@Bluntness100
The word 'fat is pejorative and often turns us heavier people off wanting to talk about the subject. So I am not against talking about weight or issues but here are the basics....
fat and other words like tubby, chubby, and, I could go on, are likely to switch the overweight person off from seriously engaging.
"The reason I disagree is because I believe there should be more conversations about weight and being fat. I think society pushing us into never mentioning it to the person, so they don't get upset, isn't helpful. We know they are fat. They know they are fat"
So why is pushing them into talking about it helpful?
I think loved ones, including children do have a right to discuss it. Even friends, but it needs to be done very VERY sensitively.
At the school gate - No
In front of onlookers - No
Using words that upset the person - No
I think doctors and medical people should be talking about this a lot more. I think they should be talking to their patients when a condition could be improved by weight loss.
"And as said, I'm not talking about random strangers, im talking about friends and family members who are unable to discuss it without being perceived as being rude."
Yes, I agree with you.
I've not read all the posts here and not sure what the OP's stance is, so would rather talk in general terms.
So to be clear, from my perspective, 'Fat' as opposed to heavy, bigger, larger, overweight etc is an unhelpful word.
How we talk about this sensitive issues is important, as is where and in front of whom.
IMHO. 
Plus the reason people overeat is literally (excuse the phrase) a smorgasbord of reasons. Ignorance about food, for some, comfort and emotional eating, for others, compulsive eating, lazy eating, all kinds of reasons, and although some things will help some the reason and the mind set is important.
For many people who overweight it is not ignorance, we know a lot about food. There are so many reasons and it is not as simple as some think.
Anyway, must make dinner!