How to lose weight during menstruation? Seize the opportunity to lose weight once a week ‖ the best slimming period. Within one week after menstruation, people have a happy mood, stable mood, fast metabolism, good digestion and detoxification function, strong estrogen secretion in the body and smooth skin. Countermeasures to lose weight: These days are the best time to lose weight. If you want to lose weight quickly, you should first reduce your food intake, pay attention to less sugar and starch in your diet, and then do more aerobic exercise, such as running, swimming, skipping rope, etc. These exercises can consume a lot of fat and calories. Losing weight in these 7 days can be described as getting twice the result with half the effort.