The association between Planetary Health Diet, body mass index and polygenic risk score for obesity

Abstract Background The way we eat and produce food are threatening our health and environmental sustainability. The EAT-Lancet Planetary Health Diet (PHD) was launched to consider both aspects. The association between PHD and body mass index (BMI) has barely been studied, and especially the role of inheritance in this context is unclear. Therefore, we examined the association between PHD and BMI and further evaluated whether the association differs by the level of genetic susceptibility for obesity. Methods In total, 4377 participants (≥18 years, female 56%) from the Finnish FinHealth 2017 Study were included. A validated food frequency questionnaire was used to assess the habitual diet. We developed an energy-standardized dietary index based on the PHD adapted for the Finnish food culture (score range 0 − 13 points). Genetic susceptibility for obesity was evaluated with a polygenic risk score (PRS) based on one million obesity associated single nucleotide polymorphisms. Linear regression was used for the statistical analyses. Results The mean PHD score for all participants was 4,0 (SD 1,5). There was a borderline negative association between PHD and BMI (β -0.01 95% CI -0.02, 0.00). When the genetic background was considered, this negative association reached statistical significancy in two lowest quartiles of PRS (lower susceptibility for obesity) (p