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Obesity and Overweight: Research Activities and Scientific Advances

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Institute Activities and Advances

Obesity is a growing epidemic, but prevention efforts have not been successful. To a great extent, this is due to the challenging task of changing the way people eat, move, and live. Obesity is both a biological and a social problem and must be considered as a function of these larger contexts. Several NICHD organizational units conduct and support research on a broad range of areas related to excess weight gain, including the causes, effects, prevention, and treatment of obesity and related conditions.

Because environment and genetics play important roles in childhood obesity, the NICHD’s Section on Growth and Obesity works to increase understanding of the metabolic and behavioral factors involved in determining body weight regulation and body composition during childhood. The section also studies prevention and treatment interventions, and places a special emphasis on minority populations that are at an increased risk for obesity. For example, in one study on African American and Caucasian children and adolescents, researchers found that the gastrointestinal lipase inhibitor orlistat improved weight loss. Another study found that the medication metformin added to a behavioral program significantly improved weight loss and lowered insulin resistance in severely obese, insulin-resistant children.

The Pediatric Growth and Nutrition Branch (PGNB) also supports a wide range of childhood obesity research, including studies on psychosocial risks of obesity, the natural history and clinical pathophysiology of body composition, metabolic syndrome and diabetes, environmental and policy research in relation to obesity, and preventive and therapeutic interventions for childhood obesity. Funding from the PGNB has led to several noteworthy advances, including one of the first large genome-wide association studies (GWAS) on weight among U.S. children.

  • PGNB-supported finding: Historical Data Show Childhood Obesity Epidemic is Recent and Sudden

    To identify whether the obesity epidemic is entirely a recent phenomenon or a continuation of longstanding trends, researchers used a longitudinal study of over 1,100 children born between 1930 and 1993. Between the birth cohorts of 1930 and 1993, the prevalence of obesity rose from 0% to 14% among boys and from 2% to 12% among girls. The prevalence of overweight rose from 10% to 28% among boys and from 9% to 21% among girls. Among boys, all these increases began after birth year 1970. Among girls, obesity began to rise after birth year 1980, but overweight was already rising as early as the 1930s and 1940s. The results show that although some rise is body weight is a longstanding trend, most of the child obesity epidemic was recent and sudden. (PMID: 23512972)
  • PGNB-supported finding: After Pediatricians’ Guidance, Mothers Improve Infant Diets

    Childhood obesity is a growing concern around the world. In the United States, a sizeable portion of infants and toddlers are overweight or obese, and young children with less healthy diets are at risk for obesity early in life. Despite the importance of preventing obesity early and getting infants off to a healthy start, researchers have little information about what types of prevention efforts are most effective.

    Researchers compared two different prevention approaches to each other and to a “usual care” approach. The first prevention strategy, “healthy moms,” was designed to promote healthy eating among the mothers. This program was developed on the premise that mothers are role models for the children and that if mothers develop healthy habits for themselves, this will lead to healthy eating for the children as well. The second prevention approach, called “ounce of prevention,” was designed to teach mothers about healthy infant feeding practices (such as allowing the child to determine when he or she is full, and not using food as a reward). The “usual care” approach included typical guidance provided to new mothers, such as recommending breastfeeding, but did not incorporate special efforts to prevent childhood obesity. Researchers conducted the study at 3 clinics in Ohio, randomly assigning each clinic to implement one approach.

    After 1 year, the researchers found that mothers in the “healthy moms” group gave their infants less juice and more daily servings of fruit and vegetables compared with mothers in the “usual care” group. Mothers in the “ounce of prevention” group also gave less juice and more fruit to their children than the mothers in the “usual care” group. However, neither group provided the full number of servings of fruits and vegetables recommended. The results showed that providing specific obesity prevention guidance to mothers resulted in positive but not dramatic changes in infant diets. (PMID: 22891225)
  • PGNB-supported finding: New Childhood Obesity Genes Identified

    The substantial increase in the prevalence of obesity has created a global health crisis. In the United States, childhood obesity has tripled in recent decades, and the related health care costs have quadrupled. Obesity in children often leads to type 2 diabetes later in life, which is accompanied by costly, chronic health problems involving heart, kidney, and nerve damage from high blood sugar levels. Recently, the significant contribution of genetic factors to obesity was revealed in GWAS done in adults.

