Obesity and non‐alcoholic fatty liver disease are the most common metabolic disorders in society today. Previously, we found that supplementing the maternal diet during pregnancy with chocolate and fructose has negative effects on the well‐being of the offspring that were ameliorated if the offspring were fed a normal diet during postnatal life. In the present study, we investigated whether feeding offspring a high‐fat diet would augment the maternal programming effects and whether extra protein supply can correct the low birth weight resulting from the chocolate‐supplemented maternal diet. Pregnant Sprague‐Dawley rats were divided into three groups and fed either standard chow (normal nutrition; NN), chocolate‐ and fructose‐supplemented standard chow with casein sodium (overnutrition; ON) or the supplemented standard chow without casein sodium (malnutrition; MN) throughout pregnancy. Male offspring were weaned on either standard or high‐fat chow. Dams in the MN group exhibited moderate weight gain, consumed 50% less protein (P < 0.001) but more carbohydrates during gestation and delivered pups with a 12% lower birth weight (P < 0.05) than pups in the NN group, results that are consistent with previous findings. When fed on a high‐fat diet after birth, pups from dams in the MN group (MNHD) had 30% more body fat (P = 0.023) and liver triglyceride (TG) levels that were double (P < 0.01) those in offspring in the other groups, leading to fatty livers in these offspring at 14 weeks of age. Hepatic expression of the PPARα, ApoB100, MTTP, CPT1 and SREBP1c genes was significantly downregulated in the MNHD group (P < 0.05 for all), indicating changes in lipid metabolism. Although dams in the ON group exhibited marked gestational weight gain (P < 0.01), they gave birth to normal weight pups that only manifested mild increases in body fat and liver TG content (P < 0.05), without significant changes in the expression of most genes when fed with the high‐fat diet. The results suggest that the extra protein supply in the form of casein sodium was able to correct some negative programming effects of the chocolate and fructose supplementation of the maternal diet, which, in conjunction with a high‐fat diet in the offspring, may facilitate the onset of metabolic disorders, with impaired liver gene expression possibly a key contributor.