Burger King Vs McDonald's: Which Serves A Healthier Fish Sandwich

Next to a giant double-pattied Big Mac or a Big King, a humble fish sandwich looks almost virtuous in comparison. While not exactly the most healthy item, it's a great alternative to a beefy burger on a cheat day or when you're watching your intake. But while a classic McDonald's Filet-O-Fish and Burger King's Big Fish both share the same basic construction of a fried fish filet on a bun with tartar sauce, their nutritional content is vastly different.

When we look at the McDonald's Filet-O-Fish's nutritional information, it comes in at 380 calories with 16 grams of protein. Burger King's Big Fish increases the former and bumps up the latter; 570 calories, for 19 grams of protein. Almost double the caloric count aside, the biggest concern with BK's Big Fish is the sodium content. At 1,270 milligrams, it's sky-high — a little over half the FDA's daily recommended sodium intake of 2,300 milligrams.

So, why such a big gap? Breaking it down, the fish patty (Alaskan pollock for both) is lean and so doesn't add much to the caloric equation. BK adds lettuce and pickles on top of its panko-crusted patty, while McDonald's keeps things simpler with just cheese and tartar sauce on a steamed bun. But the biggest differentiator? JustFoodReviews weighed both, and the Big Fish turned out to be about 50 grams heavier than a Filet-O-Fish. More weight means more calories, plain and simple.

You don't have to commit to ingesting 570 calories when you order a Big Fish. For a restaurant that prided itself on having over 200,000 ways to customize a Whopper, tweaking a Big Fish shouldn't be too much of a problem for the staff. The first problem is the tartar sauce. Ask for it on the side, and you can precisely control how much goes onto your burger. Or, just skip it entirely for a squeeze of hot sauce or yellow mustard. The latter will give you the tang, without the oil slick and the calories.

The buns themselves are also a problem. While BK doesn't post any official measurements of its potato buns, MyFoodData reports a generic roll of potato buns clocks in around 140 calories, so just by skipping the top bun, you cut out a good chunk of that total. You can also choose to load up on extra lettuce and pickles to bulk up on volume and crunch, which should balance out the loss of the top bun.

Honestly, though, the easiest fix is ordering "Just the Sandwich" and giving the combo a pass. A Small combo alone tacks on anywhere from 110 to 970 additional calories once fries and a drink enter the picture, turning a 570-calorie sandwich into a nearly 1,540-calorie meal at the high end. Bring your own side, like a piece of fruit or a small salad, and a regular Big Fish shouldn't be too much of an issue to absorb.