    Researchers used a powerful approach to search for childhood obesity genes by performing a large scale analysis that combined 14 existing GWAS studies for childhood obesity, which totaled 5,530 cases. Seven genes were identified, which were previously shown to be associated with body mass index in adults. These initial findings were then used to do a more rigorous analysis, which resulted in the identification of two new genes with a strong association that is specific to childhood obesity, OLFM4 (Olfactomedin 4) and HOXB5 (homeobox B5). Consistent with a role in obesity, the genes appear to make proteins that function in the stomach and intestines.

    To date, these two genes show the strongest association with obesity in the first 18 years of life. Comprehensive studies of these unique genes and the proteins they produce will be the next step towards a more complete understanding of the strong genetic component related to obesity in children and may offer clues for future therapeutic interventions. (PMID: 22484627)
  • PGNB-supported finding: Parental Stress Affects Fast Food Consumption and Childhood Obesity

    Today, nearly one in three children nationwide is overweight or obese. Studying how and what children eat today can shed some light on the causes of this epidemic. In a survey of over 2,000 parents in Pennsylvania, parents who reported that they were under more stress had children with increased consumption of fast food. Moreover, parents with a greater number of difficulties (such as poor health or financial worries) were more likely to have children that were overweight or obese. (PMID: 23090343)

Obesity affects pregnancy in several significant ways. The Pregnancy and Perinatology Branch (PPB) conducts obesity-related research in many areas, including the short- and long-term effects of maternal obesity and weight gain during pregnancy on women’s and children’s health. In addition, the Branch supports studies of lifestyle interventions during pregnancy that aim to improve maternal and child health through healthy changes in diet and physical activity levels. The PPB also has explored the possible connection between obesity and postpartum depression.

Obesity also can affect fertility. The NICHD’s Fertility and Infertility (FI) Branch explores ways to prevent and treat infertility related to obesity. One recent scientific advance provided new insights into the relationship between obesity, androgen excess, and polycystic ovary syndrome in adolescents.

Other NICHD units, such as the Intellectual and Developmental Disabilities Branch (IDDB), explore issues related to obesity in specific populations, such as people with Down syndrome. The Child Development and Behavior Branch (CDBB) supports research on the behavioral factors that can lead to obesity and behavior-based prevention and treatment strategies for obesity. In addition, the Division of Intramural Population Health (DIPHR) works to fill critical data gaps to advance understanding of such factors as obesity that affect health. For example, DIPHR launched a 7-year assessment of U.S. adolescents and young adults to identify several health-related factors, including genetic, personal, family, school, and social factors that promote or sustain positive health behaviors.

  • DIPHR finding: Patterns of Physical Activity, Sedentary Behavior, and Diet in U.S. Adolescents

    Lack of physical activity, an unhealthy diet, and too much time spent on screen-based activities contribute to adolescent obesity and early development of heart disease risk factors, as well as other health problems. Researchers surveyed a nationally representative sample of U.S. adolescents about their daily amounts of physical activity, screen-based activity, and healthy and unhealthy food consumption. They also asked the adolescents to describe their emotional health, body image, and general satisfaction with life. The survey showed the adolescents’ diet and activity patterns fall into three general groups:
    • The healthful group (27%) had the highest rates of exercising five or more days a week, and was least likely to spend time with screen-based activities. They were the most likely group to eat fruits and vegetables at least once a day, and were least likely to consume sweets, soft drinks, chips, and fries. They were the most likely to be normal weight. Also, these adolescents reported the highest rates in life satisfaction and the lowest rates in symptoms of depression.
    • The unhealthful group (26%) were more likely than the other groups to report screen-based activities more than two hours a day. They consumed the most sweets, chips, fries, and soft drinks. However, despite consuming a lot of high calorie foods, these adolescents were more likely to be underweight and to report needing to put on weight. They also were more likely to report symptoms of depression and poor physical health.
    • The typical group (47%) were the least likely to exercise five or more times a week. They were more likely to spend time on screen-based activities than the healthful group, but less likely to do so than the unhealthful group. This group rarely ate fruits and vegetables, but also rarely consumed sweets, chips, fries, or soft drinks. Adolescents in this group were more likely than those in the other two groups to be overweight or obese and to be dissatisfied with their body image.
    These results indicate that about three out of four adolescents didn’t have a healthy dietary and activity behavior pattern. Moreover, the researchers’ results suggest that adolescents in the typical group—the one most likely to be overweight—could benefit more from additional exercise than from efforts to reduce consumption of high-calorie foods. (PMID: 23642973)

