July 16, 2008 -- The debate about the best weight
loss diet is on again, with all the usual contenders.
A low-fat diet is not the only safe and effective way to shed pounds,
according to a new study that shows low-carbohydrate and Mediterranean diets
also result in weight
loss, and appear to also offer other health benefits.
"We saw a reduction in weight in all three diets," says Iris Shai,
RD, PhD, the study's lead author and a researcher in nutrition and chronic
diseases at Ben-Gurion University of the Negev, Beer-Sheva, Israel. "But we
saw that other diet strategies, which are higher in fat proportions, like the
Mediterranean diet, and the low-carb diet, even result in an increase in weight
loss and improvement in blood lipids and blood glucose measurements."
Mediterranean and low-carb diets may be effective alternative diets to the
low-fat plan, the researchers conclude. "There are some other diet
strategies out there," Shai says.
The study is published in The New England Journal of Medicine.
Comparing Low-Fat, Low-Carb, and Mediterranean Diets
Shai and researchers from Harvard University and other institutions assigned
322 moderately obese men and women, average age 52 and with a body
mass index (BMI) of 31, to one of three diets.
The low-fat diet was based on American Heart Association guidelines. In the
group following this diet, women ate 1,500 calories a day and men ate 1,800
calories. They took in just 30% of calories from fat, including 10% saturated
fat, and were limited to 300 milligrams of cholesterol a day. (A large egg has about 200 milligrams
of cholesterol). They focused on eating low-fat grains, vegetables, legumes,
and fruits -- and reduced intake of extra fats, sweets, and fatty snacks.
The Mediterranean diet was based on the writings of Walter Willett from
Harvard Medical School. In the group following this diet, women consumed 1,500
calories a day and men consumed 1,800 calories. The goal was to eat no more
than 35% of calories from fat, and the main sources of added fat were olive oil
and a few nuts a day. The diet was rich in vegetables and low in red meat, with
fish and chicken replacing beef and lamb.