Objective: To describe characteristics of self-identified popular diet followers and compare mean BMI across these diets, stratified by time following diet.
Design: Cross-sectional, web-based survey administered in 2015.
Setting: Non-localised, international survey.
Participants: Self-selected followers of popular diets (n 9019) were recruited to the survey via social media and email announcements by diet community leaders, categorised into eight major diet groups.
Results: General linear models were used to compare mean BMI among (1) short-term (<1 year) and long-term (≥1 year) followers within diet groups and (2) those identifying as ‘try to eat healthy’ (TTEH) to all other diet groups, stratified by time following the specific diet. Participants were 82 % female, 93 % White and 96 % non-Hispanic. Geometric mean BMI was lower (P < 0·05 for all) among longer-term followers (≥1 year) of whole food, plant-based (WFPB), vegan, whole food and low-carb diets compared with shorter-term followers. Among those following their diet for 1–5 years (n 4067), geometric mean BMI (kg/m2) were lower (P < 0·05 for all) for all groups compared with TTEH (26·4 kg/m2): WFPB (23·2 kg/m2), vegan (23·5 kg/m2), Paleo (24·6 kg/m2), vegetarian (25·0 kg/m2), whole food (24·6 kg/m2), Weston A. Price (23·5 kg/m2) and low-carb (24·7 kg/m2).
Conclusion: Our findings suggest that BMI is lower among individuals who made active decisions to adhere to a specific diet, particularly more plant-based diets and/or diets limiting highly processed foods, compared with those who simply TTEH. BMI is also lower among individuals who follow intentional eating plans for longer time periods.