An example of willpower is someone being able to quit smoking.
It took every ounce of her willpower to keep from devouring his body with her eyes.
It took every ounce of willpower not to run after him.
You will need to harness the willpower to keep exercising regularly.
If you are counting fat grams, save your willpower for saturated fats and allow yourself a little more leniency when you are consuming healthier fats.
It took great willpower to keep my face straight.