Acute Responses to Dietary Carbohydrate Manipulation

Nutrition and Energy Balance Clinical Trial

Official title:

The Acute Responses to Manipulating Dietary Carbohydrate Content and Type on All Major Aspects of Energy Balance

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT03509610
• Other study ID #: EP 17/18 87
• Status: Completed
• Phase: N/A
• Start date: December 4, 2017
• Est. completion date: May 21, 2021

Study information

• Verified date: June 2021
• Source: University of Bath
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

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 comprises just one half of the energy balance equation (e.g. balance = intake - expenditure). Without considering energy expenditure, it is impossible to understand the effects of sugar on health. Sugar, and perhaps total carbohydrate intake, may be important for energy balance - perhaps by stimulating increased energy expenditure.

Understanding dietary regulators of energy balance is more important than ever before, because diseases like obesity are a consequence of energy surplus (i.e. energy intake > energy expenditure). No studies have investigated a causal role of dietary sugar or carbohydrate on energy balance. The proposed research will seek to understand the acute (e.g. 24-hour) responses to manipulating dietary carbohydrate and sugar content on energy balance and health.

This research will contribute to enabling individuals to make informed dietary choices about carbohydrate and sugar consumption.

To achieve this, healthy non-obese adults will be recruited to a randomised crossover study. Measures of energy intake, energy expenditure, metabolic health, appetite, food preference, and gut microbiota will be taken. All laboratory trials will take place at the University of Bath.

Three diets will be investigated:

1. Control - 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 and <8% energy intake from carbohydrate, replacing carbohydrate energy with fat

The study will consist of a 3-day lead-in period with the control diet followed by one trial day with each diet.

Description:

Dietary sugar is increasingly perceived in a negative way. This has led to taxation by government and guidelines by global public health bodies to reduce sugar intake to <5% of energy intake. All available public health guidelines regarding sugar advocate a reduction in sugar intake, despite a lack of evidence to support these recommendations. These guidelines focus on the association between sugar intake and energy intake, without regard for energy expenditure. This oversimplifies situations in which energy surplus is pathological, for example in diseases like obesity. This complexity is demonstrated by evidence that dietary sugar intake is decreasing in the United Kingdom, whilst rates of obesity have increased in the same timeframe.

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.

Carbohydrate availability dictates the capacity to perform physical work. However, the role of carbohydrate in regulating physical activity behaviours has only recently been considered. Ingestion of a carbohydrate-rich breakfast causes a significant increase in 24-hour PAEE compared with no breakfast consumption before midday. The magnitude of this difference is greatest prior to midday, near to when carbohydrate had been ingested and when glucose uptake to peripheral tissue is increased. This points towards a stimulatory role of carbohydrate or sugar on PAEE when carbohydrate is readily available to peripheral tissue. The amount of carbohydrate present in skeletal muscle is dictated by the amount of carbohydrate in the diet. As physical activity is performed by skeletal muscle, dietary carbohydrate intake may regulate physical activity behaviour. Consequently, reducing total carbohydrate intake may result in reduced PAEE.

Studies in which carbohydrate has been manipulated and physical activity has been measured have not been sufficient in answering this research question. Often self-report measures of physical activity are used, which are not sensitive enough to discern meaningful differences. Studies which have measured physical activity objectively, i.e. using pedometers or accelerometers, are confounded by a lack of information about actual carbohydrate intake or concurrent prescription of exercise interventions. Furthermore, government targets of reduced sugar intake to <5% of total energy intake are not aimed at overall carbohydrate intake per se. In the breakfast study mentioned, sugar intake was significantly greater amongst individuals who ate breakfast compared with individuals who fasted until midday. Therefore, it is also plausible that a regulatory role of carbohydrate on PAEE may be due to the type of carbohydrate rather than the absolute amount.

If the availability of carbohydrate to peripheral tissue plays a regulatory role on PAEE, then theoretically the effects of manipulating the amount or type of carbohydrate will be detectable acutely, within 24 hours.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 25
• Est. completion date: May 21, 2021
• Est. primary completion date: May 21, 2021
• 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 or contraceptive use

• No anticipated changes in diet/physical activity during the study (e.g. holidays or diet plans)

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%)

Related Conditions & MeSH terms

• Nutrition and Energy Balance

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. Review. — 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. Review. — View Citation

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	24-hour physical activity energy expenditure (kcal/day)	24-hour physical activity energy expenditure (kcal/day)	24 hours
Secondary	24-hour energy intake (kcal/day)	24-hour energy intake (kcal/day)	24 hours
Secondary	Fasting glucose concentrations	Fasting glucose concentrations in serum samples	24 hours
Secondary	Postprandial glucose concentrations	Postprandial glucose concentrations in serum samples	24 hours
Secondary	Fasting insulin concentrations	Fasting insulin concentrations in serum samples	24 hours
Secondary	Postprandial insulin concentrations	Postprandial insulin concentrations in serum samples	24 hours
Secondary	Fasting triglyceride concentrations	Fasting and postprandial triglyceride concentrations determined in plasma samples	24 hours
Secondary	Postprandial triglyceride concentrations	Postprandial triglyceride concentrations in serum samples	24 hours
Secondary	Fasting non-esterified fatty acid concentrations	Fasting non-esterified fatty acid concentrations in serum samples	24 hours
Secondary	Postprandial non-esterified fatty acid concentrations	Postprandial non-esterified fatty acid concentrations in serum samples	24 hours
Secondary	Fasting beta-hydroxybutyrate concentrations	Fasting beta-hydroxybutyrate concentrations in serum samples	24 hours
Secondary	Postprandial beta-hydroxybutyrate concentrations	Postprandial beta-hydroxybutyrate concentrations in serum samples	24 hours
Secondary	Subjective appetite	Measured by 0-100 mm visual analogue scale	24 hours
Secondary	Food preference ratings	Food preference ratings determined by bespoke computer software	24 hours
Secondary	Resting substrate oxidation	Resting substrate oxidation determined by indirect calorimetry	24 hours
Secondary	Postprandial substrate oxidation	Postprandial substrate oxidation determined by indirect calorimetry	24 hours
Secondary	Palatability	Measured by 0-100 mm visual analogue scale	24 hours
Secondary	Fasting cholesterol, HDL, and LDL concentrations	Fasting cholesterol, HDL, and LDL concentrations in serum samples	24 hours
Secondary	Postprandial cholesterol, HDL, and LDL concentrations	Postprandial cholesterol, HDL, and LDL concentrations in serum samples	24 hours
Secondary	Fasting leptin concentrations	Fasting leptin concentrations in serum samples	24 hours
Secondary	Postprandial leptin concentrations	Postprandial leptin concentrations in serum samples	24 hours
Secondary	Macronutrient intake	Macronutrient intake across 24-h	24 hours
Secondary	Fasting FGF21 concentrations	Fasting FGF21 concentrations in serum samples	24 hours
Secondary	Postprandial FGF21 concentrations	Postprandial FGF21 concentrations in serum samples	24 hours
Secondary	Eating rate	Time taken to eat test meals	24 hours
Secondary	Body mass	Body mass	24 hours
Secondary	Waist and hip circumference	Waist and hip circumference, waist:hip ratio	24 hours
Secondary	Fasting haematology profile	Fasting haematology profile including WBC, RBC, HGB, haematocrit, platelet count	24 hours

External Links

•   SACN 2015 Report on Carbohydrates and Health