Factors Contributing to Child Obesity in the US

This is the rough draft of a research paper I had to write my first semester in grad school. I got a good grade on the final paper, but I seem to have lost it. So I'm putting this up and may make changes to it to make it more polished. If nothing else, there are some interesting facts contained in the mess :o)

In today's society, the number of overweight Americans is steadily increasing. Obesity is considered an epidemic, affecting not only adults but children as well. The percent of overweight and obese children in America is rising at an alarming rate. Today, over 4.7 million American youths between the ages of 6 and 17 years are overweight or obese (Briggs, Safaii & Beall, 2003), and this number has tripled over the past 30 years (Troiano, 2002). Although diet contributes greatly to this growing problem of obesity in children, there are many other factors that come into play when considering its cause and potential remedies.

Obesity describes the condition of carrying excess body fat (Hodges 2003). It is the result of too much energy intake from food, too little energy output in the form of physical activity, or a combination of the two. The percentage of fat, or adipose tissue, in the body can be accurately measured using a variety of methods, including magnetic resonance imaging and underwater weighing. These tools tend to be costly and are not always readily available to most people, so other more practical methods of obtaining measurements of adiposity, like skin fold thickness and Body Mass Index (BMI) are used more widely. Generally, children with BMIs above the 85th percentile with accompanying health complications are considered obese and should be evaluated for treatment (Hodges 2003). Unfortunately, BMI is only a measurement of the height-to-weight ratio and is not an accurate description of body composition. Actual body fat percentage is a more accurate measurement of what portion of the total body weight is adipose, and whether it is withing a normal range for a person's height, age and body frame.

There is no set profile describing the most likely candidate for childhood obesity. The condition is more prevalent among Hispanic, African-American and American Indian children. On average, more calories from fat are consumed by both male and female non-Hispanic blacks (Troiano, Biefel, Carroll & Bialostosky 2000). Studies have shown that overweight children in America often come from low-income households where there is not enough income to keep a variety of healthy and nutritious foods around the house. In these cases, the cost of food, rather than nutritious content, determines what is purchased and, consequently, what is available to the children in that household (Gable & Lutz 2000).

Regardless of race or income, childhood obesity can lead to health problems in the future. One of the conditions most commonly associated with overweight children is non-insulin dependent diabetes mellitus. Cardiovascular disease, cancer and hypertension are all major health risks that increase as a result of obesity. The excess weight carried on the body can lead to orthopedic problems and arthritis. Finally, low self-esteem often occurs in children who are noticeably bigger than their peers (Troiano, Biefel, Carroll & Bialostosky, 2000). Habits and attitudes towards food during childhood create long-term eating patterns that can seriously affect health as adults. One study found that 26-41% of obese preschoolers become obese adults (Atkins & Davies, 2000).

The underlying cause of excessive weight is when more energy is consumed than expended, over a long periods of time. Guidelines have been set for what is an appropriate requirement for energy intake for children, derived from total energy expenditure with an allowance for growth and development (Butte, 2000). Much concern is centered around fat consumption, stemming from the belief that the more dietary fat consumed, the more adipose is deposited. Organizations like the American Academy of Pediatrics and the American Heart Association recommend that for children over the age of 2, about 30% of total energy consumed be derived from fat, in order to ensure adequate growth. Less than 10% of total energy consumed should be derived from saturated fat. Children under the age of 2 should consume about 30-40% of their total energy intake from fat to allow for growth and development (Butte 2000). In terms of actual fat intake, there is little difference between the dietary guidelines set by these organizations and what is currently being consumed. Generally, children between the ages of 2 and 19 are consuming about 34% of energy from dietary fat (Butte 2000). Diets that are lower in fat usually result in unsatisfactory intakes of many vitamins and minerals, especially fat-soluble vitamins (Butte 2000). This decreased intake of vitamins and minerals may result in poor growth rates, implying that low-fat diets may not be the best option for children. Research suggests that children are consuming more than the recommended amounts of energy from fat, but not meeting the recommendations for fruit and vegetable intake (Bordi, Park, Watkins, Caldwell & DeVitis 2002). Since the early 1970's, however, fat intake has declined from 36-37% of total energy intake to 33-34%; and saturated fat intake has decreased from 14% to 12% of total energy intake (Troiano, Briefel, Carroll & Bialostosky 2000). Additionally, it's been found that the actual amount of dietary fat consumed had little or no impact on the percentage of body fat in children ages 2-3. While it is true that dietary fat contains more energy per gram than other micro nutrients (compare 9kcal/g of fat to 4kcal/g of protein and 4 kcal/g of carbohydrates), it appears from the above statistics that excessive fat consumption is not a leading cause for concern regarding obesity in children. Consumption of excessive calories creates a bigger difference between energy intake and output.

