This study evaluated global trends in ultraprocessed food and drink (UPFD) volume sales/capita and associations with adult body mass index (BMI) trajectories. Total food/drink volume sales/capita from Euromonitor for 80 countries (2002-2016) were matched to mean adult BMI from the NCD Risk Factor Collaboration (2002-2014). Products were classified as UPFD/non-UPFD according to the NOVA classification system. Mixed models for repeated measures were used to analyse associations between UPFD volume sales/capita and adult BMI trajectories, controlling for confounding factors. The increase in UPF volume sales was highest for South and Southeast Asia (67.3%) and North Africa and the Middle East (57.6%), while for UPD, the increase was highest for South and Southeast Asia (120.0%) and Africa (70.7%). In 2016, baked goods were the biggest contributor to UPF volume sales (13.1%-44.5%), while carbonated drinks were the biggest contributor to UPD volume sales (40.2%-86.0%). For every standard deviation increase (51 kg/capita, 2002) in UPD volume sales, mean BMI increased by 0.195 kg/m2 for men (P < .001) and 0.072 kg/m2 for women (P = .003). For every standard deviation (40 kg/capita, 2002) increase in UPF volume sales, mean BMI increased by 0.316 kg/m2 for men (P < .001), while the association was not significant for women. Increases in UPFD volume sales/capita were positively associated with population-level BMI trajectories.