Ehh, many people are probably eating several boxes a day of tick tacks which are ~100 calories each. I used to pop them like the candy they are, and that adds up fast.

So I wouldn’t be surprised if a few thousand people are overweight due to Tick Tacks not actually being 0g of sugar.

In addition to Retric's point, many (most?) people are overweight due to symphony of small poor health choices. A box of tic tacs here, a candy bar there, a soda and a beer at night, driving instead of walking: each of those might add ~100 net calories a day, but together they add ~500 a day, which absolutely can cause weight gain.

Make a serving of potatoe chips 2gr and call it "0 calorie"

That's exactly the same thing, and it's as dumb as it sounds