Fetal and early postnatal nutritional environments contribute to lifelong health. High-protein (HP) intake in early life can increase obesity risk in response to specific feeding conditions after weaning. This study investigated the effects of a maternal HP diet during pregnancy and/or lactation on the metabolic health of offspring. Three groups of dams received a normal-protein (NP, 20E% proteins) diet during gestation and lactation (Control group), an HP diet (55E% proteins) during gestation (HPgest group), or an HP diet during lactation (HPlact group). From weaning until 10 weeks, female pups were exposed to the NP, the HP or the western (W) diet. HPgest pups had more adipocytes ( = 0.009), more subcutaneous adipose tissue ( = 0.04) and increased expression of genes involved in liver fatty acid synthesis at 10 weeks ( < 0.05). HPgest rats also showed higher food intake and adiposity under the W diet compared to the Control and HPlact rats ( ≤ 0.04). The post-weaning HP diet reduced weight ( < 0.0001), food intake ( < 0.0001), adiposity ( < 0.0001) and glucose tolerance ( < 0.0001) compared to the NP and W diets; this effect was enhanced in the HPgest group ( = 0.04). These results show that a maternal HP diet during gestation, but not lactation, leads to a higher susceptibility to obesity and glucose intolerance in female offspring.