For example, I could say, just start running/cycling/swimming if you want to lose weight. It's really easy! If you slowly work up to working out 5 hours a week, and keep at it, your obesity will probably disappear.
However, most people won't be able to do that, because it's boring, takes a lot of time, and they will stop sooner or later. There are some success stories of people who stuck with it and lost 50kg, but these stories are so rare that they are noteworthy.
Taking daily meds on the other hand is something that most people manage to do just fine.
