The Mars Bar is available and says "can be part of a healthy diet" BECAUSE of the calorie bullshit. People see "it's only 250 calories" and "it's less fat than cheese" and happily chomp on them, while demonising red meat or saturated fat.
I genuinely don't see a logic chain of reasoning from you. 250 calories is massive. If someone were worried about calories they wouldn't be eating something that's over 10% of their daily allowance.
The "it's less fat than cheese" isn't a calorie thing. You seem to be mixing things up.
