Still Life with Bread and Eggs

Alternate Day Fasting Hype Should Be Fading Fast

As a spiritual practice, fasting has deep roots in many religions. But when spiritual practices try to make the leap into health practices, look out. For a prime example, it now looks like the hype about the alternate day miracle fast should be fading fast. A new randomized, controlled study published in JAMA Internal Medicine finds no benefit for alternate day fasting compared to daily caloric restriction.

A Careful Study, But No Advantage for Fasting

Researchers randomized 100 people with obesity to an alternate day fast, a standard reduced-calorie diet, or a control group making no change in dietary habits. They followed the subjects for six months of weight loss, and six months of weight maintenance. At the end of 12 months, both of the treatment groups had lost about five percent of their starting weight – virtually identical outcomes. And of course, the control group had no change in weight.

Likewise, the researchers found no difference in markers of heart or metabolic health. For two treatment groups, blood pressure, heart rate, cholesterol, insulin resistance, cholesterol, and a number of other measures were the same at the end of 12 months.

Capping Years of Excessive Hype

Hopefully, this will put a capstone on years of hype about the health benefits of fasting. We’ve seen claims that it will “reboot your body” and “slow aging.” Health reporters have hyped animal studies to suggest that it will prevent cancer, improve brain function, and cure diabetes.


Fasting is a fine spiritual practice. It’s not a bad way to lose weight. But don’t count on it for miraculous health benefits.

Click here for the study and here for more from Time.

Still Life with Bread and Eggs, painting by Paul Cezanne / WikiArt

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May 3, 2017

2 Responses to “Alternate Day Fasting Hype Should Be Fading Fast”

  1. May 03, 2017 at 5:35 pm, Adam Tsai said:

    I think that the appropriate way to describe this study to patients and to the public is that the two approaches are equivalent. This is helpful for some people who struggle with restricting intake every day and are looking for an alternative

    • May 03, 2017 at 8:19 pm, Ted said:

      Yes. It’s a fine way to lose weight, Adam. But some of the hype needs to fall away.