If you’re on the lookout for healthier fast food, Shake Shack’s Single hamburger might be your best option; it's high in protein and relatively low on calories. However, you may also be tempted by the ‘Shroom burger, which uses a portabello mushroom "patty" instead of beef — but if you're looking to enjoy your meal in moderation, think again.

The vegetarian-friendly ‘Shroom burger comes with a portabello mushroom stuffed with muenster and cheddar cheese, plus lettuce, tomato and ShackSauce. What you may not know is that the mushroom is fried, not baked or grilled like other mushroom-based burgers, and it features way more cheese than the chain's other offerings.

One ‘Shroom burger has 550 calories, 31 gm fat, and 49 gm carbs, and only 18 gm protein, compared to the Single hamburger's 25 gm. If you're not looking to indulge at Shake Shack, and want to stick to your diet instead, you’re better off ordering classic options like a hamburger or even a cheeseburger over the 'Shroom.