Risk factors for childhood overweight

PURPOSE OF REVIEW: We review the 2004 literature on risk factors for childhood overweight. Given the steady increase in the prevalence of childhood overweight, the identification of risk factors is of increasing importance. RECENT FINDINGS: A number of studies confirmed that parental overweight is the most potent risk factor for childhood overweight. Childhood temperament was found to mediate the effects of parental overweight with a difficult temperament increasing the risk of overweight. Newer findings implicate regular consumption of fast food and sweetened drinks as risk factors, as well as sedentary behavior; although a meta-analysis suggested that the effects of the latter factor are small. Other work was consistent with the finding that parental overcontrol of children's feeding behavior, particularly for those at high risk of developing overweight, may lead to overweight. SUMMARY: Identification of groups of children at high risk for becoming overweight offers the potential for early intervention to reduce the intergenerational transfer of obesity. This is an area for future research because the nature of effective intervention is at present unclear. There is a suggestion that focused behavior change efforts on one target such as reducing the intake of sweetened beverages may be more successful than attempts to make broader dietary changes. There is also evidence that targeting parental behaviors may be more effective than interventions directed solely toward children, suggesting that modification of the environment that a child is exposed to during early development may have a lasting effect.     

Family environmental factors influencing the developing behavioral controls of food intake and childhood overweight

Although a large body of research has assessed direct genetic links between parent and child weight status, relatively little research has assessed the extent to which parents (particularly parents who are overweight) select environments that promote overweight among their children. Parents provide food environments for their children's early experiences with food and eating. These family eating environments include parents' own eating behaviors and child-feeding practices. Results of the limited research on behavioral mediators of familial patterns of overweight indicate that parents' own eating behaviors and their parenting practices influence the development of children's eating behaviors, mediating familial patterns of overweight. In particular, parents who are overweight, who have problems controlling their own food intake, or who are concerned about their children's risk for overweight may adopt controlling child-feeding practices in an attempt to prevent overweight in their children. Unfortunately, research reveals that these parental control attempts may interact with genetic predispositions to promote the development of problematic eating styles and childhood overweight. Although the authors have argued that behavioral mediators of family resemblances in weight status, such as parents' disinhibited or binge eating and parenting practices are shaped largely by environmental factors, individual differences in these behaviors also have genetic bases. A primary public health goal should be the development of family-based prevention programs for childhood overweight. The findings reviewed here suggest that effective prevention programs must focus on providing anticipatory guidance on parenting to foster patterns of preference and food selection in children more consistent with healthy diets and promote children's ability to self-regulate intake. Guidance for parents should include information on how children develop patterns of food intake in the family context. Practical advice for parents includes how to foster children's preferences for healthy foods and how to promote acceptance of new foods by children. Parents need to understand the costs of coercive feeding practices and be given alternatives to restricting food and pressuring children to eat. Providing parents with easy-to-use information regarding appropriate portion sizes for children is also essential as are suggestions on the timing and frequency of meals and snacks. Especially during early and middle childhood, family environments are the key contents for the development of food preferences, patterns of food intake, eating styles, and the development of activity preferences and patterns that shape children's developing weight status. Designing effective prevention programs will, however, require more complete knowledge than currently available regarding behavioral intermediaries that foster overweight, including the family factors that shape activity patterns, meals taken away from home, the impact of stress on family members' eating styles, food intake, activity patterns, and weight gain. The research presented here provides an example of how ideas regarding the effects of environmental factors and behavioral mediators on childhood overweight can be investigated. Such research requires the development of reliable and valid measures of environmental variables and behaviors. Because childhood overweight is a multifactorial problem, additional research is needed to develop and test theoretic models describing how a wide range of environmental factors and behavioral intermediaries can work in concert with genetic predispositions to promote the development of childhood overweight. The crucial test of these theoretic models will be in preventive interventions.     

