Friday October 17, 2003

A Calorie is a Calorie... or is it?

The dietary establishment has long argued it's impossible, but a new study offers intriguing evidence for the idea that people on low-carbohydrate diets can actually eat more than folks on standard lowfat plans and still lose weight.
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[This] strikes at one of the most revered beliefs in nutrition: A calorie is a calorie is a calorie. It does not matter whether they come from bacon or mashed potatoes; they all go on the waistline in just the same way ...

[c.f. Study surprise: Low-carb dieters eat more, lose weight, Fort Lauderdale, Florida (AP), Oct 4, 2003]

Then again, we've been wrong before about other "revered beliefs". Maybe trying to understand physiological and biochemical processes using physics just isn't quite the right approach :-)

Now a small but carefully controlled study offers a strong hint that maybe Atkins was right: People on low-carb, high-fat diets actually can eat more.

Maybe not high but certainly more than the "low fat" pitch we've been getting for all these years...

The study, directed by Penelope Greene of the Harvard School of Public Health and presented at a meeting [in Ft. Lauderdale] this week of the American Association for the Study of Obesity, found that people eating an extra 300 calories a day on a very low-carb regimen lost just as much during a 12-week study as those on a standard lowfat diet.

Over the course of the study, they consumed an extra 25,000 calories. That should have added up to about seven pounds. But for some reason, it did not.

Not only that, the low-carb dieters lost more weight than the low-fat dieters!

In the study, 21 overweight volunteers were divided into three categories: Two groups were randomly assigned to either lowfat or low-carb diets with 1,500 calories for women and 1,800 for men; a third group was also low-carb but got an extra 300 calories a day.
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Instead of lots of red meat and saturated fat, which many find disturbing about low-carb diets, these people ate mostly fish, chicken, salads, vegetables and unsaturated oils.

The red meat and saturated fats is a feature of the Atkins diet, by the way, not the South Beach diet (and Atkins may well have revised this if he were alive to do so).

Everyone's food looked similar but was cooked to different recipes. The low-carb meals were 5 percent carbohydrate, 15 percent protein and 65 percent fat. The rest got 55 percent carbohydrate, 15 percent protein and 30 percent fat.

In the end, everyone lost weight. Those on the lower-cal, low-carb regimen took off 23 pounds, while people who got the same calories on the lowfat approach lost 17 pounds. The big surprise, though, was that volunteers getting the extra 300 calories a day of low-carb food lost 20 pounds.

Although the numbers for all three groups were very close, still... the low-fat dieters lost the least amount of weight.

Personally, I think biologists and biochemists should study the "insulin reaction" in more depth. Also the effect of dietary fat on human physiology and metabolism, the differences between saturated, unsaturated, and trans fats (let's not lump all fats together), the effects of increasing fiber in the diet, ... I could go on :-)

References:
The South Beach Diet (Arthur Agatston, M.D.)
The Fat Fallacy (William Clower)
How I Gave Up My Low-Fat Diet and Lost 40 pounds (Dana Carpender )

A Calorie is a Calorie... or is it? ( in category Special Interests ) - posted at Fri, 17 Oct, 23:23 Pacific | «e»