|Population||All adults aged 18 years and over. Studies where participants were drawn from a population with a psychiatric condition such as an eating disorder were excluded.|
Diet: for the purpose of this review, an intervention involving a “whole dietary pattern” such as the Mediterranean diet  Dash diet  MIND diet  or foods analysed from 4 out of 5 of the food groups (protein, grains/carbohydrates, oil and fats, dairy, fruit/vegetable. Studies were not included where the dietary behaviour was a de facto medical treatment e.g. gluten free diet, also single food group and nutrients diet studies such as, fruit and vegetable, or omega 3 were excluded, as these don’t from a “whole dietary” pattern.|
Theoretical model: Studies were included that used a theoretical framework to deliver their intervention. Theoretical models such as the Health Belief Model (HBM)  Stages of Change Model  and Health Action Process Approach (HAPA)  were included.
|Comparison||Usual diet, information booklet.|
|Outcome||Improved diet quality, increased adherence to diet.|
|Study design||Randomised controlled trials and non-randomised controlled trials published in English.|