Dietary Treatment for Post Bariatric Weight Regain

Study Overview
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Brief Summary
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Metabolic surgery has, among all obesity treatments, the best long term efficacy, but weight regain (weight regain, WR) or insufficient weight loss (IWL) are relatively common. These are hard to treat, with dietary treatment often failing, and redo surgery being commonly proposed.The ketogenic diet is vastly utilised to obtain weight loss in obesity, but little data is available regarding its application on post bariatric patients. Ad hoc designed studies are needed to confirm the efficacy and safety of a VLCKD in the treatment of WR and IWL. The aim of this study is to test whether the ketogenic diet is a safe and effective treatment in post bariatric weight regain, compared to its application before bariatric surgery.

Detailed Description
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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.

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

Conditions
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Obesity

Intervention / Treatment
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* Behavioral: ketogenic diet


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: -obesity (BMI ≥ 30 Kg/m2) Exclusion Criteria: Type 1 diabetes mellitus Renal failure (GFR<60) Liver failure (decompensated cirrhosis) Congenital metabolic diseases Pregnancy lactation Major psychiatric disorder Alcoholism drug addiction patients who are not self-sufficient and without adequate family and social support

Ages Eligible for Study
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Minimum Age: 18 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Bariatric naive<br>patients with obesity who have not undergone bariatric surgery in the past | Behavioral: ketogenic diet<br>* a low calorie ketogenic diet<br>|
| Post Bariatric<br>patients with obesity who have undergone bariatric surgery in the past and have experienced weight regain or insufficient weight loss | Behavioral: ketogenic diet<br>* a low calorie ketogenic diet<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| weight change | body mass change (kg) within and between groups | at baseline and right after the dietary intervention (8 weeks) | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| body fat change | body fat change (kg) within and between groups | at baseline and right after the dietary intervention (8 weeks) | 
| muscle mass change | lean mass change (kg) within and between groups | at baseline and right after the dietary intervention (8 weeks) | 
| waist circumference change | waist circumference change (cm) within and between groups | at baseline and right after the dietary intervention (8 weeks) | 
| mean blood pressure change | mean blood pressure change (mmHg) within and between groups | at baseline and right after the dietary intervention (8 weeks) | 
| glucose concentration change | glucose change (mg/dL) within and between groups | at baseline and right after the dietary intervention (8 weeks) | 
| insulin concentration change | insulin change (UI/mL) within and between groups | at baseline and right after the dietary intervention (8 weeks) | 
| uric acid concentration change | uric acid change (mg/dL) within and between groups | at baseline and right after the dietary intervention (8 weeks) | 
| creatinine concentration change | creatinine change (mg/dL) within and between groups | at baseline and right after the dietary intervention (8 weeks) | 
| cholesterol concentration change | cholesterol change (mg/dL) within and between groups | at baseline and right after the dietary intervention (8 weeks) | 
| triglycerides concentration change | triglycerides change (mg/dL) within and between groups | at baseline and right after the dietary intervention (8 weeks) |