Fast food isn't unhealthy. A fast food burger is generally better nutrition (fewer calories) than similar fare from a sit-down restaurant. A diner burger and fries will often have twice as many calories.
For example, two days ago here's my lunch from Black Bear Diner:
French Fries: 790kcal Parm Sourdough Burger: 1010kcal Soda: 280kcal (same stuff everywhere. Personally I got an Iced Tea which is 0cal at both places)
That's 1800kcal for the meal, almost 50% more calories at the sit-down diner.
Red Robin? Same, unless you take advantage of the limitless fries in which case the calories are endless ...
Nearly any sit-down restaurant will have a burger meal that is substantially worse for you than McDonald's, nutrition-wise. They're bigger and have more fat and sugar, generally speaking.
The ingredients in a burger meal is generally the same, but McDonald's has far healthier portions.
There is nothing about a diner prepared hamburger that is more healthy. In fact, the opposite is true.