The role of parents in preventing childhood obesity

As researchers continue to analyze the role of parenting both in the development of childhood overweight and in obesity prevention, studies of child nutrition and growth are detailing the ways in which parents affect their children's development of food- and activity-related behaviors. Ana Lindsay, Katarina Sussner, Juhee Kim, and Steven Gortmaker argue that interventions aimed at preventing childhood overweight and obesity should involve parents as important forces for change in their children's behaviors. The authors begin by reviewing evidence on how parents can help their children develop and maintain healthful eating and physical activity habits, thereby ultimately helping prevent childhood overweight and obesity. They show how important it is for parents to understand how their roles in preventing obesity change as their children move through critical developmental periods, from before birth and through adolescence. They point out that researchers, policymakers, and practitioners should also make use of such information to develop more effective interventions and educational programs that address childhood obesity right where it starts-at home. The authors review research evaluating school-based obesity-prevention interventions that include components targeted at parents. Although much research has been done on how parents shape their children's eating and physical activity habits, surprisingly few high-quality data exist on the effectiveness of such programs. The authors call for more programs and cost-effectiveness studies aimed at improving parents' ability to shape healthful eating and physical activity behaviors in their children. The authors conclude that preventing and controlling childhood obesity will require multifaceted and community-wide programs and policies, with parents having a critical role to play. Successful intervention efforts, they argue, must involve and work directly with parents from the earliest stages of child development to support healthful practices both in and outside of the home.     

Maternal feeding practices and beliefs and their relationships to overweight in early childhood.

To better explore possible factors that may lead to childhood obesity, we developed and analyzed two new instruments that assess maternal feeding practices and beliefs. The Infant Feeding Questionnaire (IFQ) assesses feeding during the entire first year of life and was administered to 453 mothers of children 11 to 23 months old. The Preschooler Feeding Questionnaire (PFQ) assesses feeding of young children between the ages of 2 to 5 years and was administered to 634 mothers of children this age. Each questionnaire was factor analyzed and mean factor scores were calculated and linked with the children's measured and mothers' self-reported weight and height. Mean factor scores from the IFQ and PFQ were compared between mothers who were obese (body mass index > or = 30 kg/m2) and those who were nonobese, between those who did and those who did not have an overweight child (weight-for-height > or = 90th percentile), and between those who had a low income (< or = 185% of the poverty level) and those who had a high income. To control for confounding variables and to detect interaction among variables, hierarchical linear regression was used. Results from this study did not suggest that there is a particular "feeding style" that is associated with overweight in young children; however, there were differences found in feeding behaviors between high and low income mothers.     

The relationship between knowledge and reported behavior in childhood asthma

Numerous educational interventions have been developed and tested to improve management of childhood asthma. Most programs assume that knowledge about asthma is related to initiating and/or maintaining recommended management behaviors. Although this assumption is widely accepted, some available evidence casts doubt upon its validity. We investigated the relationship between asthma management behaviors and (1) knowledge about asthma, (2) behavioral adjustment, (3) anxiety, and (4) health locus of control. Data were collected on 91 children 7 to 12 years of age with moderately severe asthma. After adjusting for covariates, reported asthma management behavior was significantly related only to knowledge about asthma (p less than .05). The relationship between knowledge and behavior is nonlinear: accurate knowledge is related to engaging in more of the recommended behaviors, but only up to a moderate level of knowledge. Also, the relationship between knowledge and asthma management behavior was especially strong for children who scored lower on behavioral adjustment. These results suggest that children's knowledge about asthma can influence behavior, but only under certain conditions. Educational interventions for children whose knowledge is already adequate may not increase adherence to recommended practices.     

Risk factors for childhood overweight: a prospective study from birth to 9.5 years

OBJECTIVES: To ascertain risk factors for the development of overweight in children at 9.5 years of age. STUDY DESIGN: This was a prospective study of 150 children from birth to 9.5 years of age, with assessment of multiple hypothesized risk factors drawn from research reports. RESULTS: Five independent risk factors for childhood overweight were found. The strongest was parent overweight, which was mediated by child temperament. The remaining risk factors were low parent concerns about their child's thinness, persistent child tantrums over food, and less sleep time in childhood. Possible mechanisms by which each of these factors influence weight gain are outlined. Two different pathways to childhood overweight/obesity were found, depending on degree of parental overweight. CONCLUSIONS: There is evidence of considerable interaction between parent and child characteristics in the development of overweight. Several of the identified risk factors are amenable to intervention possibly leading to the development of early prevention programs.     

