Oct 14, 2003 15:36 ET

New Study Suggests Calories May Not Count

CAMBRIDGE, Mass., Oct. 14 /PRNewswire/ -- One of the most controversial aspects of low-carbohydrate diets such as the Atkins Nutritional Approach(TM) is their rejection of the tyranny of calorie counting. Critics of these plans claim that the reason people lose weight on low-carb diets is the same reason they lose weight on any other diet: they actually consume fewer calories, presumably because they are bored with monotony of all that steak. Now, a new study by Harvard researchers suggests that these critics are wrong and that people lose at least as much weight on a low-carbohydrate diet than those on a low-fat diet, even when they consume significantly more calories every day.


Last May two studies were published in the New England Journal of Medicine that showed the benefits of low-carbohydrate diets, but they left some open questions. "Some people have argued that if there is a difference between low- fat and low-carb diets as some studies have shown, it's due to caloric restriction because people are either bored and thus eat less or people are satiated and thus eat less," says Penelope Greene, a nutritionist at the Harvard School for Public Health and chief author of the new study. "My own view is that if it's boring then that's a particular concern, because that's not a diet that can be maintained. If it's caloric restriction because it's satiating and people are happy, I'm not sure that that's necessarily a bad thing. That seems like a good thing."


To prove that something more than mere caloric restriction is the reason that low-carb diets work, Greene and her colleagues had to improve on the previous "free-feeding" studies. In these experiments, subjects were randomly divided into two groups, and told to follow either a low-fat or a low-carb diet on their own. The researchers did not know how much the subjects actually consumed, which meant that it was possible that the low-carb eaters were leaving food uneaten on their plates. Greene and her colleagues, Walter Willett, Juniper Devicis and Antoine Skaf set out to perform a more carefully controlled, controlled-feeding experiment in which the subjects would be given prepared meals with portions weighed to the nearest gram.


Controlled-feeding experiments are notoriously difficult, Greene explains. "A lot of people didn't think we could do this," she says. After running the pilot study, which consisted of 21 subjects, she understands why. For several months she was putting in 10- to 15-hour days, seven days a week, supervising food preparation, color coding meals, and keeping records. The researchers contracted out the preparation of the food to an upscale Italian restaurant in Cambridge, MA, Ristorante Marino. "They were very used to doing catering," she says, "but not in weighing food to the nearest gram." Furthermore, they had to produce two different preparations of most foods -- low-fat and low-carb -- at five different calorie levels.


The pilot study, which was performed last fall, consisted of three sets of seven subjects each. "This was a very motivated group," Greene explains. "They were all over-fifty, overweight and overly scared. We had hundreds of people who wanted to enroll." The subjects would pick up their meals every evening and return the uneaten portion from the previous day. "There was very, very little of that," Greene says. "What I got back were little dregs of lettuce, literally."


The first group was fed a low-fat diet, consisting of 1,500 calories a day for women and 1,800 calories a day for men. The second group was given a low-carbohydrate diet, but the same number of calories. To test the hypothesis that the weight loss is not due to caloric restriction, the third group was also fed a low-carb diet, but 1,800 calories a day for women and 2,100 calories a day for men. Over the 12-week course of the study this group consumed 25,000 extra calories. According to many diet books, 3,500 calories equals one pound, which means that the third group should have lost 7 pounds less than the other two groups. In fact, to within statistical error the subjects in all three groups lost more or less the same weight. "I think this was the most surprising thing, and made this very much worth doing," Greene said. "Keep in mind that there are people who would have argued that the second group should have not done as well because of all the fat they ate."


Greene is quick to point out that this was only a pilot study, though "probably the most elaborate pilot study I have ever heard of. The purpose of the experiment was to see if under these controlled conditions there was really anything to warrant a larger study. And the answer is yes, certainly."


Source: WWR Public Relations

CONTACT: Penelope Greene of Harvard School of Public Health,
+1-617-738-2995; Gina Mangiaracina of WWR Public Relations, +1-212-714-0300 or
gmangiaracina@wwafsp.com

That's fascinating.

