Low-carb v. low-fat: No clear loser, studies find

After one year, weight-loss on the two diet regimes was about the same, researchers find



By ANDRÉ PICARD
PUBLIC HEALTH REPORTER


UPDATED AT 9:16 AM EDT Tuesday, May. 18, 2004

Over a six-month period, low-carb diets like Atkins and South Beach result in greater weight-loss than traditional low-fat diets, but by one year, the results are about the same for each regime, according to two new studies.

While the research is, by no means, the final word in the fierce diet debate, it will no doubt provide a boost to the immensely popular but much disparaged proponents of low-carbohydrate weight-loss.

Even Walter Willett, chairman of the department of nutrition at Harvard University and one of the world's foremost nutritional experts, said that, based on the new research, "We can no longer dismiss very-low-carbohydrate diets." He stressed, however, that this should not be taken as an endorsement.

Rather, Dr. Willett said, the message to retain is that people who are overweight should "experiment with various methods of weight control" to find the one that works best for them and "find ways to eat [that] they can maintain indefinitely rather than seeking diets that promote rapid weight-loss."

Dr. Willett, the author of Eat, Drink and Be Healthy, is a proponent of a Mediterranean-style diet rich in fresh fruits and vegetables, fish and nuts. He believes people should consume healthy fats and healthy carbs, and avoid refined sugars, flours and other processed foods.

The new studies, published in today's edition of the Annals of Internal Medicine, are the first to compare low-carb and low-fat approaches to dieting head-to-head for a period of up to 12 months.

The first study, conducted by researchers at Duke University in Durham, N.C., followed 120 healthy, moderately obese people over a six-month period. During that time, average body weight dropped by 12 kilograms in the low-carb group, compared to 6.5 kilograms in the low-fat group.

The low-carb dieters also saw greater improvements in their blood lipids (markers for heart-disease risk), notably lower triglycerides and higher high-density lipoproteins (good cholesterol). However, two people in the low-carb group dropped out of the study because their low-density lipoprotein (bad cholesterol) rose sharply and, overall, they reported more bad reactions (such as constipation, diarrhea and general weakness) than the low-fat group.

The second study, conducted at the Veterans Affairs Medical Center in Philadelphia, followed 132 severely obese adults for one year. At six-months, the low-carb group had lost more weight than the low-fat group.

But, afterward, weight stabilized for the low-carb group, while it continued to drop for the low-fat group.

By the one-year mark, both diets had virtually identical results, with the low-carb dieters having lost 5.1 to 8.7 kilos, and the low-fat group 3.1 to 8.4 kilos.

In the end, however, the low-carb dieters had better lipid readings, particularly triglycerides and HDL cholesterol.

Linda Stern, an internist at the VA hospital and lead author of the study, cautioned that "more research is needed to see if a low-carbohydrate diet remains safe and effective for the longer term."

But she said the ability of people on low-carb diets to drop weight quickly and keep that weight off was impressive, and may be a good choice for many people.

"I think a low-carbohydrate diet is a good choice because much of our overeating has to do with consumption of too many carbohydrates," she said.

Gord Brethour, a retired General Motors worker who lives in Brighton, Ont., said he was not too surprised by the new research but, ultimately, what matters to him is practical results, not research findings.

"You can make the numbers say whatever you want in these studies, but the numbers on my scale don't lie," he said.

Mr. Brethour started on the South Beach diet, a low-carb regime, in February, and since then he has lost more than 15 kilos. His doctor has also cut the dose of his blood-pressure medication by half.

"For me, South Beach has been a success. The diets I tried before weren't a success because I felt I was starving myself to death," he said. Prior to taking the low-carb route, Mr. Brethour had tried three low-fat diets, a grapefruit diet, an oat-bran diet and the Slim-Fast plan.

Low-carb diets restrict grains, pastas, starchy vegetables, including potatoes, and refined sugars. Mr. Brethour said that at first, he missed staples such as potatoes and pasta, but has quickly come to enjoy the alternatives -- fresh vegetables, beans and legumes.

"In my garden this year, I'm planting Swiss chard and spinach instead of potatoes," he said.

An estimated one in nine adults in North America is on a low-carb diet, and twice as many again are planning to go the low-carb route in the coming two years, according to a recent survey.

The new research shows that one of the difficulties in judging the effectiveness of diets, whether low-carb or low-fat, is that many people have trouble sticking to them. In both studies, the dropout rate was as high as 43 per cent over six months.

Mr. Brethour said he is conscious of this pitfall, but is convinced he can keep the weight off permanently.

"I've had to change my whole style of eating. This isn't short-term for me. I'll stick to a version of this diet permanently."

Duelling diets

Low-carb v. Low-fat: How they stack up after one year*

Results....................................Low-fat.......Low-carb

Dieters at start................................68............64

Still on diet at one year.......................43.............44

Weight loss..........................3.1-8.4 kilos....5.1-8.7 kilos

Dietary intakes (numbers indicate deviations from the average diet)

Calories - daily..............................-97...........-510

Protein - grams daily........................+7............-11

Carbs - grams daily.........................-22...........-131

Fat - grams daily.............................-6............+22

Fiber - grams daily...........................-1..............-5

Saturated fat - grams daily..................-4..............-2

Dietary cholesterol - grams daily..........-26............+88

Sodium - daily micrograms...............+451............-633

Average blood pressure................132/77..........139/82

Blood lipids (numbers indicate deviations from the average person)

Triglycerides - mmol/L..................+0.05...........-0.65

Cholesterol - mmol/L.....................-0.21..........+0.16

(Good cholesterol) HDL - mmol/L.....-0.13..........-0.03

(Bad cholesterol) LDL - mmol/L......-0.10..........+0.18

-*Based on a study of 132 obese adults, only 87 of whom stuck to the diet for a full year.

SOURCE: ANNALS OF INTERNAL MEDICINE





© 2004 Bell Globemedia Publishing Inc. All Rights Reserved.

For me, this is exactly the point. There is no magic pill, there is no right or wrong. You have to find what works for you, and what you can live with. That's low carb for me, for life!

Jenn

"Dr. Willett, the author of Eat, Drink and Be Healthy, is a proponent of a Mediterranean-style diet rich in fresh fruits and vegetables, fish and nuts. He believes people should consume healthy fats and healthy carbs, and avoid refined sugars, flours and other processed foods. "

Can you say "Atkins Lifetime Maintenance" ? LOL

That is so interesting that the average protein eaten in the low-fat diet was higher, and low-carb was LOWER.

It is interesting. And hard to believe, really. I honestly find it hard to believe that people ate less protein doing low carb. Maybe I'm not typical, but that has not been my experience.

Mediterranean Diet...

http://www.westonaprice.org/traditi...anean_diet.html

Its because we ate less period! Is that not the point of any diet, to make you eat less, naturally? They keep touting the low fat diet as filling you up with hunger satisfying fiber, but every study shows that low carbers end up eating less in the end. Even better, they typically report feeling more full or satisfied, versus feeling they were going hungry.

I know I eat way less them my wife does, not in one meal, but she is snacking on apples and crackers all day, chasing the insulin dragon.

brobin

The low carbers took in a LOT less calories than the low-fatters.

I was surprised by that. But, now that I think about it, I remember from my low fat days that I was hungry all the time, so I suppose the low fat dieters were snacking a lot. My experience on low carb has been that I hardly ever snack. I just don't get hungry between meals.

It says that 45 people dropped out of the study. I wonder what percentage of those were in the low fat part?

25(66%) were low fat and 20(44%) were low carb...