Tag Archives: Obesity

A mitochondrial hormone that’s apparently a critical regulator of metabolism has been discovered

A new paper just came out in Cell Metabolism that is really cool for a couple reasons.

Lee et al. (2015) found that a hormone produced by mitochondria, parts of our cells that are important in metabolism and have their own DNA. They called the hormone MOTS-c.

Hormones, remember from earlier posts, are just signaling molecules that circulate in our cells and bodies and have important biological effects.

This discovery is especially cool for a couple reasons.

The first is that although we know that mitochondria are really important in metabolism, we don’t really know much about signaling molecules that are actually produced by our mitochondria.

The second is that the hormone appears to be really conserved among all mammals. This is often seen for hormones whose purpose is so specific, important, and widespread that its difficult for the hormone to even evolve. Insulin is another example of a hormone that is very conserved among mammals.

A final reason why this discovery is so cool is that MOTS-c seems to have really important effects on metabolism. It’s action activates AMPK. AMPK is another really important signaling molecule that we understand much more about. For now, its just important to know that AMPK regulates fat metabolism, and it looks like treatment with MOTS-c actually prevents obesity and insulin resistance in mice.

Maybe this represents a future treatment for obesity and diabetes? It’s actually quite strange to think that someday we might understand endocrinology well enough to regulate weight and even to some extent processes like aging by simply hormone injections without the current negative consequences that generally accompany these approaches.

That day is not yet here, so I’m gonna go hit the gym.

Lee, C., Zeng, J., Brew, B.G., Sallam, T., Martin-Montalvo, A., Wan, J., Kim, S., Mehta, H., Hevener, A.L., de Cabo, R., Cohen, P. (2015) The mitochondrial-derived peptide MOTS-c promotes metabolic homeostasis and reduces obesity and insulin resistance. Cell Metabolism 21, 443-454.

Should we refer to obesity as a disease?

I just read an interesting paper reviewing a few articles looking at the effects of a disease-based approach to obesity education. In brief, the authors reviewed previous studies they had carried out. On June 18th, 2013 the American Medical Association classified obesity as a disease. The authors of this study found that when given the message through a New York Times article that obesity is a disease, obese people were less concerned about their weight, less interested in dieting, and made higher-calorie food decisions compared to a similar group of people (the control group) who were given a alternative (non-disease based) informational description of obesity. Interestingly, people in the study who were presented with the information that obesity is a disease reported lower levels of body dissatisfaction.

In summary, telling people that obesity is a disease might make them happier with their weight, while simultaneously making them less likely to lose weight. It is obviously very important that people be happy with themselves at whatever weight they are at, especially given the degree of shame imposed upon overweight people. Nevertheless, the resulting increased risk of other health problems that either are caused by obesity or co-occur with obesity, such as diabetes, heart disease, joint problems, and even some kinds of cancer certainly puts a burden on health care practitioners to be careful in such nuances as to how they refer to obesity (as a disease, or as a result of lifestyle choices).

TLDR. Calling obesity a disease makes obese people feel better about their weight, but also makes them less interested in losing weight, and less likely to make healthy decisions.

Over the next couple weeks I’ll read a few related articles and report on how the authors’ conclusions hold up. For the near future my blog will stick to this style, reporting on an interesting paper I have read recently.

Crystal L. Hoyt, Jeni L. Burnette and Lisa Auster-Gussman (2014) ‘Obesity Is a Disease”: Examining the Self-Regulatory Impact of This Public-Health Message. Psychological Science. 25: 997 originally published online 24 January 2014. DOI: 10.1177/0956797613516981