Overweight and Obesity
Conditions
Keywords
Overweight, Obesity, Exercise
Brief summary
The investigators are doing this study to learn more about how exercising at different times of the day (morning versus evening) affects body weight, sleep, eating patterns, and other factors.
Detailed description
Does the time of day that exercise is performed matter for weight loss? The objective of this proposal is to examine the impact of an equivalent dose of morning vs. evening aerobic exercise on change in body weight, energy intake (EI) and components of energy expenditure (EE) in adults with overweight or obesity. Nearly two-thirds of US adults who attempt to lose weight report engaging in exercise as a primary strategy for weight loss. However, weight loss from exercise alone is often substantially less than predicted based on calories burned in exercise. This is due to compensatory changes that occur in response to exercise initiation (e.g. increases in EI and decreases in non-exercise EE) that limit the energy deficit produced by exercise. Thus, strategies that reduce the compensatory response to exercise could enhance the weight loss efficacy of exercise. It is possible that exercise time of day could impact compensatory behaviors and weight loss, however, there have been no adequately powered, prospective, randomized studies comparing weight loss induced by morning vs. evening exercise. The study design is a 7-month supervised trial in which adults with overweight or obesity will be randomized to supervised aerobic exercise (2000 kcal/wk) performed either in the morning (AM-Ex, 6-10 AM) or the evening (PM-Ex, 3-7 PM). The supervised exercise phase will be followed by a 6-month maintenance phase during which participants continue to exercise at the target of 2000 kcal/week during the randomized AM or PM exercise windows, but exercise is no longer supervised. Aim 1 will compare the effects of AM-Ex vs. PM-Ex on changes in body weight and body composition with the primary study outcome of weight change at 7-months. Aim 2 will compare the effects of AM-Ex vs PM-Ex on changes in EI and appetite. Aim 3 will compare the effects of AM-Ex vs PM-Ex on changes in EE, non-exercise physical activity and sedentary time. Exploratory Aim 4 will compare the effects of AM-Ex vs PM-Ex on changes in meal and sleep timing. This approach is rigorous and innovative as the exercise energy deficit will be matched between groups, exercise will be prescribed based on EE, and free-living total daily energy expenditure (TDEE) and EI will be assessed objectively (using doubly-labeled water). This study is significant as it could provide important insight on how the timing of exercise impacts weight loss and compensatory behaviors.
Interventions
BEHAVIORALMorning Exercise
Morning Exercise will be instructed to perform 2000 kcal/wk of moderate to vigorous intensity aerobic exercise between the hours of 6 and 10 AM.
BEHAVIORALEvening Exercise
PM will be instructed to perform 2000 kcal/wk of moderate to vigorous intensity aerobic exercise between the hours of 3 and 7 PM.
