Middle class millennial French here: there's a very real concept of guilt in relation to food at least (somewhat less for electricity and water, but still).

It's considered a normal habit to always finish what's on your plate, even when you're not hungry anymore. But it's true that attitudes have softened a bit in this regard, especially at the restaurant; but when you're in control of the amount you're taking, you're still expected to not have "eyes bigger than your belly".