Fat old people do live longer than skinny old people

by Fred Lane PhD

Getting good workouts at the gym? Want to keep your brain in shape? Try internet sites such as www.aarp.com and search there for “games.” Take your pick of on-screen trivia, crosswords or other beneficial, entertaining and educational problems.

But, at the same time, be careful to avoid obsessing about being slightly overweight. Contrary to mainstream medical and popular magazine advice, it has long been suspected that people over age 65 live longer if they are a bit fat, rather than a bit skinny. The Journal of the American Medical Association published a 20 April 2005 article (Flegal et al 2005) that strongly supports the “bit fat” position.This in turn is supported by many studies, including an important paper presented at the  2008 Australian Gerontological Conference and published in the prestigious Journal of the American Geriatric Society (Flicker et al 2010).

Major Surveys

Scientists from the Centers for Disease Control (CDC) and the National Cancer Institute (NCI) analysed data from three major American community surveys conducted between 1971 and 1994, involving nearly half a million person-years. Their findings clearly debunk myths published by the CDC in 2004 that obesity was killing an extra 400,000 people a year. The CDC  later revised this figure downwards to 365,000, but even this was found to be exaggerated.

There is no doubt that extreme obesity, as measured chiefly by belly fat, together with a lack of fitness, threatens life and increases the chance of contracting diabetes, arthritis and other potentially crippling disorders. However, it is a simple fact of life that few people with extreme obesity see their 65th birthday. On top of that, when potentially confounding factors, including smoking, sex and race, are taken into account, a body mass index (BMI) of 25-29 is not only nothing to worry about, it is suprisingly superior to the “normal” BMI.

(One of the best measures of obesity is the BMI, see the table below.)

Too rich? Too thin?

The study also confirms serious concern for those with BMIs of 18.5 or below. Contrary to Wallace Simpson, Duchess of Windsor, who said you could never be too rich or too slim, this study once more stresses the danger of being too thin after age 65.

There is no doubt that extreme obesity kills. It might well be responsible for some 112,000 extra American deaths a year in all age groups. On the other hand, being modestly overweight probably prevents 86,000 American deaths a year. Maybe modestly overweight elderly people weather medical emergencies better.

All this is no more a licence to overindulge or regress to couch potato behaviour than it is for the uncritical rejection of all the diet industry’s propaganda. Instead, as some of the propaganda correctly says, keep your brain active, exercise regularly, observe a sensible well-balanced diet and  control stress. Adopt a lifestyle that contributes to normal blood pressure and low ‘bad’ cholesterol intake. Drink alcohol moderately and ditch the cigarettes and junk food. Have regular medical checkups. However, importantly, don’t obsess about trying to get below a BMI of 25-29.

Bottom line

If you are over 65 and fit, don’t worry yourself into a depression if you can’t hit the “Normal” BMI touted by the crash diet and insurance industries. On the other hand, seek help if you can’t boost your BMI to a figure above18.5.

Reference

Flegal K., Graubard B.I. et al. Excess deaths associated with underweight, overweight and obesity. Journal of the American Medical Association. Vol 293. pp 1861-7. 2005.

Flicker,L., K. McCaul, et al. Body Mass Index and Survival in Men and Women Aged 70 to 75, Journal of the American Geriatric Society, 58:234-241, 2010.

Body Mass Index for Adults

There are two methods:

1. BMI = WEIGHT in kg divided by HEIGHT in metres SQUARED. A person 1.67m in height and weighing 65kg would have a BMI of 23.3 (BMI = 65 divided by 1.67² = 65 divided by 2.79 = 23.3). OR

2. Use the table below to determine your BMI. First, find your approximate height on the far left column. Next, move across the row to find your weight. Once you’ve found your weight, move to the very top of that column. This number is your BMI.

What does BMI mean?   BMI 18.5–24.9 = “Normal”; BMI 25.0–29.9 = Overweight;
BMI 30.0–39.9 = Obese; BMI 40.0 and above = Extreme obesity.