Oral Presentation ANZOS-Breakthrough Discoveries Joint Annual Scientific Meeting 2018

Improved vascular structure and function following intermittent energy restriction in adolescents with obesity (#112)

Hiba Jebeile 1 2 , Megan L Gow 2 3 , Natalie B Lister 1 2 , Marjan Mosalman Haghighi 2 , Kerryn Chisholm 2 , Alicia Grunseit 2 , Shirley Alexander 2 , Christopher T Cowell 2 , Louise A Baur 1 2 , Julian Ayer 1 2 , Sarah P Garnett 1 2
  1. Children's Hospital at Westmead Clinical School, The University of Sydney, Sydney, NSW, Australia
  2. Endocrinology, Cardiology and Weight Management Services, The Children’s Hospital at Westmead, Westmead, NSW, Australia
  3. Children’s Hospital Westmead Clinical School, The University of Sydney, Sydney, NSW, Australia

Background: In adults, intermittent energy restriction (IER), popularised as the 5:2 diet, is as effective for weight loss and improved cardiovascular risk as continuous energy restriction. We investigated the impact of IER on vascular structure and function in adolescents with obesity.

Methods: During weeks 1-12, participants followed an IER plan consisting of a Very Low Energy Diet (VLED) 3 days/week (500-600kcal/day) and a standard healthy diet 4 days/week. For weeks 13-26, participants were given a choice to continue with 1-3 days of VLED/week or follow a standard healthy diet. Outcomes measured at 0, 12 and 26 weeks were BMI expressed as a percentage of the 95th percentile (BMI%95th), blood pressure, fasting lipids, pulse wave velocity (PWV), carotid intima-media thickness (CIMT), and flow meditated dilation (FMD). 

Results: 30 participants, aged 12-17 years (median 15.2 years, female n=25) with a median BMI 34.9kg/m2 (range: 27.7 - 52.4), were recruited.  Compared with baseline, BMI%95th was significantly reduced at 12 weeks (mean difference [SD], n=23, -5.4 [2.2], p<0.0001) and 26 weeks (n=21, -5.0 [9.3], p=0.02). Triglycerides and brachial systolic blood pressure were also reduced at 26 weeks compared with baseline (n=21, -0.22mmol/L [0.31], p=0.008 and n=13, -5.6mmHg [8.9], p=0.042, respectively). CIMT (n=16, -0.06µm [0.05], p=0.001) and FMD (n=15, absolute increase of 0.51% [0.5], p=0.001) improved between baseline and 12 weeks.  The improvement was maintained at 26 weeks. Reduced BMI%95th was associated with improved PWV (rho=0.63, p=0.022) and FMD (r2=0.80, p<0.0001) at 26 weeks.  

Conclusion: IER is an effective dietary intervention in adolescents with obesity, resulting in reduced BMI%95th and cardiovascular risk in the short term. Findings demonstrate a potential benefit to cardiovascular health if maintained. A 12-month RCT is underway comparing IER with continuous energy restriction.

This study was funded by the Foundation for Children and Heart Foundation of Australia Vanguard Grant.