How bad is fast food?

Extremely Bad. Fast food although convenient is extremely bad for you. Chicken nuggets, french fries, and donuts have about 4-5 grams of trans fatty acids each. This is what leads to obesity and clogged arteries. Although fast food chains do offer salads and smoothies of late, most americans still choose the higher fat meals unfortunately.
Sometimes it's not. It's possible to eat healthily at many fast food places. Choose grilled items and salads and pass on the bacon and cheese. Limit salad dressings. Stay away from fried menu items and high fat sauces. Avoid supersizing your order. If you do, the fat content and calorie content of your meal will be much higher. This may contribute to obesity, raise your cholesterol, and threaten your health.