary-syndrome.cfm#b.

Prinz, P. (2004). Sleep, appetite and obesity: What is the link? Retrieved April 8, 2010, from the National Center for Biotechnology Information Web site: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC535424/.

Mayo Clinic. (2010). Special report. Retrieved July 26, 2010, from http://www.healthsource.mayoclinic.com/secure/pdf/SRHW.pdf.

Taheri S., Lin L., Austin D., Young T.