The perinatal period is a critical period during which the quality of the environment has long lasting effects on adult phenotype. Early adversity in childhood has been associated with higher risks to develop neuropsychiatric disorders later in life. Nowadays, modern societies are characterized by a high consumption of fat. Although these changes also affect nutritional environment during the perinatal period, their impacts on brain functioning and behavior remain still unknown. Our study is aiming to determine the programming effects of maternal high-fat diet (HFD, western diet) and early stress (maternal separation) on offspring behaviour in particular emotional behavior, cognition and food intake. Our results reveal that maternal separation enhances motivation for palatable food and combined with maternal HFD exacerbates vulnerability to diet induced obesity. In contrast, maternal HFD protects the offspring against the emotional and cognitive impairments induced by maternal separation. This protective effect of maternal HFD could be related to the increase of maternal care in stressed dams exposed to HFD and to the attenuation of neurodevelopmental alterations in the prefrontal cortex of stressed pups. In conclusion, our work demonstrates that stress and nutrition during early life interact and influence later adult phenotype.