So I am obese. I have underlying health issues that have basically caused it through no fault of my own.
If a family member was constantly bringing up my weight I think I would feel attacked and upset.
Please remember that unless your family member is actually blind, they know what they look like.
They know when clothes that used to fit don't
They know when they see that double chin is bigger.
They know when they are out of breath more
And they know, as surely do you, that the only person who can change it is them
IME making a fat person feel shit about being fat is likely to exacerbate the problem
Emotional eating and obesity are heavily linked
Eating because of :
Depression
Loneliness
Trauma
Lots of things
Becoming obese isn't just laziness or lifestyle for a lot of people there is an unspoken MH factor.