What is more painful? The gym for a few hours a week and losing the crap from your diet or your reality?!
'Change happens when the pain of staying the same becomes greater than the pain of change!'
So the first thing you need to do is face your reality. Look in the mirror, take a naked selfie, take a fitness test or a health check up. Face it, then you can change it. If it doesn't need changing then great. If you are healthy and happy with a beer gut then good on ya. Stay that way.
But if you see something you don't like in your current reality AND it's more painful to see that than it is to embark on a fitness mission then you're ready!
You're ready to make changes. They might hurt a little but you've admitted it, staying the same hurts more!
A literal example;
Office worker is in agony with a bad back due to sitting for 8 hours a day. The fix is simple, go to 3 yoga classes a week. If he / she is unwilling to go to 3 yoga sessions a week to reduce or even get rid of the back pain then guess what?... His back doesn't really hurt that bad. When it does he'll go to yoga.
Read it again;
CHANGE HAPPENS WHEN THE PAIN OF STAYING THE SAME BECOMES GREATER THAN THE PAIN OF CHANGE!
Hope that makes sense!
More love, more fitness. No bullshit!