Food and Behaviour Research

Donate Log In

Building a Better Brain with Micronutrients - BOOK HERE

A maternal 'junk food' diet in pregnancy and lactation promotes an exacerbated taste for 'junk food' and a greater propensity for obesity in rat offspring

Bayol SA, Farrington SJ, Stickland NC (2007) British Journal of Nutrition 98(4) 843-51. Epub 2007 Aug 15. 

Web URL: View this and related abstracts via PubMed here


Obesity is generally associated with high intake of junk foods rich in energy, fat, sugar and salt combined with a dysfunctional control of appetite and lack of exercise.

There is some evidence to suggest that appetite and body mass can be influenced by maternal food intake during the fetal and suckling life of an individual. However, the influence of a maternal junk food diet during pregnancy and lactation on the feeding behaviour and weight gain of the offspring remains largely uncharacterised.

In this study, six groups of rats were fed either rodent chow alone or with a junk food diet during gestation, lactation and/or post-weaning. The daily food intakes and body mass were measured in forty-two pregnant and lactating mothers as well as in 216 offspring from weaning up to 10 weeks of age.

Results showed that 10 week-old rats born to mothers fed the junk food diet during gestation and lactation developed an exacerbated preference for fatty, sugary and salty foods at the expense of protein-rich foods when compared with offspring fed a balanced chow diet prior to weaning or during lactation alone. Male and female offspring exposed to the junk food diet throughout the study also exhibited increased body weight and BMI compared with all other offspring.

This study shows that a maternal junk food diet during pregnancy and lactation may be an important contributing factor in the development of obesity.


This study shows that a maternal diet high in junk foods during pregnancy and breastfeeding can lead to an enhanced taste for junk foods, overeating and obesity in the offspring - at least in rats.

Media reports cite some commentators as saying that these results cannot be generalised to humans. See BBC News – Craving for Junk Food ‘Inherited’. Strictly speaking, this may be true - but

  • similar carefully controlled research trials would not be permitted in humans for ethical reasons, and yet
  • the 'uncontrolled experiment' has already been going on for some time - in that the amount of junk food eaten by pregnant mothers has been increasing for many years, along with the general prevalence of such energy-dense, nutrient-poor foods in modern western-type diets.

Other evidence already shows that normal, self-regulating mechanisms of appetite control and energy expenditure can be destabilised by the consumption of sugar-rich junk foods, creating a vicious spiral of overeating, lack of exercise and weight gain: see

The findings from this latest study now suggest that similar self-perpetuating links between junk food diets, overeating and obesity can actually start before birth. Further research is urgently needed to confirm and extend the current findings, but their potential implications surely deserve to be taken seriously now by those providing dietary advice to pregnant mothers.