The latest diet that wellness influencers and health geeks are obsessed with is all about simply not eating — that is, during certain periods of time. As the name suggests, intermittent fasting involves fasting for a set period of time (some people fast for 16 hours, then eat for 8 hours a day; others alternate full days) and then eating.
During the "feeding" periods, you're technically allowed to eat whatever you want, which is part of what appeals to many people who are looking to lose weight but don't want to change what they eat. There have also been a couple of promising small studies (on animals) that suggest intermittent fasting can have some health benefits, like lowering your risk of heart disease, limiting inflammation, and even slowing aging. These findings are interesting, for sure, but they don't paint the full picture of what intermittent fasting looks like in practice.
The idea that you're only "allowed to" eat during set points during the day or week completely contradicts the concept of intuitive eating, which encourages you to listen to hunger cues and let those signals drive your decisions about what and when to eat. And it certainly seems like intermittent fasting could lead to restrictive eating patterns or disordered eating habits down the line. For these reasons, and the fact that there hasn't been enough research yet, not all nutrition experts are totally on board with intermittent fasting.
It's too soon to say how adopting intermittent fasting would change people's relationship to food in the long run. Given what we do know about the trend, we asked four registered dietitians whether intermittent fasting is ever a good idea. Their opinions are certainly not the final say on intermittent fasting, because everyone is different, but they can give you insight into this hyped-up diet trend.
If you are struggling with an eating disorder and are in need of support, please call the National Eating Disorders Association Helpline at 1-800-931-2237. For a 24-hour crisis line, text “NEDA” to 741741.