Poster Presentation Australian and New Zealand Obesity Society Annual Scientific Conference 2023

Safety and acceptability of a very-low-energy diet for the treatment of adolescent obesity: a Fast Track to Health sub-study (#234)

Megan L Gow 1 2 , Eve T House 3 , Alicia M Grunseit 3 , Mary-Kate Inkster 4 5 , Kaitlin Day 5 , sarah Lang 5 , Cathy Kwok 3 , Hiba Jebeile 2 3 , Natalie B Lister 2 3 , on behalf of the Fast Track to Health study team 1 2 3 4 5
  1. University of New South Wales, Sydney, NSW, Australia
  2. University of Sydney, Sydney, NSW, Australia
  3. The Children's Hospital Westmead, Westmead, NSW, Australia
  4. Monash Children's Hospital, Clayton, VIC, Australia
  5. Monash University, Melbourne, VIC, Australia

Introduction: Very-low-energy diets (VLED) induce rapid weight loss. However, concerns remain surrounding their safety for adolescent use. This study aimed to report on the safety and acceptability of a 4-week VLED for adolescents with obesity.

Methods: Adolescents were participants in the Fast Track to Health 52-week randomised controlled trial which recruited 13–17 year olds, with obesity and ≥1 obesity-related complication. Participants undertook a 4-week micronutrient complete VLED (800 kcal/day), with weekly dietitian support, before commencing their randomised dietary intervention: intermittent or continuous energy restriction. Weight was recorded at baseline and week-4 and side-effects at weeks 0, 1, 2 and 4. Adolescents completed an acceptability survey at week-4.

Results: Of 141 adolescents recruited to Fast Track, 134 (14.9±1.2 years, 50% male) completed the 4-week VLED and lost an average of 5.5±2.9 kg (p<0.001). Nearly all (92%) experienced ≥1 and most (59%) experienced ≥3 side-effects during the VLED. Side-effects peaked during week-1. Hunger, fatigue, headache, irritability, loose stools, constipation, nausea and lack of concentration were most common. More side-effects during week-0 was associated with greater weight loss at 4-weeks (r=-0.188, p=0.03). Seven participants experienced viral infections; two modified their VLED regimen consequently. On a 100-point Likert scale, adolescents rated the intervention 61±24 for easy to follow (easy=100-points, difficult=0-points) and 53±24 for enjoyable to follow (enjoyable=100-points, not-enjoyable=0-points). Losing weight (34%) and the prescriptive structure (28%) were reported as the most positive aspects of the VLED intervention. The restrictive nature (45%) and taste of meal replacement products (20%) were liked least.

Conclusions: A health professional monitored VLED can be implemented safely in the short-term and is acceptable for many adolescents, despite being associated with frequent side-effects. More emphasis on the utility of VLED interventions in clinical practice guidelines for adolescent obesity treatment is required, especially as an intermediate step before pharmacological/surgical intervention.