I think the recommendation is for 250 minutes per week to lose weight through cardio.
You could slice this several ways: 4 x 60, 5 x 50, 6 x 40. It's all pretty much the same.
But the question ACSM asks "how much cardio to lose weight" is probably too narrow (but it is the American College of SPORTS Medicine after all). The question that most people probably really want answered is "How should I best structure my overall program to lose weight".
And the answer is that it is a lot easier to lose weight through a COMBINATION of watching your intake, cardio and strength training, than it is through cardio alone. Once you have achieved the minimum cardio consistent with good health (3 x 30 mins), you are probably better off adding strength training to your program, rather than yet more cardio. But watching your intake is, and always has been, the most effective way to lose weight, rather than lots and lots of exercise.