14 DAY TRIAL // Less candies won't make you look like Kate Moss.
Less food would better do ...
Or at least less caloric ...
A new complex research at the Jean Mayer US Department of Agriculture Human Nutrition Research Center on Aging (USDA HNRCA) at Tufts University discovered that calorie-restricted diets varying substantially in glycemic level can lead to similar long-term weight loss results.
The research assessed factors that affect hunger and satiety, employed laboratory techniques to determine adherence, and was the first to provide a complete set of diets to the subjects.
"Participants in our pilot study achieved and maintained comparable weight loss after one year, regardless of whether they were on a low-glycemic-load or a high-glycemic-load diet," said Dr Susan Roberts, director of the USDA HNRCA's Energy Metabolism Laboratory and professor at the Friedman School of Nutrition Science and Policy at Tufts.
"The goal was for both groups to restrict calories by 30 % and, after one year, both groups had lost an average of 8 % of their original body weight. We found that the two groups did not differ significantly in their average body fat loss, energy intake, metabolic rate, or reports of hunger and satiety. Because there was careful attention to factors that influence hunger and satiety, like palatability, dietary variety, and fiber, participants were generally satisfied on a calorie-restricted diet," said Roberts.
34 overweight but healthy men and women were included randomly to a low-glycemic-load (LG) or high-glycemic-load (HG) diet.
After six months, the LG group had lost an average of 10.4 % body weight, while the value for the HG group was 9 %, while after 12 months, both the LG and HG groups had lost about 8 % of their initial body weight. "Unlike several other long-term studies, which have reported greater weight loss with low GL diets at six months but no differences by 12 months, our data show no significant short-term or long-term differences," signaled lead researcher Dr Sai Das, scientist at the USDA HNRCA.
"However, we did detect a greater tendency for weight and body-fat regain among LG participants. This finding suggests that reduced calorie intake may be harder to sustain on LG diets over time."
The LG diet was made of 40 % carbohydrates (sugars), 30 % fat, and 30 % protein; while HG diet consisted of 60 % carbohydrate, 20 % fat, and 20 % protein.
The glycemic load of an aliment measures approximately the carbohydrate level in the food and how quickly that type of carbohydrate is digested and enters the blood stream.
LG aliments are e.g., bean and barley stew, low-fat cottage cheese, and pumpernickel bread while bagels, candied sweet potatoes and shepherd's pie with mashed potatoes are HG foods.
The diets of both types decreased the caloric income by 30 %, but provided the recommended levels of vitamins, minerals, and essential fatty acids. All subjects attended weekly behavioral support groups and had a dietitian.
The scientists employed doubly labeled water technique to assess the actual dietary intakes. Both groups were found to ingest more calories than required by the study; at six months the HG group actually ate 16 % less calories and the LG group 17 % less calories.
But the level of non-adherence did not vary significantly between the LG and HG groups. "An important difference between our study and other weight-loss trials is that we did not rely on self-reported intakes," said Das, an assistant professor at the Friedman School. "Underreporting of caloric intake can vary between 5 and 50 %. By providing the study food for the first six months, we did not have to worry as much about lifestyle factors like shopping and cooking habits interfering with dietary change."
Roberts had made a research revealing that a diet's overall glycemic load can influence the weight loss for people with high insulin levels, like diabetes patients. "We have observed that for some groups, glycemic load may impact weight loss. However, in terms of calorie-restricted diets, we see little difference among diets of varying glycemic load when we account for factors that affect dietary adherence."