Oral Presentation ANZOS-ASLM-ICCR 2019

Evidence for the protein leverage hypothesis in children and adolescents with obesity (#18)

Christoph CS Saner 1 2 3 , Daniella DT Tassoni 1 , Brooke BEH Harcourt 1 2 4 , Jeff JKT Kao 1 2 4 , Erin EA Alexander 1 , Zoe ZM MaCallum 1 2 , Timothy TO Olds 5 , Alex AR Rowlands 6 7 , David DPB Burgner 2 4 , Stephen SJS Simpson 8 9 , David DR Raubenheimer 8 9 , Alistair AMS Senior 9 10 , Markus MJ Juonala 2 3 , Matthew MAS Sabin 1 2 4
  1. Department of Endocrinology, Royal Children`s Hospital, Parkville, Victoria, Australia
  2. Murdoch Children's Research Institute, Parkville, Victoria, Australia
  3. Department of Medicine, University of Turku and Division of Medicine, Turku, Finland
  4. Department of Paediatrics, The University of Melbourne, Parkville, Victoria, Australia
  5. Alliance for Research in Exercise Nutrition and Activity (ARENA), Sansom Institute, Adelaide, South Australia, Australia
  6. Diabetes Research Centre, University of Leicester, Leicester, United Kingdom
  7. Biomedical Research Centre, NIHR Leicester , Leicester, United Kingdom
  8. Charles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia
  9. School of Life and Environmental Sciences, University of Sydney, Sydney, New South Wales, Australia
  10. Charles Perkins Centre, University of Sydney, Sydney, New South Wales, Australia

Background      The protein leverage hypothesis states that human beings will prioritize the consumption of protein in food over other macronutrients and will eat until protein needs have been met (regardless of energy content). This leads to over-consumption of food when protein content is low. The hypothesis has never been tested in obese youth.

Objective         To test the protein leverage hypothesis in a cohort of youth with obesity.

Methods          Retrospective study in a cohort of youth with obesity attending a tertiary weight management service. Validated food questionnaires (ACAES-FFQ) from 203 individuals were collected, identifyingtotal energy intake (TEI), and percentage energy intake from carbohydrates (%EC), fats (%EF) and proteins (%EP). Individuals with validated measures (Goldberg cut-off >1.2 for reported energy intake/basal metabolic rate from fat free mass) were included for further analysis. Statistics included compositional data analysis (CoDA) to predict TEI from macronutrient-ratios and modelling a power function to estimate the strength of protein leverage (L-coefficient; -1 is complete leverage, 0 no leverage).

Results             137 of 203 participants were included (Goldberg >1.2), mean age 11.3y (SD 2.7), 68 (50%) females, BMI z-score 2.47 (SD 0.27). Mean TEI was 10330 kJ (SD 2728), mean %EC 50.6% (SD 6.1), mean %EF 31.6% (SD 4.9) and mean %EP 18.4 (SD 3.1). The relationship between %EP and TEI followed a power function (Lcoefficient -0.48, p <0.001). Dietary macronutrient content affected total energy intake such that increasing the % of energy from protein was associated with lower total energy intake (p=0.04).

Conclusion       This is the first study to show that protein dilution by either carbohydrate or fat is associated with increases in TEI in obese youth. Assessment of dietary protein may therefore be useful in the management of youth with obesity. Further studies are required to show whether manipulation of dietary protein may be beneficial in these patients.