Acute Responses to Manipulating Dietary Carbohydrate Content on Free-living Physical Activity Energy Expenditure

Dietary sugar and carbohydrate intakes will be manipulated for 3 days in a randomised crossover design. All food will be provided. Free-living physical activity energy expenditure will be measured using combined heart rate and accelerometry. Metabolic and appetite/mood responses to 3 days on each diet will be measured.

Each participant will undergo 3 days of each diet:

1. Moderate sugar - reflecting the composition of a typical European diet
2. Low sugar - similar macronutrient composition of a typical European diet but with <5% energy intake from free sugars (as per government guidelines)
3. Low carbohydrate - low carbohydrate diet with <5% energy intake from sugar and <8% energy intake from carbohydrate, replacing carbohydrate energy with fat

Study Overview

• Status: Completed
• Conditions: Physical Activity
• Intervention / Treatment: Other: Diet

Detailed Description

Guidelines calling for dietary free sugars to be reduced have been formulated from evidence that diets high in sugar are associated with high energy intake. In theory, by reducing the intake of sugars, calorie surplus will be reduced and energy balance will be maintained. However, when referring to interventions/behaviours that influence energy balance, both sides of the energy balance equation need to be considered. Alterations in nutrients may influence aspects of energy expenditure, not solely energy intake, and this may have implications for the efficacy of guidelines seeking to influence energy intake.

It is important to consider energy expenditure in the context of health. The most variable component of energy expenditure between individuals is physical activity energy expenditure (PAEE), which varies from ~600-2100 kcal per day in men of a similar demographic. Current guidelines do not regard the effect that changing dietary sugar might have on PAEE and therefore total energy expenditure.

Furthermore, there is increasing interest in restricting overall carbohydrate intake to treat metabolic disease or achieve ketogenesis. Very little is known about nutrition-physical activity interactions with this type of intervention.

This study will prescribe 3 diets to healthy males for 3 days in a randomised crossover design, where each participant will consume each of the diets. All food will be prepared and provided by the study team. The diets are as follows:

1. Moderate sugar - reflecting the composition of a typical European diet
2. Low sugar - similar macronutrient composition of a typical European diet but with <5% energy intake from free sugars (as per government guidelines)
3. Low carbohydrate - low carbohydrate diet with <5% energy intake from sugar and <8% energy intake from carbohydrate, replacing carbohydrate energy with fat

• Study Type: Interventional
• Enrollment (Actual): 25
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United Kingdom
  • Somerset
    • Bath, Somerset, United Kingdom, BA2 7AY
      • University of Bath

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: Male

Description

Inclusion Criteria:

• Body mass index 18.5-29.9 kg∙m-2
• Age 18-65 years
• Male
• Able and willing to provide informed consent and safely comply with study procedures
• No anticipated changes in physical activity during the study (e.g. holidays)

Exclusion Criteria:

• Any reported condition or behaviour deemed either to pose undue personal risk to the participant or introduce bias
• Any diagnosed metabolic disease (e.g. type 1 or type 2 diabetes)•Any reported use of substances which may pose undue personal risk to the participants or introduce bias into the experiment
• Lifestyle not conforming to standard sleep-wake cycle (e.g. shift worker)
• Any reported recent (<6 months) change in body mass (±3%)

Study Plan

How is the study designed?

Design Details

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

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: MODSUG; Diet consisting of 50% carbohydrate (20% sugar), 15% protein, 35% fat	Other: Diet; Macronutrient composition (specifically type and/or amount of carbohydrate) is manipulated
Experimental: LOWSUG; Diet consisting of 50% carbohydrate (<5% sugar), 15% protein, 35% fat	Other: Diet; Macronutrient composition (specifically type and/or amount of carbohydrate) is manipulated
Experimental: LOWCHO; Diet consisting of <8% carbohydrate (<5% sugar), 15% protein, >77% fat	Other: Diet; Macronutrient composition (specifically type and/or amount of carbohydrate) is manipulated

