It is known that adverse stimuli, such as altered diets during pregnancy and lactation, can result in deleterious effects on the progeny. The aim of this study was to evaluate the possible gastrointestinal repercussions in the offspring of Wistar rats exposed to high-fat diets. Pregnant rats were divided into three groups: normolipidic diet (3.5% lipids), a diet containing 28% lipids, and a diet with 40% lipids. Body weight and food, water, daily caloric, and macronutrient intake were evaluated in the pregnant rats. Structural and functional gastrointestinal parameters were assessed in 30-day-old male pups. Depending on the lipid content of the maternal diet, the pups may exhibit gastric mucosal thickening, an increase in the relative weight of the small intestine, a reduction in the jejunal and ileal mucosa, and a decrease in the total thickness of the ileum. Additionally, there may be a reduction in the number of villi per area in these organs and a thinning of the muscular layer in the large intestine. The structural changes induced by the maternal high-fat diet seem to reduce the stomach’s sensitivity to ethanol-induced ulcers, which is the only functional alteration observed. Therefore, the offspring of dams exposed to high-fat diets during pregnancy and lactation exhibits impaired gastrointestinal development, with alterations depending on dietary fat content and specific gastrointestinal regions. Structural changes did not always result in functional abnormalities and, in some cases, appeared protective. The long-term consequences of the observed morphological alterations require further investigation.