Fast Food Linked Again With Obesity Epidemic

Some Teens Can't Resist Overeating

Teens are more likely to overeat when served fast food, according to a study in the Journal of the American Medical Association. 

But, lean adolescents tend to compensate for over-consumption by eating less at other meals, whereas individuals who are overweight do not cut back, the study says. 

"Consumption of fast food has increased rapidly since the 1970s among adolescents from all socioeconomic and racial and ethnic groups across the United States," the study authors write.

"An estimated 75 percent of adolescents eat fast food one or more times per week," says Dr. Cara B. Ebbeling, a nutrition expert from Children's Hospital in Boston.

Excessive Eating Adds Up

The increase in fast food consumption parallels the escalating obesity epidemic, the authors suggest.

"Characteristics of fast food previously linked to excess energy intake [overeating] or adiposity [fat] include enormous portion size, high energy density, palatability, excessive amounts of refined starch and added sugars, high fat content, and low levels of dietary fiber," Dr. Ebbeling says.

Dr. Ebbeling and her colleagues conducted two studies to evaluate the effects of fast food on energy intake in overweight versus lean adolescents.

Fifty-four adolescents ages 13 to 17 years who reported eating fast food at least one time per week were enrolled in the studies (26 overweight, 28 lean).

Fifty-one (24 overweight, 27 lean) of the 54 participants enrolled in the first study also completed the second study.

In this investigation, the researchers grouped adolescents who were overweight and at risk of overweight into one group and adolescents considered lean into another group. Lean was defined as a BMI [body mass index = weight in kilograms divided by the square of height in meters] not exceeding the 85th percentiles for their ages.

In study one, participants were fed extra large fast food meals in a food court and instructed to eat as much or as little as desired during the one-hour meal.

In study two, the researchers assessed how much food was eaten under free-living conditions for two days when fast food was consumed and two days when it was not consumed. The participants recalled dietary and physical activity on telephone interviews.

In study one, average energy intake from the fast food meal among all participants was extremely large (1,652 calories), accounting for 61.6 percent of estimated daily energy requirements.

"Overweight participants ate more than lean participants whether energy was expressed in absolute terms (1,860 calories vs. 1,458 calories) or relative to estimated daily energy requirements (66.5 percent vs. 57 percent), the authors report.

In study two, overweight participants consumed significantly more total energy on fast food days than non-fast food days (2,703 calories per day vs. 2,295 calories per day; plus 409 calories per day), an effect that was not observed among lean participants (2,575 calories per day vs. 2,622 calories per day; less 47 calories per day).

The researchers also found that overweight participants tended to under-report total energy intake compared with lean participants.

Regulating Fast Food Consumption Varies

"The overweight participants consumed more total energy on days with and without fast food, in contrast to the lean participants, who consumed virtually the same amount on both days," Dr. Ebbeling reports.

"This observation suggests that overweight individuals do not compensate completely for the massive portion sizes characteristic of fast food today," the authors note.

The authors say these findings suggest that, at least, fast food consumption serves to maintain or exacerbate obesity in susceptible individuals.

"In this study, adolescents over-consumed fast food regardless of body weight, although this phenomenon was especially pronounced in overweight participants," says Dr. Ebbeling.

"Moreover, overweight adolescents were less likely to compensate for the energy in fast food, by adjusting energy intake throughout the day, than their lean counterparts," the authors conclude.

Always consult your child's physician for more information.

Overweight and Obesity Estimates Updated

The high levels of overweight among children and obesity among adults remain a major public health concern, according to a report in the Journal of the American Medical Association.

"The prevalence of overweight and obesity is considered an important public health issue in the United States," the authors say. "Healthy People 2010 identified overweight and obesity as one of the 10 leading health indicators."

Dr. Allison A. Hedley, a Centers for Disease Control and Prevention (CDC) health expert, and colleagues updated the US prevalence estimates of overweight in children and obesity in adults using the most recent national data of height and weight measurements.

The researchers analyzed data from the National Health and Nutrition Examination Survey (NHANES). Both height and weight measurements were obtained from 4,115 adults and 4,018 children in 1999 to 2000 and from 4,390 adults and 4,258 children in 2001 to 2002.

"For adults, overweight, obesity, and extreme obesity, were defined as body mass index (BMI, calculated as weight in kilograms divided by the square of height in meters) of 25.0 to 29.9, 30.0 or more, and 40.0 or more, respectively," Dr. Hedley says.

For children, "at risk for overweight was defined as at or above the 85th percentile but less than the 95th percentile of the sex-specific BMI for age," as defined by the CDC growth charts.

"Overweight was defined as at or above the 95th percentile of the sex-specific BMI-for-age growth chart," the authors say.

The authors' findings point to no actual improvement in the overweight and obesity rates in the US.

Overall, among adults aged at least 20 years in 1999 to 2002, 65.1 percent were overweight or obese, 30.4 percent were obese, and 4.9 percent were extremely obese.

Among children ages six through 19 years in 1999 to 2002, 31 percent were at risk for overweight or obesity and 16 percent were overweight.

Always consult your child's physician for more information.

August 2004

Fast Food Linked Again With Obesity Epidemic

Excessive Eating Adds Up

Regulating Fast Food Consumption Varies

Overweight and Obesity Estimates Updated

Obesity Prevention Facts

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Obesity Prevention Facts

Obesity is a chronic disease affecting increasing numbers of children and adolescents as well as adults.

Obesity rates among children in the US have doubled since 1980 and have tripled for adolescents. Fifteen percent of children aged six to 19 are considered overweight compared to over 60 percent of adults who are considered overweight or obese.

Earlier onset of type 2 diabetes, cardiovascular disease, and obesity-related depression in children and adolescents is being seen by healthcare professionals.

The longer a person is obese, the more significant obesity-related risk factors become. Given the chronic diseases and conditions associated with obesity and the fact that obesity is difficult to treat, prevention is extremely important.

A primary reason that prevention of obesity is so vital in children is because the likelihood of childhood obesity persisting into adulthood is thought to increase from about 20 percent at four years of age to 80 percent by adolescence.

Breastfed babies are 15 percent to 25 percent less likely to become overweight, and those who are breastfed for six months or longer are 20 percent to 40 percent less likely to become overweight. Therefore, the longer babies are breastfed, the less likely they are to become overweight as they grow older.

Children and adolescents generally become overweight or obese because they do not get enough physical activity in combination with poor eating habits. Genetics and lifestyle also contribute to a child’s weight status.

Parents can help their children prevent overweight and obesity.

Gradually work to change family eating habits and activity levels rather than focusing on a child’s weight.

Parents who eat healthy foods and participate in physical activity set an example so that a child is more likely to do the same.

Children should have 60 minutes of moderate physical activity most days of the week. More than 60 minutes of activity may promote weight loss and subsequent maintenance.

Reduce “screen” time in front of the television and computer to less than two hours daily.

Encourage children to eat when hungry and to eat slowly.

Avoid using food as a reward or withholding food as a punishment.

Keep the refrigerator stocked with fat-free or low-fat milk, fresh fruit, and vegetables instead of soft drinks and snacks high in sugar and fat.

Serve at least five servings of fruits and vegetables daily.

Encourage children to drink water rather than beverages with added sugar, such as soft drinks, sports drinks, and fruit juice drinks.

Always consult your child's physician for more information.

Online Resources

American Academy of Pediatrics

Centers for Disease Control and Prevention (CDC)

Centers for Disease Control and Prevention (CDC) 5 A Day