It would stand to reason that medium fries are the "happy medium" between a large and small order. However, serving sizes differ from store to store, as in some cases, you're either paying more money for fewer fries or less money for more fries depending on who's filling your fry container — and the McDonald’s medium fry is the former.

In 2020, YouTube's "The Food Theorists" conducted an experiment to see which fast-food chain would give you the most amount of money for your fries and found that it was McDonald's at 1.26 cents per gram. Since these large fries are supposedly the cheapest option out of all other fast-food fries, the medium fries simply aren't as "cost-effective" as ordering a large fry.

Even a small order of fries was considered to be a better option than the medium order, as the little paper bag they are served in is more "flexible" than the standard cardboard fry container and can theoretically hold more fries when filled. So while medium fries aren't bad taste-wise, you may be cheating yourself by not getting a better value.