Plant-based Diet and Adiposity Over Time in a Middle-aged and Elderly Population: The Rotterdam Study.

BACKGROUND: We aimed to explore whether adhering to a more plant-based diet, beyond strict vegan or vegetarian diets, may help prevent adiposity in a middle-aged and elderly population.

METHODS: We included 9,633 participants from the Rotterdam Study, a prospective cohort in the Netherlands. Dietary data were collected using food-frequency questionnaires at baseline of three subcohorts of the Rotterdam Study (1989-1993, 2000-2001, 2006-2008). We created a plant-based diet index by giving plant-based foods positive scores and animal-based foods reverse scores. A higher score on the index reflected an overall more plant-based and less animal-based diet. Data on anthropometrics and body composition (using dual energy X-ray absorptiometry) were collected every 3-5 years from 1989 to 2016. We used multivariable linear mixed models to analyze the associations.

RESULTS: In the 9,633 participants, baseline plant-based diet score ranged from 21.0 to 73.0 with a mean ± SD of 49.0 ± 7.0. In multivariable-adjusted analyses, higher adherence to a plant-based diet was associated with lower BMI, waist circumference, fat mass index, and body fat percentage across a median follow-up period of 7.1 years (per 10 points higher score, BMI: β = -0.70 kg/m [95% CI = -0.81, -0.59]; waist circumference: -2.0 cm [-2.3, -1.7]; fat mass index: -0.66 kg/m [-0.80, -0.52]; body fat percentage: -1.1 points [-1.3, -0.84]).

CONCLUSIONS: In this population-based cohort of middle-aged and elderly participants, a higher adherence to a more plant-based, less animal-based diet was associated with less adiposity over time, irrespective of general healthfulness of the specific plant- and animal-based foods.