Childhood obesity: practically invisible

In recent years, the prevalence of obesity among children and adolescents has risen dramatically in many westernised countries and in countries undergoing economic transition,¹ making it one of the most common chronic disorders in this age group. Not only is childhood obesity prevalent, but it is also associated with a range of potential medical and psychosocial complications, as well as being a risk factor for increased morbidity and premature mortality in adulthood.² Such a serious health issue requires urgent intervention to both prevent further increases in obesity prevalence and manage established disease.

And, yet, while there is increased media attention on, and public awareness of, childhood obesity in westernised countries, it seems that many parents of overweight or obese children are unaware that their child has a weight problem. Several recent studies shed some understanding on this issue, which may have implications for effective treatment and prevention interventions.

The article by Carnell et al³ in the current edition of the Journal looks at parental perceptions of their young child's weight status. Height and weight were measured in 1085 children aged 3–5 y who were attending classes covering a diverse socioeconomic distribution in London, and 564 (52%) of their parents responded to questionnaires asking about parental appraisal of their child's current weight status and level of concern about future weight. Just over one in four children were overweight or obese according to the International Obesity TaskForce criteria,⁴ a prevalence rate in keeping with UK population data. However, of the 145 overweight or obese children, only a meagre nine (6%) were described as ‘overweight’ or ‘very overweight’ by their parents. While many parents expressed concern about their child becoming overweight in the future, this was more likely with increased child body mass index (BMI), and with increased self-reported parental BMI.

A recently published UK paper from the EarlyBird21 study⁵ presents complementary findings in an older group of children. In this study, 277 children (mean age 7.4 y) who were participants in a cohort study had heights and weights measured and their parents categorised their child's weight status based on a five-point Likert scale. While a quarter of parents correctly recognised overweight in their children and a third correctly recognised obesity, the majority of parents underestimated the weight status of their overweight or obese child. Interestingly, assessment of child weight status was more accurate for daughters than for sons, and if the assessment was performed by mothers rather than fathers.

The results from other studies from the United States and Australia further flesh out these findings. Parents underestimate their child's weight status in both population and clinical research settings.^{6, 7, 8} Weight status estimation is worse for younger rather than older children⁶ and possibly for mothers with poorer educational attainment,⁸ but is more accurate for daughters rather than for sons.⁶ Many parents of overweight and obese children do not report being concerned about their child's weight,^{9, 10} although the higher the BMI, the more likely they are to be concerned.

While these studies tell a consistent story about parents under-recognising their child's weight status, they do not tell us the reasons for this. To some extent, we are left to speculate.

One possibility is that people living in westernised communities are now desensitised to the sight of increased body fatness. Thus, because the background prevalence of paediatric overweight and obesity is high, this problem may now have been normalised: if a child no longer looks markedly larger than many of his or her peers, how can parents judge their child to be overweight? Parents may also be reluctant to acknowledge that their child has a socially undesirable and stigmatising condition, and hence may either consciously or unconsciously deny that it is present. This may particularly be the case if obesity is perceived optimistically as being a temporary problem which will resolve (‘it's only puppy fat’), or, pessimistically, as being impossible to treat (‘nothing works, so why bother?’). Two studies suggest that underestimation of overweight is particularly high among parents of preschool-aged children,^{3, 6} perhaps reflecting a persistence of views from infancy and early childhood that growth is good.

The findings by Carnell et al³ and others pose at least two challenges. Firstly, urgent research is needed in order to better understand the factors influencing parental perceptions of a child's weight status. Without such information, it will be difficult to plan and implement effective interventions.

Secondly, there is the challenge of providing effective treatment services for obese children. If parents, for whatever reason, are unaware that their child is obese, then they are unlikely to present to the family doctor or other health-care providers for help with management. This is different from the traditional situation with many other chronic illnesses, such as asthma, where the child's symptoms are usually clearly recognised as being abnormal by the family, with the result that medical treatment is then sought. Family doctors will therefore need to be pro-active in initially identifying the overweight or obese child and then engaging the parents as partners in a management plan. The most hopeful finding from the study by Carnell et al³ was that a high proportion of parents said that they were concerned about their child becoming overweight in the future (40, 63 and 76% of parents of normal weight, overweight and obese children, respectively), prompting the authors to propose that discussions around a child's weight may need to be re-framed in terms of preventing future overweight. Again, there are many opportunities for research into practical treatment strategies for such situations.

The World Health Organization describes obesity as ‘one of today's most blatantly visible—yet most neglected—public health problems’.¹¹ It is ironic that such an obvious medical condition in children can apparently be almost invisible to the parents of such children. We have much to learn about what is influencing these perceptions and what it implies for interventions to tackle the problem of childhood obesity.