Endocrine Abstracts

Introduction: Metabolic surgery is the most effective long-term treatment for obesity. However, studies reveal that up to 40% of post-bariatric subjects experience long-term weight regain (WR), particularly those who discontinue surgical and nutritional follow-ups. In contrast, the ketogenic diet emerges as a pivotal therapy for obesity, showing convincing evidence in weight loss and improvement of weight-related complications.

Purpose: This study aims to evaluate the safety and efficacy of a very-low calorie ketogenic diet (VLCKD) in the treatment of post-bariatric WR.

Materials and Methods: This prospective, single-center pilot study involved patients with previous metabolic surgery (RYGB or Sleeve gastrectomy) who had clinically significant WR after successful initial weight loss. Inclusion criteria included age between 18 and 65 years, a BMI ≥30 kg/m², while exclusion criteria included pregnancy/lactation, type 1 diabetes mellitus, renal and hepatic disease, alcoholism, and major psychiatric disorders. The primary outcome was weight loss, while secondary outcomes focused on safety, improvements in metabolic profile, and body composition. All participants followed an 8-week nutritional intervention with VLCKD, limiting their carbohydrate intake to less than 50 g/day and with adequate protein intake at 1.2-1.5 g/kg of ideal body weight. Dietary counseling was provided every 4 weeks by an experienced dietitian, and compliance was assessed by dietary recalls and beta hydroxybutyrate measurements. Patients underwent biochemical and body composition assessment by DXA scan at baseline and after dietary intervention.

Results: Fifteen patients were enrolled (10 females, 5 males) with a mean age of 49±11 years and a mean BMI of 40.27±6.59 kg/m². After 8 weeks, patients showed an average weight loss of 7.2%, a significant reduction in waist circumference (P<0.001), hip circumference (P=0.007) and improvement in body composition indices: reduction in fat mass (P<0.001) and lean mass to fat mass ratio (P=0.03). Favorable changes in glyco-metabolic balance were reported with a significant reduction in LDL cholesterol levels (P=0.03). Safety parameters (renal function, uric acid, electrolytes) remained stable; the only adverse event reported was mild constipation.

Conclusions: This study emphasizes the efficacy of the VLCKD in the management of post-bariatric WR, demonstrating satisfactory weight loss and improved body composition without safety concerns. However, long-term weight loss maintenance remains uncertain without significant changes in lifestyle or pharmacotherapy. Further studies should explore the efficacy of dieting, including different weight loss scenarios and emphasizing maintenance strategies.