What happens if you eat vegetables and fruit every now and then and eat other foods regularly but within your calorie intake for the day?

Food plan. If you are on a Weight Watchers plan then stay w/the intake they suggest. Our psyche rebels against "no" so a very occasional splurge is ok, e.g., a favorite food once a week. See doctor to make sure you are eating a diet healthy for you and ask about a low car diet. Peace and good health.