Say it isn't so! A recent study out of the University of North Carolina at Chapel Hill cites what animal studies have hinted at for years: MSG (aka monosodium glutamate) could be a factor in weight gain.
The study focused on 750 Chinese men and women, ages 40-59, living in 3 rural villages in north and south China. Most of the study subjects prepared their meals at home without commercially processed foods and roughly 82 percent used MSG. Those participants who used the highest amounts of MSG had nearly 3 times the incidence of overweight as those who did not use MSG, even when physical activity, total caloric intake, and other possible explanations for body mass differences were accounted for. The positive correlation between MSG and higher weight confirmed what animal studies have been suggesting for years.
Maybe you're wondering what monosodium glutamate is exactly, and what you can do to avoid it in your diet. MSG is a flavor enhancer in foods—some believe it may even provide a fifth basic taste sensation (in addition to sweet, sour, salt, and bitter), what the Japanese call "umami" (roughly translated as "tastiness"). MSG is considered an "excitotoxin," since its action in the body is to excite neurotransmitters (important brain chemicals), causing nerve cells to discharge and also exciting nerves related to taste. Perhaps this ability to excite these nerves is a factor in an association between increased MSG usage and weight gain.
How prevalent is MSG in the U.S. diet? Americans consumed about 1 million pounds of MSG in 1950, and today that number has increased by a factor of 300!
The Food and Drug Administration (FDA) describes MSG as "naturally occurring," and has it on the GRAS ("generally regarded as safe") list. However, not only could MSG be causing us to gain weight, but some studies also reveal that as many as 25 to 30 percent of Americans have adverse reactions to it (e.g., palpitations and migraine headaches), and as many as 30 percent are extra sensitive to it if they consume more than 5 grams at one sitting.
OK, if you're an MSG user who could stand to lose a little weight (or know someone who is), what should you do?
Unfortunately, eliminating MSG from the diet is much easier said than done, since—given the fact that food processors often change recipes—there's no list of "safe" foods that never contain MSG. A good start is to avoid anything with MSG anywhere in the ingredient list, but there will still be many foods that have MSG hidden inside other ingredients. Likewise, even products labeled "no MSG added" can still contain these hidden sources.
Best bets for avoiding MSG
- Buy organic produce whenever possible.
- Make things from scratch, avoiding processed ingredients as much as possible.
- Limit making stews or soups in a crock pot, since slow-cooking tends to cause small amounts of glutamic acid to be released from the protein sources (e.g., meat, chicken) in the recipe.