Beverages consistently appear as a main contributor of excessive energy intake in children and adolescents, especially soft drinks (Troiano, Briefel, Carroll & Bialostosky 2000). Calories in beverages often add up unnoticed, but can account for 20-24% total energy intake in most children, with soft drinks alone making up 8% of total calories consumed. These soft drinks are full of "empty calories" that generally contain little or no nutrients but are high in calories.

A more beneficial and healthy way to consume calories is to eat more nutrient-dense foods like fruit and vegetables, which contain higher amounts of nutrients per calorie. Consumption of nutrient-dense foods like these is low: only 2% of school-age children currently meet the recommendations set by the Food Pyramid Guide for all 5 of the food groups. Less than 30% meet the recommendations for any one of the food groups (Briggs et al., 2003). Slightly over half of school age children eat less than one serving of fruit per day, and 29% don't even eat one serving of non-fried vegetables each day.

One in five 15-18 year-olds skip breakfast each day, and depending on gender and age, 56-85% of children consume soda on any given day (Briggs et al., 2003. Although statistics like these are less than favorable for a proper diet, eating habits are not entirely to blame for the nation's obesity issue. Even a healthy, balanced diet can lead to weight gain if the energy expended is consistently far lower than energy consumed. Studies show that current rates of total energy expenditure (TEE) are 10-12% below recommendations set by associations such as the World Health Organization (Atkin & Davies, 2000). While it is true that some energy goes towards growth and maturation, it is not likely that that has changed from 2% of TEE. Gable & Lutz found that 20% of children ages 8-16 exercise vigorously twice per week or less. A 1998 study shows that 67% of children in the same age group watch over 2 hours of television per day. Not surprisingly, it has also been determined that leaner children spend less time watching television than heavier children (Jonides, Buschbacher, & Barlow, 2002).

A major influence on a child's eating and fitness habits is school. Of the 53.2 million school age children in the United States, 27 million participate in the National School Lunch program. School lunches provide on average one-third the Recommended Daily Allowances for most nutrients, but contain excessive amounts of fat, saturated fat and sodium (Seo, Hiemstra & Boushey, 2003). The school systems have a lot of potential to create lunches for children that will provide adequate vitamins and minerals and acceptable amounts of all the macro nutrients. Schools can help combat obesity in other ways as well. The amount of physical education taught in schools is decreasing. This may very well be the only physical activity some students participate in at all.

Education can increase knowledge about food and exercise, but may not change behavior. In a study by Blom-Hoffman & DuPaul in 2003, students who received a nutrition education class over a 13-week period showed improvement on a post-test nutrition examination, but showed no remarkable change in behavior. Role models, especially parents and teachers, are a huge influence on a child's lifestyle, including diet and exercise habits. Children ages 4-7 who have parents that are physically active are nearly six times more likely to be physically active than children with parents who are not physically active (Hodges 2003). In today's busy society where both parents work full-time, fresh meals are often exchanged for processed or fast food; both of which usually contain high amounts of sodium, fat and calories and little amounts of vitamin-rich fruits and vegetables. Regular consumption of these high-calorie meals, along with minuscule amounts of physical activity, creates a large amount of energy left to be stored as fat. Habits like these are formed during childhood and the overweight child becomes an obese adult. The longer these habits are practiced, the more difficult it becomes to make the changes necessary to transform the lifestyle into a healthier one.

There is not one specific factor that causes obesity in children, but a combination of lifestyle choices that result in excessive amounts of energy being consumed compared to the low amount of energy expended. There is no question that being severely overweight as a child leads to health complications. In order to decrease the prevalence of obesity, people must be educated at an early age of the benefits of healthy food selection, and good habits must be formed regarding exercise and activity. Attention must be paid the the total amount of calories consumed, especially from beverages, and more effort must be placed on choosing nutrient-dense foods. Daily physical activity is a must. Efforts must be made by role models such as parents and teachers to encourage healthy lifestyles both through education and example.