Quick MSG update

I included 'that MSG is bad for you' in my list of "5 Oft Repeated Medical Myths" a while ago and, while my overall conclusion still holds, a new study (gated) in the journal Obesity has found that it might cause weight gain. As one of the researchers puts it in the Science Daily press release, "The U.S. Food and Drug Administration and other health organizations around the world have concluded that MSG is safe but the question remains – is it healthy?" The researchers controlled for caloric intake, physical activity and so on and concluded:

Prevalence of overweight was significantly higher in MSG users than nonusers. For users in the highest tertile of MSG intake compared to nonusers, the multivariable-adjusted odds ratios of overweight (BMI 23.0 and 25.0) were 2.10 (95% confidence interval, 1.13–3.90, P for trend across four MSG categories = 0.03) and 2.75 (95% confidence interval, 1.28–5.95, P = 0.04). This research provides data that MSG intake may be associated with increased risk of overweight independent of physical activity and total energy intake in humans.

A couple of points: this was an observational study and so control of confounds is certainly imperfect. Moreover, while the sample-size was decent (~750), all the participants were rural Chinese, so it's unclear whether these findings will hold up elsewhere. In other words, the study should be taken seriously, but considered preliminary. More research is needed. That said, you might want to consider avoiding MSG if you're concerned about your weight.