There are two critical windows during the developmental pathway to adulthood when exposure to junk food is most harmful, particularly for female offspring, according to a recent study.

Researchers at the University of Adelaide revealed that there may be a chance to turn around this junk food addiction in two critical windows -- equating to late pregnancy and in adolescence in humans.

"Our research suggests that too much junk food consumed late in pregnancy for humans has the potential to be more harmful to the child than excess junk food early in the pregnancy," Dr. Jessica Gugusheff, post-doctoral researcher in the School of Agriculture, Food and Wine, said in a statement.

The first critical window is during pregnancy. However, if excess junk food was consumed by the mother in those early stages of pregnancy, there may be a chance to reduce those negative effects on the baby by eating a healthy diet in late pregnancy, researchers said.

The second critical window is adolescence. Researchers found that eating a healthy diet during adolescence could reverse the junk-food preference. However, this only works for males, not females.

The junk food preference is believed to result from a desensitization of the normal reward system (the opioid and dopamine signaling pathway) fuelled by highly palatable high fat, high sugar diets. Offspring with less sensitive reward systems need more fat and sugar to get the same "good feeling".

"This brain area grows at its fastest during these critical windows and is therefore most susceptible to alteration at these times," Dr. Beverly Mühlhäusler, project leader and senior research fellow with the University's FOODplus Research Center.

The researchers believe their work will ultimately allow pregnant women to be better informed about the lasting effect their diet has on the development of their child's life-long food preferences.