Inclusion and exclusion criteria:
Only randomised controlled trials (RCT) were eligible for this review. The eligibility criteria of the study participants involved obese subjects (BMI ≥ 30), adults (18-69 years of age), metabolically healthy participants (no co-morbid diseases such as diabetes or insulin resistance), non-smokers. The diet intervention eligibility criteria were based on hypocaloric (at least Basal Metabolic Rate (BMR)-250 kcal/day), high-protein diets (at least 25% of diet comes from proteins). High-protein diets with a sole focus on plant-proteins, intermittent-fasting and studies shorter than 4 weeks were excluded. Finally, the control diets had to be hypocaloric, and less than 25% of diet macronutrient composed of protein, if there were no control diets in the RCT, the study would still be included in the systematic review.