Adaptive Responses to Overfeeding and Weight (ARrOW)

Adaptive Responses to Overfeeding and Weight Regain in Reduced Obese Individuals

To more effectively address the problem of weight regain following weight loss for obese individuals, this study will evaluate the underlying biology of the reduced obese state. In depth studies of appetite, energy expenditure, physical activity levels and fat metabolism will be completed in obese and reduced obese individuals; with the latter subdivided into those who have lost weight with diet alone or diet plus exercise. Individuals will be studied following a brief overfeeding period to better understand how differences in biological responses to overeating might be involved in promoting or protecting against weight gain.

Study Overview

• Status: Recruiting
• Conditions: Obesity
• Intervention / Treatment: Other: Overfeeding; Other: Weight Loss; Other: Exercise training

Detailed Description

The persistent problem of weight regain following weight loss is perhaps the most significant barrier to addressing the current obesity epidemic. The biological drive to regain weight following weight loss is due in part to increased appetite leading to increased energy intake (EI) and reductions in energy expenditure (EE) in part due to changes in energy expended in physical activity (PA). These physiological adaptations to weight loss are most relevant during episodes of dietary indiscretion resulting in overfeeding (OF) when reduced obese (RO) people fail to respond to the state of positive energy balance in a way that maintains the reduced state. There is increasing evidence that RO individuals who exercise (RO-Ex) are less like to regain as compared to RO individuals who are sedentary (RO-Sed). Previous studies were conducted on the effects of OF on EI, EE, PA and fat metabolism in non-obese individuals either prone (OP) or resistant to obesity (OR). Subjects were then followed for 5 years to measure weight change. These studies showed that differences in the response of nocturnal fat oxidation and higher levels of moderate/vigorous PA following OF correlated with 5 year weight gain suggesting that these factors were potentially important mechanisms for weight gain. Previous work has shown that measures of hunger fail to suppress with OF in RO individuals and that nocturnal fat oxidation is reduced in RO-Sed but maintained in RO-Ex following a day that included a bout of exercise. This study will look at the responses of EE, EI, PA and fat metabolism to OF (40% above basal energy for 3 days) in obese, RO-Sed and RO-Ex men and women and correlate these responses to weight change over the subsequent year. The hypothesis is that changes in the response of one or more of these variables to OF will correlate with weight regain. The Significance of the studies lies in the fact that subjects will begin to clarify the metabolic mechanisms that underlie a propensity for weight regain in RO individuals. Innovation: The proposed studies will systematically examine a range of responses to OF and prospectively correlate them with weight gain while taking into account aspects of behavior relevant to weight regain. The hope is that these studies will lay a foundation for future studies that will examine the mechanisms underlying specific adaptive responses that directly relate to weight regain and help with the design of strategies to address and/or respond to these processes.

• Study Type: Interventional
• Enrollment (Anticipated): 75
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Colorado
    • Aurora, Colorado, United States, 80045
      • Recruiting
      • University of Colorado Hospital

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 30 years to 50 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion criteria.

• BMI of 30-38 kg/m2 and weight stable over the previous 6 months.
• Satisfied with current weight and not planning to lose weight at the time of enrollment (persons with obesity control group) -or- not satisfied with current weight and motivated to lose weight at the time of enrollment (reduced obese groups)
• No more than 90 min or 3 bouts of planned physical activity/wk.
• Pass a medical and physical screening performed by the study physician.
• Reporting a habitual, regular sleep-wake cycle for the month preceding screening that involved going to bed between 2200 and 0100 h and getting up between 0600 and 0900 h with >7 h and <9.25 h in bed.
• Live or work within 45 minutes of the CU-AMC (reduced obese groups only) (exceptions may be made at the discretion of the Study PI on a case by case basis for highly motivated subjects).
• Own a smartphone (Android or Apple iOS).
• For Females
• Not currently pregnant or lactating
• Not pregnant within the past 6 months
• Not planning to become pregnant in the next 12 months; sexually active women of childbearing potential may be enrolled if they use a reliable means of contraception
• Capable and willing to provide informed consent, understand exclusion criteria, and accept the randomized group assignment (reduced obese groups)

Exclusion criteria.

