I would guess, the first time a person comes across this type of statement, they would simply dismiss it.

After hearing similar sentiments from 10 or 20 people, they may start to feel bothered and wonder if they're doing something wrong; if they ought to do research to justify their existing behavior.

Then they may come something like the New Nordic Diet, and find it has an aesthetic appeal; plus they are also primed to appreciate that it addresses the excess sugar problem. This offers a way forward.

Alternatively, they simply come to terms with the fact that other people disapprove of their lifestyle choices. It's just as important to be able to withstand social pressure as it is to eat healthy.