What are the Health Benefits of Fasting?

Will fasting make you healthier or help you lose weight?

Monica Reinagel, M.S.,L.D./N
4-minute read
Episode #60

I’ve gotten a lot of questions from listeners about fasting: Is it safe? Is it beneficial? How long should one fast? How often?

What are the Health Benefits of Fasting?

People have fasted as a spiritual practice since ancient times. Today, there are a lot of people claiming that fasting also has a lot of health benefits. And, in fact, research shows that short fasts, lasting anywhere from 20 to 36 hours can in fact reduce some risks for heart disease and diabetes--and maybe even cancer.

As I explained in episodes #31 and #32, going without food for several hours does NOT cause your metabolism to slow down nor does it wreak havoc with your blood sugar. Short fasts actually improve insulin sensitivity and this is pretty big deal. When your cells are sensitive to the effects of insulin, they do a much better job modulating your blood sugar levels after meals and this makes life a lot easier for your poor old pancreas. Loss of insulin sensitivity is a risk factor for both heart disease and diabetes.

Short fasts also reduce oxidative stress and inflammation in cells. Many theorize that this helps prevent and repair DNA damage that could otherwise develop into cancer. There’s even some research suggesting that fasting slows the little clocks that tick inside our mitochondria and trigger senescence, or aging. In other words, fasting might help us live longer by keeping our organs youthful.

I want to emphasize that this is all still very much in the theoretical and experimental phase, but there are a lot of people who have embraced intermittent fasting as an anti-aging strategy. Some of them fast one day a week or one weekend a month. Others fast every other day. If you’re curious about how this works, I’ve put a link in the show notes to an interesting blog about one man’s experience with intermittent fasting.

Interestingly, you can get the metabolic benefits of fasting even if you make up for the lost calories by eating more when you’re not fasting. It doesn’t seem to be about eating less as much as it’s about going longer between meals.

Fasting for Weight Loss

Intermittent fasting doesn’t necessarily lead to weight loss, but it often does. Research shows that when people skip a meal or stop eating for an entire day, they do tend to eat more at the next meal. But even if they allow themselves to eat as much as they want, they don’t quite make up for the calories they missed.

I know that flies in the face of everything you hear, but skipping meals can actually be an effective weight loss strategy. I’ll post a link in the show notes to a summary of some research on this as well as a link to an article I wrote on the pros and cons of fasting as a weight control strategy.