Body Fusion are dietitian specialists based in Sydney providing the best nutrition and »Body Fusion are dietitian specialists based in Sydney providing the best nutrition and diet advice. Body Fusion is a private Sydney based Nutrition and Dietetic practice run by Ashleigh Brunner. Ashleigh is an Accredited Practising Dietitian & Accredited Nutritionist who specialises in assisting in a wide spectrum of diet related issues for all ages, from children through to adults.