ARE ALL CALORIES EQUAL? HOW TO SLIM AVOIDING WEIGHT RE-GAIN

With 62% of women admitting in a recent British survey (Daily Mail) that they plan to slim down for the festive season, November has been earmarked as the time to start in order to safely drop a dress size. So let's see how scientific reaserch can help us getting fit choosing the right diet plan...

Reducing refined carbs may help maintain weight loss better than reducing fat.
 
A new study recently published in the Journal of the American Medical Association (JAMA) challenges the notion that “a calorie is a calorie.”

The study finds diets that reduce the surge in blood sugar after a meal — either low-glycemic index or very-low carbohydrate — may be preferable to a low-fat diet for those trying to achieve lasting weight loss.
Furthermore, the study finds that the low-glycemic diet had similar metabolic benefits to the very low-carb diet without negative effects of stress and inflammation as seen by participants consuming the very low-carb diet.

Weight re-gain is often attributed to a decline in motivation or adherence to diet and exercise, but biology also plays an important role. After weight loss, the rate at which people burn calories (known as energy expenditure) decreases, reflecting slower metabolism. Lower energy expenditure adds to the difficulty of weight maintenance and helps explain why people tend to re-gain lost weight.

The study suggests that a low-glycemic load diet is more effective than conventional approaches at burning calories (and keeping energy expenditure) at a higher rate after weight loss.
“We’ve found that, contrary to nutritional dogma, all calories are not created equal,” says Professor Ludwig, who led the study and is the director of the Optimal Weight for Life Clinic at Boston Children’s Hospital.

“Total calories burned plummeted by 300 calories on the low-fat diet compared to the low-carbohydrate diet, which would equal the number of calories typically burned in an hour of moderate-intensity physical activity,” he says. Each of the study’s 21 adult participants (ages 18-40) first had to lose 10 to 15 percent of their body weight, and after weight stabilization, completed all three of the following diets in random order, each for four weeks at a time.

Results

- The very-low carbohydrate diet produced the greatest improvements in metabolism but with an important warning: this diet increased partecipants' cortisol levels, which can led to insulin resistance and cardiovascular disease. The very-low carbohydrate diet also raised C-reactive protein levels, which may also increase risk of cardiovascular disease.
 - Though a low-fat diet is traditionally recommended by the U.S. government and American Heart Association, it caused the greatest decrease in energy expenditure, an unhealthy lipid pattern, and insulin resistance.

“In addition to the benefits noted in this study, we believe that low-glycemic diets are easier to stick to on a day-to-day basis, compared to low-carb and low-fat diets, which many people find limiting,” says Assistant Professor Cara Ebbeling (who led the study with Professor Ludwig). “Unlike low-fat and very-low-carbohydrate diets, a low-glycemic-load diet doesn’t eliminate entire classes of food, likely making it easier to follow and more sustainable.”

DON'T MISS TOMORROW'S ARTICLE IN WHICH YOU'LL BE INFORMED ABOUT 

THE LOW-GLYCEMIC DIET

Sources:Journal of the American Medical Association; Boston Childrens Hospital
              Harvard Gazette by Andrea Mooney, Boston Children’s Hospital Communications