FOS and obesity due to melanocortin 4 receptor deficiency: Noteworthy, the quality of evidence supporting the application of inulin for weight loss is low, considering that most of the analyzed studies are heterogeneous in terms of interventions (inulin and FOS dosages and method of administration, hypocaloric or ad libitum diets), study population (normal weight, patients with obesity or T2D), trial duration, and outcomes analyzed, which may hinder the strength of the results.