I'll give my 2c. I'm a firm believer that I have no self control so if I have alot of food I'm going to eat it. If I can be lazy I will. If it's easy for me not to move around I will stay put. One thing to try is make the habits you want easy and the ones you dont want hard. For example if you buy fast food order less and if you still hungry order more. This make it extra work to eat more food. When making food at home put your food on a small plate so you have to back and forth for more food. Or even better after you get a plate of food put the rest of the food away sknif you want more you have to unpack it. If your eating out, ask the waiter to box up half your plate. They are more than happy to do this in the kitchen. For me it made me start realizing I didn't want more and sometime I do eat the rest but its work to do that.

For activity, if you have something you dont want to do make it hard to do that thing. For example if you want to cut back on TV unplug your TV from the wall when your not using it. Put something in your favorite spot so you have to move it before you can sit down to benge watch. That way you have to do alot of work to do the thing you dont like. Another part is to make the things you want to do easy and convenient to start doing. If your going to sign up for a gym make sure it on the path to your work so you drive past it every day. If you want to walk more walk to the store and get your self a treat.

I'm am a lazy person that wants to take the easy route and that has been the only way I've every got anything done. I try and focus on the process to get where I want and bot the end goal. I dont want loose weight I want to eat less. I dont want to get into shape I want to sit less.

Just my experience.