4 diet studies found best way to lose weight

10:36 PM, Feb 25, 2009   |    comments
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St. Petersburg, Florida--When all is said and done, it comes down to calories.

A landmark study shows that people can lose weight on a variety of diets — including low-fat plans and low-carb ones — as long as they consume fewer calories.

Yes, it does seem like common sense, but weight loss has become a big business. Diet programs and best-selling books offer a banquet of different approaches, including cutting fats or cutting carbohydrates.

To see a sample 1400 calorie diet menu, click here.

To get to the heart of the matter, the National Heart, Lung, and Blood Institute of the National Institutes of Health financed a two-year study of hundreds of overweight people. The research was conducted by experts at the Harvard School of Public Health in Boston and the Pennington Biomedical Research Center in Baton Rouge, part of the Louisiana State University system.

They came up with "a very simple message that cuts through all the hype: To lose weight, it comes down to how much you put in your mouth — it's not a question of eating a particular type of diet," says Frank Sacks, a lead researcher and professor of cardiovascular disease prevention at Harvard.

It really pays to figure out what kind of plan works best for you, says George Bray, the other lead researcher and a professor of medicine at Pennington.

Four diets, 811 overweight participants

The researchers recruited 811 overweight or obese older adults and put them on one of four diet plans, including two low-fat diets with 20% of calories from fat and two high-fat plans with 40% of calories from fat. The calories from carbohydrates ranged from 35% to 65%. Protein was either 15% or 25% of calories.

All four plans adhered to heart-healthy guidelines, which emphasize eating less than 8% of calories from artery-clogging saturated (animal) fat, eating vegetables, fruits and whole-grain products, and consuming at least 20 grams of fiber a day.

The eating plans were based on the DASH (Dietary Approaches to Stop Hypertension) diet, not on popular plans such as the Atkins or South Beach diets.

Dieters were encouraged to attend regular individual and group weight-loss counseling sessions and keep an online food diary. Everyone was given a personalized calorie goal, and most aimed for 750 calories below their daily needs. No one was supposed to eat fewer than 1,200 calories a day.

Participants' exercise goals were modest: about 90 minutes of moderate physical activity a week. Researchers were focused on how the composition of the diets affected weight loss and did not want to distort the results.

Among the findings, presented in today's New England Journal of Medicine:

•In six months, the dieters lost an average of 13 pounds no matter which diet they were on.

•After two years, they had kept off an average of 9 pounds and lost 1 to 3 inches in the waist, regardless of which diet they were on.

•Dieters had improvements in heart-disease risk factors, including increases in the HDL (good) cholesterol, and decreases in LDL (bad) cholesterol and triglycerides (blood fats) at six months and two years.

•People reported similar levels of fullness, hunger and satisfaction on the different diets.

'Reasonable range' of fats, protein, carbs

The plans did not include a very low-carb Atkins-type diet, Sacks says, because most "people don't stick with that low-carbohydrate intake, and we didn't want to try anything unrealistic. We tried a big range but a reasonable range of fats, protein and carbohydrates."

Some research indicates that dieters may feel full longer on higher-protein diets, but these dieters did not report any differences in feelings of fullness, says Catherine Loria, a nutritional epidemiologist with the heart, lung and blood institute.

Keith Ayoob, a registered dietitian at the Albert Einstein College of Medicine in New York, says healthful weight loss comes down to picking a balanced diet that you can maintain "for the long haul."

USA Today

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