The latest research shows obesity beginning to decline in the U.S including children. The greatest change seems to have been a decrease in soda and sugar-sweetened beverage consumption by children — down by 79 daily calories between 2004 and 2012. Unfortunately, calories from Desserts went up by 20 in that period, while those from fruits and vegetables increased by only 16. Overall, their daily intake dropped by about 185 calories.

http://acsh.org/2015/07/data-suggest-were-seeing-a-real-decrease-in-americans-calorie-consumption/

This is great to hear. In my opinion, the biggest change that is and will impact children is removing high fructose corn syrup from processed food.