The prevalence of overweight and obesity in Australian preschool-aged children has doubled in the past 10–15 years and is continuing to rise.1,2 Studies in the United Kingdom, United States and Australia have provided a convincingly consistent message that, on an individual level, parents often do not accurately perceive overweight in their children, and report low levels of concern,3-7 which may be lowest when children are young, especially for boys. This is important because, during the preschool and early school years, the course of the body mass index (BMI) curve changes from a state of progressive decline to steady increase,8 and this may be the best time to maximise the child’s chances of staying on a healthy growth trajectory. It is also the period during which the family environment plays an important role in health and development.9
Our study was a cross-sectional survey of healthy 4-year-old children and their parents.
Participants were recruited from an established cohort of 493 first-born infants whose parents participated in an earlier longitudinal study, the PEAS (Parent Education and Support) Program, from 1998 to 2001.10 Families were initially enrolled from maternal and child health centres in three local government areas (one inner urban, one suburban and one semi-rural) in Melbourne, Victoria, when the children were 2 weeks of age. They were followed closely for 2 years. From mid-2002, all contactable PEAS families still living in Melbourne (n = 402) were invited to take part in a longitudinal follow-up study, beginning at the child’s fourth birthday; 341 families (85%) agreed to participate.
Children were measured by trained research staff according to a standardised protocol.11 Height was measured to the nearest 0.1 cm with an Invicta portable stadiometer (Oadby, Leicester, UK), and weight to the nearest 0.1 kg on digital scales (TI-THD 646, Tanita, Tokyo, Japan), without shoes and in light clothing.
In a written questionnaire, mothers responded to the following items using a 5-point Likert scale (range “disagree a lot” to “agree a lot”): “I am worried my child is overweight right now”; “I am worried my child will become overweight”; and “I am worried my child is underweight right now”.12 Responses were dichotomised to “agree” or “disagree”, with the neutral answer classified as “disagree”.
Child BMI was transformed to a z score according to the UK 1990 Growth Reference.13 Overweight and obesity status was determined from International Obesity Task Force cut-points, using software that calculated exact cut-points for sex and age through linear interpolation.14,15 The overweight and obese categories were combined for further analyses. In the absence of international standard cut-points to define underweight, the proportion of children below the 5th and 10th percentiles for BMI (z scores less than − 2.0 and − 1.28) were also identified.
Complete height, weight and questionnaire data were available for 324 children (48% male). These 324 did not differ significantly in sex distribution, maternal country of birth or area of recruitment from the 169 children in the original study who were lost to follow-up. Characteristics of the children with follow-up and their parents are summarised in Box 1. Sixty-three children (19%) were classified as overweight or obese, with similar prevalence in boys and girls. Most (92%) children lived with both biological parents, and three-quarters lived with at least one overweight parent.
Box 2 summarises maternal responses regarding concern about their child’s weight and perceptions of their child relative to their peers, according to the child’s measured weight status. Only 15 mothers (5%) reported concern that their child was currently overweight, including 11 of the 63 mothers whose children were actually overweight or obese. Another 40 of these 63 mothers (63%) strongly disagreed that they were concerned about their child’s current weight. Concern that a child would become overweight in the future was reported by 53 mothers (16%), over three times more often than concern about a child’s current weight. Although no children in our sample had a BMI below the 5th percentile, and only five (2%) below the 10th percentile, 27 mothers (8%) indicated concern that their child was currently underweight; these included 10 (37%) whose child had a BMI at or above the 50th percentile.
Box 3 shows the distribution of child BMI z scores according to level of maternal concern about current and future overweight, respectively. For concern about current overweight, there was a significant difference in median BMI z score between the concerned and not-concerned groups (concerned, 1.53; not concerned, 0.42; Mann– Whitney U test P < 0.001). However, 52 (17%) of those not concerned had children who were overweight or obese. Concern for future overweight encompassed a wider range of BMI z scores, with mothers of non-overweight children also expressing this concern.
