I think it depends on the willpower.

For exercise or implement something into routine, learning how to encourage yourself is key (at least it is for me). If you want to exercise every day, do something you like at the same time, and only let yourself do the thing you like while exercising. For me it’s certain tv/YouTube shows and podcasts. Sometimes I’ll blast music I love while doing cardio.

If you want the willpower not to eat unhealthy, try balancing what you want with what you have. There are two posts to this: keeping what you have limited for things unhealthy, like not having sweets around, and having small treats for yourself that you can consume a little of regularly. Having a small cookie each day that you bake fresh from cookie dough in your fridge may be enough reward for not eating nachos for lunch.

Persistence and routine are also important. If you don’t exercise regularly, you will often find yourself slipping back to where you started. If you don’t give some thought to your diet and what you are eating, you will skip back into old habits. Creating a habit you want to form and sticking to it is key. I will suggest start slow with whatever habit you choose. Make small obtainable changes over time, otherwise you may find the dramatic shift in lifestyle jarring, and your ‘cheat days’ will be a bigger step back.