Overweight or healthy weight?

Thursday January 3rd, 2013

Calling people "overweight" may give a false impression of the state of their health, researchers revealed yesterday.

People classed as overweight emerged as having the lowest risk of dying prematurely of all weight groups in a major analysis of the issue.

US researchers analysed nearly 100 studies involving nearly three million people and 270,000 deaths.

They found that people judged to be overweight enjoyed a 6% reduced risk of dying than others of the same age.

And while obese people faced an 18% increased risk of dying, those with mild obesity enjoyed a 5% reduced risk, according to the report in the Journal of the American Medical Association.

One possibility is that the figures are distorted by the effect of many serious illnesses on weight - leading to weight loss.

But experts say the findings challenge the current view as to what is a healthy weight, suggesting that humans may benefit from small reserves of fat.

The researchers, led by Dr Katherine Flegal, of the US Centers for Disease Control and Prevention, Hyattsville, Maryland, say: "Possible explanations have included earlier presentation of heavier patients, greater likelihood of receiving optimal medical treatment, cardioprotective metabolic effects of increased body fat, and benefits of higher metabolic reserves."

Also writing in the journal Dr Steven Heymsfield and Dr William Cefalu, of the Pennington Biomedical Research Center, Baton Rouge, Louisiana, USA, say that measuring body mass index should only be the first step towards establishing a patient's state of health.

They write: "Even in the absence of chronic disease, small excess amounts of adipose tissue may provide needed energy reserves during acute catabolic illnesses, have beneficial mechanical effects with some types of traumatic injuries, and convey other salutary effects that need to be investigated in light of the studies by Flegal et al and others.

"Not all patients classified as being overweight or having grade 1 obesity, particularly those with chronic diseases, can be assumed to require weight loss treatment."

JAMA January 1 2013;309(1):71-82, 87-88

Tags: Diet & Food | Fitness | General Health | North America

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