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.

The correct answers are:

- Children are snacking more today;

- Unhealthy snacks add about 200 calories more each day;

- Americans are eating more high-calorie, high-fat, and high-sugared snacks today;

In the past few decades the lifestyle of the people in the US has changed significantly. The people have become much less active than they were few decades ago. The reason for that is that type of jobs they are engaged in, as well as living in large cities where they have to use vehicles to get to their workplace. The food has changed as well, and lot of new very tasty dishes and snacks have emerged on the market, and over time have become more and more popular. These new dishes and snacks are much high in calories, fats, and sugars, which over-saturates the human body very easily. With this kind of intake of food, plus at bigger amounts, and the lesser activity, the body is accumulating all of those things in it, thus the people become obese.

the causes of the dust bowls were severe droughts,   lands became dry and hard, temperature was higher than usual, hot and dry conditions killed crops, high winds. because of those factors, the winds kicked up dry soil and created clouds of dust.

this is a good question! i'll do some research and come back when i have the answer!