While there is no shame in asking for the dessert menu, could pregnant women be forcing unhealthy habits upon their unborn children? A new study, done by the FOODplus Research Centre at the University of Adelaide, has found that a mother's preference for, or addiction to, junk food is heritable.

The basis of junk food addiction lies in the brain and its many hormone receptors. Upon eating foods high in fat and sugar, opioid, or "feel good," receptors are stimulated. These receptors stimulate the production of dopamine, a neurotransmitter, which will prolong that satisfied and happy feeling. Given time, dopamine will not be produced as much when the receptor is stimulated.  

If opioid receptors are overstimulated by a persistent consumption of junk food, the amount of dopamine that must be produced will need to increase as well. As a result, people are more inclined to eat more junk food in order to sustain this satisfied feeling.  

This effect transfers from mother to child. If a mother, while pregnant, consumes excess amounts of junk food, the continuously high levels of sugar and fats in her bloodstream not only nourish her fetus, but prepare it to need the same amount of junk food that she, an adult, does. The study has found that children of mothers who followed diets high in junk food during their pregnancies are more likely to overeat and prefer more fatty and sugary foods after they are weaned.  

This 'junk food legacy' comes from the overstimulation of opioid receptors from such a young age, according to the study. When the receptors are overstimulated in adults, the levels of dopamine produced are high, but slowly build to a high response throughout their lives. However, these soon-to-be newborns with junk food eating mothers experience the same overstimulation of the "feel-good" receptors before they are born. As a result, they will feel the need to over consume comfort food when they are old enough to make choices themselves

Pregnant women, already mindful of their health, must take extra steps to be weary of fast foods and sweets that they consume while pregnant if they hope to instill positive food habits in their children. Clearly, mothers set examples for their children, starting in the womb.