Association between dietary factors and brown adipose tissue volume/18F-FDG uptake in young adults.

Abstract Objective To study the association between usual dietary factors (dietary energy density, nutrient intake, food group consumption, and dietary pattern) and brown adipose tissue (BAT) volume/18F-fluorodeoxyglucose (18F-FDG) uptake after personalized cold exposure in young healthy adults. Methods A total of 122 young adults (n=82 women; 22.0±2.1 years old; 24.8±4.8 kg/m2) took part in this cross-sectional study. Dietary factors were measured via a food frequency questionnaire and three non-consecutive 24 h recalls. Dietary energy density (foods and caloric beverages included) and macronutrient intakes were subsequently estimated using EvalFINUT® software, food group consumption was estimated from the food frequency questionnaire, and different dietary patterns and quality indices were determined according to the reference methods. BAT volume, BAT 18F-FDG uptake, and skeletal muscle 18F-FDG uptake were assessed by static 18F-FDG positron-emission tomography and computed tomography (PET-CT) scans after a 2 h personalized exposure to cold. Results A direct association was detected between dietary energy density and BAT Standardized Uptake Value (SUV)mean (β=0.215; R2=0.044; P=0.022), and between ethanol consumption and BAT volume (β=0.215; R2=0.044; P=0.022). The a priori Mediterranean dietary pattern was inversely associated with BAT SUVmean and SUVpeak (β=-0.273; R2=0.075; P=0.003 and β=-0.255; R2=0.066; P=0.005 respectively). In addition, the diet quality index for a Mediterranean diet and a pro-inflammatory dietary pattern (as determined via the dietary inflammatory index) were directly associated with BAT SUVmean and SUVpeak (SUVmean: β=0.238; R2=0.053; P=0.013 and β=0.256; R2=0.052; P=0.012 respectively; SUVpeak: β=0.278; R2=0.073; P=0.003 and β=0.248; R2=0.049; P=0.016 respectively). After controlling for multiplicity and possible confounders (sex, the evaluation wave and BMI), all the detected associations persisted. Conclusion Dietary factors are slightly associated with BAT volume and/or 18F-FDG uptake after a personalized cold exposure in young adults. Our results provide an overall picture of the potential relationships between dietary factors and BAT-related variables in humans.