ARRA IMPACT REPORT:
Childhood Obesity


Public Health Burden
Childhood obesity has more than tripled in the past 30 years. The percentage of children aged 6–11 years in the U.S. who were obese increased from 7 percent in 1980 to nearly 20 percent in 2008. Similarly, the percentage of adolescents aged 12–19 years who were obese increased from 5 percent to 18 percent over the same period. Clinicians are now reporting precursors of type 2 diabetes and cardiovascular disease in children and even the emergence of these disorders in children and young adults. Excessive weight in childhood increases the probability of excessive weight in adulthood, with increased risk for diabetes, cardiovascular disease, stroke, certain cancers, and other disorders and disabilities. It was estimated that the annual medical burden of obesity in children and adults reached almost 10 percent of all medical spending, or $147 billion, in 2008. 1

Origins of Childhood Obesity and Overweight
The causes of childhood obesity may seem apparent, but complex processes are at work. Problematic food choices and lack of exercise appear the most obvious origins of pediatric overweight, but scientists think that multiple factors beyond the control of an individual child, or even a child’s family, play important roles. Factors such as a child’s genetic makeup; the health and weight of the child’s mother during pregnancy; in utero environmental exposures; family, neighborhood, and school attitudes; opportunities with regard to diet and exercise; and larger societal influences may interact to determine a child’s weight. Multiple ARRA-funded projects addressed the specific contributions of a range of factors to childhood obesity.

  • Infant Nutrition & Obesity Risk: Infant nutrition, the first few months after birth, may be a critical window for the development of obesity. ARRA-funded researchers followed 850 infants that had been introduced to solid food between 3 and 6 months and then determined which were obese at age three. Among formula-fed infants or infants weaned before the age of 4 months, introduction of solid foods before the age of 4 months was associated with a 6-fold greater risk for obesity at the age of three. Among infants breastfed for 4 months or longer, the timing of the introduction of solid foods did not increase obesity risk. 2
  • Prenatal and Infant Environmental Exposures and Obesity RiskScientists continue to find that increased risk for adult health disorders, including obesity, can be markedly influenced by prenatal and infant environmental exposures, a phenomenon known as developmental programming. Researchers identified a protein in fat cells, PPAR, which is involved in fat production and is activated in the fetus because of exposures in the mother’s diet. Scientists are now working on ways to inhibit PPAR in order to block programming events that result in obesity later in life. 3
  • Discretionary Calories: There are many contributors to obesity, including excess consumption of "discretionary calories" (foods high in sugar and fat and low in essential nutrients), lack of fruit/vegetable consumption, and insufficient physical activity. ARRA-funded investigators compared dietary patterns in Los Angeles County and Southern Louisiana to the 2005 dietary guidelines. Discretionary calories exceeded the guidelines by 60 to 120 percent. In contrast, the average consumption of fruits and vegetables was 20 percent below the 2005 dietary guidelines. The results indicated that over consumption of foods high in sugar and fat was much greater than under consumption of fruits and vegetables. These findings suggest that unless the excessive consumption of foods high in sugar and fat is significantly reduced, interventions focusing on increasing fruit and vegetable consumption will have limited impact on obesity control. 4

Prevention and Treatment of Childhood Obesity and Overweight
Short-term interventions may help obese and overweight children to lose excess weight, but maintaining healthy weight over time is an elusive goal for many young patients. ARRA funds supported studies of interventions addressing a range of factors that may enhance a child’s efforts to achieve healthy weight control.

  • Ectopic Fat Deposits in Adolescents and Effect on Metabolism: There is a complex interplay between body fat, hormones and metabolic disorders related to obesity. ARRA-funded researchers studied fat deposits in adolescents that are not in obvious places (such as around the waist) and their effect on metabolism. The researchers found that fat deposited in the liver and in skeletal muscle before puberty played a major role in the development of insulin resistance, which can progress to diabetes. The results identify these pockets of “ectopic” fat as important targets for fat reduction that can delay the onset of insulin resistance and decrease the risk for the development of type 2 diabetes in children. 5
  • National Recommendations for Physical Education and Recess: ARRA-funded researchers analyzed a group of over 8,000 children from 970 schools across the country to determine the effectiveness of current national standards for physical education and recess time as defined by the National Association of Sport and Physical Education (NASPE). Following the progression of body mass index from first to fifth grade, researchers found that 70 percent of children met the NASPE recommendations for recess, which resulted in a decrease in body mass index for children overall. For the group of children meeting NASPE recommendations for physical education, there was a decrease in body mass index for boys but not girls. The results indicate that meeting the national recommendations for physical education and recess is generally effective in alleviating body mass increase among children. 6
  • Fasting and Lipid Screening in Children: Fasting lipid panels are recommended to screen for lipid abnormalities; however, fasting can be difficult for children and their parents, which may significantly limit the use of these important tests. In a nationally representative sample of over 12,000 children, ARRA-funded researchers found small but likely unimportant differences in lipid panel results between children who had fasted and those who had not fasted before testing. Thus, fasting before lipid screening in children does not appear to be necessary and should ultimately result in more children obtaining these important lipid screens. 7

Contributing NIH Institutes & Centers

  • National Heart, Lung, and Blood Institute (NHLBI)
  • National Institute on Alcohol Abuse and Alcoholism (NIAAA)
  • Eunice Kennedy Shriver National Institute of Child Health & Human Development (NICHD)
  • National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)

  1. Childhood Obesity Facts: Centers for Disease Control and Prevention. August 2012. Retrieved 8/30/1012.
  2. 5P30DK040561-15 - AUSUBEL, FREDERICK M - MASSACHUSETTS GENERAL HOSPITAL - BOSTON - MA
    2R01HD034568-10A1 - GILLMAN, MATTHEW W - HARVARD PILGRIM HEALTH CARE, INC. - BOSTON - MA
    5K24HL068041-10 - GILLMAN, MATTHEW W - HARVARD PILGRIM HEALTH CARE, INC. - BOSTON - MA
    http://www.ncbi.nlm.nih.gov/pubmed/21300681
  3. 1R56DK081756-01A1 - DESAI, MINA - LA BIOMED RES INST/ HARBOR UCLA MED CTR - TORRANCE - CA
    5R03HD060241-02 - DESAI, MINA - LA BIOMED RES INST/ HARBOR UCLA MED CTR - TORRANCE - CA
    5R01HD054751-03 - ROSS, MICHAEL GLENN - LA BIOMED RES INST/ HARBOR UCLA MED CTR - TORRANCE - CA
    http://www.ncbi.nlm.nih.gov/pubmed/21710399
  4. 5R01AA013749-04 - COHEN, DEBORAH A - RAND CORPORATION - SANTA MONICA - CA
    3R01HD057193-01A1S1 - STURM, ROLAND - RAND CORPORATION - SANTA MONICA - CA
    http://www.ncbi.nlm.nih.gov/pubmed/20402200
  5. 5R01HD041071-02 - SOTHERN, MELINDA S - LOUISIANA STATE UNIV HSC NEW ORLEANS - NEW ORLEANS - LA
    5P30DK072476-05 - YORK, DAVID A. - LSU PENNINGTON BIOMEDICAL RESEARCH CTR - BATON ROUGE - LA
    http://www.ncbi.nlm.nih.gov/pubmed/21181394
  6. 5R01HD057193-04, http://www.ncbi.nlm.nih.gov/pubmed/21415444 - STURM, ROLAND - RAND CORPORATION - SANTA MONICA - CA