A study from the University of Wisconsin has found that super-sizing your meal takes a hidden toll on your pocketbook, and in more ways that you might expect.

[Researchers] found that for the initial 67-cent average cost of upsizing a fast-food meal — and the subsequent 36-gram weight gain — the total cost for increased energy needs, gasoline and medical care would be between $4.06 and $7.72 for men and $3.10 and $4.53 for women, depending on their body type.

It’s difficult to know how much credence to lend this without reading the entire study. But do you really need another reason not to super-size? (And why are you eating in fast food restaurants, anyhow? Learn to eat more meals at home!)