Arrow pointing up
Doximity share button
plate with clock on it

May 19, 2022 - Intermittent fasting has become a popular diet because it has a simple structure and, according to a lot of "online experts," offers a plethora of benefits beyond weight loss. In case you weren't aware, fasting is the new fountain of youth, as it drops insulin levels, increases growth hormone, induces cellular repair, and reduces inflammation. No word yet on whether it improves your sex life, gives you energy, and makes you wealthy, but one can only assume. Anyway, several recently published studies compared the effects of intermittent fasting to usual eating; we break them down for you below.

In the first study (N=116), intermittent fasting (no calories between 8 PM and noon) was compared to usual eating for weight loss in overweight adults. Participants were not given recommendations on calorie intake or exercise. At the end of 12 weeks, the intermittent-fasting group had lost 2 lbs, and the usual-eating group had lost 1.5 lbs (p=0.63) [SH review]. In a second study (N=139), intermittent fasting (no calories from 4 PM to 8 AM) was again compared to usual eating, but the participants were instructed to follow a calorie-restricted diet (1200 - 1800 kcal/day). After a year, the intermittent-fasting group had lost 17.6 lbs pounds, and the usual-eating group had lost 13.9 lbs pounds (p=0.11). Changes in body fat mass, blood pressure, glucose levels, and lipid levels were also similar between groups. [SH review]

In the two studies above, intermittent fasting did not significantly improve weight loss or other metabolic markers when compared to usual eating. Intermittent fasting may help some people reduce calorie intake, but it's hard to fathom that most people can maintain the strict eating interval for any significant amount of time. Lasting weight loss is still most likely to occur the old-fashioned way, with lifestyle changes, portion control, calorie counting, and exercise.


Weight loss


Weight loss procedures