New Studies Eat Into Diet Math

Wall Street Journal ^ | April 3, 2010 | Carl Bialik

[reaganaut1]

How many calories must a dieter cut to lose a pound?

The answer most dietitians have long provided is 3,500. But recent studies indicate that calories can't be converted into weight through a simple formula.

The result is that the 3,500-calorie rule of thumb gets things very wrong over the long term, and has led health analysts astray. Much bigger dietary changes are needed to gain or shed pounds than the formula suggests.

Consider the chocolate-chip-cookie fan who adds one 60-calorie cookie to his daily diet. By the old math, that cookie would add up to six pounds in a year, 60 pounds in a decade and hundreds of pounds in a lifetime.

But new research—based on studies of volunteers whose calorie consumption is observed in laboratory settings, rather than often-unreliable food diaries—suggests that the body's self-regulatory mechanisms tamp down the effects of changes in diet or behavior. If the new nutritional science is applied, the cookie fiend probably will see his weight gain approach six pounds, and then level off, pediatrician David Ludwig and nutrition scientist Martijn Katan wrote in the Journal of the American Medical Association earlier this year. The same numbers, in reverse, apply to weight loss.

Rewriting the math on weight change has major implications for efforts to fight obesity.

New York City officials estimated that a local law requiring chain restaurants to post calorie information about their menu items, which took effect in 2008, would reduce the number of obese city residents by at least 150,000 over five years. That law was a model for a national measure included in the recently passed health-care bill. But the estimate of obesity reduction was built on the old calorie math.

[WackySam]

I’ve always thought it would be impossible to ride more than 100 miles a week without losing weight.

I did go from 225 to 170 over the course of 18 months, but now I just hold at 170 on 2500 calories per day even though every calorie/weight loss chart says I should be losing 1-2 pounds per week.

[my_pointy_head_is_sharp]

Buy a pedometer. It tells you how many steps you take (and converts it into miles), and how many calories you burn off. You have to walk more than you think to burn off a certain number of calories. Having the pedometer makes it fun.

[csmusaret]

Maybe you should weigh 195.

[Mr. Blonde]

Your body figures out how to work less to get the same thing done. You would probably keep losing if you added in running or some other type of exercise. If that is what you wanted of course. I would be ecstatic to be able to get to and hold 170.