All participants followed a very-low-calorie ketogenic diet according to a commercial weight loss program (Pronokal method), which includes lifestyle and behavioural modification support. This method is based on high-biological-value protein preparations which contained 15 g protein, 4 g carbohydrates, 3 g fat and 50 mg docosahexaenoic acid, and provided 90-110 kcal. The study was divided in two phases. The first phase consists of a very-low-calorie ketogenic diet (600-800 kcal/day), low in carbohydrates and lipids. Throughout this ketogenic phase, supplements of vitamins and minerals such as K, Na, Mg, Ca and omega-3 fatty acids were provided. In this study the ketogenic step was maintained for 2 months. Then, the patients started a low-calorie diet (800-1500 kcal/day) which lasted two months.
During the first phase consisting of a very-low-calorie ketogenic diet, subjects were randomly divided into two groups, the treatment group who received synbiotic supplementation as capsules, a complex of B. lactis, Lactobacillus rhamnosus, B. longum ES1 and prebiotics fiber (synbiotic 1) and the control group who received a placebo. During the second phase consisting of a low-calorie diet, the treatment group received synbiotic supplementation as capsules consisting of B. animalis subsp. lactis and prebiotics fiber (synbiotic 2) (synbiotic1 + synbiotic 2 group), while the control group was divided into two groups: one continued receiving a placebo (control group) whilst the other group received synbiotic 2 (placebo + synbiotic2 group).