For a long time, I've believed that the benefit of low-carbing was probably all in the reduction of appetite leading to a voluntary lower calorie intake. But, in this study, they actually measured the leftover portions. That means reduction in appetite wasn't an issue.

The second thing from the study that impresses me is that the people doing low-calorie and low-carb didn't do significantly better than people doing low-carb alone. I would have thought they would. However, I've experienced this myself. I seem to be doing better with my program this time by not restricting my calories as I had done in some past low-carbing attempts.

**************
"Sometimes I think you have to march right in and demand your rights, even if you don't know what your rights are, or who the person is you're talking to. Then on the way out, slam the door."

<<< .... sigh ....>>> The laws of thermodynamics yadda, yadda, yadda, carbon based life forms.

Maggie
5'1" ~~ Atkins since '98 (160)/Maintaining nicely (110) ~~ Redhead until further notice!

I totally agree, Maggie. I get tired of hearing that from people.

Member since 2001
http://www.ilovelowcarb.com
Size 24(start lowfat)/Size 18(start LC)/Size 14/Size 8

While I hate to disagree with my esteemed colleagues, especially Andrea who has given me a voice on the board and may occasionally regret it, it's my opinion that to say "calories don't count" is as one-sided an argument as saying "calories are all that count."

I don't think there is any question to those of us who low carb that there is a metabolic advantage to this way of life. What we don't know yet from studies is "how much" of a metabolic advantage. It is inconceivable to me that humans can ingest an unlimited amount on even the best of LC plans and expect to lose weight. At some point on the continuum the advantage must disappear.

I do think there are laws of human metabolic thermodynamics--we just don't know them all yet.



BC
172/108/108
Zone since 4/98

I don't disagree with you, Brenda.

My "less abridged" version is : The laws of thermodynamics do not apply as would be expected or across the board to carbon based life forms. Not saying they don't have any application.

The problem is that a calorie is just a term to discuss heat and energy - or, more correctly, heat and energy potential. Period. Specifically, it is the amount of heat necessary to raise the temperature of one gram of water from 14.5 degrees centigrade to 15.5 degress centigrade, when the water is at normal atmospheric pressure. Works that way every time.

How a unit of heat potential will act in the context of a dynamic, multi-systemed, organism cannot be reduced to a +1/-1 forumula. It's understandable why we latched on to calories in and calories out, since it's a handy way of talking about energy potential, but much of the calculation is based on approximation, and the effect of numerous factors (like for instance hormones, neurotransmitters and circadian rhythms) are left out of the equation. I frustrated the hell out of a number of nutritionists over the years by not giving them the results they expected from their prescribed inake and activity. They figured I was a liar. I'm not. Their formula was insufficient. That's all I'm saying.

Maggie
5'1" ~~ Atkins since '98 (160)/Maintaining nicely (110) ~~ Redhead until further notice!

Believe me, I understand what you mean, Maggie, and my interjection here isn't aimed at you. It's just a reminder to all of us that most people believe exactly what they hear, especially if they hear it often enough.

Thus my concern that that an overly enthusiastic use of the phrase "calories don't count" may be a disservice in the long run, just as the belief that calories were all that counted or that low fat is the only way to lose weight ill-served so many of us for the last 20 or so years.

Little phrases pack a whollup--witness the billion dollar advertising industry. So my plea is for the occasional dose of "truth in packaging" along with the good news of the low carb message



BC
172/108/108
Zone since 4/98

BC:

I agree with you wholeheartedly, and if the members read the articles in my "Soapbox", they'll see that said over and over.

"It's not that calories don't count, " said the late Dr. Rober C. Atkins in DANDR (p 18 on the mass market paperback version i have). "It's just that you will burn more of them, with less hunger, when your body is operating on a fat-based metabolism."

CALORIES DO COUNT, but they are not all there is to the equation.