Can MSG Make Us F-A-T?
by Deborah Neffa
(filed under: nutrition)
Having trouble losing weight? Cutting back on monosodium glutamate might help. People who use the common flavor enhancer MSG are more likely than nonconsumers to be overweight — even when they have the same calorie intake and physical activity levels, according to a study by School of Public Health researchers.
The study measured MSG use in 752 people from north and south China who ate most of their meals at home. Ka He, lead author of the study, says measuring MSG consumption by people who eat mainly home-cooked food is easier than measuring consumption by people who eat out frequently. “Restaurants would be hesitant to give us the ingredients they put in their food,” He says.
MSG stimulates taste buds, tempting people to eat more. Previous studies have linked MSG consumption to weight gain in animals, but this study was the first to link MSG use to obesity in humans.
He says that MSG consumption has increased dramatically during the past few decades. “Almost everyone consumes it in foods they make at home, eat at restaurants, or buy in stores,” he says.
He and his colleagues in the United States and China found that participants who used the most MSG were nearly three times more likely than nonusers to be overweight. About 82 percent of participants used MSG; the average intake was 0.33 grams per day. The median intake for participants consuming the most MSG was 0.7 grams per day.
He says that MSG may also affect the brain’s hypothalamus and alter the functioning of leptin, a hormone that regulates food intake and energy balance.
MSG is commonly used in Asian dishes and other popular foods, including some brands of snacks, salad dressings, soy sauce, packaged lunch meats, and canned soups and vegetables. The Food and Drug Administration uses the term MSG to mean a 99-percent pure combination of glutamic acid and sodium. “Food companies can make it 95 percent or 80 percent purified and call the seasoning anything they want,” He says. “But it still contains substantial amounts of MSG.”
He is creating another study to test the link between MSG consumption and weight gain in humans. “Based on only this single study, we cannot say MSG causes obesity,” He says. “Our weight is determined by our lifestyle, not just a single factor like MSG consumption. MSG’s effects can be attenuated by exercise or healthful eating.”
Deborah Neffa is a senior majoring in journalism at Carolina.
Ka He is an assistant professor of nutrition and epidemiology in the Gillings School of Global Public Health. The study appeared in the August 2008 issue of the journal Obesity and was funded by the National Institutes of Health.
