If you're already lean and lift weights, taking two days a week to eat normal calories—especially from carbs—while cutting calories the rest of the week might help you keep more muscle compared to cutting calories every day.

What we've found so far suggests that a weekly 2-day carb refeed might help lean, resistance-trained people preserve muscle while dieting. Our analysis of the available research shows the evidence leans toward this approach being beneficial, based on the data we’ve reviewed. We analyzed two assertions and found that both are supported by the evidence we examined—108.0 supporting claims in total, with none refuting it. The first assertion indicates that for individuals who are already lean and regularly lift weights, eating at normal calorie levels—especially from carbohydrates—on two days per week while cutting calories the other five days may help maintain muscle better than continuous daily calorie restriction [1]. The second assertion builds on this, suggesting that over a 7-week fat-loss period, those who include two higher-carb days each week might lose only about 0.2 kg of muscle, compared to nearly 2 kg when calories are reduced every day [2]. We don’t yet know how these findings apply to people who aren’t already lean or experienced with resistance training. Also, the exact role of carbs—versus simply eating more calories on refeed days—isn’t fully clear from what we’ve reviewed so far. Still, the pattern across the evidence we analyzed consistently points in the same direction: structured carb refeeds may reduce muscle loss during dieting in this specific group. Our current analysis is based on limited assertions—just two—but the support within them is strong and consistent. As we gather more data, our understanding may evolve. Practical takeaway: If you're lean and lift weights, adding two higher-carb days per week while cutting calories the rest of the time might help you hold on to more muscle as you lose fat.