The teen watching her two vegetarian sons eats poorly. I get that. The mom tells the teen that they just need salad an potatoes, for example, when the teen mom is making dinner choices.
FIRST OF ALL - growing boys need more protein than that.
Then she LECTURES the teen (note: this is NOT the most effective way to speak to teenagers, which this mom will find out when her sons are older) that if she eats poorly her children will automatically be obese and sickly.
Now, I do eat poorly. I should eat better. No veggies and fruit for me, in general, although I do love fresh corn on the cob w/butter and green beans cooked in bacon fat. I drink diet coke and water, in that order. BUT... my kids are awesome eaters. They eat a lot of fruit and some vegetables (including carrot-apple juice). If you introduce it when they're young they will drink/eat it and get used to the texture and flavor.
My children are not obese - far from it. They are little powerhouses (the 2 boys have awesome six-pack abs) and the little girl isn't far behind. For weight, they're around 50th percentile, although about 100th percentile for height. EVERY MEAL has fruit or veggies as the first course. EVERY MEAL. If we go out, they eat their fruit at home or in the car before we goto the restaurant or I bring their fruit to the restaurant and they eat it before the food comes.
Should that teen eat a better diet? Of course. Will trying to scare her into a better diet work? No, and the mom was WRONG about how the kids turn out if the kids don't eat well.
AND I know TONS of parents that DO eat fresh fruits and veggies all the time and their kids live off mac&cheese and nuggets! Generally, my kids eat a better variety than their kids (2 of my kids eat tofu! Broccoli!)