Regional differences in overweight: an effect of people or place?

OBJECTIVE: To examine UK country and English regional differences in childhood overweight (including obesity) at 3 years and determine whether any differences persist after adjustment for individual risk factors. DESIGN: Nationally representative prospective study. SETTING: England, Wales, Scotland and Northern Ireland. PARTICIPANTS: 13 194 singleton children from the UK Millennium Cohort Study with height and weight data at age 3 years. MAIN OUTCOME MEASURE: Overweight (including obesity) was defined according to the International Obesity TaskForce cut-offs for body mass index, which are age and sex specific. RESULTS: At 3 years of age, 23% (3102) of children were overweight or obese. In univariable analyses, children from Northern Ireland (odds ratio 1.30, 95% confidence interval 1.14 to 1.48) and Wales (1.26, 1.11 to 1.44) were more likely to be overweight than children from England. There were no differences in overweight between children from Scotland and England. Within England, children from the East (0.71, 0.57 to 0.88) and South East regions (0.82, 0.68 to 0.99) were less likely to be overweight than children from London. There were no differences in overweight between children from other English regions and children from London. These differences were maintained after adjustment for individual socio-demographic characteristics and other risk factors for overweight. CONCLUSIONS: UK country and English regional differences in early childhood overweight are independent of individual risk factors. This suggests a role for policies to support environmental changes that remove barriers to physical activity or healthy eating in young children.     

Children's health and social mobility

Children from low-income families are more likely than other children to have serious health problems. And, as Anne Case and Christina Paxson show, childhood health problems can prevent poor children from achieving economic success as adults. Income-related disparities in childhood health are evident at birth or even before, and the disparities grow more pronounced as children grow older. Not only do poor children have more severe health problems than wealthier children, but they fare less well than wealthier children who have the same problems. They also receive less and lower-quality medical care for their problems. And poor families may be less well equipped to manage their children's health problems, which could worsen their effects. The available U.S. data sets do not allow researchers to track individuals' health and economic well-being from birth into adulthood, but three British data sets are producing growing evidence that health in childhood is a determinant of educational attainment, which in turn affects adults' employment opportunities and wages. Children in poor health are also more likely to have poor health as adults, and their health as adults adversely affects their economic status. Case and Paxson note that eliminating income-related disparities in health problems in childhood would do little to reduce earnings disparities between richer and poorer adults. However, they emphasize that, for children in poor health, improvement in physical condition in childhood would lead to substantial improvement in economic circumstances. The authors cite several areas, including expanded prenatal care, maternal smoking cessation programs, and nutrition programs, as deserving particular attention. They contend that increased access to health care is not sufficient to improve children's health. The next wave of policies should focus on improving the quality of health care and strengthening the ability of parents to manage their children's health problems.     

The impact of peer victimization, parent distress and child depression on barrier formation and physical activity in overweight youth

OBJECTIVE: With the prevalence of childhood overweight reaching epidemic proportions, there is an increased need to identify factors which may aid in the development of successful weight intervention programs. Given that lower levels of physical activity are inversely correlated with weight status in children, research has focused on identifying and addressing reported barriers to physically activity. A relationship exists between the number of reported barriers and weight status such that children who are overweight report more barriers to being physically active. However, important demographic and psychosocial correlates of barriers have not been examined. METHODS: This study investigates the relationship among parent distress, peer victimization, childhood depression, barriers to physical activity, and physical activity among a sample of 95 clinically overweight children and adolescents. Higher levels of parent distress, peer victimization, and childhood depression are predictive of a variety of barriers to physical activity, with peer victimization emerging as the strongest predictor of barriers. Barriers to physical activity mediate the relationships between peer victimization, parent distress, child depression and physical activity. RESULTS: These findings have significant implications for the development/design of weight intervention programs. Interventions targeting increases in physical activity should not only focus on the barriers children report, but should also include a psycho-emotional component to address factors such as parent distress, peer victimization and child mood that may contribute to barrier formation/maintenance. CONCLUSION: Future interventions may benefit from the identification of additional factors that impact barrier formation and physical activity levels among children.     

