> Refined/processed food should be eaten in minimal quantities because it spikes blood sugar and causes insulin fatigue, which in the long run causes Type II di

> Refined/processed food should be eaten in minimal quantities because it spikes blood sugar and causes insulin fatigue, which in the long run causes Type II diabetes. What precisely does refined/processed food mean, from a chemistry standpoint? Is there a particular common process that transforms my homegrown lettuce into "refined lettuce"?