Although the flavor enhancer MSG (monosodium glutamate) is associated with Chinese restaurants, it is used by major fast-food chains and is also found in a variety of processed foods. A study of 750 Chinese men and women found that those who used the most MSG in their cooking were nearly three times more likely to be overweight than those who didn’t use any. The increase in obesity risk was independent of physical activity and total calories consumed.
4. Artificial Sweeteners
Many people use sugar substitutes as a weight-loss aid, but these sweeteners may actually contribute to weight gain. In a study published in Nature, scientists found that mice fed saccharin, sucralose or aspartame developed glucose intolerance, a metabolic condition associated with obesity and type 2 diabetes. The artificial sweeteners altered the animals’ gut microbiomes towards a balance of bacteria associated with metabolic diseases. In a follow-up study on 7 human volunteers, 4 became glucose intolerant after consuming the maximum recommended dose of saccharin for one week.