Risk factors for obesity in 7-year-old European children: the Auckland Birthweight Collaborative Study.

OBJECTIVE: To identify risk factors associated with obesity in primary school children, with a particular focus on those which can be modified. To identify critical periods and growth patterns in the development of childhood obesity. METHODS: 871 New Zealand European children were enrolled in a longitudinal study at birth and data were collected at birth, 1, 3.5 and 7 years of age. Data collected at 7 years included weight, height, bioelectrical impedance analysis (BIA), television viewing time and a 24 h body movement record (actigraphy). The outcome measure was percentage body fat (PBF), which was calculated at 3.5 and 7 years using BIA. Univariate and multiple regression analyses were carried out using PBF as a continuous variable. RESULTS: Multivariable analysis found maternal overweight/obesity, maternal age, female gender, sedentary activity time and hours of television viewing to be independently associated with PBF at 7 years. Growth variables (birth weight, rapid weight gain in infancy, early (1-3.5 years) and middle childhood (3.5-7 years)) were also independently associated with adiposity at 7 years. There was a strong correlation between PBF at 3.5 years and PBF at 7 years. CONCLUSIONS: Many primary school aged children start on the trajectory of obesity in the preschool years, which suggests interventions need to start early. Maternal overweight/obesity, television watching, sedentary activity time and rapid weight gain in infancy, early and middle childhood are risk factors for childhood obesity, and are all potentially modifiable.     

Assessment of child and adolescent overweight and obesity

Accurate appropriate assessment of overweight and obesity in children and adolescents is a critical aspect of contemporary medical care. However, physicians and other health care professionals may find this a somewhat thorny field to enter. The BMI has become the standard as a reliable indicator of overweight and obesity. The BMI is incomplete, however, without consideration of the complex behavioral factors that influence obesity. Because of limited time and resources, clinicians need to have quick, evidence-based interventions that can help patients and their families recognize the importance of reducing overweight and obesity and take action. In an era of fast food, computers, and DVDs, it is not easy to persuade patients to modify their diets and to become more physically active. Because research concerning effective assessment of childhood obesity contains many gaps, this report is intended to provide a comprehensive approach to assessment and to present the evidence available to support key aspects of assessment. The discussion and recommendations are based on >300 studies published since 1995, which examined an array of assessment tools. With this information, clinicians should find themselves better equipped to face the challenges of assessing childhood overweight and obesity accurately.     

Is neonatal phototherapy associated with an increased risk for hospitalized childhood bronchial asthma?

This population-based register study examined if factors during the fetal and neonatal period influence the risk for the child to develop bronchial asthma (asthma). From the Swedish Hospital Discharge Register we identified children, born between 1987 and 1999, who had been hospitalized for asthma up to 2001. Thus, the outcome measure contains only hospitalized cases, not all children with asthma. Children younger than 2 yr at admission were excluded because of the uncertainty about the diagnosis of asthma in younger children. The remaining 14,803 children were compared with all children born the same years, recorded in the Swedish Medical Birth Registry, for information on pre- and perinatal characteristics. Odds ratios (ORs) were calculated with Mantel-Haenszel technique and 95% confidence intervals (CIs) with Miettinen's test-based method. The presence of various maternal and neonatal confounders were identified and adjusted for in the analyses. The association between some known factors and childhood asthma were confirmed: young maternal age, maternal smoking, period of unwanted childlessness, low maternal level of education, maternal diabetes, preterm birth, low birth weight, small-for-gestational age, caesarean section, and instrumental vaginal delivery. A number of neonatal characteristics were shown to be independent risk factors: sepsis or pneumonia, neonatal respiratory problems and treatments, neonatal icterus, and/or neonatal phototherapy. The association with icterus and phototherapy remained after exclusion of cases showing other neonatal risk factors and after adjustment for maternal factors (OR 1.27, 95% CI: 1.08-1.50), and increased to 1.5 if the children had been hospitalized for asthma more than once. In conclusion, our results suggest an association between neonatal icterus and/or treatment with neonatal phototherapy and hospitalized childhood asthma. This association needs further exploration.     

