Intermittent Fasting
What is intermittent fasting? Also called "time-restricted feeding", it's a strategy of eating with specific eating and fasting periods within a day. One popular example is a 16:8 fasting:feeding approach, in which a person does not consume any calories for 16 hours a day and only eats within 8 hours of the day. With this approach, a person might have their first meal of the day at 12 noon and not eat anything after 8pm that day.
Is intermittent fasting effective for fat loss? Studies have shown that people who adhere to intermittent fasting do consume fewer calories, so it can be used as a strategy to minimize caloric intake. However, intermittent fasting is not more effective for fat loss than a calorie deficit achieved without intermittent fasting. In other words, there's no "magic" to the timed feeding approach.
Do you recommend intermittent fasting? As a general rule, I do not recommend this approach to my clients since the evidence does not support that it's more effective than a calorie deficit in general. It would not be appropriate for anyone who has a past history of eating disorders or disordered eating, as it has been known to trigger binge eating behaviors, in which a person becomes so hungry from restriction that they overeat during the feeding window.
What about other fasting strategies? There are other approaches to fasting, such as "Alternate Day Fasting" and the "5:2 Diet." Alternate Day Fasting is, as the name implies, alternating between a day of complete fasting and a day of eating. The 5:2 Diet involves cycling through eating for five days in a row followed by two days of fasting. Just as with intermittent fasting, these approaches can help an individual achieve a calorie deficit, but they are not any more effective than achieving a calorie deficit by simply eating less and moving more. These more extreme versions of fasting can also have negative side effects like fatigue, dizziness, and irritability. They can also negatively impact the amount of movement and exercise a person can do on the fasting days. For these reasons, I do not recommend these approaches to my clients.
Of course, we've all heard of someone's friend/brother/cousin who loves intermittent fasting and swears by it. Each person is an individual, and it could be a useful strategy for some people. If you're unsure if intermittent fasting is right for you, reach out and let's chat about it!
