The food additive monosodium glutamate (MSG) could lead to obesity. Recent research found that people who eat more MSG are more likely to be overweight or obese. What's more, the link between high MSG intake and being overweight held even after accounting for the total number of calories people ate.
MSG is a widely used food additives. It is often present in processed foods although it is frequently not clearly labeled.
"In the latest research ... [scientists] followed more than 10,000 adults in China for about 5.5 years on average. The researchers measured MSG intake directly by before-and-after weighing of products, such as bottles of soy sauce, to see how much people ate ... Men and women who ate the most MSG (a median of 5 grams a day) were about 30 percent more likely to become overweight by the end of the study".