In the last thirty years, childhood obesity rates in the united states have tripled. nearly one-third of all american children are overweight or obese. americans consume 31 percent more calories, 56 percent more fats and oils, and 14 percent more sugars and sweeteners than they did forty years ago. forty years ago, americans were less likely to eat fast food. portion sizes for foods have increased two to five times the size they were forty years ago. today, american children tend toward eating three snacks a day, compared to only one snack a day forty years ago. additional snacks mean an increase of 200 calories in the daily diet. children are less physically active today than forty years ago. only one-fourth of high school students get the recommended amount of daily physical activity. why have obesity rates for american children increased in the last thirty years? check all that apply. children are snacking more today. fast food is less popular today. snack portion sizes are smaller today. unhealthy snacks add about 200 calories more each day. americans are eating more high-calorie, high-fat, and high-sugared snacks today.