You can have all the wealth in the world, however, without your health it will be difficult to enjoy your wealth.
If you misuse your car you can replace it. If you misuse your phone you can replace that too. However, you only have one body which can never be replaced.
Exercising at the gym or by playing sports; having good sleep daily, and a proper diet plan all aid a healthy body.
Taking care of your body may not be a top priority for you because it is not urgent. But, in the grand scheme it is very (if not most) important!