Postprandial Nutrient Homeostasis Before and After Weight Loss Induced by Low-calorie Diet or RYGB

Purpose

The purpose of this study is to compare the metabolic responses to low-carbohydrate and standard-carbohydrate meals in African Americans and non-Hispanic White adults with obesity and the effect of weight loss induced by low-calorie diet (LCD) or Roux-en-Y gastric bypass (RYGB) on the metabolic responses to low-carbohydrate and standard meals. Participants will consume: 1) a standard-carbohydrate meal (~49 g glucose) and 2) a low-carbohydrate (~3.4 g glucose) meal on separate study visits performed in a randomized order. We will evaluate the meals' effect before and after ~16-18% weight loss on postprandial i) insulin kinetics, ii) glucose kinetics iii) β-cell function; iv) plasma triglyceride and non-esterified fatty acid concentrations; v) plasma hormone concentrations; vi) plasma cytokine concentrations; vi) plasma metabolomics; and vii) adipose tissue transcriptomics.

Condition

  • Obesity

Eligibility

Eligible Ages
Between 25 Years and 65 Years
Eligible Sex
All
Accepts Healthy Volunteers
Yes

Inclusion Criteria

Surgery Group (RYGB): - Males and Females - Scheduled for RYGB surgery - Body Mass Index 35-60 kg/m² - Without Type 2 Diabetes (T2D) LCD group: - Males and Females - Body Mass Index 35-60 kg/m² - Without Type 2 Diabetes (T2D)

Exclusion Criteria

  • Regular use of tobacco products - Previous intestinal resection - Pregnant or breastfeeding - Evidence of significant organ system dysfunction or disease other than obesity and T2D - Use of any medication that might, in the opinion of the investigator, affect metabolic function - Exercise ≥90 minutes per week - Use or past use of hormone replacement therapy within the past 6 months

Study Design

Phase
N/A
Study Type
Interventional
Allocation
Non-Randomized
Intervention Model
Parallel Assignment
Primary Purpose
Other
Masking
None (Open Label)

Arm Groups

ArmDescriptionAssigned Intervention
Experimental
RYGB group
Subjects in this group are scheduled to undergo Roux-en-Y gastric bypass surgery and will be assessed after ~16-18% weight-loss
  • Procedure: Roux-en-Y gastric bypass surgery
    Roux-en-Y gastric bypass surgery will be performed with post-weight loss testing performed after ~16-18% weight loss is achieved.
Active Comparator
LCD Group
Subjects in this group will participate in a low-calorie diet intervention to achieve ~16-18% weight loss.
  • Behavioral: Low-calorie diet
    Subjects will meet with a dietitian and/or behaviorist over 4-6 months to lose ~16-18% of their body weight.

Recruiting Locations

Washington University in St. Louis and nearby locations

Beth Henk
St Louis, Missouri 63110
Contact:
Beth Henk
314-362-8250
bhenk@wustl.edu

More Details

NCT ID
NCT03091725
Status
Recruiting
Sponsor
Washington University School of Medicine

Study Contact

Beth Henk
314-362-8250
bhenk@wustl.edu