Growing evidence suggests that maternal malnutrition during pregnancy and lactation initiates obesity and related disorders in the developing offspring. However, most of the evidence comes from maternal undernutrition studies and the influence of maternal overeating is less well characterised. Such characterisation is crucial given that 65% of the world’s population live in countries where overweight kills more people than underweight1.
We have developed a rat model to determine the effects of maternal overeating in pregnancy and lactation on offspring development, growth and health into adult life.
With this model, we have shown that offspring born to mothers fed an obesogenic "Western" diet in pregnancy and lactation developed exacerbated overeating and selective preference for fat, sugar and salt, leading to obesity by the end of adolescence2. These offspring also exhibited impaired skeletal muscle development and increased intramuscular fat, indicative of insulin resistance, at weaning3, followed by reduced muscle strength4, a predictor of early mortality5, at the end of adolescence. Offspring born to mothers fed the obesogenic diet exhibited elevated glycaemia, insulinemia and lipidemia6 as well as non-alcoholic fatty liver disease7 at the end of adolescence, while these parameters were unaffected in rats fed the obesogenic diet post-weaning. Gene expression analyses revealed gender dimorphism in the molecular response to diet-induced obesity in adipose and liver tissues6,7. Rehabilitation to a lean diet post-weaning prevented obesity2 but did not restore muscle function4 nor fully reversed adiposity6 , hepatic steatosis and oxidative stress7.
This model brings direct physiological evidence that maternal overeating in pregnancy and lactation promotes the early onset of obesity and related diseases in offspring. Some effects are not reversible through rehabilitation to a lean diet post-weaning. This supports the need to tackle obesity from the early stages of life through prevention of excessive gestational weight gain and adequate nutrition while pregnant and breastfeeding.