There's a good reason obesity was classified as a disease a couple years ago: It can increase your risk of autoimmune diseases (conditions where the immune system attacks its own body), such as Crohn's disease and multiple sclerosis, according to a meta-analysis published in Autoimmunity Reviews.
Surprised? It turns out that a hormone secreted by fat tissue can create an environment that breeds inflammation and allows autoimmune diseases to flourish, according to the study. Sadly, autoimmune diseases aren't the only downsides of obesity. Here are a few more:
Cancer: Specifically, breast, colon, endometrium, esophagus, gallbladder, kidney, pancreas, and thyroid cancer. Fat produces high levels of estrogen, which has been linked to a higher risk of cancer, and leptin (a type of adipokine), which may stimulate the growth of cancer cells. According to the National Cancer Institute, there will be an additional half million new cases of cancer by 2030, if obesity trends continue to increase.
Your child's risk of heart disease: You already know that obesity increases your risk of heart disease, but it's bad news for your children, too. Children of overweight or obese mothers had a 90 percent higher risk of cardiovascular disease or death, according to research presented at the American Heart Association 2014 Scientific Sessions in Chicago.
Fatty liver: Nonalcoholic fatty liver disease is the number-one liver disease in the U.S. According to the CDC, approximately 29 million Americans suffer from it. Obesity causes insulin resistance, which might contribute to the disease.
Sleep apnea: The effects of obesity on sleep come from the extra weight obstructing the upper airways, whether through enlarge tonsils, enlarged tongue, or an increase in neck fat, according to a study published in the Proceedings of the American Thoracic Society.
More sick days: The effects of obesity spill into the workplace by lowering productivity and increasing the number of days that workers are out for obesity-related illnesses, says the Journal of Occupational and Environmental Medicine. Researchers estimate that this may cost American businesses $8.65 million dollars a year.