Effect of Speed of Weight Loss on Compensatory Mechanisms Activated During Weight Reduction

Not Applicable

Completed

• Conditions: Obesity
• Interventions: Behavioral: Low calorie diet (LCD); Behavioral: Very-low calorie diet (VLCD)

• Registration Number: NCT01912742
• Lead Sponsor: Norwegian University of Science and Technology

Brief Summary

Obesity has become a global epidemic with huge public health implications. Although clinical significant weight loss (WL) can be achieved by a combination of diet and behavioral modification, strong metabolic adaptations, with increased appetite and suppressed energy expenditure, are activated, which compromise WL maintenance and increase the risk of relapse. The aim of this project is to investigate the potential role of WL rate in modulating such responses. More specifically, the investigators want to determine if a similar WL achieved rapidly vs slowly induce the same compensatory responses to weight reduction. A secondary aim is to assess if speed of weight loss can influence motivation. A large battery of assessments will be performed before and after weight reduction including body composition, resting metabolic rate, substrate oxidation, exercise efficiency, fasting and postprandial release of several appetite-regulating hormones, subjective feelings of hunger and fullness and motivation. This project can bring large practical benefits concerning the design of weight loss programs to minimize weight relapse.

Detailed Description

Not available

Study Timeline

• Study First Submitted: 2013-07-29
• Study First Submitted QC: 2013-07-30
• Study First Posted: 2013-07-31
• Study Start: 2013-08
• Primary Completion: 2013-12
• Study Completion: 2014-12
• Status Verified: 2017-09
• Last Update Submitted: 2017-09-19
• Last Update Posted: 2017-09-21

Recruitment & Eligibility

• Status: COMPLETED
• Sex: All
• Target Recruitment: 35

Inclusion Criteria

• Adult (18-50 years old)
• Obese healthy volunteers (30<BMI<45 kg/m2)
• Weight stable on the last three months (<2kg), not currently dieting to lose weight and with an inactive lifestyle)

Exclusion Criteria

• History of endocrine/cardiovascular/pulmonary/kidney disease, anaemia, gout, milk intolerance, depression or other psychological disorders, eating disorders, drug or alcohol abuse within the last two years and current medication known to affect appetite or induce weight loss. Those with a planned surgery during the study period or participating in another research study will also not be accepted to take part in this study

Study & Design

• Study Type: INTERVENTIONAL
• Study Design: PARALLEL

Arm && Interventions

Group	Intervention	Description
Slow weight loss group	Low calorie diet (LCD)	The slow weight loss group will be prescribed an individualized low calorie diet (LCD) (1200-1500kcal/day), during 8 weeks, using meal replacements (such as smoothies, soups and cereal bars) and conventional foods. The macronutrient composition will be matched with that of the VLCD.
Rapid weight loss group	Very-low calorie diet (VLCD)	The rapid weight loss group will follow a commercial very-low calorie diet (VLCD) during 4 weeks. The participants allocated to this group will follow a 550 (women) - 660 (men) kcal/day diet. The VLCD products provide 110kcal/pack and include a variety of milkshakes, smoothies and soups. In addition to VLCD products, calorie-free drinks and some low-starch vegetables (maximum 2 cups/day) will be allowed. Drinking at least 2.5 liters of non-caloric liquids will be recommended.

Primary Outcome Measures

Name	Time	Method
Body composition	Baseline, 2 and 4 weeks (VLCD group) and 4 and 8 weeks (LCD group) and 12 weeks (both groups)	Body composition measured by air displacement plethysmography
Appetite related hormones	Before the start of the study and again at week 2 and 4 (VLCD group) and 4 and 8 (LCD group). And also, on week 12 (for both groups).	Appetite-related hormones (active ghrelin, PYY, GLP-1, CCK) will be measured in fasting and every 30 minutes up to 2,5 hours

Secondary Outcome Measures

Name	Time	Method
Exercise efficiency	Baseline, 2 and 4 weeks (VLCD group) and 4 and 8 weeks (LCD group) and 12 weeks (both groups)	Exercise efficiency measured by graded exercise on a bike
Resting metabolic rate (RMR)	Baseline, 2 and 4 weeks (VLCD group) and 4 and 8 weeks (LCD group) and 12 weeks (both groups)	RMR measured by indirect calorimetry

Trial Locations

Locations (1)

Norwegian University of Science and Technology; 🇳🇴 Trondheim, Norway