Risk factors for overweight in 2- to 6-year-old children in Beijing, China.

OBJECTIVE: To assess the prevalence of overweight among Chinese preschool children and to explore risk factors of childhood obesity focusing on parental characteristics, feeding practice and lifestyle. METHODS: Data on 930 families with 2- to 6-year-old children in five kindergartens were obtained in a cross sectional study. Families were randomly selected from two of all six urban districts in Beijing, China. Information on parental characteristics, dietary habits, lifestyle habits, and feeding practice was collected by parental self-report questionnaires. The children's stature and weight were measured in light clothing and without shoes. Overweight and obesity were defined according to international cut-off values, as proposed by the International Obesity Task Force. Multivariate regression analysis was used to explore risk factors of child overweight. RESULTS: The overall prevalence of overweight and obesity was 10.7% and 4.2%, respectively, and increased with age. The prevalence of child overweight was 14.1% and 7.5% in obese and non-obese families, respectively. Significant associations were observed between child and parent characteristics for overweight, frequency of eating in restaurant, television hours, and hours of physical activity. Child overweight was associated with parental overweight (Odds Ratio [OR] 2.43, 95% CI 0.78, 6.59), low maternal education level (OR 2.22, 95% CI 1.39, 3.55), food restriction (OR 2.68, 95% CI 1.64, 4.29), and television watching >2h/d (OR 1.56, 95% CI 1.17, 2.09), after adjusting for sex, age, family income and kindergarten (for cluster study design). CONCLUSIONS: Overweight prevalence among Chinese preschool children in Beijing is comparable to some European countries. Prevention strategies should include identified lifestyle risk factors.     

Childhood Obesity in India: A Meta-Analysis

Developing countries are now facing the double burden of childhood underweight and obesity. Childhood obesity is a recent epidemic with a high magnitude in India. Therefore, the authors decided to assess the prevalence of overweight and obesity among Indian children. Studies were identified through computer-based and manual searches. Estimates of prevalence were studied using random effects meta-analysis. Nine studies including 92,862 subjects were identified and analysed. The prevalence of overweight was estimated to be 12.64% (95% CI 8.48-16.80%) and that of obesity to be 3.39% (95% CI 2.58-4.21%). Current evidence suggests that policies and interventions for children should prioritize reduction of obesity and overweight.     

Understanding the double burden of malnutrition in food insecure households in Brazil

Household food insecurity (HFI) has been associated with both obesity among mothers and undernutrition among children. However, this association has not been well investigated in mother/child pairs living in the same household. The objective of this study was to examine the relationship of coexistence of maternal overweight and child stunting with HFI in Brazil. We conducted secondary data analyses of the 2006 Brazilian National Demographic and Health Survey. We analyzed the nutritional status of 4299 pairs of 15–49‐year‐olds mothers and their children under 5 years of age. The double burden of malnutrition (DBM) was defined as the presence of an overweight mother and a stunted child in the same household. HFI was measured with the Brazilian HFI Measurement Scale. The association between DBM and HFI was examined with hierarchical multivariable logistic regression analyses. Severe HFI was associated with DBM after adjusting for macroeconomic and household level socio‐economic and demographic variables (Adjusted OR: 2.65 – CI: 1.17–8.53). Findings suggest that policies and programmes targeting HFI are needed to prevent the coexistence of child chronic undernutrition and maternal overweight/obesity in the same household. These investments are likely to be highly cost‐effective as stunting has been identified as one of the major risk factors for poor child development and adult overweight/obesity and a strong risk factor for the development of costly chronic diseases including type 2 diabetes and cardiovascular disease.     

