It is rare for knees to gain weight. Is there a meat pit on your knee when your legs are straight? Try applying slimming cream on your knees and wrapping it with plastic wrap. It's summer now, and you can sweat for half an hour without exercising or turning on the fan. I believe it will be effective to persist for more than 10 days.

My waist has lost two centimeters in this way, and the effect is obvious.