Sponsors
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
University of Colorado, Denver
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Investigator)
Eligibility
Sex/Gender
ALL
Age
18 Years to 55 Years
Healthy volunteers
No
Inclusion criteria
* Female or Male * Age 18-55 years * Body Mass Index 25-40 kg/m2 * Physically inactive: defined as self-reporting \<150 minutes per week of physical activity at moderate intensity or greater on a regular basis over the past 3 months. * No self-report of acute or chronic disease (cardiovascular disease (CVD), diabetes, gastrointestinal disorders and orthopedic problems in particular) * No plans to relocate within the next 15 months. * No plans for extended travel (\> 2 weeks) within the next 13 months * Live or work within 30 minutes of the Anschutz Health & Wellness Center (AHWC) (exceptions may be made at the discretion of the Study PI on a case-by-case basis for highly motivated subjects). * Capable and willing to give informed consent, understand
Exclusion criteria
, accept the randomized group assignment, and complete outcome measures. * No contraindications to exercise or limitations on ability to be physically active. * Willing to be randomized to either AM or PM exercise and complete 4 exercise sessions per week. * Own a smart phone and willing to download and use text messaging for meal intake and other related assessments. * Willing and able to wear activity/sleep monitor for 7-14 consecutive days. * Willing not to enroll in any other formal weight loss or physical activity programs over the next 13 months. * Fully vaccinated, or willing to be fully vaccinated, against COVID-19 prior to study enrollment (fully vaccinated is defined as at least 2 weeks post final vaccine dose). * Have a primary care physician (or are willing to establish care with a primary care physician prior to study enrollment) to address medical issues which may arise during screening or study procedures/interventions. * For Females * Not currently pregnant or lactating * Not pregnant within the past 6 months * Not planning to become pregnant in the next 15 months; sexually active women of childbearing potential may be enrolled if they have had a tubal ligation or use a reliable means of contraception
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Weight Change (kg) | Baseline (0) - 13 Months | Body weight will be measured using a digital scale at baseline, 3.5, 7, and 13 months. The primary outcome will be change in weight from baseline to 7 months. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Lean Mass | Baseline (0) - 13 Months | Lean Mass will assessed using Dual-Energy X-Ray Absorptiometry (DXA) at baseline, 7, and 13 months. |
| Energy Intake | Baseline (0) - 7 Months | Energy Intake (EI) will be assessed using the Doubly Labeled Water (DLW) Intake-Balance Method at baseline and 7 |
| Total Daily Energy Expenditure | Baseline (0) - 7 Months | Total Daily Energy Expenditure (TDEE) will be assessed using doubly labeled water (DLW) at baseline and 7 months |
| Hunger and Satiety | Baseline (0) - 13 Months | Assessed with visual analog scale (0-100 range). Higher scores indicate higher levels of hunger (worse outcome) and satiety (better outcome). Measured at baseline, 3.5, 7, and 13 months |
| Fat Mass | Baseline (0) - 13 Months | Fat mass will assessed using Dual-Energy X-Ray Absorptiometry (DXA) at baseline, 7, and 13 months. |
| Aspects of Eating Behavior | Baseline (0) - 13 Months | Measured via Three-Factor Eating Questionnaire at baseline, 3.5, 7, and 13 months. This assessment is designed to measure 3 dimensions of human eating behavior: cognitive restraint of eating (Factor I - 20 items), disinhibition (Factor II - 16 items), and hunger (Factor III - 15 items). The minimum score for factors I-II-III is therefore 0-0-0, and maximum possible score is 20-16-15. Part I includes items 1-36 and are rated either 1-True or 0-False. Part II includes items 37-51 and is rated on a 4-point scale with the exception of item 50, which is rated on a 6-point scale. |
| Non-Exercise Physical Activity (NEPA) | Baseline (0) - 13 Months | NEPA will be measured with the ActivPAL device at baseline, 3.5, 7, and 13 months |
| Sedentary Time | Baseline (0) - 13 Months | Sedentary Time will be measured with the ActivPAL device at baseline, 3.5, 7, and 13 months |
| Food Cravings | Baseline (0) - 13 Months | Assessed with 2 questionnaires at baseline, 3.5, 7, and 13 months: Food Cravings Questionnaire Trait-reduced (FCQ-T-r) and and FCI-II. Higher scores indicate greater cravings (worse outcome). Food Cravings Questionnaire-Trait-reduced (FCQ-T-r) is a Likert Scale using scoring associated with it Strongly disagree = 1, Disagree = 2, Neither agree nor disagree = 3, Agree= 4, Strongly agree = 5. The FCI-II is scored on a Likert scale from 1-5, with 1 being Never, 5 being Always/Almost every day. It has 4 subscales: High Fats, Sweets, Carbohydrates/Starches, and Fast-Food Fats. The score for each subscale is obtained by averaging the responses to the items listed for the subscale. The total score is obtained by averaging the responses to all 28 items. |
Countries
United States
Contacts
Primary ContactLiza Wayland
Backup ContactKristen Bing
Outcome results
None listed