Association between Fat-Free Mass Loss, Changes in Appetite, and Weight Regain in Individuals with Obesity

Catia Martins; Siren Nymo; Silvia R Coutinho; Jens F Rehfeld; Gary R Hunter; Barbara A Gower

doi:10.1016/j.tjnut.2023.03.026

Association between Fat-Free Mass Loss, Changes in Appetite, and Weight Regain in Individuals with Obesity

J Nutr. 2023 May;153(5):1330-1337. doi: 10.1016/j.tjnut.2023.03.026. Epub 2023 Mar 23.

Authors

Catia Martins¹, Siren Nymo², Silvia R Coutinho³, Jens F Rehfeld⁴, Gary R Hunter⁵, Barbara A Gower⁵

Affiliations

¹ Department of Nutrition Sciences, University of Alabama at Birmingham (UAB), USA; Obesity Research Group, Department of Clinical and Molecular Medicine, Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; Centre for Obesity and Innovation (ObeCe), Clinic of Surgery, St. Olav University Hospital, Trondheim, Norway. Electronic address: catia197@uab.edu.
² Obesity Research Group, Department of Clinical and Molecular Medicine, Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; Nord-Trøndelag Hospital Trust, Clinic of Surgery, Namsos Hospital, Norway.
³ Obesity Research Group, Department of Clinical and Molecular Medicine, Faculty of Medicine, Norwegian University of Science and Technology (NTNU), Trondheim, Norway; Department of Public Health Nutrition, Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo (UiO), Norway.
⁴ Department of Clinical Biochemistry, Rigshospitalet, University of Copenhagen, Copenhagen, Denmark.
⁵ Department of Nutrition Sciences, University of Alabama at Birmingham (UAB), USA.

PMID: 36963504
DOI: 10.1016/j.tjnut.2023.03.026

Abstract

Background: The role of fat-free mass loss (FFML) in modulating weight regain in individuals with obesity, as well as the potential mechanisms involved, remain inconsistent.

Objectives: The aim of this study was to determine if % FFML following weight loss (WL) is a predictor of weight regain and to investigate the association between %FFML and changes in appetite markers.

Methods: Seventy individuals with obesity (BMI: 36 ± 4 kg/m²; age: 44 ± 9 y; 29 males) underwent 8 wk of a very low energy diet (550-660 kcal/d), followed by 4 wk of gradual refeeding and weight stabilization and a 9-mo maintenance program (eucaloric diet). The primary outcomes were body weight and body composition (fat mass and fat-free mass). The secondary outcomes were plasma concentrations of β-hydroxybutyrate (a marker of ketosis) in fasting and appetite-related hormones (ghrelin, glucagon-like peptide 1, peptide YY, and cholecystokinin) and subjective appetite feelings during fasting and every 30 min after a fixed breakfast for 2.5 h. All were measured at baseline, week 9, and 1 y [week 13 in 35 subjects (25 males)]. The association between FFML, weight regain, and changes in appetite was assessed by linear regression.

Results: WL at week 9 was 17.5 ± 4.3kg and %FFML 20.4 ± 10.6%. Weight regain at 1 y was 1.7 ± 8.2 kg (8.8 ± 45.0%). After adjusting for WL and fat mass at baseline, %FFML at week 9 was not a significant predictor of weight regain. Similar results were seen at week 13. The greater the %FFML at week 9, but not 13, the smaller the reduction, or greater the increase in basal ghrelin concentration (β: -3.2; 95% CI: -5.0, -1.1; P = 0.003), even after adjusting for WL and β-hydroxybutyrate.

Conclusions: %FFML was not a significant predictor of weight regain at 1 y in individuals with obesity. However, a greater %FFML was accompanied by a greater increase in ghrelin secretion under ketogenic conditions, suggesting a link between fat-free mass and appetite regulation. This trial was registered at clinicaltrials.gov as NCT01834859.

Keywords: appetite; fat-free mass; ghrelin; hunger; weight loss; weight regain.

Published by Elsevier Inc.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

3-Hydroxybutyric Acid
Adult
Appetite*
Ghrelin*
Humans
Male
Middle Aged
Obesity
Peptide YY
Weight Gain
Weight Loss / physiology

Substances

Ghrelin
3-Hydroxybutyric Acid
Peptide YY

Associated data

ClinicalTrials.gov/NCT01834859