Metabolic Effects of a Low Carbohydrate Versus a Standard Diet in Morbidly Obese With Prediabetes

Not Applicable

Completed

• Conditions: PreDiabetes; Bariatric Surgery Candidate; Obesity, Morbid
• Interventions: Other: Low carbohydrate diet; Other: Energy-matched standard diet

• Registration Number: NCT03880162
• Lead Sponsor: Insel Gruppe AG, University Hospital Bern

Brief Summary

To investigate the metabolic effects of a low carbohydrate versus energy-matched standard diet in morbidly obese individuals with prediabetes awaiting bariatric surgery.

Detailed Description

The metabolic benefits of calorie restriction in obese people with or without impaired glycaemia are well-established. The impact of diet composition, however, remains poorly understood. Hepatic lipid content strongly correlates with hepatic insulin resistance, which is a key feature of the pre-diabetic state. The investigators hypothesize that a low carbohydrate diet compared to an energy-matched standard diet in morbidly obese patients with prediabetes scheduled for bariatric surgery results in greater reduction in liver fat.

Study Timeline

• Study First Submitted: 2019-03-07
• Study First Submitted QC: 2019-03-15
• Study First Posted: 2019-03-19
• Study Start: 2019-05-13
• Primary Completion: 2024-05-03
• Study Completion: 2024-05-03
• Status Verified: 2024-12
• Last Update Submitted: 2024-12-04
• Last Update Posted: 2024-12-09

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 20

Inclusion Criteria

• Female and male subjects aged 18 years or older
• BMI >35 kg/m2 awaiting bariatric surgery
• Pre-diabetes according to American Diabetes Association criteria (HbA1c 5.7%-6.4%)
• Capacity to give informed consent and adhere to study procedures

Exclusion Criteria

• Excess alcohol consumption (> 3 units/day for men, > 2 units/day for women)
• Moderate to severe kidney disease
• Nephrolithiasis
• Pregnancy/breastfeeding
• Current participation in another clinical trial
• Claustrophobia
• MRI-contraindications (pacemaker/defibrillator, neurostimulator, drug pump, cochlear implant, heart valve/vascular clips, shunt valve)

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Study intervention	Low carbohydrate diet	Participants will follow an energy deficient (30% deficit) low carbohydrate diet (10% of carbohydrates) for minimum two weeks.
Control intervention	Energy-matched standard diet	Participants will follow an energy deficient (30% deficit) standard diet (50% of carbohydrates) for minimum two weeks.

Primary Outcome Measures

Name	Time	Method
Change from baseline in intrahepatic triglyceride content	2 weeks	The intrahepatic triglyceride content will be evaluated by magnetic resonance spectroscopy

Secondary Outcome Measures

Name	Time	Method
Change from baseline in liver size	2 weeks	The liver size will be evaluated by magnetic resonance imaging
Change from baseline in whole body fat mass	2 weeks	Fat mass will be evaluated by bioimpedance
Change from baseline in body weight	2 weeks	The body weight will be measured using a pre-defined person scale
Change from baseline in insulin secretion	2 weeks	The insulin secretion will be evaluated during an oral glucose tolerance test using the oral minimal model
Change from baseline in visceral adipose tissue	2 weeks	The adipose tissue content will be evaluated by magnetic resonance imaging
Change from baseline in insulin sensitivity	2 weeks	The insulin sensitivity will be evaluated during an oral glucose tolerance test using the oral minimal model

Trial Locations

Locations (1)

Division of Endocrinology, Diabetes and Clinical Nutrition, Bern University Hospital; 🇨🇭 Bern, Switzerland