Weight Loss and Hunger

NCT07739095 | Not Yet Recruiting

• 2 other identifiers: H-10-25-12071541343
• Study Type: interventional
• Target: 40
• Locations: 1 country
• Sites: 1

Brief Summary

Weight loss is difficult and weight maintenance even worse. The principles of dieting dictate that to maintain weight loss, one has to eat less calories than they did before the diet. However, there is evidence to show that it may be the diet per se and not the weight loss that makes people more hungry and vulnerable to weight regain. This study will explore whether appetite control can be restored to normal levels through an individually tailored increase in calories after weight loss. If supported, the findings from this study could alter the way we view dieting.

Conditions

Obesity & Overweight

Keywords

Appetite; weight loss; exercise; dietary intervention

Outcome Measures

Primary Outcomes (1)

• Appetite measurements

  Desire to eat, hunger, fullness, and prospective food consumption (PFC) will be rated immediately before (after a 12 h overnight fast) and every 30 min\*3 h after the standardized breakfast on a 100-mm visual analog scale (VAS) adapted from Hill and Blundell. Scores range from 0 to 100 millimeters. For hunger, desire to eat, and prospective food consumption, higher scores indicate greater appetite. For fullness, higher scores indicate greater fullness (lower appetite). The satiety quotient will be calculated for each subject.

  Baseline (1 week before the dietary intervention), end of week 20 (after the weight-loss intervention), onset of week 25 (after the 1-month weight-maintenance period).

Secondary Outcomes (16)

• Plasma concentrations of appetite-regulating hormones

  Blood samples will be collected at each experimental session: Baseline (1 week before the dietary intervention), end of week 20 (after the weight-loss intervention), and onset of week 25 (after the 1-month weight-maintenance period).

• Resting Energy Expenditure

  Resting Energy Expenditure will be measured during the screening session (2 weeks before baseline), at baseline, end of week 20 (after the weight-loss intervention), onset of week 25 (after the 1-month weight-maintenance period).

• Exercise Energy Expenditure

  Accelerometer: worn for 7 days at each sampling period (screening, week 20 (end of weight loss intervention), weeks 22 and 24 (middle and end of weight maintenance). Exercise energy expenditure will be measured once per week during weight maintenance.

• Total Energy Expenditure

  The DLW dose will be consumed during the screening session, and participants will provide their first urine sample. A second sample will be collected on the following day, and a 3rd 7 days later.

• Energy Intake

  In-lab energy intake: Baseline, end of week 20 (after the weight-loss intervention), and at the onset of week 25 (after one month of weight maintenance). Free-living energy intake will be measured for 3 days after the screening session.

Study Arms (2)

High Energy Flux

EXPERIMENTAL

After weight loss through a dietary intervention, the high flux group will remain in a state of energy balance through an increase in exercise and an increase in energy intake to pre-weight loss values.

Behavioral: Exercise; Behavioral: Dietary Intervention

Low Energy Flux

PLACEBO COMPARATOR

After weight loss through a dietary intervention, the low-energy flux group will remain in energy balance but at a lower energy flux, with no changes in exercise levels and energy intake remaining lower than pre-weight-loss values.

Behavioral: Dietary Intervention

Interventions

Exercise BEHAVIORAL

Daily kilometer target at normal walking pace (\~5km/h). The American College of Sports Medicine (ACSM) metabolic equation for the caloric cost of walking will be used to assess the distance needed to be covered daily.

High Energy Flux

Dietary Intervention BEHAVIORAL

Participants will be prescribed a 20-week energy-restricted diet (-25% of energy requirements). A registered dietitian will be responsible for nutrition counselling and will use the Canadian Diabetes Association's Exchange System to prescribe the diet plan. During the weight loss phase, participants will receive a revised diet plan, based on the adjusted energy requirements that will account for the achieved weight loss. After weight loss, the diet plan will be revised based on the group (high-energy flux vs low-energy flux) to be in a state of energy balance.

High Energy Flux; Low Energy Flux

Eligibility Criteria

• Age: 18 Years - 55 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64)

You may qualify if:

• years of age;
• non-smoking;
• obese class I-II (30 kg/m2 ≤ BMI \< 40 kg/m2);
• weight stable (± 2 kg during the 6 months prior to enrollment);
• Sedentary (\<2 times/week of 30 min of continuous exercise)
• In addition, Females will be included if:
• \) premenopausal (2 menses in the 3 months preceding testing, no increase in cycle irregularity in the 12 months preceding testing).

