Efeito do consumo de alimentos ultraprocessados na composição corporal de adultos

Abstract

This thesis aimed to investigate the effect of consumption of ultra-processed foods (UPF) on body composition measurements (fat mass, fat mass distribution, lean mass and bone mass) of Brazilian adults. This is a longitudinal study carried out with healthy adults followed by the 1978/1979 birth cohort in Ribeirão Preto, São Paulo, Brazil. Food consumption was assessed at 23-25 years old using a Food Frequency Questionnaire (FFQ) and foods were grouped according to the NOVA classification. UPF consumption was expressed as a percentage of total daily intake (g/day) and as a percentage of caloric contribution (%kcal). At 37-39 years old, body mass index (BMI) and body composition were assessed. All variables were evaluated continuously. Two manuscripts were prepared. The first aimed to evaluate the effect of UPF consumption on the composition and distribution of body fat and lean muscle mass. 1,021 individuals participated in the analysis of fat mass and 815 in the analysis of lean muscle mass and distribution of fat mass. A theoretical model was created based on the construction of Directed Acyclic Graphs (DAG) according to the backdoor criterion to define the adjustment variables for analyzing the effect of AUP consumption on fat mass and lean muscle mass. Linear regression models were used to estimate the effect of UPF consumption (g/day) on BMI, percentage of body fat (%BF), fat mass index (FMI), android fat (AF), gynoid fat (GF), android-gynoid fat ratio (RAG), percentage of lean mass (%LM), lean mass index (LMI) and appendicular lean mass index (ALMI). Marginal plots were plotted to visualize interactions. The average daily consumption in grams of AUP was 35.8% (813.3 g). There was an association between UPF consumption and an increase in BMI, %BF, FMI, AF and GF and a decrease in %LM, only in women. Similar results were found for analysis in % of caloric contribution. The second manuscript aimed to analyze the association between the consumption of ultra-processed foods at 23-25 years old and the bone mass of individuals at 37-39 years old. 831 individuals participated in the analysis of the Bone Mineral Density (BMD, g/cm2

) of the whole body, 1,016 for analysis of the lumbar spine (L1-L4) and 1,009 for analysis of the left femoral neck. A theoretical model based on the construction of Directed Acyclic Graphs (DAG) according to the backdoor criterion to define the adjustment variables for analyzing the effect of UPF consumption on bone mass. Linear and non-linear regression models were used to estimate the effect of UPF consumption on bone mass. Marginal plots were plotted to visualize these effects. An analysis of the interaction between UPF consumption and sex and between UPF consumption and physical activity level was performed, using a significance level of p<0.10. None of the tested interactions was significant. A non-linear longitudinal association was found between UPF consumption and BMD of the entire body and left femoral neck in the analysis in % caloric contribution, and between UPF and BMD of the entire body and spine in the analysis in % grams. We conclude that a high consumption of UPF at age 23-25 years old is associated with long-term increase in fat mass and decrease in lean mass in adult women and is associated with changes in BMD in both sexes at age 37-39 years old.