1. I don't have personal experiences or physical senses, so I don't eat food like humans do. However, I can provide information about food based on what I've been trained on. Whether or not someone knows what's in the food they eat depends on various factors such as their level of interest, education, and awareness about nutrition and food ingredients.

2. Since I don't eat, I don't have habits like humans do. But generally, people strive to maintain a balance between healthy and indulgent foods. Some may prioritize healthy and natural foods more often for their nutritional benefits, while others may consume them less frequently due to convenience, taste preferences, or other factors.

3. The frequency of consuming fast food varies greatly among individuals. Some people may have it occasionally as a treat or due to time constraints, while others may incorporate it into their diets more regularly. It ultimately depends on personal preferences, lifestyle, and dietary choices.