Factors influencing the intention of young adults to adopt genotype-based personalised advice on diet and physical activity according to perceived weight status.

Genotype-based dietary and physical activity advice can be delivered to young adults before unhealthy lifestyle behaviours or metabolic and physiological conditions have developed. The aim of the present study was to investigate the factors that influence the intention to adopt genotype-based personalised advice on diet and physical activity in young adults who perceive themselves to be a healthy weight versus those who perceive themselves to be overweight or obese. An online survey of 396 young adults (18-25 years) evaluated background factors (participant characteristics (including perception of body weight), psychological factors, belief composites) and constructs of the Theory of Planned Behaviour (TPB) related to the adoption of genotype-based personalised advice. The association between background factors and TPB constructs was assessed using multiple linear regression. The constructs of TPB predicted intention to adopt genotype-based personalised nutrition (P < 0.001, adj. R ² = 0.54; attitude: B = 0.24, subjective norm: B = 0.25, PBC: B = 0.45). Background factors including belief composites, health locus of control, gender, physical activity, and food choice motives of 'health', 'price', 'familiarity', 'weight control', and 'convenience' significantly added to models of TPB constructs related to the intention to adopt personalised advice (P < 0.05). The influence of background factors varied between TPB constructs and differed based on participants perception of their body weight. The study provides support for the use of the TPB in understanding the intention of young adults to adopt gene-based advice for dietary and physical activity behaviour. In addition to perceived body weight, the background factors identified should help to inform and modify the delivery of advice in behaviour change interventions that seek to use genotype-based personalised advice in young adult populations.