Somebody commented that one of my kids look thin. I've always thought as long as my kids aren't sickly, all's well even if they may fall a little behind the ideal weight for their age at times. Do I need to step it up a notch and make sure they not only are not sickly, but don't look sickly as well?

Personally, I feel that as long as your child is healthy and growing, there is no need to be too worried. Do they fall sick often or take very long to recover from a sickness? If they are healthy, active and have no issues with their meals, I think it should be fine. I guess unless they are severely underweight or often falling sick, then there may be a need to reconsider their diets. Children are very active and could easily work off the calories that they have consumed. Just my two cents.. hope this helps!