Introduction: Breastfeeding is a protective factor against childhood obesity; however, its association with the intake of critical nutrients in the development of obesity is unknown. Objective: To analyze the association between the duration of breastfeeding with the intake of total sugar, added sugar and total fat in the diet of children aged 5 to 8 years. Methods: A cross-temporal correlational study was carried out in 62 boys and girls from 5 to 8 years old and their tutors. Sugar and fat intake was obtained through two 24-h recalls, analyzed with Food Processor® software. The duration of breastfeeding was evaluated by asking the tutors and the association with fat and sugar intake was determined with the Spearman correlation coefficient. Results: The average age of the boys and girls was 6.4 ± 0.9 years and that of the tutors was 34.2 ± 7.2 years. 43.5% received exclusive breastfeeding and the average duration was 18.1 ± 12.7 months. High daily consumption of sugars was observed (90.7 ± 37.4 g), the average total fat consumption was 48.9 ± 22.4 g. No. correlation was evident between the duration of lactation and the intake of sugars and total fat. Conclusions: The duration of breastfeeding was not associated with the intake of total sugar, added sugar, and dietary fat, critical nutrients for the development of childhood obesity