The aging and infirmity will come a lot quicker if you don't look out for your health. Being healthy might mean you live say 30 years longer, but that isn't just 30 more years of being infirm, it's say 20 more years of good hack-healthy years and 10 more infirm.
Besides, the energy benefits right now and the impact that has on how much you can hack is far more easily noticed than the potential lifespan differences.