Being Slightly Overweight Improves Life Expectancy, Study Claims


While most people are obsessed with losing weight, mainly due to the media’s portrayal of obesity as unhealthy, a new study has revealed that being slightly overweight may be a good thing.

The study, published in a journal called Cell Metabolism, claims that an enzyme secreted by fat tissue controls energy levels in the brain and its response to a lack of food. As a result of which, researchers concluded, there is an optimal amount of body fat required for maximising health and living to a ripe age.

The senior author of the study, Professor Shin-ichiro Imai, of Washington University School of Medicine in St Louis, said:

We showed that fat tissue controls brain function in a really interesting way. The results suggest that there is an optimal amount of fat tissue that maximizes the function of the control centre of ageing and longevity in the brain. We still don’t know what that amount is or how it might vary by individual. But at least in mice, we know that if they don’t have enough of a key enzyme produced by fat, an important part of the brain can’t maintain its energy levels.

Professor Imai added, “As we age, people who are slightly overweight tend to have fewer problems. No one knows why people categorised as being slightly overweight tend to have a lower mortality rate. But our study suggests that if you don’t have an optimal amount of fat, you are affecting a part of the brain that is particularly important for controlling metabolism and ageing.”

The importance of an enzyme called NAMPT was highlighted in the study.

As Imai explained, “There’s been a lot of controversy in the field about whether extracellular NAMPT has any function in the body. Some researchers have said it’s just a result of leakage from dead cells. But our data indicates it is a highly active enzyme that is highly regulated.”

The study does not of course suggest that being heavily obese is a good thing, only that there may be some positive benefits of having just enough fat to encourage the positive enzymes to do their job.

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