October 12, 2012
Researchers Find Long-term Benefits From Healthy Dieting Practices
Brett Smith for redOrbit.com - Your Universe Online
Dieting can be a long, slow process that can seem hopeless and pointless at times, but a new study from Israeli researchers suggests that certain diets can have long-lasting health benefits even with a partial weight gain.According to their peer-reviewed letter in the New England Journal of Medicine, the scientists discovered the benefits during a follow-up examination meant to update their 24-month dietary intervention study of moderately obese individuals from four years previous. That study, the workplace-based Dietary Intervention Randomized Controlled Trial (DIRECT), guided participants to one of three weight-loss plans: “a low-fat, restricted-calorie diet; a Mediterranean, restricted-calorie diet; or a low-carbohydrate diet without calorie restriction.”
"Our follow-up subsequent data shows lasting, positive effects of Mediterranean and low-carbohydrate diets six years later,” said Dan Schwarzfuchs from the Nuclear Research Center Negev in Dimona, Israel.
The results from their follow-up exams indicate that the lipid profile (lower cholesterol, triglycerides and arteriosclerosis) improved for the long term, despite weight gain in some participants. The study showed that the diets conveyed benefits beyond the dietary period.
"Data from trials comparing the effectiveness of weight-loss diets are frequently limited to the intervention period," explained Ben-Gurion University of the Negev professor Iris Shai.
Many exams showed a six-year weight loss that was significantly lower from the baseline metric for those participants that followed the Mediterranean and low-carbohydrate diets. The low-fat dieters show only a slight weight loss.
Four years after the intervention, more than 67 percent of the DIRECT participants had maintained their original assigned diet, 11 percent had switched diets and 22 percent were not dieting at all.
The six-year exams showed the HDL/LDL ratio remained significantly lower only in the low-carbohydrate diet, while triglyceride levels remained significantly lower in the Mediterranean and low-carbohydrate diets. All three diet groups showed total cholesterol levels that remained persistently and significantly lower.
During the diet intervention, 322 moderately obese subjects were randomly assigned to a diet and were given specific color-labeled food in their workplace cafeteria. The adherence rate after two years was 85 percent and, at the time, physical exams suggested significant benefits to low-carbohydrate and Mediterranean diets.
After two of the interventions, the average weight loss was 6.4 pounds in the low-fat group, about 10 pounds in the Mediterranean group and 10.3 in the low-carbohydrate group.
In an interview with Toronto-based paper The Star, Schwarzfuchs said sticking to a diet was probably the most important factor in reaping its extended benefits.
“When a person needs to change their life habits, adherence to the complete strategy and stability are key factors,” he said. “I try to tailor the dietary strategy to their personal preferences and metabolic needs.”
The Mediterranean diet is based on the dietary patterns of Portugal, Spain, Greece, and Italy, yet it is somewhat of a misnomer as it is not typical of all Mediterranean cuisine. Key elements of the diet include fish, vegetables, fruits, whole grains, and poultry. Followers of this diet are also advised to exercise regularly and reducing their salt intake.