Inclusion Criteria:  28<BMI>35 Age: 18-65 Capable of working with a smartphone application  Exclusion Criteria:  Consumption of antibiotics/probiotics/oral antifungals 3 months prior to the first day of the experiment. Pregnancy, fertility treatments, breastfeeding women six months prior to enrollment and during the study. Chronic disease (e.g. AIDS, Cushing syndrome, CKD, acromegaly, hyperthyroidism/hypothyroidism etc.) Cancer and recent anticancer treatment Psychiatric disorders Coagulation disorders IBD (inflammatory bowel diseases) Bariatric surgery Eating disorders (Anorexia nervosa. Bulimia nervosa. Binge eating disorder, Night eating syndrome). Alcohol or substance abuse Weight loss attempts one year prior to the first day of the experiment - independent or with a dietitian.