(CNN) Abstaining from food for 16 to 18 hours a day could be key to treating a variety of health conditions -- even if you've got to train yourself to push past the hunger.

The report functions as a road map of sorts for physicians to prescribe fasting as a method of prevention or treatment for obesity, cancer, diabetes and heart disease.

Study author Mark Mattson, a professor of neuroscience at Johns Hopkins University, hones in on two types: Daily time-restricted feeding (eating 6-8 hours a day and fasting for 16-18 hours) and 5:2 intermittent fasting (fasting two days a week, usually capping a fasting day at 500 calories).

The catch? Most Americans don't intermittently fast (the norm is three meals a day plus snacks) and thus physicians are less inclined to consider fasting a solution to a broad range of health conditions, according to the review.