Introduction to complementary feeding in the first year of life and risk of overweight at 24 months of age: changes from 2004 to 2015 Pelotas (Brazil) Birth Cohort.

: Complementary feeding (CF) and overweight relation during early childhood is inconsistent in the literature. We described CF during the first year of life and risk of overweight at 24-months of age association in the population-based 2004- and 2015-Pelotas (Brazil) Birth Cohorts (2004c and 2015c). CF introduction was evaluated at the 3- and 12-month follow-ups by asking mothers using a list of foods. Risk of overweight at 24-months of age was body mass index-for-age z-score above +1 standard deviation from the median of the WHO 2006 growth standards. Our analyses included 3,823 (2004c) and 3,689 (2015c) children. Early introduction CF (before 6-months of age) prevalence in 2004c was 93.3% (95%CI 92.5-94.1) and 2015c was 87.2% (95%CI 86.1-88.2). Tea was the item introduced earlier in both 2004c (68.8%) and 2015c (55.7%). At 6-months of age, vegetable mash was the most introduced food in 2004c (33.5%) and 2015c (47.9%). Between 2004c and 2015c, the introduction of fresh milk decreased 82.1% to 60.5% and yogurt from 94.4% to 78.1% during the first year. Risk of overweight prevalence at 24-months was 33.0% (95%CI 31.6-34.5) in 2004c and 32.0% (95%CI 30.5-33.5) in 2015c. In the 2015c, the adjusted odds of risk of overweight at 24-months were increased 1.66 and 1.50 times with the early introduction of fresh/powdered milk: plus water, tea or juice, and plus semi-solid/solid food groups, respectively. It is essential to reinforce the adherence to global recommendations on timely feeding introduction and encourage exclusive breastfeeding until 6-months of age to prevent child overweight.