ABSTRACT The aim of this study was to evaluate the nutritional and behavioral effects of a cafeteria diet in dams during the breastfeeding period and in their offspring from weaning until early adulthood (70 days old). Pregnant Wistar rats were fed a chow diet until delivery. Postnatally (D0), litters were culled to 8 pups and lactating dams received control (CTRL n= 6) or cafeteria (CAF n= 6) diets and water ad libitum. At the end of the breastfeeding period, male offspring were placed in individual boxes receiving the same treatment from their respective dams (CTRL or CAF) until adulthood (70 days). All nutritional and behavioral evaluations were performed with the dams (n= 12) during the breastfeeding phase and with the male offspring (n= 24) after weaning to adulthood. CAF dams demonstrated a lower caloric and protein intake; higher intake of fats; loss of weight; greater accumulation of adipose tissue; and an anxiolytic effect. CAF male offspring showed lower caloric intake; higher intake of fats; and accumulation of adipose tissue. In addition, these animals continued to have decreased body weight, body length and tibia-femur length in relation to CTRL. In dams, a cafeteria diet promoted alterations in body composition and anxiety, and in offspring the diet resulted in adequate development.