Dietary Treatment for Post Bariatric Weight Regain:Evaluation of the Efficacy of a KD

Metabolic surgery is, to date, the strategy for the treatment of obesity with the greatest long-term efficacy. However, especially in those lost to surgical and nutritional follow-up, weight regain (weight regain, WR) or insufficient weight loss (IWL) are relatively common. In particular, depending on the type of surgery considered, it has been observed that up to 40% of subjects undergoing surgery report a WR long term, where data on IWL are still insufficient to draw well-defined estimates. WR and IWL are hard to treat, with dietary treatment often failing, and redo surgery being commonly proposed, with increased risk of complications and little effect.

The ketogenic diet is one of the pivotal dietary therapies for the treatment of obesity, with excellent evidence in terms of weight loss and improvement in complications of excess weight. Very little data is available regarding its application on post bariatric patients: Correa and colleagues reported in a retrospective case series the efficacy and safety of a very low calorie ketogenic diet (VLCKD) in 11 patients with IWL or WR after gastric bypass, reporting a good safety profile, good tolerability, and an average weight loss of 9 kg in 2 months of therapy. Although promising, the data in the literature are extremely scarce, and therefore ad hoc designed studies are needed to confirm the efficacy and safety of a VLCKD in the treatment of WR and IWL.

The objective of this study is to test whether the application of a ketogenic diet is a safe and effective treatment in post bariatric weight regain, compared to its application before bariatric surgery.