I figure out what fills me up and fuels my body to get through my day and workouts. Then I am not tempted to eat junk food as I am not hungry and my body is not craving anything.
Some need a high carb breakfast like oatmeal, others need high protein to be filled up & fueled ready for their day.
Experiment until you figure out what works for you - may be different for different days if your physical activity changes. You figured it out when you feel good and are not hungry or craving sugar/fats. Less processed foods work best to fuel & fill, e.g. Oatmeal works better than cold cereal.