What a planned return to maintenance is meant to do
A diet break is a deliberate pause in a calorie deficit, usually one to two weeks at maintenance intake, while a refeed is a shorter rise in calories (often a day or two, weighted toward carbohydrate). The proposed rationale is that prolonged dieting lowers leptin, raises hunger signaling, and nudges energy expenditure down, and that briefly eating more partially restores leptin and replenishes muscle glycogen.
Refeeding carbohydrate reliably refills glycogen and adds water weight, which can briefly raise the scale. That rebound is fluid, not fat, and typically settles within days of returning to the deficit.
What the trial evidence actually supports
Some randomized work, such as the MATADOR study, found that intermittent diet breaks preserved more fat loss and resting energy expenditure than continuous dieting, but results across studies are mixed and the long-term advantage is not firmly established. The clearest benefits reported are often psychological: a break can improve adherence and reduce the sense of restriction.
This is general educational information, not a treatment plan. Diet structure should fit the individual, and anyone with a metabolic or eating-related condition should work with a qualified professional.