Comparing Low-Fat, Low-Carb, and Mediterranean Diets continued...
The low-carb diet was based on the Atkins plan. In this group, calories weren't restricted. These participants were told to eat about 20 grams of carbs a day (about the amount in two slices of bread) for two months, and then increase it to no more than 120 grams a day. They focused on vegetarian sources of fat and protein and avoided foods with trans fat.
Study participants were from a workplace in Dimona, Israel, and ate their lunch, typically the big meal of the day in Israel, in the company cafeteria. Cooks at the company made sure the subjects had the food items they needed. Participants were weighed in every month and had other measurements, such as cholesterol and blood sugar taken four times during the two-year study, from 2005 to 2007.
The maximum weight loss occurred during the first six months; then dieters went on maintenance.
Weight Loss Comparisons
Overall, at the end of two years, the low-fat dieters lost an average of 6.5 pounds, while those on the Mediterranean diet lost 10 pounds and those on the low-carb plan lost 10.3.
Women tended to lose more on the Mediterranean diet. At the 24-month mark, women on the low-fat diet averaged a loss of less than a pound, while those on the low-carb plan lost about 5 pounds and those on the Mediterranean more than 13 pounds.
The drop-out rate in the study was much less than in other diet studies, Shai tells WebMD. At one year, less than 5% had dropped out, compared to up to 60% in other studies, she says. At two years, about 15% had dropped out.
Beyond the weight loss differences, the researchers found some additional health benefits with the low-carb and Mediterranean diet. "The low-carb diet improved HDL ["good" cholesterol] the most,'' she says. And in the 36 dieters with diabetes, those on the Mediterranean diet had better blood sugar and insulin measures.
Diet Debate: Which Is Best?
"I'm not saying the low-fat diet is not efficient," Shai tells WebMD. "I don't think we can say there is one diet that fits all."