Plain English Summary
Background and study aims
Different fats have different effects on appetite, hunger and fullness, and, as a result, energy balance – the relationship between energy in (i.e. food and drink eaten) versus energy out (i.e. energy expended for body functions and movement). As energy balance, not energy expenditure alone, is important for weight management strategies, it is important to examine the responses in appetite and food intake around exercise. Fats called medium-chain triglycerides (MCT) lead to reduced feelings of hunger and reduced food intake compared to long-chain triglycerides (LCT). Further, exercise can burn energy without increasing food intake at a later date, which creates an energy deficit and ultimately could lead to weight loss. This is in spite of the fact that these energy deficits also increase the overall desire to eat. It is not known, however, if the combination of a meal containing MCT with an acute bout of exercise leads to greater reductions in energy balance. The aim of this study is to find out whether a combination of MCT and exercise suppresses hunger and appetite more than MCT alone.
Who can participate?
Generally fit and healthy males, aged 18-65
What does the study involve?
This study involves four trials in a random order, with a break of 48 hours to 10 days between trials. In the 24 hours before each trial, participants abstain from alcohol and strenuous physical activity and record all the food and drink they consume, and then fast overnight. Participants then come to the laboratory and are randomly allocated to eat a high-fat breakfast meal containing either MCT or LCT before either a bout of cycling or a period of rest. Participants' metabolic rate, appetite and energy intake at a self-served lunch are measured in order to examine the effect of the two different meals on energy balance. The rate of food leaving the stomach (gastric emptying) is also measured in order to provide insight into the potential differences between the two test fats. After lunch, participants leave the laboratory and record all food and drink consumed in the evening to examine their 24 hour energy intake.
What are the possible benefits and risks of participating?
There are no direct benefits to participants. Participants may experience strong feelings of hunger. Consuming MCTs has previously been linked with digestive distress, but in higher doses that are provided in the current study. There is a risk of weakness and nausea associated with the exercise test, as well as the cycling tests as part of the trials.
Where is the study run from?
Oxford Brookes University (UK)
When is the study starting and how long is it expected to run for?
May 2016 to June 2017
Who is funding the study?
Oxford Brookes University (UK)
Who is the main contact?
Dr Miriam Clegg
Trial website
Contact information
Type
Scientific
Primary contact
Dr Miriam Clegg
ORCID ID
http://orcid.org/0000-0002-8871-0116
Contact details
Department of Sport and Health Sciences
Faculty of Health and Life Sciences
Oxford Brookes University
Gipsy Lane
Oxford
OX3 0BP
United Kingdom
Additional identifiers
EudraCT number
ClinicalTrials.gov number
Protocol/serial number
161020
Study information
Scientific title
The effect of triglyceride chain length combined with exercise on appetite, satiety and energy balance
Acronym
Study hypothesis
The aim of this study is to elucidate whether a combination of medium-chain triglycerides (MCT) and exercise would suppress hunger and appetite more than MCT alone compared to a control.
Ethics approval
Oxford Brookes University Research Ethics committee, 06/07/2016, ref: UREC 161020
Study design
Randomised cross-over design
Primary study design
Interventional
Secondary study design
Randomised cross over trial
Trial setting
Other
Trial type
Other
Patient information sheet
Not available in web format, please use the contact details to request a patient information sheet
Condition
Energy balance
Intervention
Following provision of informed consent and study screening, which includes a VO2max test, eligible participants are given weighing scales and a standardisation booklet in order to fulfil standardisation requirements. This requires abstaining from alcohol and strenuous physical activity, and to record all food and drink consumed throughout the 24 hours preceding each trial. This was to be repeated in the same period before the remaining trials.
