This is bullshit. There are lots of simple tricks you can employ to improve yourself. For example:
>If you want to stop eating sugar
If you want to stop eating sugar, throw it all away, and when you go to the supermarket go when you have just eaten, and avoid buying sugar and sugary products.
This gets recommended a lot, but because it is good - Atomic Habits by James Clear.
So much easier when you live alone. My spouse buys sugary crap for my kids and then I have to resist all the time. Which I can't. Thus I am overweight.
Also, suggest lower-calorie snacks.
If your spouse doesn't want to collaborate with you on your goals and things related to your health, then you have some serious discussions to have.
I really don't get your defeatist attitude:
1. You don't have the willpower to stop eating sugary stuff
2. You don't have the willpower to have a conversation with your spouse to stop buying sugary crap
3. Barring 1 or 2, you aren't talking to your kids to convince them to stop demanding less sugary stuff or aren't presenting them with tasty alternatives.
I'm sure in response to this I'll get a lot of angry replies to the tune of "it's not so simple" or "I don't have enough time for that" or "willpower theory is a myth".
C’mon, just say no
It's really simple and intuitive once you actually think about it. If you found yourself in a situation in which eating sugar was more effort you would be less prone to doing it. Not doing something makes it easier to not doing it afterwards too.
Treatment of any addiction steers right away from the "just don't". It's silly, humans just don't work by simply willing things into place harder and harder, they can either just do things or not, in the former case it's not a problem and in the latter there are things that work and can transition into the former.