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

Not Applicable
Completed
Conditions
Physical Activity
Interventions
Other: Diet
Registration Number
NCT03917810
Lead Sponsor
University of Bath
Brief Summary

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

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

Recruitment & Eligibility

Status
COMPLETED
Sex
Male
Target Recruitment
25
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 & Design

Study Type
INTERVENTIONAL
Study Design
CROSSOVER
Arm && Interventions
GroupInterventionDescription
LOWSUGDietDiet consisting of 50% carbohydrate (\<5% sugar), 15% protein, 35% fat
MODSUGDietDiet consisting of 50% carbohydrate (20% sugar), 15% protein, 35% fat
LOWCHODietDiet consisting of \<8% carbohydrate (\<5% sugar), 15% protein, \>77% fat
Primary Outcome Measures
NameTimeMethod
Physical activity energy expenditure (kj/day or kcal/day)3 days

Physical activity energy expenditure measured using individually-calibrated combined heart rate and accelerometry (kj/day or kcal/day)

Secondary Outcome Measures
NameTimeMethod
Fasting blood fibroblast growth factor-21 concentrations3 days

Measures of blood fibroblast growth factor-21 concentrations pre- and post-intervention.

Fasting blood high density lipoprotein concentrations3 days

Measures of blood high density lipoprotein concentrations pre- and post-intervention.

Food preference ratings3 days

Food preference ratings determined by computer task measured pre- and post-intervention

Subjective appetite and mood ratings3 days

Measured by 0-100 mm visual analogue scales measured pre- and post-intervention

Fasting blood insulin concentrations3 days

Measures of blood insulin concentrations pre- and post-intervention.

Fasting blood triglyceride concentrations3 days

Measures of blood triglyceride concentrations pre- and post-intervention.

Fasting blood lactate concentrations3 days

Measures of blood lactate concentrations pre- and post-intervention.

Fasting blood beta-hydroxybutyrate concentrations3 days

Measures of blood beta-hydroxybutyrate concentrations pre- and post-intervention.

Fasting blood leptin concentrations3 days

Measures of blood leptin concentrations pre- and post-intervention.

Energy expended in different physical activity intensities (MET categories) (kJ/day or kcal/day)3 days

Energy expended in different physical activity intensities (MET categories) (kJ/day or kcal/day) using individually-calibrated combined heart rate and accelerometry

Fasting blood glucose concentrations3 days

Measures of blood glucose concentrations pre- and post-intervention.

Fasting blood total cholesterol concentrations3 days

Measures of blood total cholesterol concentrations pre- and post-intervention.

Blood pressure3 days

Blood pressure using an automated sphygmomanometer pre- and post-intervention

Time spent in different physical activity intensities (MET categories) (minutes)3 days

Time spent in different physical activity intensities (MET categories) (minutes) using individually-calibrated combined heart rate and accelerometry

Energy expended in the postprandial period (kJ or kcal)3 days

Energy expended in the postprandial period (kJ or kcal) measured using individually-calibrated combined heart rate and accelerometry

Fasting blood non-esterified fatty acid concentrations3 days

Measures of blood non-esterified fatty acid concentrations pre- and post-intervention.

Fasting blood low density lipoprotein concentrations3 days

Measures of blood low density lipoprotein concentrations pre- and post-intervention.

Trial Locations

Locations (1)

University of Bath

🇬🇧

Bath, Somerset, United Kingdom

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