Eating red meat can make you fat because it makes you hungrier.
When you eat foods that are high in iron, such as red meat, it increases your appetite by suppressing leptin, a hormone that regulates appetite, energy expenditure and metabolism, according to researchers from Wake Forest Baptist Medical Center.
Iron is the one mineral that humans can't excrete, so the more iron that is consumed the greater the likelihood that leptin levels will drop, resulting in increased appetite and the potential to overeat.
High levels of iron not only increase your risk of weight gain, but also have been implicated as a contributing factor in many diseases, including type 2 diabetes, fatty liver disease and Alzheimer's disease.
"This is yet another reason not to eat so much red meat because the iron in red meat is more readily absorbed than iron from plants," advised study leader Dr. Don McClain, director of the Center on Diabetes, Obesity and Metabolism at Wake Forest Baptist.
The two-part study was conducted with mice and humans:
The Study, Part One: Male mice were fed high (2000 mg/kg) and low-normal (35 mg/kg) iron diets for two months. At the end of the two months, the researchers measured the rodents' levels of iron in their fat tissue. There was a 115 percent increase of iron in the mice fed a high iron diet, compared with the mice fed the low-normal diet. In addition, leptin levels in blood were 42 percent lower in mice on the high iron diet compared to those on the low-normal diet.
The Study, Part Two: Results from the animal model were verified through ferritin blood tests from 76 human participants who had been part of a previous clinical study. Ferritin blood tests measure the amount of iron stored in the body. The fat tissue responded to the amount of iron and then adjusted the amount of leptin.
The study findings were published in the Journal of Clinical Investigation.
--From the Editors at Netscape