Neither.
It’s the Cola and fries. Depending on what you smother the hamburger with, could be that, too.
Meat and bread are not intrinsically unhealthy. OK so the bread you’re served at McD just barely fails to qualify as “candy”, but it’s still made mainly from flour.
The fries, however, are not just diced and heated potatoes. They are processed to within an inch of their lives, and then deep-fried so that they are saturated with fats, often fats that are unhealthy even for being fats.
The soft drink is normally just nutrient-free calories.
A dollop of ketchup is OK, even if it’s more sugar than Fanta by weight – the thing is, you don’t actually eat huge amounts. It’s when you add mayonnaise-based dressings and barbecue sauces that calories pile on. Barbecue sauce especially is often sweeter than your average marmalade.
No, those two figures are not exaggerated, I was in the kitchen when I wrote the answer. Heinz tomato ketchup 22% sugar, Fanta 14% sugar, Sweet Baby Ray’s barbecue sauce 47% sugar (!), my home made marmalade 45% sugar.
It’s OK to eat one of those, occasionally. Don’t do it every week unless it’s your only meal that day.
A burger made with good quality meat, artisanal bread, good quality condiments, and serve with a substantial vegetable side, and a small beer is actually a pretty healthy meal. What makes fast food burger not healthy (if eaten frequently) is that they are made with the worst quality meat, the worst quality bread, the cheapest and worst quality condiments, and served with frozen fries and a huge soda.

If you get a good quality meat pattie, or better ground quality meat and shape the patties yourself. You grill the patties over a barbecue fed with aromatic coal.

Buy or make some really good quality bread rolls, stuff that is made with only four ingredients (flour, water, yeast or sourdough, and a pic of salt), slice them and lightly toast them.

Buy a piece of good quality cheddar (or other cheese of your choice, as long as it is good quality) and cut a thin slice, place it on the pattie and cover so that the cheese melts.

Spread a thin layer of your favorite sauce on the bread, place the pattie and melted cheese on the bread, add a slice of onion (maybe after lightly grilling it). Add the other half of the bun. What you get is a pretty healthy dish. Eat it with a great salad

or maybe with grilled bell peppers

(Place the bell peppers on the grill, turn them so that the skin blackens all over, rest in a covered bowl for 5–10 minutes, then peel off the blackened skin, remove the seeds and white inner parts, rip into strips, garnish with a pinch of salt, and a tablespon of pesto diluted in a tablespoon of extravirgin olive oil.)

Serve with a glass of fresh but not too cold beer.

As a dessert serve a nice, delicious fruit salad topped with a teaspoon of honey.
That’s a very healthy meal, and delicious too.

Do you see the difference?