• Being considered unsafe to participate as determined by the study physician;
• Taking medications affecting weight, triglycerides, or energy intake/energy expenditure in the last 3 months;
• Having abnormal blood chemistry and/or hematology as deemed significant by the study physician;
• Ever having a history of systemic, psychiatric, neurological disease, or drug and alcohol abuse;
• History of cardiovascular disease, diabetes, uncontrolled hypertension, untreated thyroid, renal, hepatic diseases, dyslipidemia or any other medical condition affecting weight or lipid metabolism;
• Score > 18 on Beck Depression Index (BDI) will require further assessment by the study physician to determine if it is appropriate for the subject to participate in the study;
• Use of a continuous positive airway pressure (CPAP) device for the treatment of obstructive sleep apnea (OSA). A score of >10 on the Epworth sleepiness scale or >5 on the Pittsburgh Sleep Quality Index will require further assessment by the study physician to determine if it is appropriate for the subject to participate in the study;
• Being positive for human immunodeficiency virus or hepatitis B or C;
• History of surgical procedure for weight loss at any time (e.g. gastroplasty, gastric bypass, gastrectomy or partial gastrectomy, adjustable banding, gastric sleeve);
• Being a smoker or having been a smoker in the previous 6 months;
• Abnormal eating patterns identified by registered dietitian interview (dietary fat<15%, dietary fat>45%, dietary protein >30%);
• Working night shifts;
• Night eating syndrome (at least 25% of food intake is consumed after the evening meal and/or at least two episodes of nocturnal eating per week);
• Traveling > 2 time zones 2 weeks prior to an inpatient CTRC study visit;
• Currently participating in any formal weight loss or physical activity programs or clinical trials.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Parallel Assignment
• Masking: None (Open Label)

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Control; Persons with obesity who do not undergo weight loss will participate in an inpatient assessment to measure metabolic responses to a 3 day eucaloric diet or a 3 day overfeeding challenge. Participants will be followed for 1 year after the metabolic studies to track longitudinal changes in body weight and other relevant health outcomes.	Other: Overfeeding; 3-day hypercaloric diet designed to overfeed by 40% above total daily energy requirements
Experimental: Reduced obese + diet + exercise; Persons with obesity randomized to a weight loss program consisting of caloric restriction, behavioral support, and supervised endurance exercise training. Following weight loss persons in this group will participate in an inpatient assessment to measure metabolic responses to a 3 day eucaloric diet or a 3 day overfeeding challenge. Participants will be followed for 1 year after the metabolic studies to track longitudinal changes in body weight and other relevant health outcomes.	Other: Overfeeding; 3-day hypercaloric diet designed to overfeed by 40% above total daily energy requirements; Other: Weight Loss; 12-wk weight loss intervention using a meal replacement strategy (Health & Nutrition Technology, Carmel, CA), with an 8-10% weight loss goal; Other: Exercise training; 16-wk supervised endurance exercise training program
Active Comparator: Reduced obese + diet group; Persons with obesity randomized to a weight loss program consisting of caloric restriction and behavioral support. Following weight loss persons in this group will participate in an inpatient assessment to measure metabolic responses to a 3 day eucaloric diet or a 3 day overfeeding challenge. Participants will be followed for 1 year after the metabolic studies to track longitudinal changes in body weight and other relevant health outcomes.	Other: Overfeeding; 3-day hypercaloric diet designed to overfeed by 40% above total daily energy requirements; Other: Weight Loss; 12-wk weight loss intervention using a meal replacement strategy (Health & Nutrition Technology, Carmel, CA), with an 8-10% weight loss goal

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Fat oxidation as a correlate of weight regain as measured by room calorimetry	Fat oxidation as a correlate of weight regain will be assessed in both reduced obese groups with room calorimetry on two occasions, once after 3 days of overfeeding and once after 3 days of an energy balanced diet.	24 hour period on day 7 of two diet conditions - one overfed & one eucaloric condition; weeks 16 & 20