Participants completed four trials in a random order, with a minimum of 48 hours and a maximum of 10 days between trials:
1. 18.4g control oil (vegetable oil) at rest
2. 18.4g control oil (vegetable oil) with exercise
3. 20g MCT oil at rest
4. 20g MCT oil with exercise
Upon arriving at the laboratory, participants are to rest for 10 minutes before a 30 minute baseline resting metabolic rate sample is taken, followed by baseline visual analogue scale and gastric emptying breath test. After this, the porridge breakfast containing the lipid is served. After this, participants either rest for 4 hours (rest trials); or rest for two hours, cycle for an hour at 65% VO2max and then rest for the remaining hour (exercise trials) until an ad libitum lunch is served. Gastric emptying breath tests are taken every 15 minutes, visual analogue scales every 30 minutes, and gaseous exchange data collected every 15 minutes for a 15 minute sample, other than during hours 2-3, where a continuous sample is taken (during exercise or the hour of rest).
After the ad libitum lunch finishes, participants are free to leave the laboratory, with another diet diary, which is to be filled for the remainder of the day. They are also provided with a gastrointestinal symptoms questionnaire to fill the following morning.
Intervention type
Other
Phase
Drug names
Primary outcome measure
1. Energy intake, assessed by the ad libitum buffet lunch that participants consume at the end of trials in the lab at 255–285 mins
2. Subjective sensations of appetite (hunger, fullness, desire to eat, prospective food consumption and nausea), measured using Visual Analogue Scales at 0 mins, 10 mins, 30 mins, 60 mins, 90 mins, 120 mins, 180 mins, 210 mins, 240 mins and 285 mins
3. Energy balance, measured using the CPX Ultima and combined with energy intake data, at -30 mins – 0 mins, 30 mins – 45 mins, 60 mins – 75 mins, 90 mins – 105 mins, 120 mins – 180 mins, 210 mins – 225 mins, 240 mins – 255 mins
Secondary outcome measures
1. 24 hour energy intake, measured using recorded diet diaries completed after the morning in the lab
2. Gastrointestinal distress (to identify any adverse effects associated with the lipids), measured using a GI Distress questionnaire on the morning following the lab visit
3. Gastric emptying, measured through the 13C octanoic acid breath test at 0 min, 15 min, 30 min, 45 min, 60 min, 75 min, 90 min, 105 min, 120 min, 135 min, 150 min, 165 min, 180 min, 195 min, 210 min, 225 min, 240 min, 285 min
4. Hedonic properties of the lipid (to outline palatability issues with the breakfasts which may confound the results), assessed by Quantitative Descriptive Analysis at 10 min
Overall trial start date
01/05/2016
Overall trial end date
01/06/2017
Reason abandoned (if study stopped)
Eligibility
Participant inclusion criteria
1. Aged 18-65
2. Male
3. BMI of 18.5-29.9 kg/m2
Participant type
Healthy volunteer
Age group
Adult
Gender
Male
Target number of participants
12
Total final enrolment
12
Participant exclusion criteria
1. Allergic/intolerant to any of the foods provided in the study
2. Taking medication which could affect appetite
3. Smokers
4. A ‘restrained eater’, as defined by the TFEQ and DEBQ
5. Not weight stable (losing/gaining 3kg in the last 3 months)
6. Currently dieting to lose weight
Recruitment start date
01/09/2016
Recruitment end date
01/05/2017
Locations
Countries of recruitment
United Kingdom
Trial participating centre
Oxford Brookes University
Gipsy Lane
Headington
Oxford
OX3 0BP
United Kingdom
Funders
Funder type
University/education
Funder name
Oxford Brookes University
Alternative name(s)
Funding Body Type
private sector organisation
Funding Body Subtype
Universities (academic only)
Location
United Kingdom
Results and Publications
Publication and dissemination plan
At the close of the trial, participants who have expressed interest in knowing the results of the study will be contacted. The results will be analysed, and written up for publication to relevant nutrition/exercise related scientific journals. Results will also be presented at relevant conferences.
IPD sharing plan
The datasets generated during and/or analysed during the current study are/will be available upon request from Dr Miriam Clegg
Intention to publish date
01/06/2018
Participant level data
Available on request
Basic results (scientific)
Publication list
2019 results in https://pubmed.ncbi.nlm.nih.gov/31690357/ (added 03/06/2020)