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Direct Causes: Too Much Food, Too Little Physical Activity

Energy balance: As we chow down on burgers, fries, apples, and granola bars, our bodies break down these complex foods into simple energy-rich compounds like fats and carbohydrates. When people eat too much and move too little – i.e., consume more energy from food than they expend through physical activity – they overload their bodies with calories and cause the excess energy to be stored as fat. (2) In extreme cases of energy imbalance, overweight and obesity result. (3,4)

[(Calories IN) food > (Calories OUT) exercise] = Energy imbalance & FAT buildup.

Too much food: On 1 side of the energy balance equation, poor eating habits are overloading children's bodies with excess calories. 6 Kids are skimping on nutrient-dense foods like fruits and vegetables in favor more energy-dense, “empty-calorie” foods like soda, candy, chips, and fries. 6 The end result is a growing mass of unhealthy children, deficient in vitamins and minerals and laden with the burdens of overweight. (6)

Over the past 20 years, soft drink consumption among children and adolescents has more than doubled. (6,7) Only 3% of the U.S. population meet 4 of the 5 U.S. Department of Agriculture recommendations for daily intake of grains, fruits, vegetables, meats, and dairy products. (2) Ask adolescents what their favorite vegetable is, and it will most likely be fried potatoes. (6,9)

Portion sizes are steadily increasing for both ready-to-eat and restaurant meals. (21) 50 years ago, 6.5-oz Coke bottles were the norm; today, individual soft drinks come in 20- and 32-oz bottles. (21) In many fast food restaurants, a single “super-sized” or “extra-value” meal provides more than an entire day's worth of calories. (10,21) Unfortunately, almost 1/3 of the population base the amount of food they eat on how much food is on their plates; for these people, growing portion sizes can easily contribute to growing waistlines. (11)

Too little physical activity: On the other side of the energy balance equation, sedentary lifestyles are placing an ever-growing burden on children's bodies. Interestingly, studies suggest that youths have consumed a relatively constant number of calories over the past 25 years. (6) What, then, has caused our population-wide energy imbalance and weight gain? Experts point to physical inactivity as a driving factor. (6)

Together with cars, elevators, TVs and dishwashers, urban development, transportation, entertainment, and education have decreased the physical demands built into daily life. (12,13)

An important risk factor for physical inactivity is increasing age: adolescents, particularly African American girls, become increasingly sedentary during their teenage years. (15)

Sedentary activity, particularly television viewing, has a profound impact on youth behavior and health: the amount of time spent watching television, surfing the web, or playing video games correlates significantly with childhood overweight. (19) In 1999, 43% of high school students watched more than 2 hours of TV per day (2) , and an estimated 50% of all children aged 8-16 watch 3-5 hours of TV daily. (20)