You may not qualify if:

• have a current diagnosis of an axis 1 psychiatric disorder (i.e. mood, anxiety and eating disorders);
• currently use antidepressants, thyroid medication, or any medication that could affect appetite;
• have a history of cardiac problems or symptoms suggestive of any cardiac condition;
• have a current diagnosis or history of diabetes, confirmed by a measure of HbA1c during the screening visit;
• have alcohol intake that exceeds recommendations or alcoholism, or current addictions to opiates, cocaine or stimulants;
• currently taking monoamine oxidase inhibitors, pressor agents, warfarin, anticonvulsants, phenylbutazone, or tricyclic antidepressants;
• have uncontrolled thyroid disease;
• have any osteoarticular condition, or other reasons that would prevent them from achieving the proposed walking targets.
• In addition, Females will be excluded if they:
• are pregnant or planning to become pregnant over the course of the study;
• are peri- or post-menopausal or have had surgically induced menopause.

Sponsors & Collaborators

• University of Ottawa: lead
• Canadian Institutes of Health Research (CIHR): collaborator

Study Sites (1)

University of Ottawa

Ottawa, Ontario, K1S 5S9, Canada

Location

Related Publications (9)

• Machado AM, Guimaraes NS, Bocardi VB, da Silva TPR, Carmo ASD, Menezes MC, Duarte CK. Understanding weight regain after a nutritional weight loss intervention: Systematic review and meta-analysis. Clin Nutr ESPEN. 2022 Jun;49:138-153. doi: 10.1016/j.clnesp.2022.03.020. Epub 2022 Mar 31.

  PMID: 35623805 BACKGROUND

• Doucet E, McInis K, Mahmoodianfard S. Compensation in response to energy deficits induced by exercise or diet. Obes Rev. 2018 Dec;19 Suppl 1:36-46. doi: 10.1111/obr.12783.

  PMID: 30511511 BACKGROUND

• Cameron JD, Goldfield GS, Riou ME, Finlayson GS, Blundell JE, Doucet E. Energy depletion by diet or aerobic exercise alone: impact of energy deficit modality on appetite parameters. Am J Clin Nutr. 2016 Apr;103(4):1008-16. doi: 10.3945/ajcn.115.115584. Epub 2016 Feb 17.

  PMID: 26888712 BACKGROUND

• Leibel RL, Rosenbaum M, Hirsch J. Changes in energy expenditure resulting from altered body weight. N Engl J Med. 1995 Mar 9;332(10):621-8. doi: 10.1056/NEJM199503093321001.

  PMID: 7632212 BACKGROUND

• Schwartz A, Doucet E. Relative changes in resting energy expenditure during weight loss: a systematic review. Obes Rev. 2010 Jul;11(7):531-47. doi: 10.1111/j.1467-789X.2009.00654.x. Epub 2009 Sep 17.

  PMID: 19761507 BACKGROUND

• Dulloo AG, Jacquet J, Girardier L. Poststarvation hyperphagia and body fat overshooting in humans: a role for feedback signals from lean and fat tissues. Am J Clin Nutr. 1997 Mar;65(3):717-23. doi: 10.1093/ajcn/65.3.717.

  PMID: 9062520 BACKGROUND

• Anderson JW, Konz EC, Frederich RC, Wood CL. Long-term weight-loss maintenance: a meta-analysis of US studies. Am J Clin Nutr. 2001 Nov;74(5):579-84. doi: 10.1093/ajcn/74.5.579.

  PMID: 11684524 BACKGROUND

• Ryan DH. Risks and benefits of weight loss: challenges to obesity research. European Heart Journal 2005; (7): L27-L31.

  BACKGROUND

• Anderson JW, Luan J, Hoie LH. Structured weight-loss programs: meta-analysis of weight loss at 24 weeks and assessment of effects of intervention intensity. Adv Ther. 2004 Mar-Apr;21(2):61-75. doi: 10.1007/BF02850334.

  PMID: 15310080 BACKGROUND

MeSH Terms

Conditions

Obesity; Overweight; Weight Loss; Motor Activity

Interventions

Exercise; Diet Therapy

Condition Hierarchy (Ancestors)

Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Body Weight Changes; Behavior

Intervention Hierarchy (Ancestors)

Motor Activity; Movement; Musculoskeletal Physiological Phenomena; Musculoskeletal and Neural Physiological Phenomena; Nutrition Therapy; Therapeutics

Study Officials

• Eric Doucet, PhD

  University of Ottawa

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Eric Doucet, PhD

CONTACT

‭613-562-5800‬; edoucet@uOttawa.ca

Noemie Beauregard, PhD (c)

CONTACT

613-857-3960; nbeau029@uottawa.ca

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: OTHER
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Full Professor

Study Record Dates

• First Submitted: July 14, 2026
• First Posted: July 31, 2026
• Study Start (Estimated): September 1, 2026
• Primary Completion (Estimated): September 1, 2028
• Study Completion (Estimated): September 1, 2028
• Last Updated: July 31, 2026

Record last verified: 2026-07

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1)