To ensure that NICHD organizational units advance the most effective obesity-related science, the NICHD’s Obesity Research Strategic Core (ORSC) brings together research and translational activities from across the Institute. Some of the ORSC’s focus areas include:

  • Interventions, such as pediatric obesity prevention or treatment studies in the primary care setting, at home, in schools, and in camps
  • Behavioral and psychosocial observational research, including observational studies that examine social and psychological antecedents, consequences, or correlates of diet, physical activity, sedentary behavior, and/or obesity in children and adolescents
  • Basic sciences research, including human in vitro or animal studies that focus primarily on the genetic, molecular, cellular, or organ-system factors related to diet, physical activity, development of adiposity, or other aspects of energy metabolism
  • Clinical physiology, such as human studies that focus on clinical cohorts of either normal weight or overweight children and adolescents

The ORSC also is working to promote a systems-oriented approach to childhood obesity that includes the following key features:

  • Framing obesity as a complex systems problem
  • Emphasizing cross-level and cross-disciplinary hypotheses at the outset of research
  • Increasing efforts in structural or upstream interventions
  • Building capacity for multilevel research, in terms of training and collaborating with partner organizations
  • Investing in complex systems research methodologies
  • Maintaining a global perspective

Additional scientific advances include:

  • Weight Gains in Children Not Associated with School Snack Foods

    Researchers supported by the NICHD’s Population Dynamics Branch tracked the body mass index of 19,450 students and found that children’s weight gain between the 5th and 8th grades was not associated with the introduction of or the duration of exposure to snack foods such as soft drinks, candy bars, or chips made available in school settings, often through vending machines and other sources. The researchers hypothesized that middle- and high-school schedules may be so regimented that they leave little time for unsupervised eating. Scientifically, the findings underscore that childhood obesity is a complex problem linked to the interplay of many genetic, environmental, and behavioral factors. The findings underscore the need for a range of behavioral-related research to provide a solid base for health policy. These types of studies also show that ultimately, even solutions that may seem self-evident may not prove helpful. (PMID: 22611291)

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Other Activities and Advances

The NICHD works to promote collaborative efforts to understand overweight and obesity and to promote healthy weight. For example:

  • In 2003, the NIH director began addressing the problem of the obesity epidemic by forming the Obesity Research Task Force to promote obesity research efforts across the NIH.
  • The NICHD is a member of the National Collaborative on Childhood Obesity Research (NCCOR) External Web Site Policy, which brings together leading research funders (including the NIH, the Centers for Disease Control and Prevention, the Robert Wood Johnson Foundation, and the U.S. Department of Agriculture) in a public-private collaboration to accelerate progress on reversing the epidemic of overweight and obesity among U.S. youth. The mission of NCCOR is to improve the efficiency, effectiveness, and application of childhood obesity research, and to halt—and reverse—childhood obesity through enhanced coordination and collaboration.
  • The NICHD created the Maternal-Fetal Medicine Units Network to focus on clinical questions in maternal-fetal medicine and obstetrics. The Network is composed of 14 university-based clinical centers and a data coordinating center that have explored a number of issues, including weight gain and nutrition.
  • The NICHD also works to encourage a healthy weight among young people. It joins several other NIH Institutes to support We Can! (Ways to Enhance Children’s Activity and Nutrition), which focuses its evidence-based education activities on parents and caregivers—the primary group for influencing youth. The NICHD’s Media-Smart Youth: Eat, Think, and Be Active! curriculum is one of four youth curricula offered through We Can! Media-Smart Youth is an afterschool program that helps participants become aware of, and think critically about, the media’s influence on their nutrition and physical activity choices.
  • Research supported by NICHD and other NIH Institutes was featured in the HBO documentary The Weight of the Nation External Web Site Policy, which explored many topics related to the obesity epidemic in the United States, from causes to treatments. Leaders of the NIH Obesity Research Task Force provided guidance and materials to the filmmakers throughout the creation of the piece.

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The Pediatric Growth and Nutrition Branch (PGNB) also supports a wide range of childhood obesity research, including studies on psychosocial risks of obesity, the natural history and clinical pathophysiology of body composition, metabolic syndrome and diabetes, environmental and policy research in relation to obesity, and preventive and therapeutic interventions for childhood obesity. Funding from the PGNB has led to several noteworthy advances, including one of the first large genome-wide association studies on weight among U.S. children. Researchers funded by the PGNB identified two genes that appear to increase the likelihood of common childhood obesity.

