The Effects of Combined Energy and Carbohydrate Restriction on Exercise Capacity (CHO-EX)

University of Aarhus

Status: Enrolling

Conditions: Overweight and Obesity

Treatments: Other: Calorie-restriction with moderate carbohydrate; Other: Calorie-restriction with low carbohydrate

Study type: Interventional

Funder types: Other

Identifiers

NCT06381908

1-10-72-19-24

Details and patient eligibility

About

The effect of calorie restriction combined with low or moderate carbohydrate availability on exercise capacity, metabolism and metabolic health indicators will be measured in a randomized parallel group design. Forty overweight (BMI 25-30) and relatively inactive women (20-35 of age) will be included. These will be randomized into one of two experimental groups both receiving a calorie-restricted diet (-1000 kcal) combined with either low carbohydrate availability or moderate carbohydrate availability across a 10 day period. Laboratory-based physical capacity tests and blood and muscle sampling will be performed before and after the intervention. In addition, an additional follow-up test day will be performed after continuing the diet for another 48 h and then standardizing the pre-testing carbohydrate availability before repeating the tests of physical capacity.

Full description

Overweight (BMI 25-30), but healthy premenopausal women aged 20-35 years (n=40) will be included in the trial, which is structured as a randomized, parallel group design where participants are randomized to either consume a hypocaloric diet (-1000 kcal) with concurrent carbohydrate restriction (low carbohydrate, L-CHO, n=20) or a similar hypocaloric diet with moderate carbohydrate availability (moderate carbohydrate, M-CHO, n=20). The trial will be single-blinded since it might be transparent to the participants which diet they are consuming, whereas the test personnel collecting and processing test results will be blinded to diet allocation. Diet handling will be managed by specific individuals in the research group who do not partake in executing the physical capacity tests. Additionally, the direction of the trial's primary hypothesis will not be disclosed to the participants to avoid creating preconceived expectations about the effects.

After an initial screening interview and two familiarization visits, participants will complete the intervention period consisting of 10 days with the allocated diet manipulation with preceding and subsequent test days with a series of tests. The tests before and after each test period include measurements of the participants' physical capacity level and energy metabolism in the laboratory as well as blood and muscle sampling. In addition, resting metabolism and body composition will be measured. During each test period, participants' habitual activity level will be monitored with an accelerometer attached to the wrist (Axivity). There will also be monitoring of the activity level with an accelerometer in a 7-day cycle before the start of the trial as a baseline measurement.

Similarly, a glucose monitor will be placed on the upper arm for continuous glucose readings via a Freestyle Libre2 sensor during the trial period.

Enrollment: 40 estimated patients

Sex: Female

Ages: 20 to 35 years old

Volunteers: Accepts Healthy Volunteers

Inclusion criteria

• Age: 20-35
• BMI: 25-30

Exclusion criteria

• Irregular menstruation within the last 6 months (shorter end 24 days or longer end 35 days cycle)
• Injuries / pain in the lower body, which prevents participation in intense cycling
• Medication consumption that may affect primary outcome measures.
• Smoking
• Pregnancy
• Systematic physical activity more than 2 hours per week

Trial design

Primary purpose: Treatment

Allocation: Randomized

Interventional model: Parallel Assignment

Masking: Triple Blind

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40 participants in 2 patient groups

Low-carbohydrate calorie-restriction

Active Comparator group

Description:

Minimum of 3 g carbohydrate/kg body weight/day and a \~1000 kcal calorie restriction

Treatment:

Other: Calorie-restriction with low carbohydrate

Moderate-carbohydrate calorie-restriction

Experimental group

Description:

Maximum of 1 g carbohydrate/kg body weight/day and a \~1000 kcal calorie restriction

Treatment:

Other: Calorie-restriction with moderate carbohydrate