How can you be sure it's not a lie? What I meant by "lie" is this: let's say you ask someone how much they sleep. Currently society tells us that working as much as possible is a virtue. So they tell you they sleep 4 hours every night. You have no way of verifying this information. For all you know they could be sleeping 8 or 9 hours. But it is very easy and tempting for them to lie for a small boost in social standing.
Not common? How do you know?
Eating nothing but pizza is not healthy? I disagree, Pizza has carbohydrates, protein, vegetables, vitamin, etc. Not always but it can be healthy.