A bantam eats an average of 0.5lb of feed during a week, a light breed eats 2lb, and a heavy breed 4lb. Of course, it depends on the quality of the food, its energy and protein content. It also varies with the chicken’s age, breed, activity level, and health. The external temperature is also a factor. Chickens eat more when it’s cold than when it’s hot. Normally chickens should be free fed so they can eat whenever they feel like it.