The obesity epidemic: Family matters

Abstract

Childhood and adolescent obesity (defined as BMI ≥95th percentile for age and sex-based norms) has increased in prevalence from 5.0% to 15.5% between the 1960's and 1999-2000.1.Ogden C.L. Flegal K.M. Carroll M.D. Johnson C.L. Prevalence and trends in overweight among US children and adolescents, 1999-2000.JAMA. 2002; 288: 1728-1732Crossref PubMed Scopus (3239) Google Scholar The prevalence of obesity is notably higher for African American and Hispanic youth compared with that for Caucasian children and adolescents. The differences in the prevalence of obesity by ethnic group are even more pronounced in the transition from childhood to adolescence.2.Troiano R.P. Flegal K.M. Kuczmarski R.J. Campbell S.M. Johnson C.L. Overweight prevalence and trends for children and adolescents. The National Health and Nutrition Examination Surveys, 1963 to 1991.Arch Pediatr Adolesc Med. 1995; 149: 1085-1091Crossref PubMed Scopus (1291) Google Scholar Consequently, risk factors for heart disease are occurring with increased frequency in overweight youth,3.Freedman D.S. Khan L.K. Dietz W.H. Srinivasan S.R. Berenson G.S. Relationship of childhood obesity to coronary heart disease risk factors in adulthood: the Bogalusa Heart Study.Pediatrics. 2001; 108: 712-718Crossref PubMed Scopus (978) Google Scholar and the occurrence of type 2 diabetes, previously considered an adult disease, has dramatically increased in children and adolescents.4.Pinhas-Hamiel O. Dolan L.M. Daniels S.R. Standiford D. Khoury P.R. Zeitler P. Increased incidence of non-insulin-dependent diabetes mellitus among adolescents.J Pediatr. 1996; 128: 608-615Abstract Full Text PDF PubMed Scopus (934) Google Scholar Not surprisingly, the economic burden for obesity-related diagnoses has intensified in both the pediatric5.Wang G. Dietz W.H. Economic burden of obesity in youths aged 6 to 17 years: 1979-1999.Pediatrics. 2002; 109 (E81-1. Available at: pediatrics.aappublications.org/cgi/content/full/109/5/e81. Last accessed May 6, 2004)Crossref Scopus (447) Google Scholar and adult6.Finkelstein E.A. Fiebelkorn I.C. Wang G. National medical spending attributable to overweight and obesity: how much, and who's paying?.Health Aff (Millwood). 2003; 109: W3.219, W3.226Google Scholar populations. Ultimately, poor diet and physical inactivity may lead to obesity surpassing tobacco as the leading cause of death in the 21st century.7.Mokdad A.H. Marks J.S. Stroup D.F. Gerberding J.L. Actual causes of death in the United States, 2000.JAMA. 2004; 291: 1238-1245Crossref PubMed Scopus (4292) Google Scholar The development of effective prevention and intervention models targeting youth has thus become a public health priority.8.Office of the Surgeon General (United States) The Surgeon General's call to action to prevent and decrease overweight and obesity. US Department of Health and Human Services, Public Health Service, Rockville (MD)2001Google Scholar Prevention and intervention efforts will be enhanced by more comprehensive studies that examine the behavioral and environmental factors that contribute to the development of obesity during the childhood years. Given that dietary and physical activity patterns develop within the context of the family, further examination of family and child factors, and their potential interrelationships are needed. Existing research has already documented how the family environment is influential in many weight-related facets of children's lives. Maternal9.Strauss R.S. Knight J. Influence of the home environment on the development of obesity in children.Pediatrics. 1999; 103: e85Crossref PubMed Scopus (71) Google Scholar and parental10.Locard E. Mamelle N. Billette A. Miginiac M. Munoz F. Rey S. Risk factors of obesity in a five year old population. Parental versus environmental factors.Int J Obes Relat Metab Disord. 1992; 16: 721-729PubMed Google Scholar, 11.Whitaker R.C. Wright J.A. Pepe M.S. Seidel K.D. Dietz W.H. Predicting obesity in young adulthood from childhood and parental obesity.N Engl J Med. 1997; 337: 869-873Crossref PubMed Scopus (3181) Google Scholar obesity is known to significantly increase the risk of childhood obesity and the risk of maintenance of obesity into adulthood. This is likely the result of genetic and environmental factors. Childhood obesity has been reported to be associated with lower family socioeconomic status,12.Sobal J. Stunkard A.J. Socioeconomic status and obesity: a review of the literature.Psychol Bull. 1989; 105: 260-275Crossref PubMed Scopus (1744) Google Scholar poor hygiene and parental neglect,13.Lissau I. Sorensen T.I. Parental neglect during childhood and increased risk of obesity in young adulthood.Lancet. 1994; 343: 324-327Abstract PubMed Scopus (343) Google Scholar poor living conditions,14.Lissau-Lund-Sorensen I. Sorensen T.I. Prospective study of the influence of social factors in childhood on risk of overweight in young adulthood.Int J Obes Relat Metab Disord. 1992; 16: 169-175PubMed Google Scholar and lower levels of cognitive stimulation in the home.9.Strauss R.S. Knight J. Influence of the home environment on the development of obesity in children.Pediatrics. 1999; 103: e85Crossref PubMed Scopus (71) Google Scholar Further, caregivers do not necessarily appreciate the physical health risk associated with obesity in childhood,15.Young-Hyman D. Herman L.J. Scott D.L. Schlundt D.G. Care giver perception of children's obesity-related health risk: a study of African American families.Obes Res. 2000; 8: 241-248Crossref PubMed Scopus (131) Google Scholar may not perceive their obese children as obese, and may only be concerned about their child's weight if it limits their physical activity or the child is being teased by peers.16.Baughcum A.E. Powers S.W. Johnson S.B. Chamberlin L.A. Deeks C.M. Jain A. et al.Maternal feeding practices and beliefs and their relationships to overweight in early childhood.J Dev Behav Pediatr. 