Dietary Carbohydrate Manipulation and Energy Balance: RCT

Physical Activity Clinical Trial

Official title:

The Effect of Dietary Carbohydrate Manipulation on All Major Aspects of Energy Balance: A 12-week Randomised Controlled Trial

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT03574987
• Other study ID #: CHEB-Intervention
• Status: Completed
• Phase: N/A
• Start date: October 1, 2018
• Est. completion date: March 30, 2022

Study information

• Verified date: January 2024
• Source: University of Bath
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

This study will investigate how dietary sugar and carbohydrates influence metabolism and health across a 12-week period, with a focus on physical activity. One third of participants will eat a diet with typical amounts of sugar and carbohydrate, one third of participants will eat a diet with sugar intake restricted, and the final third of participants will eat a diet where both sugar and total carbohydrates are restricted and replaced with fat.

Description:

Sugar is perceived negatively, leading to government taxation and targets to reduce consumption. These actions have been taken based on the limited evidence that high-sugar diets are associated with greater total energy intake. However, energy intake is only one half of the energy balance equation (energy in vs energy out). Without considering energy expenditure, it is impossible to fully understand the effects of sugar on health. Removing dietary sugar or carbohydrates from the diet may influence energy balance through mechanisms other than energy intake - for example by reducing levels of physical activity.

Understanding dietary regulators of energy balance is more important than ever because diseases like obesity are a consequence of energy surplus (i.e. energy in > energy out). No studies have investigated a causal role of dietary sugar or carbohydrate on energy balance. The proposed research will seek to understand the responses to manipulating dietary carbohydrate and sugar content on energy balance and health. This research will enable the public to make informed dietary choices about carbohydrate and sugar consumption.

To achieve this, healthy non-obese adults, aged 18-65 years will be recruited to take part in an intervention study with measures of energy intake, energy expenditure, metabolic health, gut microbiota, and appetite. All laboratory trials will take place at the University of Bath. Participants will be randomised to consume one of three diets for a period of 12 weeks, with laboratory visits at baseline, at week 4, and at week 12:

1. CONTROL (moderate sugar) - reflecting the composition of a typical European diet

2. Low sugar - the same composition of a typical European diet but with <5% energy intake from sugar

3. Low carbohydrate - low carbohydrate diet with <5% energy intake from sugar, replacing carbohydrate energy with fat

Recruitment information / eligibility

• Status: Completed
• Enrollment: 60
• Est. completion date: March 30, 2022
• Est. primary completion date: February 11, 2022
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 65 Years

Eligibility

Inclusion Criteria:

• Body mass index 18.5-29.9 kg·m-2

• Age 18-65 years

• Able and willing to provide informed consent and safely comply with study procedures

• Females to maintain record of regular menstrual cycle phase/contraceptive use

• No anticipated changes in physical activity during the first 4 weeks of the study (e.g. holidays or training programmes)

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%)

• Use of antibiotic medication in the last 3 months

• Use of prebiotic or probiotic products in the last month

Related Conditions & MeSH terms

• Diet Modification
• Physical Activity

Intervention

Other:
• Diet
Macronutrient composition (specifically type and/or amount of carbohydrate) is manipulated

Locations

Country	Name	City	State
United Kingdom	Department for Health, University of Bath	Bath

Sponsors (1)

Lead Sponsor	Collaborator
University of Bath

Country where clinical trial is conducted

United Kingdom, 

References & Publications (3)

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. — View Citation

Erickson J, Sadeghirad B, Lytvyn L, Slavin J, Johnston BC. The Scientific Basis of Guideline Recommendations on Sugar Intake: A Systematic Review. Ann Intern Med. 2017 Feb 21;166(4):257-267. doi: 10.7326/M16-2020. Epub 2016 Dec 20. — View Citation

