Acute Metabolic Effects of Carbohydrate Restriction at Varying Energy Levels

Investigation Into the Postprandial Effects of Varying Calorie Content of Low-Carbohydrate Diets on Human Metabolic Health

This study investigates how different low-carbohydrate diets affect metabolism and hunger in overweight adults. We will measure metabolic rates and blood metabolites.

Study Overview

• Status: Completed
• Conditions: Healthy
• Intervention / Treatment: Other: nEB Diet, followed for 36 hours; Other: LCEB Diet, followed for 36 hours; Other: LC25 Diet, followed for 36 hours

Detailed Description

Participants will engage in three distinct eating plans: a standard diet with usual carbohydrate and calorie levels, a low-carb diet with typical calories, and a low-carb diet with reduced calories. Each diet is followed for a single day, with subsequent monitoring to assess how the body processes food and manages hunger after a meal. The goal is to understand the potential metabolic benefits of reducing carbohydrate intake, either alone or in combination with calorie reduction. This research aims to identify simpler dietary strategies that could improve heart health and assist in weight management without the need for severe calorie restriction or fasting, offering valuable insights for enhancing health outcomes in overweight individuals.

• Study Type: Interventional
• Enrollment (Actual): 12
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • Guildford, United Kingdom, GU2 7XH
    • University of Surrey

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• stable weight within ±3 kg over the past three months
• no significant medical history.

Exclusion Criteria:

• pregnancy
• breastfeeding,
• using medications that could affect the study's outcomes
• high intake of caffeine and alcohol
• existing eating or psychiatric disorders
• adherence to strict dietary regimens like veganism
• high BMI resulting from significant muscle mass

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Supportive Care
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: normal carbohydrate, energy-balanced diet, (nEB); provided participants' 100% daily energy needs, following the balanced Eatwell Guide recommendations.	Other: nEB Diet, followed for 36 hours; nEB diet first, then LC25 and LCEB in random order with a 5 days washout between each diet
Active Comparator: low-carbohydrate, energy-balanced diet, (LCEB); diet contained just 50g of carbohydrates but still met 100% of the participants' estimated daily energy needs.	Other: LCEB Diet, followed for 36 hours; LCEB diet first, then LC25 and nEB in random order with a 5 days washout between each diet
Active Comparator: low-carbohydrate, energy-restricted diet, (LC25); The diet consisted of only 50g of carbohydrates and provided 25% of the estimated daily energy needs.	Other: LC25 Diet, followed for 36 hours; LC25 diet first, then nEB and LCEB in random order with a 5 days washout between each diet

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Biomarkers in blood Measured	Measured with ELISA assay and clinical analyser (INDIKO)	8 hours (fasting and post-meal)
Resting metabolic rate	Measured with indirect calorimetry (GEM)	8 hours (fasting and post-meal)

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Perceived Appetite Scores	Measured with a Visual Analog Scale	8 hours (fasting and post-meal)
Food intake	Measured using food diaries	baseline and after each diet arm for 1 day

Collaborators and Investigators

• Sponsor: University of Surrey
• Investigators: Principal Investigator: Hayriye Biyikoglu, University of Surrey

Study record dates

Study Major Dates

• Study Start (Actual): November 5, 2019
• Primary Completion (Actual): April 1, 2020
• Study Completion (Actual): November 20, 2022

Study Registration Dates

• First Submitted: April 17, 2024
• First Submitted That Met QC Criteria: April 23, 2024
• First Posted (Actual): April 29, 2024

Study Record Updates

• Last Update Posted (Actual): April 29, 2024
• Last Update Submitted That Met QC Criteria: April 23, 2024
• Last Verified: April 1, 2024

More Information

Terms related to this study

• Other Study ID Numbers: UEC 2019 008 FHMS

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No