Ketogenic Diet Prior to Bariatric Surgery

NCT06850493 | Recruiting DMC

• 1 other identifier: NL81550.015.22
• Study Type: interventional
• Target: 46
• Locations: 1 country
• Sites: 1

Brief Summary

Standard dietary regiments for bariatric are advised prior to surgery. The most used diet is a very low calorie diet (VLCD). These diets potentially have multiple pittfalls. Very low-calorie ketogenic diets (VLCKD) have been proposed as a new regimen for achieving weight- and liver volume loss in patients undergoing bariatric surgery. The beneficial effect of VLCKDs compared to (V)LCDs is the aimed preservation of FFM and RMR, while still reducing FM. Only a few small studies addressed the role of VLCKDs prior to bariatric surgery, and the data including FFM and FM is actually scarce. Therefore, a well-designed randomised controlled trial is necessary to establish the efficacy of a VLCKD.

Conditions

Bariatric Surgery Candidate; Ketogenic Dieting

Outcome Measures

Primary Outcomes (1)

• Change in FFM (%) in proportion to TBWL

  The main outcomes are the change in FFM (percentage) in proportion to total body weight loss (TBWL) measured from baseline to two weeks after start of the diet.

  2 weeks prior to surgery, day of surgery and 3 months after surgery

Secondary Outcomes (29)

• Change in weight

  2 weeks prior to surgery, day of surgery and 3 months after surgery

• Physical activity questionnaire

  2 weeks prior to surgery, day of surgery and 3 months after surgery

• Patient satisfaction assessed by a questionnaire

  2 weeks prior to surgery, day of surgery and 3 months after surgery

• Incidence of side effects, assesed by questionnaire

  2 weeks prior to surgery, day of surgery and 3 months after surgery

• Compliance assesed by return of diet sachets

  2 weeks prior to surgery till the day of surgery

Study Arms (2)

VLCD (Very-Low-Calorie-Diet)

ACTIVE COMPARATOR

Patients in the VLCD group receive, as prescribed by a dietician, three meal sachets a day. Each meal contains ±240kcal (=1004 kJ), 17-20g carbohydrates and 14-17g proteins. Altogether, this diet contains less than 800 kcal/day, 50-60g carbohydrates per day and 42-51g protein per day. The diet is continued for 14 days, until the day prior to surgery. In addition to using liquid meals, patients are allowed to consume raw vegetables (e.g., endive, spinach, cucumber, lettuce; without oil or dressings), and clear soups. Patients are advised to drink at least two liters per day of mineral water, tea, infusions or coffee without milk and/or sugar.

Dietary Supplement: VLCD (Very-low-calorie-diet)

VLCKD (Very-Low-Calorie-Ketogenic-Diet)

ACTIVE COMPARATOR

Six meal sachets are given to patients in the VLCKD group each day. A single meal has 16-19g of proteins, 2-3g of carbohydrates, and ±86kcal (=363 kJ). Together, the daily energy intake from this diet is less than 800 kcal, 50 g of carbohydrates, and 100 g of proteins. The diet is followed up to the day before surgery for a total of 14 days. Patients are recommended to ingest vegetables with a low glycaemic load (such as sprouts, lettuce, spinach, and tomatoes) in addition to the liquid meals. Patients are encouraged to consume at least two liters of mineral water, tea, infusions, or coffee without milk or sugar each day.

Dietary Supplement: VLCKD (ketogenic diet)

Interventions

VLCKD (ketogenic diet) DIETARY_SUPPLEMENT

diets prior to bariatric surgery

Also known as: VLCKD

VLCKD (Very-Low-Calorie-Ketogenic-Diet)

VLCD (Very-low-calorie-diet) DIETARY_SUPPLEMENT

diets prior to bariatric surgery

Also known as: VLCD

VLCD (Very-Low-Calorie-Diet)

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Eligible for bariatric surgery (≥35 kg/m2 with obesity-related comorbidities, or a BMI of
• kg/m2 with or without comorbidities)
• Roux-en-Y Gastric bypass (RYGB)

You may not qualify if:

• Weighing over 150kg because this amount is a limitation by the DXA device
• Diabetes mellitus type 1
• Allergic to milk proteins
• A recent history of a heart attack (\< 12 months), heart failure or cardiac arrhythmias
• Kidney and/or liver failure (creatinine levels \>1.3 mg/dl or liver enzyme levels (AST, ALT, GGT)) less than three times over the upper normal threshold
• Current infectious, sepsis or malignant disease
• Rare condition like galactosemia, phenylketonuria or porphyria
• Persistent diarrhoea
• Hypokalaemia, chronic therapies with diuretics as furosemide and hydrochlorothiazide
• Pregnancy or plans to get pregnant in the coming months
• Patients who did not meet criteria to be eligible for bariatric surgery (BMI \<35, psychological or unstable psychiatric disorders, inadequate dietary regimen or inadequate exercise pattern which can't be resolved in the upcoming 6 months)

Sponsors & Collaborators

• Maxima Medical Center: lead

Study Sites (1)

Maxima Medical Center

Veldhoven, North Brabant, 5500MB, Netherlands

RECRUITING

MeSH Terms

Interventions

Diet, Ketogenic

Intervention Hierarchy (Ancestors)

Diet, Carbohydrate-Restricted; Diet Therapy; Nutrition Therapy; Therapeutics; Diet; Nutritional Physiological Phenomena; Diet, Food, and Nutrition; Physiological Phenomena

Study Officials

• Francois van Dielen, MD PhD

  Maxima Medical Center

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Aliyar Esfandiyari Noushi, MD

CONTACT

+31408888550; aliyar.esfandiyarinoushi@mmc.nl

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: SUPPORTIVE CARE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Doctor of Medicine

Study Record Dates

• First Submitted: July 30, 2024
• First Posted: February 27, 2025
• Study Start: September 1, 2022
• Primary Completion: September 1, 2025
• Study Completion: December 1, 2025
• Last Updated: February 27, 2025

Record last verified: 2025-01

Data Sharing

• IPD Sharing: Will not share

Locations

NL (1)