During a healthy cleanse, where the emphasis is on the diet, certain foods are excluded, such as caffeine, alcohol, additives, preservatives, GMOs, trans fats and sugar because they stress the P450 mechanisms that the body uses for the biotransformation of toxic chemicals. Non-organic meats and dairy are also excluded as they are a known source of PCBs and xenoestrogens. Other excluded food items include those that are difficult to digest and increase intestinal permeability of toxic substances.
It seems like today we are exposed to more toxins than our bodies are designed to handle. Until our systems can evolve to keep up, we need to be kind to ourselves.