Clinical trial NCT04019418: Carbohydrate Intake and Gut Hormone Release During Exercise
Official title: Carbohydrate Intake and Gut Hormone Release During Exercise
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Obesity
Keywords: carbohydrate
exercise
PYY
GLP-1
ghrelin
hormones
Lead sponsor: Imperial College London
Sponsor class: OTHER
First posted: 2019-07-15
Enrollment: 12
Sex: MALE
Minimum age (years): 18
Maximum age (years): 40
Standard ages: ADULT
Accepts healthy volunteers: yes
Allocation: RANDOMIZED
Intervention model: CROSSOVER
Intervention model description: Participants perform all four trials in a randomized order
Primary purpose: BASIC_SCIENCE

Brief summary: It is well known that following a single session of moderate-to-high intensity exercise individuals experience a temporary suppression of hunger and a delay in the commencement of eating. This effect is believed to be due to changes in blood concentrations of specific hormones released from the gut that influence appetite.

Individuals undertaking physical activity often consume foods immediately before exercise in order to improve their performance. However, it is currently unknown whether this eating practice influences the gut hormone response to exercise as well as how hungry an individual feels post-exercise.

Therefore, the aim of this study is to investigate the effect of consuming a sugary (carbohydrate) drink immediately before starting an exercise session on the concentration of these gut hormones as well as the amount of food eaten in the hours following exercise completion.

Detailed description: It is well established that following an acute bout of moderate-to-high intensity exercise individuals experience a transient suppression of hunger and a delay in the commencement of eating - a phenomenon referred to as exercise-induced anorexia. Acute exercise modulates the concentrations of gut hormones known to influence satiety, including the anorexigenic hormones glucagon-like peptide 1 (GLP-1) and peptide tyrosine tyrosine (PYY), as well as the acylated form of the orexigenic hormone ghrelin. These alterations in gut hormone concentrations have consequently been hypothesised to play a key role in exercise-induced anorexia.

Despite suppressing hunger and delaying eating, acute exercise does not appear to alter short-term energy intake in the immediate hours following exercise completion. The absence of a compensatory response therefore creates an energy deficit capable of inducing weight loss. Strategies that augment the gut hormone response to acute exercise may thus increase the potency of exercise as a weight-loss tool.

Research investigating the effect of exercise on appetite has frequently utilised participants in a fasting state. Undertaking exercise in this physiological condition contradicts current practices, as athletes often consume a carbohydrate source immediately prior to exercise in an attempt to maximise performance. It is currently unknown as to whether the consumption of carbohydrate during this period may further enhance the gut hormone response to exercise, and thus research into a potential additive effect is warranted.

High-intensity exercise increases sympathetic nervous system activity and catecholamine release. Catecholamine concentrations are negatively correlated with acylated ghrelin concentrations and may directly stimulate GLP-1 and PYY release via activation of β-receptors located on L-cells. The decrease in gastric emptying rate that is observed during high-intensity exercise is also attributed to this increase in sympathetic activity. Consequently, an increase in sympathetic nervous system activity has been postulated as a key mechanism underlying exercise-induced changes in gut hormone concentrations. However, to our knowledge, no study has directly measured the relationship between sympathetic nervous system activity and anorexigenic gut hormone release during exercise.

Therefore, the aim of this study is to examine any potential additive effects of carbohydrate ingestion immediately prior to exercise on gut hormone release and post-exercise appetite suppression. Furthermore, this study will look to investigate the mechanisms underlying changes in gut hormone concentrations experienced during exercise.

Eligibility criteria: Inclusion Criteria:

* Male
* Age between 18-40 years (inclusive)
* Body mass index (BMI) of 18-30 kg/m2
* Willingness and ability to give written informed consent and willingness and ability to understand, to participate and to comply with the study requirements

Exclusion Criteria:

* Abnormal ECG
* Screening blood results outside of normal reference values
* Current smokers
* Current or history of substance abuse and/or excess alcohol intake
* Diabetes
* Cardiovascular disease
* Cancer
* Gastrointestinal disease e.g. inflammatory bowel disease or irritable bowel syndrome
* Kidney disease
* Liver disease
* Pancreatitis
* Started new medication within the last 3 months likely to interfere with energy metabolism, appetite regulation and hormonal balance, including: anti-inflammatory drugs or steroids, antibiotics, androgens, phenytoin, erythromycin or thyroid hormones.
* Participation in a research study in the 12 week period prior to entering this study.
* Any blood donation within the 12 week period prior to entering this study

Primary outcomes:
measure: Changes in GLP-1 concentration
timeFrame: During the study visit, 165 minutes
measure: Changes in PYY concentration
timeFrame: During the study visit, 165 minutes
measure: Changes in acylated ghrelin concentration
timeFrame: During the study visit, 165 minutes
Secondary outcomes:
measure: Changes in energy intake
timeFrame: During the study visit, 165 minutes
measure: Changes in Energy expenditure
timeFrame: During the study visit, 165 minutes
measure: Changes in energy balance
timeFrame: During the study visit, 165 minutes
measure: Glucose homeostasis
timeFrame: During the study visit, 165 minutes
measure: Changes in subjective nausea
timeFrame: During the study visit, 165 minutes
measure: Changes in subjective appetite
timeFrame: During the study visit, 165 minutes
Other outcomes:
Locations:
city: London
country: United Kingdom
facility: Imperial Clinical Research Facility
Study officials:
affiliation: Imperial College London
name: Edward Chambers, PhD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Frampton J, Serrano-Contreras JI, Garcia-Perez I, Franco-Becker G, Penhaligan J, Tan ASY, de Oliveira ACC, Milner AJ, Murphy KG, Frost G, Chambers ES. The metabolic interplay between dietary carbohydrate and exercise and its role in acute appetite regulation in males: a randomized controlled study. J Physiol. 2023 Aug;601(16):3461-3480. doi: 10.1113/JP284294. Epub 2023 Jun 15.