Addressing obesity in the first 1000 days in high risk infants: Systematic review

Early intervention is critical for addressing the challenge of childhood obesity. Yet many preventive interventions do not target infants most at risk of future overweight or obesity. This systematic review examines interventions delivered before 2 years that aim to ameliorate excess weight gain among infants at high risk of overweight or obesity, due to sociodemographic characteristics, parental weight or health status, infant feeding or health behaviours. We searched six databases for interventions: (a) delivered before age two, (b) specifically aimed at infants at high risk of childhood obesity and (c) that reported outcomes by weight status beyond 28 days. The search identified over 27,000 titles, and 49 papers from 38 studies met inclusion criteria: 10 antenatal interventions, 16 postnatal and 12 conducted both before and after birth. Nearly all targeted infant and/or maternal nutrition. Studies varied widely in design, obesity risk factors, outcomes and quality. Overall, nine interventions of varying quality reported some evidence of significantly improved child weight trajectory, although effects tended to diminish over time. Interventions that improved weight outcomes tended to engage parents for a longer period, and most offered health professional input and support. Two studies of limited quality reported significantly worse weight outcomes in the intervention group.     

Low and high birth weight as risk factors for obesity among 4 to 5-year-old Australian children: does gender matter?

Studies testing whether birth weight and childhood obesity differ by gender are lacking. We aimed to describe the relationship between birth weight and childhood overweight/obesity and investigate the influence that gender has on this relationship among 4 to 5-year-old children. We performed a secondary analysis of an Australian nationally representative cross-sectional study in 4 to 5-year-old children. The main outcome measure was child overweight and obesity. We found that low birth weight (LBW) was associated with lower risk of overweight/obesity among girls at 4–5 years before (OR 0.50, 95%CI 0.32, 0.77) and after adjusting for socio-demographic factors (OR 0.51 95% CI 0.33, 0.80) and ethnicity (OR 0.52, 95%CI 0.33, 0.81) but was not associated with child overweight/obesity among boys before or after adjustment. High birth weight (HBW) was associated with a higher risk of overweight/obesity among both girls (adjusted OR: 1.76, 95%CI 1.12, 2.78) and boys (adjusted OR: 2.42 95% CI 2.06, 2.86). Conclusion: There are gender differences in the association of birth weight with child overweight/obesity. HBW was associated with a higher risk of child overweight/obesity in boys and girls before and after adjustment for socio-demographic factors. However, LBW was associated with a lower risk of child overweight/obesity in girls but not in boys. These gender differences need to be considered when planning interventions to reduce child overweight/obesity.     

Text messages to improve child diets: Formative research findings and protocol of a randomised controlled trial in Nepal

Given the role of malnutrition in childhood morbidity and mortality, the prioritisation of maternal and child nutrition programmes has grown significantly in the 21st century. Policies and programmes aim to improve infant and young child feeding, but questions persist about the most effective combination of interventions to achieve desired behaviour change. There is increasing interest in mobile-based interventions globally, but scant evidence exists to guide donors, policymakers and programme implementers on their effectiveness. Formative research was conducted to assess the feasibility and acceptance of text message-based interventions and to guide the final design of the text message intervention. This protocol is for a cluster-randomised controlled trial to test the effectiveness of adding text messaging to other ongoing SBC interventions to promote egg consumption, dietary diversity and other ideal dietary practices, particularly among children 12–23 months of age in Kanchanpur, Nepal. The trial findings will contribute to the emerging body of evidence on the effectiveness of using text messages for behaviour change, specifically for young child dietary outcomes in South Asia. Recent studies have suggested that mobile-based interventions alone may be insufficient but valuable when added to other social and behavioural interventions; this trial will help to provide evidence for or against this emerging theory. This trial was registered at ClinicalTrials.gov on 11 March 2019 (ID: NCT03926689) and has been updated twice.     

Exercise interventions in obese youth: are they effective?

Given the increasing prevalence of childhood obesity, effective and cost-efficient strategies to enhance children's physical activity levels are needed. Unfortunately, exercise interventions evaluated to date have had little impact on overweight and obesity in youth. Physical activity counseling interventions have emerged as an effective and inexpensive alternative to traditional, structured exercise programs in adults, and may be an interesting option for the treatment of obesity in youth.