Well... you could use this and sell a new marketing pitch! Diet toothpaste or Toothpaste Zero! lol
My daughter actually asked me if toothpaste had calories before! Apparently, this is becoming a big concern! I would show some pictures of girls with rotten teeth along with researching a little about toothpaste with her. Guide her into agreeing with and understanding the importance of good dental hygiene! From my experiences if kids get an opportunity to figure it out instead of just being told by parents, they respond better. Possibly show some examples of what toothpaste prevents vs what sugar can cause. If she is that concerned I might even gradually provide evidence and education on how calories are a positive and not a negative. Nutrition and calories go hand in hand..The word "Calories" gives off a negative vibe because weight loss has become such big business! Learning about and how to read nutrition labels has helped my family! Eventually letting them choose between items at a grocery store based on the nutrition label's differences. Your daughter has an interest already! Good luck! Let me know how it goes or how you go about it!
Continued health & success,
Coach Ron