Consumers may be able to reduce their need for obesity treatment by cutting MSG from their diet, experts believe.
MSG, or monosodium glutamate, is a flavour enhancer which is used in many processed foods to bring out the products' flavour.
Although it is safe to eat, a number of studies in animals have indicated that it may contribute to unwanted weight gain.
Now, scientists at the University of North Carolina have found that people who use MSG regularly in their recipes are more likely to be overweight or obese than those who rarely consume MSG.
The researchers studied more than 750 men and women in rural China - where MSG is commonly used in home-prepared meals - and found that the third who used the most MSG were nearly three times more likely to be overweight than non-users.
Dr Ka He, assistant professor of nutrition and epidemiology at the university's School of Public Health, confirmed: "We found that prevalence of overweight was significantly higher in MSG users than in non-users."