Para Abigail, José Antônio e Martin, mesmo longe, sempre presentes.
AGRADECIMENTOSAo meu orientador, Prof. Carlos, profunda admiração e agradecimento pela paciência, confiança, dedicação, entusiasmo e incentivo;À Renata, meu grande exemplo de profissional;À Ana Paula, pelo acolhimento, aprendizado e conforto; À Regina, pela competência e parceria;Às professoras Patrícia, Rosely e Sônia e ao professor Aluísio, pela participação valiosa na comissão avaliadora desta tese; were classified according to characteristics of food processing. Ultra-processed foods were defined as industrial formulations that are predominantly made from substances that are extracted from food (oils, fats, sugar), derived from food constituents (hydrogenated fats, modified starch) or synthesized in a laboratory from organic materials (colorants, flavorings, flavor enhancers). Examples included candies, chocolates, ice cream and confectionary in general, cookies, crackers, chips, sugarsweetened beverages, hamburgers and other "fast food" dishes. Regression models were fitted to evaluate the association of quintiles of consumption of ultra-processed foods (% of energy intake) with the nutrient intake profile (manuscripts 1 and 2) and obesity indicators (manuscript 3). In the fourth manuscript, estimates of the consumption of ultra-processed food obtained from the module of household food acquisition and from the module of individual food intake were compared. Results: The nutrient profile of ultra-processed foods, compared to the rest of the diet, revealed higher energy density, higher content in added sugar and in total, saturated, and trans fats, and lower in fiber, protein and many micronutrients. Higher contribution of ultra-processed foods to the total diet was associated with an overall deterioration of the nutrition profile of the diet.The 20% lowest consumers of ultra-processed foods were anywhere near reaching international nutrient goals for the prevention of obesity and chronic non-communicable diseases. Individuals in the highest quintile of consumption of ultra-processed foods had significantly higher body-mass-index (0.94 kg/m 2 ; 95% CI: 0.42,1.47) and higher odds of being obese (OR=1.98; 95% CI: 1.26,3.12) compared with those in the lowest quintile of consumption. Comparative analyses showed a reasonable agreement between the estimates of ultra-processed foods consumption obtained from household acquisition and individual food intake inside home data. Conclusions: The results from this study highlight the damage to health that is arising based on the observed trend of replacing traditional meals, based on natural or minimally processed foods, with ultra-processed foods. These results also support the recommendation of avoiding the consumption of these foods. In addition, our findings strengthen the use of household acquisition data, which is collected systematically in Brazil since the 70s, as a proxy of the actual intake of ultra-processed foods. In the absence of nationally representative dietary intake surveys, household d...