ABSTRACT
BACKGROUND/OBJECTIVES: The escalating obesity epidemic necessitates effective, sustainable weight loss (WL) and maintenance strategies. This study aimed to evaluate the effectiveness of the Weight Loss Maintenance 3 Phases Program (WLM3P) in achieving a clinically significant long-term weight loss (WL) (≥5% initial WL at 18 months) in adults with obesity compared to a standard low-carbohydrate diet (LCD). SUBJECTS/METHODS: In this two-phase trial, 112 participants targeting initial WL (0-6 months) and subsequent maintenance (7-18 months) were randomly assigned to either WLM3P or LCD groups. Outcomes assessed included change in body weight (kg, %), improvements in body composition, and metabolic profile. RESULTS: Of 112 randomized participants, 69% (n = 77) completed the study. At 18 months, WL in the WLM3P group (n = 40) was 15.5 ± 8.3% compared to 9.6 ± 8.5% in the LCD group (n = 37) (p < 0.001). The odds ratio of achieving WL ≥ 10% and ≥15% were significantly higher in the WLM3P group. Complete-case analysis revealed significantly greater improvements in BMI, body fat mass, visceral fat area, waist circumference, waist-to-hip ratio, HDL, and triglyceride/HDL ratio in WLM3P than in LCD. No serious adverse events were reported. CONCLUSION: Both programs effectively promoted clinically relevant WL and its maintenance. However, the WLM3P program was more successful in helping participants achieve greater WL targets of ≥10% and ≥15%, along with other clinical benefits, after an 18-month intervention. TRIAL REGISTRATION NUMBER: NCT04192357.
ABSTRACT
BACKGROUND: Adaptive thermogenesis, defined as the decrease in the energy expenditure components beyond what can be predicted by changes in body mass stores, has been studied as a possible barrier to weight loss and weight maintenance. Intermittent energy restriction (IER), using energy balance refeeds, has been pointed out as a viable strategy to reduce adaptive thermogenesis and improve weight loss efficiency (greater weight loss per unit of energy deficit), as an alternative to a continuous energy restriction (CER). Following a randomized clinical trial design, the BREAK Study aims to compare the effects of IER versus CER on body composition and in adaptive thermogenesis, and understand whether participants will successfully maintain their weight loss after 12 months. METHODS: Seventy-four women with obesity and inactive (20-45 y) will be randomized to 16 weeks of CER or IER (8x2 weeks of energy restriction interspersed with 7x1 week in energy balance). Both groups will start with 2 weeks in energy balance before energy restriction, followed by 16 weeks in energy restriction, then 8 weeks in energy balance and finally a 12-month weight maintenance phase. Primary outcomes are changes in fat-mass and adaptive thermogenesis after weight loss and weight maintenance. Secondary outcomes include weight loss, fat-free mass preservation, alterations in energy expenditure components, and changes in hormones (thyroid function, insulin, leptin, and cortisol). DISCUSSION: We anticipate that The BREAK Study will allow us to better understand adaptive thermogenesis during weight loss and weight maintenance, in women with obesity. These findings will enable evidence-based decisions for obesity treatment. TRIAL REGISTRATION: ClinicalTrials.gov: NCT05184361.
