What's more fattening: a salad or a burger?

Most people assume McDonald's or Wendy's are not as healthy as Chop't or Panera, but that's not always the case.

The digital health program, Noom, just did a national computer analysis of restaurant chain menus, looking for salads with the most calories at the biggest fast food and healthy food chains. They discovered many salads at fast food chains actually have fewer calories than the so-called healthy chains. In some cases, those salads had more calories than signature burgers.

Here's a glimpse at what they found.

Most fattening salads vs famous burgers

• Cosi (Cobb Salad) 720 calories vs Wendy's (Dave's Single) 570 Calories

• Wendy's (Spicy Chicken Caesar Salad) 720 Calories vs Burger King (Whopper) 630 Calories

• Chop't (Classic Cobb) 670 Calories vs Shake Shack (Single) 550 Calories

• Panera (Fuji Apple Salad) 570 Calories vs McDonald's (Big Mac) 540 Calories

• Taco Bell (Fiesta Taco Salad - Beef) 745 Calories vs McDonald's (Quarter Pounder) 530 Calories