MSG Linked to Obesity

MSG (monosodium glutamate). We've all eaten it, but now you can say you've seen it: Here's what MSG looks like close-up. Photo courtesy: SixWise.com

Monosodium glutamate (MSG) is a flavour enhancer used liberally in processed foods and Asian cuisine. While MSG is a permitted ingredient in the food supply, questions have been asked about its potential role in weight gain and obesity.

Several studies have been done linking MSG with obesity. The results of these studies showed that higher MSG levels were associated with a higher BMI (Body Mass Index). The association remained even after factors such as food intake and activity levels were taken into consideration.

If you believe that weight is only determined by caloric balance, then these results will not make sense. The authors of the study discuss the potential mechanisms behind their findings. They focus on the impact glutamate can have on a part of the brain known as the hypothalamus. Although small in size, the hypothalamus has a regulatory role in key processes including metabolism and hunger.

It is also worth noting the role that the hormone leptin has in body wight regulation through its impact on the hypothalamus. Leptin suppresses appetite and stimulates the metabolism. However, if the hypothalamus is not sensitive to leptin (leptin resistance), this does not bode well for maintenance of a healthy body weight.

As the authors of the MSG paper point out, glutamate has the ability to damage the hypothalamus and cause leptin resistance. This mechanism and its potential impact on metabolism could explain how MSG might predispose to obesity, even when food intake and activity levels are taken into account.

If you want to avoid MSG ensure your diet is made from natural, unprocessed foods; and, avoid soy sauce and other condiments likely to be laced with MSG, including gravy mixes and concentrates.