Effect of a Low-carbohydrate, High-protein Energy-restricted Diet on Weight and Body Composition Using DXA

The high protein diet (HPD) group is instructed to follow a low carbohydrate, high protein ketogenic diet. This diet has 4 phases, two of weight loss until reaching the ideal weight (attack and cruise) and two of maintenance (consolidation and stabilization). During the first 2 phases, it allows 100 foods (28 vegetables). The first phase lasts 3-10 days and 72 high-protein, low-fat foods are allowed. In the second phase, there are alternate days between consuming the low glycemic index vegetables plus protein and the next day with just protein. The first two phases are ad libitum. Phase 3 (consolidation) aims to avoid rebound and begins the introduction of complex carbohydrates and legumes in individual servings. In phase 4 (stabilization), the subject returns to a free diet. However, three basic rules are introduced: protein one day a week, the exercise of at least 20 min/day (optional) and consumption of 3 tablespoons of oat bran/day.

No high protein diet (NHPD) group received an oat beverage consisted of 55 g of oats in 250 ml of water. Beverage contained 1.6 g of betaG per portion according to FDA recommendations corresponding to 50 % of betaG required per day. Weekly bags containing oat mixture were provided on day 0 and in the third week of the trial. No additional instructions about diet, exercise program or pharmacological treatment was implemented.