Image

NUTritional Impact of a Hypocaloric Hyperprotein Diet Before Obesity Surgery

NUTritional Impact of a Hypocaloric Hyperprotein Diet Before Obesity Surgery

Recruiting
18-65 years
All
Phase N/A

Powered by AI

Overview

Obesity is a major public health problem and is constantly on the rise. Therapeutic approaches based on dietary advice, physical activity and the management of psychological difficulties are not always sufficient to achieve a lasting weight reduction.

Bariatric surgery (or obesity surgery), accompanied by therapeutic education and adequate medical and dietary monitoring, can lead to significant and lasting weight loss. It is indicated as a second-line treatment for patients who have failed medical treatment, whose BMI is greater than or equal to 40 or whose BMI is greater than or equal to 35 with comorbidities (type 2 diabetes, arterial hypertension, obstructive sleep apnoea-hypopnoea syndrome, severe joint disorders).

The surgeon may be very bothered by the intra-abdominal fat mass and especially by steatotic hepatomegaly (increase in the size of the liver and its fat load).

Faced with this problem, various preoperative strategies such as the placement of an intra gastric balloon have been tried to decrease the size of the liver but a systematic review from 2016 indicates that a low calorie diet is preferable. Preoperative weight loss can reduce fat load and liver volume very rapidly. This meta-analysis shows that all low-calorie, high-protein diets are effective and that the optimal duration (4 weeks), compliance and tolerance are important factors for success.

Description

Obesity is a major public health problem and is constantly on the rise. Therapeutic approaches based on dietary advice, physical activity and the management of psychological difficulties are not always sufficient to achieve a lasting weight reduction.

Bariatric surgery (or obesity surgery), accompanied by therapeutic education and adequate medical and dietary monitoring, can lead to significant and lasting weight loss. It is indicated as a second-line treatment for patients who have failed medical treatment, whose BMI is greater than or equal to 40 or whose BMI is greater than or equal to 35 with comorbidities (type 2 diabetes, arterial hypertension, obstructive sleep apnoea-hypopnoea syndrome, severe joint disorders).

The surgeon may be very bothered by the intra-abdominal fat mass and especially by steatotic hepatomegaly (increase in the size of the liver and its fat load).

Faced with this problem, various preoperative strategies such as the placement of an intra gastric balloon have been tried to decrease the size of the liver but a systematic review from 2016 indicates that a low calorie diet is preferable. Preoperative weight loss can reduce fat load and liver volume very rapidly. This meta-analysis shows that all low-calorie, high-protein diets are effective and that the optimal duration (4 weeks), compliance and tolerance are important factors for success.

However, there is no consensus on the benefit/risk balance of a preoperative diet and there is considerable variability in approach at national and international level.

The present clinical study involves a triad of dietician, surgeon, physician (endocrinologist/nutritionist or internist) to secure this diet. It could provide a database to help estimate the risk of undernutrition in the obese subject.

This diet, designed to facilitate the surgical procedure and potentially reduce intraoperative complications, is inexpensive, easily accessible and reproducible by other teams. This innovative management could standardise the preoperative management of patients undergoing bariatric surgery at national level. It would also improve the results of bariatric surgery both in the short term by reducing complications and in the long term by increasing weight reduction as reported in the Livhits meta-analysis. The risk of undernutrition should be reduced by this hypocaloric hyperprotein diet and consequently cancel out the increased risk of mortality, infections, delayed healing, longer hospital stay and the costs that this would entail.

Eligibility

Inclusion Criteria:

  • Patient eligible for bariatric surgery (according to HAS criteria) whose sleeve gastrectomy is scheduled
  • Patient with morbid obesity (BMI ≥ 40)
  • Age ≥ 18 years and ≤ 65 years
  • Haemoglobinemia ≥ 12 g/dL in men and ≥ 11 g/dL in women
  • Patient speaking and understanding French
  • Adult having read and understood the information letter and signed the consent form
  • Woman of childbearing age with effective / very effective contraception (Cf. CTFG) (estrogen-progestin or intrauterine device or tubal ligation) prior to surgery and a negative -HCG blood pregnancy test at inclusion, for the duration of the study
  • Postmenopausal woman: confirmatory diagnosis (non-medically induced amenorrhoea for at least 12 months prior to the inclusion visit)
  • Patient affiliated with, or beneficiary of a social security (health insurance) category

Exclusion Criteria:

  • Contraindication to bariatric surgery detected during the preoperative assessment
  • Medical contraindication to a restrictive diet
  • Type I or II insulin-requiring diabetes
  • Severe renal insufficiency defined by a blood filtration rate < 30 mL/min
  • Person wearing a pacemaker or any other implant with the same functions (cochlear implant, bladder battery, etc.)
  • Person deprived of liberty by an administrative or judicial decision or person placed under judicial protection / sub-guardianship or curatorship
  • A history of illness or psychological or sensory abnormality likely to prevent the subject from fully understanding the conditions required for participation in the protocol or to prevent him/her from giving informed consent

Study details
    Diet
    Healthy
    Obesity
    Visceral
    Bariatric Surgery Candidate

NCT04942093

University Hospital, Rouen

15 October 2025

Step 1 Get in touch with the nearest study center
We have submitted the contact information you provided to the research team at {{SITE_NAME}}. A copy of the message has been sent to your email for your records.
Would you like to be notified about other trials? Sign up for Patient Notification Services.
Sign up

Send a message

Enter your contact details to connect with study team

Investigator Avatar

Primary Contact

  Other languages supported:

First name*
Last name*
Email*
Phone number*
Other language

FAQs

Learn more about clinical trials

What is a clinical trial?

A clinical trial is a study designed to test specific interventions or treatments' effectiveness and safety, paving the way for new, innovative healthcare solutions.

Why should I take part in a clinical trial?

Participating in a clinical trial provides early access to potentially effective treatments and directly contributes to the healthcare advancements that benefit us all.

How long does a clinical trial take place?

The duration of clinical trials varies. Some trials last weeks, some years, depending on the phase and intention of the trial.

Do I get compensated for taking part in clinical trials?

Compensation varies per trial. Some offer payment or reimbursement for time and travel, while others may not.

How safe are clinical trials?

Clinical trials follow strict ethical guidelines and protocols to safeguard participants' health. They are closely monitored and safety reviewed regularly.
Add a private note
  • abc Select a piece of text.
  • Add notes visible only to you.
  • Send it to people through a passcode protected link.