2001; 22: 391-408Crossref PubMed Scopus (315) Google Scholar, 17.Jain A. Sherman S.N. Chamberlin D.L. Carter Y. Powers S.W. Whitaker R.C. Why don't low-income mothers worry about their preschoolers being overweight?.Pediatrics. 2001; 107: 1138-1146Crossref PubMed Scopus (422) Google Scholar Finally, family-based interventions for obese children (ages 6-12) that have targeted both a parent and the child, and incorporated parent training in child management skills, have demonstrated positive short-term outcomes18.Epstein L.H. Wing R.R. Steranchak L. Dickson B. Michelson J. Comparison of family-based behavior modification and nutrition education for childhood obesity.J Pediatr Psychol. 1980; 5: 25-36Crossref PubMed Scopus (95) Google Scholar and long-term treatment efficacy.19.Epstein L.H. Valoski A. Wing R.R. McCurley J. Ten-year outcomes of behavioral family-based treatment for childhood obesity.Health Psychol. 1994; 13: 373-383Crossref PubMed Scopus (691) Google Scholar More systematic inquiry into whether specific family/parent characteristics, child-rearing practices, and parent beliefs contribute to the development of obesity in childhood and how these factors may interrelate with child characteristics is needed. Prospective observational studies that track these factors over the course of child development are severely lacking. These types of data can provide information about the potentially modifiable child and family correlates of obesity that serve as barriers to successful obesity prevention and intervention efforts. For example, general parenting practices (ie, warmth, control) have reportedly not differed between families of children who were obese versus nonobese (ages 6-10).20.Gable S. Lutz S. Household, parent, and child contributions to childhood obesity.Family Relations. 2000; 49: 293-300Crossref Scopus (200) Google Scholar Some studies have suggested excessive parental control over children's eating results in deficits in the development of self-control in eating and consequent obesity21.Costanzo P.R. Woody E.Z. Domain-specific parenting styles and their impact on the child's development of particular deviance: the example of obesity proneness.J Soc Clin Psychol. 1985; 1: 425-445Crossref Google Scholar, 22.Johnson S.L. Birch L.L. Parents' and children's adiposity and eating style.Pediatrics. 1994; 94: 653-661PubMed Google Scholar; however, other research has failed to support this hypothesis.23.Robinson T.N. Kiernan M. Matheson D.M. Haydel K.F. Is parental control over children's eating associated with childhood obesity? Results from a population-based sample of third graders.Obes Res. 2001; 9: 306-312Crossref PubMed Scopus (49) Google Scholar, 24.Saelens B.E. Ernst M.M. Epstein L.H. Maternal child feeding practices and obesity: a discordant sibling analysis.Int J Eat Disord. 2000; 27: 459-463Crossref PubMed Scopus (83) Google Scholar In this issue of The Journal, Agras et al25.Agras W.S. Hammer L.D. McNicholas F. Kraemer H.C. Risk factors for childhood overweight: a prospective study from birth to 9.5 years.J Pediatr. 2004; 145: 19-24Abstract Full Text Full Text PDF Scopus (435) Google Scholar contribute to our understanding of these issues. In their prospective study, they begin to uncover important relationships predicting the development of overweight and risk of overweight (BMI ≥85th percentile) in a sample whom they followed from birth to age 9.5 years. Their data lend further support to the considerable impact of parental overweight in the prediction of a family legacy of overweight. More novel, however, is their finding of how a highly emotional child temperament may mediate this relationship. Further, their data document the predictive power for future obesity of persistent tantrums around food intake in preschool-aged children. It is these types of data that will inform the direction of future prevention and intervention efforts by providing evidence of the specific family factors to target in behavioral treatment. The generalizability of the study results of Agras et al to the larger population is somewhat limited given the homogeneity of their largely Caucasian, highly educated, and two-parent sample. Their results need replication across other ethnic groups and levels of socioeconomic status. Nonetheless, their study provides an important starting point for the work that lies ahead. It is necessary for researchers to broaden their scope of inquiry to gain a better understanding of the environmental contexts and dynamic processes by which childhood obesity develops. This inquiry should not be limited to the individual and family level, but should include the multiple environments that have influence on the child, such as the peer group, the school, the neighborhood community, and the media. Prospective studies with appropriate behavioral and social measures would document the developmental course of childhood obesity and complement efforts in basic and clinical science to uncover whether there are critical periods to be targeted in prevention or interventions efforts. One of the national health objectives of Healthy People 2010 is to reduce the substantial health disparities between ethnic groups in the United States. Data generated by prospective studies of minority families may be translated into targeted prevention and intervention models that focus on specific behavioral factors to promote and maintain a healthful lifestyle for successful weight control.