My family runs a slimming hospital. First of all, a person normally consumes about 2200-2400 calories a day, while jogging for an hour consumes about 160-240 calories, and one kilogram of fat consumes 7800 calories, so he has to lose 20 kilograms of fat, which is 78000 calories, so it is between 325 days and 487.5 days!

Hehe, thanks for your hard work!