How often does the average person eat?

First of all, it depends on the person. Everyone needs different caloric intake depending on your weight, level of activity and exercise, and your age. In general, a good model to follow is to eat every 2-3 hours. That does not mean a full meal each time, however. It means a healthy breakfast of about 300 calories, a snack of about 150, a 300 calorie lunch, 150 calorie snack, and a 300-500 calorie dinner. That is about 1500 calories a day and is a healthy way to lose weight if that is your plan. Eat a little more calories each time if you do not need to lose weight, or break up the snacks or add a little more to them. 
And again - it all depends on your body composition!!