New Study Finds Differences In Three Popular Diets
Israeli researchers reported Wednesday that three popular, but different, diets produce similar results in terms of weight loss, but differ in the health benefits they deliver.
The long-term study examined dieters over a two year time period, each of whom consumed a low-fat regimen, a Mediterranean diet or a primarily vegetarian form of the Atkins diet. Most of the 322 participants, more than 82 percent, were moderately obese men who weighed an average of just over 200 pounds at the study’s outset.Â
The research found that, on average, dieters lost 7.3 pounds on the low-fat regimen, 10 pounds on the Mediterranean diet and 12 pounds on the low-carbohydrate Atkins diet.
"If we fail in one strategy, we may want to choose another diet. We cannot think any more that one diet fits all," Iris Shai of Ben-Gurion University of the Negev, who led the study, told Reuters.
"The good news is, we have alternatives," she said.
"This study will open clinical medicine to considering low-carb and Mediterranean diets as safe alternatives for patients."
Shai noted that after two years, the amount of weight lost was similar to the effects of some prescription diet drugs.
The study showed that the low-carbohydrate diet was extremely effective at improving the cholesterol profile, reducing the total cholesterol-to-good cholesterol ratio by 20 percent. The low-fat diet showed a 12 percent reduction in the ratio. The Mediterranean diet proved best for lowering fasting glucose levels in diabetics.
Both the Mediterranean and low-fat diets restricted calories, with the Mediterranean diet containing the highest amounts of dietary fiber and monounsaturated/saturated fat. The low-carb diet had the highest amounts of protein, fat and dietary cholesterol.
"Women tended to lose more weight on the Mediterranean diet," the researchers reported.
Nearly 85 percent of the study’s participants were maintaining their diets at the two-year mark, due in part to their workplace cafeteria, the Nuclear Research Center in Israel, which prepares healthy dishes every day for each group. Additionally, the participants’ spouses were taught to help the volunteers at home.
"The low-fat, restricted-calorie diet was based on American Heart Association guidelines. We aimed at an energy intake of 1,500 calories per day for women and 1,800 calories per day for men, with 30 percent of calories from fat, 10 percent of calories from saturated fat, and an intake of 300 mg of cholesterol per day," the researchers wrote in a report about the study.
"The participants were counseled to consume low-fat grains, vegetables, fruits, and legumes and to limit their consumption of additional fats, sweets and high-fat snacks."
The Mediterranean diet allowed for 1,800 calories for men and 1,500 for women, and was high in vegetables and low in red meat, with fish and poultry typically replacing beef. The fat consisted primarily of olive oil and a few nuts each day.
The low-carbohydrate diet was modeled on the Atkins diet, which did not limit calories but instead cut back on the intake of processed carbohydrates.
"However, the participants were counseled to choose vegetarian sources of fat and protein and to avoid trans fat," the researchers wrote.
The study was published in the New England Journal of Medicine.
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