A very cool study by Dr. Bill Campbell looking at different dieting techniques. One group dieted for 7 weeks straight, while the other group dieted for 7 weeks as well but had two refeed days every week. The refeed brought the subjects back up to maintenance level through increasing carbohydrates. Both groups had a weekly deficit of 25% and protein was equal between groups at 1.8g/kg. The subjects also did every workout inside the lab at the University of South Florida. A big drawback to a lot of studies is that they don't always take into account a lot of variables that are paramount to making the study more applicable to others and more valid. The same workout program, protein set for all subjects, and making sure a weekly deficit was equated for both groups. The straight dieting group had a 25% deficit all week and the refeed group had a 35% deficit Monday through Friday so that when they had their refeed it would bring their deficit back down to 25% total for the week.
The results showed that each group lost the same amount of fat 5.5lbs but the group with refeeds were able to maintain more muscle while dieting. They only lost .4kgs and the straight diet group lost 1.3kgs. This is so important for athletes dieting because it is very hard to gain muscle and if you can have a diet style that allows you to retain as much muscle as possible you will not have as much of a metabolic shut down, your BMR would not fall as fast, and your performance in the gym will remain constant. The key here is that the refeed was done by increasing carbs, the increase in other macros won't have the same effect. The refeed was also two days which is important as well because that time frame allows for the re-uptake in metabolism and other deficiencies that a diet can have on a person. 1 day refeeds or cheat meals won't do that.
Study found here https://www.mdpi.com/2411-5142/5/1/19
