Study Suggest Lower Mortality Risk For the Overweight

[General Mung Beans]

http://www.nytimes.com/2013/01/02/healt ... eight.html

Study Suggests Lower Death Risk for the Overweight
By PAM BELLUCK
Published: January 1, 2013



A century ago, Elsie Scheel was the perfect woman. So said a 1912 article in The New York Times about how Miss Scheel, 24, was chosen by the “medical examiner of the 400 'co-eds'” at Cornell University as a woman “whose very presence bespeaks perfect health.”
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Miss Scheel, however, was hardly model-thin. At 5-foot-7 and 171 pounds, she would, by today's medical standards, be clearly overweight. (Her body mass index was 27; 25 to 29.9 is overweight.)

But a new report suggests that Miss Scheel may have been onto something. The report on nearly three million people found that those whose B.M.I. ranked them as overweight had less risk of dying than people of normal weight. And while obese people had a greater mortality risk over all, those at the lowest obesity level (B.M.I. of 30 to 34.9) were not more likely to die than normal-weight people.

The report, although not the first to suggest this relationship between B.M.I. and mortality, is by far the largest and most carefully done, analyzing nearly 100 studies, experts said.

But don’t scrap those New Year’s weight-loss resolutions and start gorging on fried Belgian waffles or triple cheeseburgers.

Experts not involved in the research said it suggested that overweight people need not panic unless they have other indicators of poor health and that depending on where fat is in the body, it might be protective or even nutritional for older or sicker people. But over all, piling on pounds and becoming more than slightly obese remains dangerous.

“We wouldn’t want people to think, ‘Well, I can take a pass and gain more weight,'” said Dr. George Blackburn, associate director of Harvard Medical School’s nutrition division.

Rather, he and others said, the report, in The Journal of the American Medical Association, suggests that B.M.I., a ratio of height to weight, should not be the only indicator of healthy weight.

“Body mass index is an imperfect measure of the risk of mortality,” and factors like blood pressure, cholesterol and blood sugar must be considered, said Dr. Samuel Klein, director of the Center for Human Nutrition at Washington University School of Medicine in St. Louis.

Dr. Steven Heymsfield, executive director of the Pennington Biomedical Research Center in Louisiana, who wrote an editorial accompanying the study, said that for overweight people, if indicators like cholesterol “are in the abnormal range, then that weight is affecting you,” but that if indicators are normal, there’s no reason to “go on a crash diet.”

Experts also said the data suggested that the definition of "normal" B.M.I., 18.5 to 24.9, should be revised, excluding its lowest weights, which might be too thin.

The study did show that the two highest obesity categories (B.M.I. of 35 and up) are at high risk. “Once you have higher obesity, the fat’s in the fire,” Dr. Blackburn said.

But experts also suggested that concepts of fat be refined.

"Fat per se is not as bad as we thought," said Dr. Kamyar Kalantar-Zadeh, professor of Medicine and Public Health at the University of California, Irvine. "What is bad is a type of fat that is inside your belly. Non-belly fat, underneath your skin in your thigh and your butt area — these are not necessarily bad." He added that, to a point, extra fat is accompanied by extra muscle, which can be healthy.

Still, it is possible that overweight or somewhat obese people are less likely to die because they, or their doctors, have identified other conditions associated with weight gain, like high cholesterol or diabetes.

“You’re more likely to be in your doctor’s office and more likely to be treated,” said Dr. Robert Eckel, a past president of the American Heart Association and a professor at University of Colorado.

Some experts said fat could be protective in some cases, although that is unproven and debated. The study did find that people 65 and over had no greater mortality risk even at high obesity.

“There’s something about extra body fat when you’re older that is providing some reserve,” Dr. Eckel said.

And studies on specific illnesses, like heart and kidney disease, have found an “obesity paradox,” that heavier patients are less likely to die.

Still, death is not everything. Even if "being overweight doesn't increase your risk of dying," Dr. Klein said, it "does increase your risk of having diabetes" or other conditions.

Ultimately, said the study’s lead author, Katherine Flegal, a senior scientist at the Centers for Disease Control and Prevention, “the best weight might depend on the situation you’re in.”

Take the perfect woman, Elsie Scheel, in whose "physical makeup there is not a single defect," the Times article said. This woman who "has never been ill and doesn't know what fear is" loved sports and didn't consume candy, coffee or tea. But she also ate only three meals every two days, and loved beefsteak.

Maybe such seeming contradictions made sense against the societal inconsistencies of that time. After all, her post-college plans involved tilling her father’s farm, but “if she were a man, she would study mechanical engineering.”

While just being overweight doesn't give you a free pass, hopefully this provides some encouragement to people who obsess over their weight and engage in unhealthy behaviour as a result.

[Broomstick]

Are they just going by BMI? Because a subset of people in the overweight category aren't carry extra fat, they're carrying extra muscle. BMI is just a relationship between height and weight, it doesn't distinguish between fat and lean body mass.

The other thing is that being underweight is characteristic of some nasty diseases, too. People on the lower end of normal BMI might be in the early stages of some of those.

Finally, there are instances where being slightly overweight truly is protective though they're becoming rarer these days (famine is pretty unusual these days). When I got sick in 2005 and couldn't eat at all for a week, and could barely keep anything down for a month, more than one doctor commented that being on the heavier end of normal BMI probably worked in my favor. People on the low end of overweight would endure such illnesses better than those with a lower weight.

[LaCroix]

There are lots of those factors which are massively misleading if you look at them in isolation.

For example, I got triglycerides in the range of 300-400+ which should be bad, like, instant cardiac arrest.

Still, my doctor told me to not worry - those are only bad in combination with high cholesterol - whose levels are in the 20 range for me, which is like half the average.

[Iron Bridge]

Wikipedia article on 'obesity' has a graph of mortality vs BMI, and the mortality rate increases for >25 category and for all higher categories (albeit, 25-35 is not as bad as being underweight). Yes it's wikipedia, but the citation is New England Journal of Medicine, so I am interested what this 'more careful' study has done differently?

It's suspect that the primary example is apparently a picture in a 100 year old lifestyle magazine, but that is probably the NYT idiot who wrote the article rather than the study itself.

[Broomstick]

Age is a factor, too - for the very old being underweight is much worse than being overweight.

And, as noted, being slightly overweight isn't as bad as being slightly underweight.

My understanding is the NEJM study looked at people as a whole. If the new study screened for certain chronic conditions beforehand, or other factors, that might have changed the results.

[Dr. Trainwreck]

Being a bit overweight helps you with lots of physical activity as well. I've tried lifting 50kg (110 pounds) after losing weight, I've tried lifting it after I put on some weight again; big difference. A small gut is especially important for your stationary strength.