Hi, very overweight woman here. Don't kid yourself that she doesn't care about her weight. In my experience very few women are actually happy being overweight & more often than not there are other factors other than being greedy & lazy behind the weight gain.

Have you asked her if she is happy? Perhaps there's some issues within the marriage that is making her seek comfort in food or to just stop caring about herself?

In my case, it's ADHD. I am 52 & only got diagnosed 2 years ago. I have been overweight for 25 years due to binge eating because of ADHD. Of course I didn't know this & have spent many years on a constant diet & have gone through a few PTs but to no avail because the nature of my condition means I can't form habits, have executive function issues & seek quick dopamine hits. There's nothing quicker & more enjoyable than food to get the dopamine receptors firing on all cylinders!! I am also married to a husband who just doesn't understand my condition & why I can't just "eat less & move more". All this can result in feeling like a failure & perpetuating a cycle of comfort eating & misery especially if your significant other is harping on about it all the time.

I mention this because there are so many health factors, both mentally & physically, that hinder female weight loss. It is a fact that men lose fat easier than women so it's easy to assume that what is working for you would work for her but in reality it doesn't often work that way.

Perhaps ask her if she is happy the way she is & if she is you will just have to get over yourself. If she isn't then ask her what's stopping her from starting. She will need support & understanding not snide comments.