Does a 2-day carb refeed during intermittent calorie restriction help maintain resting metabolism better than constant dieting in lean, weight-trained people?

We looked at 54 supporting assertions and found no studies that refute this idea ¹. The evidence we've reviewed suggests that for people who are already fit and regularly lift weights, taking a short break from calorie restriction—specifically by increasing carbohydrate intake for two days—might help prevent the slowdown in metabolism often seen with prolonged dieting. This doesn’t mean metabolism stays completely unchanged, but it may not drop as much compared to someone who restricts calories continuously.

We don’t yet know how strong this effect is, or how long it lasts, because our current analysis is based on a single assertion that aggregates multiple lines of support. We also don’t have details on the exact amount of carbs, timing, or individual differences that might affect results. Still, what we’ve seen so far points toward a potential benefit for using short, strategic increases in carbohydrate intake while dieting.

It’s important to note that this doesn’t mean carb refeeds will “boost” metabolism above normal levels or lead to faster fat loss for everyone. Our current analysis only suggests a possible role in helping maintain metabolic rate during calorie restriction.

Practical takeaway: If you're lean and train regularly, eating more carbs for two days a week while dieting might help your body keep burning calories at rest better than dieting nonstop—but it’s not a guaranteed fix, and more evidence could change what we understand.