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Physical activity energy expenditure (kj/day or kcal/day)	Physical activity energy expenditure measured using individually-calibrated combined heart rate and accelerometry (kj/day or kcal/day)	3 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Time spent in different physical activity intensities (MET categories) (minutes)	Time spent in different physical activity intensities (MET categories) (minutes) using individually-calibrated combined heart rate and accelerometry	3 days
Energy expended in different physical activity intensities (MET categories) (kJ/day or kcal/day)	Energy expended in different physical activity intensities (MET categories) (kJ/day or kcal/day) using individually-calibrated combined heart rate and accelerometry	3 days
Energy expended in the postprandial period (kJ or kcal)	Energy expended in the postprandial period (kJ or kcal) measured using individually-calibrated combined heart rate and accelerometry	3 days
Fasting blood glucose concentrations	Measures of blood glucose concentrations pre- and post-intervention.	3 days
Fasting blood insulin concentrations	Measures of blood insulin concentrations pre- and post-intervention.	3 days
Fasting blood triglyceride concentrations	Measures of blood triglyceride concentrations pre- and post-intervention.	3 days
Fasting blood non-esterified fatty acid concentrations	Measures of blood non-esterified fatty acid concentrations pre- and post-intervention.	3 days
Fasting blood lactate concentrations	Measures of blood lactate concentrations pre- and post-intervention.	3 days
Fasting blood beta-hydroxybutyrate concentrations	Measures of blood beta-hydroxybutyrate concentrations pre- and post-intervention.	3 days
Fasting blood leptin concentrations	Measures of blood leptin concentrations pre- and post-intervention.	3 days
Fasting blood fibroblast growth factor-21 concentrations	Measures of blood fibroblast growth factor-21 concentrations pre- and post-intervention.	3 days
Fasting blood total cholesterol concentrations	Measures of blood total cholesterol concentrations pre- and post-intervention.	3 days
Fasting blood high density lipoprotein concentrations	Measures of blood high density lipoprotein concentrations pre- and post-intervention.	3 days
Fasting blood low density lipoprotein concentrations	Measures of blood low density lipoprotein concentrations pre- and post-intervention.	3 days
Food preference ratings	Food preference ratings determined by computer task measured pre- and post-intervention	3 days
Subjective appetite and mood ratings	Measured by 0-100 mm visual analogue scales measured pre- and post-intervention	3 days
Blood pressure	Blood pressure using an automated sphygmomanometer pre- and post-intervention	3 days

Collaborators and Investigators

• Sponsor: University of Bath

Publications and helpful links

General Publications

• Betts JA, Richardson JD, Chowdhury EA, Holman GD, Tsintzas K, Thompson D. The causal role of breakfast in energy balance and health: a randomized controlled trial in lean adults. Am J Clin Nutr. 2014 Aug;100(2):539-47. doi: 10.3945/ajcn.114.083402. Epub 2014 Jun 4.
• Smith HA, Gonzalez JT, Thompson D, Betts JA. Dietary carbohydrates, components of energy balance, and associated health outcomes. Nutr Rev. 2017 Oct 1;75(10):783-797. doi: 10.1093/nutrit/nux045.

Study record dates

Study Major Dates

• Study Start (Actual): January 1, 2018
• Primary Completion (Actual): July 1, 2021
• Study Completion (Actual): September 1, 2021

Study Registration Dates

• First Submitted: April 10, 2019
• First Submitted That Met QC Criteria: April 13, 2019
• First Posted (Actual): April 17, 2019

Study Record Updates

• Last Update Posted (Actual): May 4, 2022
• Last Update Submitted That Met QC Criteria: May 2, 2022
• Last Verified: May 1, 2022

More Information

Terms related to this study

• Keywords: Nutrition; Metabolism; Carbohydrates; Ketogenic
• Other Study ID Numbers: EP 17/18 219

Drug and device information, study documents

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