Obesity affects pregnancy in several significant ways. The Pregnancy and Perinatology Branch (PPB) conducts obesity-related research in many areas, including the short- and long-term effects of maternal obesity and weight gain during pregnancy on women’s and children’s health. In addition, the Branch supports studies of lifestyle interventions during pregnancy that aim to improve maternal and child health through healthy changes in diet and physical activity levels. The PPB also has explored the possible connection between obesity and postpartum depression.

Obesity also can affect fertility. The NICHD’s Fertility and Infertility (FI) Branch explores ways to prevent and treat infertility related to obesity. One recent scientific advance provided new insights into the relationship between obesity, androgen excess, and polycystic ovary syndrome in adolescents.
Other NICHD units, such as the Intellectual and Developmental Disabilities Branch (IDDB), explore issues related to obesity in specific populations, such as people with Down syndrome. In addition, the Division of Intramural Population Health Research (DIPHR) works to fill critical data gaps to advance understanding of such factors as obesity that affect health. For example, DIPHR launched a 7-year assessment of U.S. adolescents and young adults to identify several health-related factors, including genetic, personal, family, school, and social factors that promote or sustain positive health behaviors.

To ensure that NICHD organizational units advance the most effective obesity-related science, the NICHD’s Obesity Research Strategic Core (ORSC) brings together research and translational activities from across the Institute. Some of the ORSC’s focus areas include:

  • Interventions, such as pediatric obesity prevention or treatment studies in the primary care setting, at home, in schools, and in camps
  • Behavioral and psychosocial observational research, including observational studies that examine social and psychological antecedents, consequences, or correlates of diet, physical activity, sedentary behavior, and/or obesity in children and adolescents
  • Basic sciences research, including human in vitro or animal studies that focus primarily on the genetic, molecular, cellular, or organ-system factors related to diet, physical activity, development of adiposity, or other aspects of energy metabolism
  • Clinical physiology, such as human studies that focus on clinical cohorts of either normal weight or overweight children and adolescents

The ORSC also is working to promote a systems-oriented approach to childhood obesity that includes the following key features:

  • Framing obesity as a complex systems problem
  • Emphasizing cross-level and cross-disciplinary hypotheses at the outset of research
  • Increasing efforts in structural or upstream interventions
  • Building capacity for multilevel research, in terms of training and collaborating with partner organizations
  • Investing in complex systems research methodologies
  • Maintaining a global perspective

[top]

Other Activities and Advances

The NICHD works to promote collaborative efforts to understand overweight and obesity and to promote healthy weight. For example:

  • In 2003, the NIH director began addressing the problem of the obesity epidemic by forming the Obesity Research Task Force (PDF - 3.29 MB) to promote obesity research efforts across the NIH.
  • The NICHD is a member of the National Collaborative on Childhood Obesity Research (NCCOR) External Web Site Policy, which brings together leading research funders (including the NIH, the Centers for Disease Control and Prevention, and the Robert Wood Johnson Foundation) in a public-private collaboration to accelerate progress on reversing the epidemic of overweight and obesity among U.S. youth. The mission of NCCOR is to improve the efficiency, effectiveness, and application of childhood obesity research, and to halt—and reverse—childhood obesity through enhanced coordination and collaboration.
  • The NICHD created the Maternal-Fetal Medicine Units Network to focus on clinical questions in maternal-fetal medicine and obstetrics. The Network is composed of 14 university-based clinical centers and a data coordinating center that have explored a number of issues, including weight gain and nutrition.
  • The NICHD also works to encourage a healthy weight among young people. It joins several other NIH Institutes to support We Can! (Ways to Enhance Children’s Activity and Nutrition), which focuses its evidence-based education activities on parents and caregivers—the primary group for influencing youth. The NICHD’s Media-Smart Youth: Eat, Think, and Be Active! curriculum is one of four youth curricula offered through We Can! Media-Smart Youth is an afterschool program that helps participants become aware of, and think critically about, the media’s influence on their nutrition and physical activity choices.

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Last Updated Date: 09/27/2013
Last Reviewed Date: 12/30/2013
Vision National Institutes of Health Home BOND National Institues of Health Home Home Storz Lab: Section on Environmental Gene Regulation Home Machner Lab: Unit on Microbial Pathogenesis Home Division of Intramural Population Health Research Home Bonifacino Lab: Section on Intracellular Protein Trafficking Home Lilly Lab: Section on Gamete Development Home Lippincott-Schwartz Lab: Section on Organelle Biology