McDonalds lists the ingredients in their foods here:
https://www.mcdonalds.com/us/en-us/about-our-food/nutrition-...Their hamburger doesn't look any different than what I would make at home. I don't have any grocery store bought buns in front of me, but I assume it would have similar ingredients. The pickles are not the most natural, but once again, it's not much different than what I would buy in a grocery store.
The biggest difference for me personally is that I would usually make a salad or another vegetable along with homemade burgers and fries, but it wouldn't even cross my mind to order that at McDonald's. I suppose I bring that on myself.
Regular Bun: Enriched Flour (Wheat Flour, Malted Barley Flour, Niacin, Iron, Thiamine Mononitrate, Riboflavin, Folic Acid), Water, Sugar, Yeast, Soybean Oil, Contains 2% or Less: Salt, Wheat Gluten, Potato Flour, May Contain One or More Dough Conditioners (DATEM, Ascorbic Acid, Mono and Diglycerides, Enzymes), Vinegar.
100% Beef Patty: 100% Pure Usda Inspected Beef; No Fillers, No Extenders.
Prepared With Grill Seasoning (salt, Black Pepper).
Ketchup: Tomato Concentrate from Red Ripe Tomatoes, Distilled Vinegar, High Fructose Corn Syrup, Corn Syrup, Water, Salt, Natural Flavors.
Pickle Slices: Cucumbers, Water, Distilled Vinegar, Salt, Calcium Chloride, Alum, Potassium Sorbate (Preservative), Natural Flavors, Polysorbate 80, Extractives of Turmeric (Color).
Onions: Onions.
Mustard: Distilled Vinegar, Water, Mustard Seed, Salt, Turmeric, Paprika, Spice Extractive.