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. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Physical Activity Energy Expenditure (kJ/Day or kcal/Day)	24-hour physical activity energy expenditure (kJ/day or kcal/day)	7 days (across 12 weeks) - Primary outcome at week 4
Secondary	Time Spent in Different Physical Activity Intensities (MET Categories) (Minutes)	Time spent in different physical activity intensities (MET categories) (minutes)	7 days (across 12 weeks)
Secondary	Energy Expended in Different Physical Activity Intensities (MET Categories) (kJ or kcal)	Energy expended in different physical activity intensities (MET categories) (kJ or kcal)	7 days (across 12 weeks)
Secondary	Energy Intake and Dietary Macronutrient Composition	Estimated using food diaries, 7 days each time concurrently measured with PAEE and 3 days per week for the rest of the intervention	12 weeks
Secondary	Body Mass	Measured weekly using electric scales	12 weeks
Secondary	Bone Mineral Density	Bone mineral density measured using dual x-ray absorptiometry	12 weeks
Secondary	Bone Mineral Content	Bone mineral content measured using dual x-ray absorptiometry	12 weeks
Secondary	Fat Mass	Fat mass measured using dual x-ray absorptiometry	12 weeks
Secondary	Fat-free Mass	Fat-free mass measured using dual x-ray absorptiometry	12 weeks
Secondary	Android Fat Mass	Android fat mass measured using dual x-ray absorptiometry	12 weeks
Secondary	Gynoid Fat Mass	Gynoid fat mass measured using dual x-ray absorptiometry	12 weeks
Secondary	Resting Metabolic Rate	Resting metabolic rate will be measured using indirect calorimetry	12 weeks
Secondary	Substrate Oxidation	Substrate oxidation will be measured using indirect calorimetry both at rest and during exercise	12 weeks
Secondary	Waist and Hip Circumference	Waist and hip circumference will be measured using a tape measure	12 weeks
Secondary	Step Count	Measured daily using pedometers	12 weeks
Secondary	Fasting Metabolite/Hormone Profile	Assessment of blood glucose, insulin, triglycerides, non-esterified fatty acids, lactate, beta-hydroxybutyrate, leptin, fibroblast growth factor-21, total cholesterol, high density lipoprotein, and low density lipoprotein concentrations, appetite hormone concentrations (including PYY, GLP-1, ghrelin)	12 weeks
Secondary	Postprandial Metabolite/Hormone Profile	Assessment of blood glucose, insulin, triglycerides, non-esterified fatty acids, lactate, beta-hydroxybutyrate, leptin, fibroblast growth factor-21, total cholesterol, high density lipoprotein, and low density lipoprotein concentrations, appetite hormone concentrations (including PYY, GLP-1, ghrelin)	4 hours (across 12 weeks)
Secondary	Blood Pressure	Measured using an automated sphygmomanometer	12 weeks
Secondary	Food Preference Ratings	Food preference ratings determined by bespoke computer software	12 weeks
Secondary	Subjective Appetite and Mood Ratings	Measured by 0-100 mm visual analogue scale	12 weeks
Secondary	Interstitial Glucose Concentrations	Measured using research-grade freestyle libre glucose monitors. Measured pre-, during- and at the end of the intervention	14 days (across 12 weeks)
Secondary	Adipose Tissue Gene Expression	Expression of a panel of genes related to glucose metabolism in adipose biopsies using real-time polymerase chain reaction	12 weeks
Secondary	Adipose Tissue Protein Expression	Expression of various proteins related to glucose metabolism in adipose biopsies via Western blot	12 weeks
Secondary	Muscle Tissue Gene Expression	Expression of a panel of genes related to glucose metabolism in muscle biopsies using real-time polymerase chain reaction	12 weeks
Secondary	Muscle Tissue Protein Expression	Expression of various proteins related to glucose metabolism in muscle biopsies via Western blot	12 weeks
Secondary	Muscle Glycogen Concentrations	Glycogen concentrations measured from vastus lateralis muscle samples	12 weeks
Secondary	Gut Microbiome Characterisation	Faecal sample DNA and water will be used to determine taxonomic and functional diversity of microbes using transcriptomic techniques	12 weeks
Secondary	Urinary Acetoacetate Concentrations	Will be measured using handheld sticks	12 weeks
Secondary	Urine Urea Nitrogen Excretion	Will be measured across trial days	12 weeks