>>81735432 (OP)There's a spectrum of fat girls where on one end they self-identify themselves as fat, while the other side is where the "big boned" or "water weight" excuses come from.
When you're at that point where you don't understand that you have a problem, you'll never improve. So if you don't have any fear of labeling them as fat, they'll be more aware of themselves and potentially lose weight. And losing that weight drastically improves your health and your image.
But at the same time, fat people are often too stupid to ever be reasoned with. So talk to them and test the waters before you try and help them.