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Body weight per scale	Body weight will be measured via clinic scale. Change in body weight in response to the weight loss intervention	Baseline, after 12 week weight loss intervention and 1 year after the end of second study condition
Body Composition via DXA	Body composition will be measured via DXA, Change in body composition in response to the weight loss intervention	Baseline, after 12 week weight loss intervention and 1 year after the end of second study condition
Change in substrate utilization as measured by room calorimetry	Substrate utilization will be measured by room calorimetry (change = overfeeding diet condition - eucaloric diet condition)	24 hour period, on day 7 of two diet conditions - eucaloric and overfed; week 1 and 4 for controls and week 16 & 20 for reduced groups
Change in nocturnal lipolysis as measured by use of stable isotope tracer	Lipolysis will be measured using stable isotope tracers (change = overfeeding diet condition - eucaloric diet condition)	24 hour period, on day 7 of two diet conditions - eucaloric and overfed; week 1 and 4 for controls and weeks 16 and 20 for reduced
Change in total energy expenditure (TEE) as measured by room calorimetry	TEE will be measured by room calorimetry (change = overfeeding diet condition - eucaloric diet condition)	24 hour period, on day 7 of two diet conditions - eucaloric and overfed; week 1 and 4 for controls and weeks 16 and 20 for reduced
Change in spontaneous physical activity (SPA) as measured by accelerometers	SPA will be measured using accelerometers (change = overfeeding diet condition - eucaloric diet condition)	7 days, on days 4-10 of two diet conditions - eucaloric and overfed; week 1 and 4 for controls and weeks 16 and 20 for reduced
Change in spontaneous food intake measured with an ad libitum diet	Spontaneous food intake will be measured during a 3 day ad libitum diet (change = overfeeding diet condition - eucaloric diet condition)	3 days - on days 8-10 - of two diet conditions - eucaloric and overfed; week 1 and 4 for controls and weeks 16 and 20 for reduced
Change in hunger and satiety using Visual Analog Scale	Hunger and satiety will be measured using visual analog scales (change = overfeeding diet condition - eucaloric diet condition)	3 days - on days 8-10 - of two diet conditions - eucaloric and overfed; week 1 and 4 for controls and weeks 16 and 20 for reduced
Change in 24h hormone and metabolite profiles as measured by assay of plasma samples	24h hormone and metabolite profiles will be assayed in plasma samples obtained during inpatient study visits (change = overfeeding diet condition - eucaloric diet condition)	3 days - days 8-10 - of two diet conditions - eucaloric and overfed; week 1 and 4 for controls and weeks 16 and 20 for reduced
Lipolysis as a correlate of weight regain as measured by stable isotope tracer	Lipolysis as a correlate of weight regain will be assessed in both reduced obese groups with a stable isotope tracer on two occasions, once after 3 days of overfeeding and once after 3 days of an energy balanced diet.	24 period, on day 7 of two diet conditions - eucaloric and overfed; week 1 and 4 for controls and weeks 16 and 20 for reduced
Total energy expenditure (TEE) as a correlate of weight regain as measured by room calorimetry	TEE as a correlate of weight regain will be assessed in both reduced obese groups with room calorimetry on two occasions, once after 3 days of overfeeding and once after 3 days of an energy balanced diet.	24 period, on day 7 of two diet conditions - eucaloric and overfed; week 1 and 4 for controls and weeks 16 and 20 for reduced
Spontaneous physical activity (SPA) as a correlate of weight regain as measured by accelerometers	SPA as a correlate of weight regain will be assessed in both reduced obese groups with accelerometers on two occasions, once after 3 days of overfeeding and once after 3 days of an energy balanced diet.	7 days, on days 4-10 of two diet conditions - eucaloric and overfed; week 1 and 4 for controls and weeks 16 and 20 for reduced
Spontaneous food intake as a correlate of weight regain as measured with an ad libitum diet	SPA as a correlate of weight regain will be assessed in both reduced obese groups with an ad libitum diet on two occasions, once after 3 days of overfeeding and once after 3 days of an energy balanced diet.	3 days - days 8-10 of two diet conditions - eucaloric and overfed; week 1 and 4 for controls and weeks 16 and 20 for reduced
24h hormone and metabolite profiles as a correlate of weight regain as measured by assay of plasma samples	24h hormone and metabolite profiles as a correlate of weight regain will be assessed in both reduced obese groups by assay of plasma samples on two occasions, once after 3 days of overfeeding and once after 3 days of an energy balanced diet.	24 period, on day 7 of two diet conditions - eucaloric and overfed; week 1 and 4 for controls and weeks 16 and 20 for reduced
Total daily energy expenditure as a correlate of weight regain as measured by doubly labeled water	Total daily energy expenditure as a correlate of weight regain will be measured in both reduced obese groups using doubly labeled water after the second diet condition intervention	two 1 week periods at 1 month and 1 year after second diet condition; week 8 and week 56 for controls and week 24 and week 72 for reduced
Correlates of Weight Regain as measured by questionnaire	Correlates of weight regain will be assessed in both reduced obese groups with questionnaires periodically over the intervention and follow-up period	30 minutes at baseline and every 8 weeks for 1 year following second diet condition; weeks 12, 20, 28, 36, 44, 52 for controls and weeks 28, 36, 44, 52, 60, 68, for reduced.

Other Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in fitness as measured by indirect calorimetry	Fitness will be measured using indirect calorimetry during a graded exercise test to volitional exhaustion	30 minutes at baseline and 1 year following second diet condition; Reduced group will have an additional measurement at week 12 following weight loss period.

Collaborators and Investigators

• Sponsor: University of Colorado, Denver
• Collaborators: University of Colorado, Boulder

Study record dates

Study Major Dates

• Study Start (Actual): February 15, 2019
• Primary Completion (Anticipated): January 1, 2024
• Study Completion (Anticipated): January 1, 2024

Study Registration Dates

• First Submitted: October 22, 2018
• First Submitted That Met QC Criteria: February 25, 2019
• First Posted (Actual): February 27, 2019

Study Record Updates

• Last Update Posted (Actual): April 7, 2023
• Last Update Submitted That Met QC Criteria: April 6, 2023
• Last Verified: April 1, 2023

More Information

Terms related to this study

• Other Study ID Numbers: 18-0091

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No