Showdown at the ok corral: low-fat vs. low-carb diet plans
by Leyla Muedin, RD
"Effects of variation in protein and carbohydrate intake on body mass and composition during energy restriction: a meta-regression" - Am J Clin Nutr. 2006; 83: 260-74.
Low-carbohydrate, high-protein (LC-HP) diets have finally been vindicated as scientific research clearly underscores their benefits in weight loss.
It is already known and accepted that a low-carbohydrate, high-protein diet is useful in weight loss and blood sugar stabilization. Other advantages include a significant reduction in serum triglycerides, improved cholesterol ratios, and increased satiation (the "full" feeling that tells us we're finished with our meal) and post-meal satiety (feeling satisfied until the next meal).
This breaking study in the American Journal of Clinical Nutrition goes further to determine the effects of a LC-HP diet on body composition. In other words, on such an eating plan, are we losing muscle or fat?
The study clearly shows that a LC-HP diet is protein-sparing. After four weeks on a 1,000-calorie diet, those participants on the LC-HP diet (less than 35-41% carbohydrate) showed a 4.5 pounds greater loss of fat mass, a 1.29% greater loss of body fat, and an overall weight loss of 3.8 pounds more than on a higher carbohydrate diet. After 12 weeks, these differences increased to a 12 pounds greater loss of fat mass, a 3.6% greater loss of body fat, and an overall weight loss of 14.5 pounds more than on a higher carbohydrate diet. That means we preserve more lean muscle mass and lose more body fat as compared with a low-fat, high-carbohydrate diet. In addition, higher protein intakes resulted in 2.6 pounds greater retention of lean body mass vs. a standard moderate protein diet. This may explain why LC-HP dieters experience improved observable changes in body shape.
With all the scientific evidence now underscoring the metabolic advantages of a LC-HP diet, the time has come to make this approach a mainstay in weight loss and maintenance.