
Malnutrition, shaping up to be a first world problem
Researchers have discovered that a bad diet has consequences on your immune system even before you notice an increase in body weight. Mice were fed a Western-style high fat diet for nine weeks. They structure and function of their immune cells was found to have been altered in the absence of weight gain. Ref. Source 6r.
Not just sugary food but I have a feeling that a lot of the processed foods that many cultures are eating nowadays is having a harmful effect on humans as they grow and develop. A high fat or a high sugar content diet is not going to help anyone either. A nice balanced diet with more healthy selections can go a long way I believe. While I have not researched this I bet someone has.
In addition to the sugar and fat mentioned by the previous poster we need to add all the chemicals, preserves, pesticides and genetic modification. Its bad enough that we're messing with nature like that but on top of it too we're making our children malnurished.