You shouldn't criticize your roommate's food habits.
Luke notices his overweight roommate eating three slices of pizza.
Luke wants to get his roommate to eat healthy.
Luke asks his friend to help him cook a healthy pizza substitute while discussing healthy diets.
Luke says that his friend should avoid eating pizza because it will cause him to gain weight and get heart disease.
Luke likes cooking so much that he stops eating out until he loses weight.
His friend orders another pizza to spite Luke.