Fasting, the practice of voluntarily going without food for a period of time, dates back centuries, and has often been performed as a religious or cultural ritual. However, people want to know: is fasting good for your health?

For many years I have practiced single-day fasts, as well as fasts lasting up to 14 days, as a way to benefit my health and the health of my patients.

After my heart disease diagnosis, I fasted every Monday. This helped me lose weight. My cholesterol dropped, and so did my weight.

Often, I fast for religious reasons, but, as a physician, I cannot help but notice the more practical benefits that accrue with fasting.

In terms of weight loss, fasting is obviously beneficial simply because going without food for a long period of time, even a day, reduces the amount of calories you take in over the longer term. So you’re already giving your diet a head start.

But there’s more to it than just saving calories. Being in a state of semi-starvation puts your body on alert; it starts using stored fat for energy. For example, the body begins drawing on fats stored in the blood. As a result, cholesterol and triglycerides begin to disappear. Fasting also cleanses the body and gives your organs a break from constantly metabolizing food. As a result, immune response appears to improve, blood pressure goes down, and people report feeling more clear-headed when they are on a fast.

If you’re doing a multiple day fast, you’ll get hungry for the first few days. I find the third day is the hardest. After that, your body becomes accustomed to it. During a fast, I drink water or juice. Also, for fasts lasting longer than a few days, you’ll want to consult your doctor, of course, and this is also true if you have certain medical conditions, such as diabetes.

By Dr. Chauncey Crandall