The efficacy of genotype-based dietary or physical activity advice on behaviour change to reduce the risk of CVD, T2DM or obesity: a systematic review and meta-analysis.

Context: Despite clear evidence that adherence to dietary and physical activity advice can reduce the risk of cardiometabolic disease, a significant proportion of the population do not meet recommendations. Personalised advice based on genetic variation has been proposed to motivate behaviour change, although research to date has been contradictory. Objective: To evaluate the efficacy of genotype-based dietary or physical activity advice on behaviour change in the general population and individuals that are at-risk of CVD or T2DM. Data sources: MEDLINE, Embase, PsycINFO and the Cochrane Central Register of Controlled Trials (CENTRAL) up to 7th January 2022. Randomised controlled trials of a genotype-based dietary and/or physical activity advice intervention that aimed to change dietary and/or physical activity behaviour were included. Data extraction: Abstracts of 7899 records were screened, 14 reports from 11 studies met the inclusion criteria. Data analysis: There was no effect of genotype-based dietary or physical activity advice on dietary behaviour for all studies SMD 0.00 (-0.11 – 0.11, p = 0.98) or when analysed by sub-group; ‘at risk’ SMD 0.00 (-0.16 - 0.16, p = 0.99); general population SMD 0.01 (-0.14 – 0.16, p = 0.87). Similar findings were identified for physical activity behaviour for all studies SMD - 0.01 (-0.10 – 0.08, p = 0.88) or when analysed by sub-group; ‘at risk’ SMD 0.07 (-0.18 - 0.31, p = 0.59); general population SMD -0.02 (-0.13 – 0.10, p = 0.77). The quality of evidence for the dietary behaviour outcome was low and for the physical activity behaviour outcome it was moderate. Conclusions: Genotype-based advice does not affect dietary or physical activity behaviour more than general advice or advice based on lifestyle or phenotypic measures. This was consistent in studies that recruited participants from the general population as well as studies that had recruited participants from populations at-risk of CVD or T2DM.