You can follow the discussion about the controverse 'junk-food' breast campaing here:
Ask yourself: who is interested in guilting the moms for not maintaining a perfect healthy diet? What nursing or pregnant woman gets to have a balanced nutrition while multitasking: breastfeeding in demand, doing house chores, taking care of several children and working outside of the house?
There is no scientific evidence supporting the notion that the quality of breast milk is damaged by ‘flawless’ nutrition. In fact, a poor diet is more likely to affect the mother than her breastfed baby. Therefore, the idea that the baby might be harmed by mom’s diet and consequently formula milk might be necessary is simply not true.