There are lots of ways to go to restaurants and not be fat. You don't have to eat anything, you can just socialize. Or you can share an entree with someone. Hell, you can share an appetizer with someone. Or you can order your own meal, eat a reasonable portion of it and then either leave the rest or takeout box it. There are options, you don't have to be afraid of restaurants or drop all your friends (not that she has any genuine ones).
Buuuuut this is all moot because Amberlynn is so goddamn fat that she doesn't even have to work so hard as described above. If she ever got under, say, 200 pounds? Sure. But in the meantime, she could lose a ton of weight if she'd so much as cut her orange chicken down from double fucking portions, or if she'd forego triple rice at the mexican buffet. She doesn't have to restrict herself to salads, not until she loses like 150 pounds at least.