Most mothers (68%) felt their children were of a similar weight to their peers, while 24% felt their child was thinner, and 8% that their child was more overweight (Box 2). Of the 63 mothers with overweight children, 71% reported their children to be of similar weight to their peers. Few mothers reported they felt their child’s diet was less healthy or that their child was less active than their peers, and this did not differ by child weight status. However, more mothers with overweight or obese children perceived that their child ate more than their peers.
Maternal concern about current overweight was significantly related to child weight status (χ2 test, P < 0.001). Box 4 shows bivariate associations between child and parent factors and maternal concern about current overweight and future overweight. When the analyses were stratified according to the child’s weight status (overweight or obese versus non-overweight), mothers of overweight daughters were more likely to report concern that their child was currently overweight than those with overweight sons (risk ratio [RR], 4.6; 95% CI, 1.1–19.8).
Our study highlights an important problem in health promotion: that general public awareness of a problem does not necessarily translate into concern on an individual level. Despite the high rate of overweight and obesity in the 4-year-olds in this study, only 5% of mothers expressed concern that their child was currently overweight. These findings are consistent with earlier studies in the US and UK showing equally low rates of concern for child overweight.4,5 Many more mothers reported concern that their child would become overweight in the future. For children not currently overweight, this was related to the number of overweight parents in the family, suggesting that awareness of familial risk of obesity does have an impact on mothers’ concern about potential weight problems in their children.
The increasing prevalence of child overweight may have “normalised” this condition and contributed to the inability of mothers to recognise when their own child is overweight. Stereotypes of overweight children portrayed in the media tend to be at the severe end of the spectrum and may also distort the lay perception of overweight. In fact, most overweight and obese young children in the community do not stand out from the crowd. Additionally, parents of preschool-aged children often express anxiety about thinness and “picky eating”, when this is developmentally normal.16 Ironically, overweight children may appear better nourished and be perceived as “better eaters”, hence causing their parents less concern.
Two other studies have found a relationship between maternal concern for a child’s current weight status and the child’s sex, with mothers of overweight daughters much more likely to perceive them as overweight than mothers of overweight sons.6,7 While this may be related to sex differences in body composition,17 it seems more likely to reflect social values. Mothers may be more sensitive to weight and body image issues for girls, while larger boys may be seen as having a physical advantage.
Health professionals can help improve recognition of childhood overweight. The charting of child BMI could be encouraged as a part of normal practice, not only to provide an objective measure of weight status, but also to reassure parents who are anxious about underweight, and to start discussion. However, there may be other important reasons that parents are reluctant to acknowledge concern for their overweight child. Other research has suggested that mothers of obese children believed that concern was not indicated if children were otherwise happy and healthy, that children would grow out of their “puppy fat”, and that there was a fear of stigmatisation or blame.18
1 Characteristics of children in the study sample and their parents
* May not add to total because of missing data. nr = variable not relevant. |
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3 Box and whisker plot of child body mass index (BMI) z score by maternal concern about overweight
Grey and black lines indicate International Obesity Task Force cut-points for overweight and obesity, respectively.15
Abstract
Objective: To assess maternal concern about overweight in Australian preschool-aged children and factors predicting maternal concern about children’s current and future weight status.
Design: Cross-sectional survey of child’s body mass index and parent questionnaire.
Setting:
Participants: A community-based cohort of 324 4-year-old children and their parents.
Main outcome measures: Mothers’ reports of concern about the child’s current and future weight status, and perceptions of the child’s weight, diet and activity relative to their peers were compared with the child’s measured weight status, and parent and child characteristics.
Results: The prevalence of overweight or obesity was 19%, but only 5% of mothers indicated concern about their child being currently overweight, while 16% worried their child would become overweight. Over 70% of mothers of overweight children saw them as being of similar weight to their peers. Most mothers saw their children as being equally or more active than other children and having a diet at least as healthy as their peers. Overweight daughters were more likely to elicit maternal concern about current weight than overweight sons (relative risk, 4.6; 95% CI, 1.1–19.8). Mothers were more likely to worry about their child’s potential for future overweight if they or the child’s father were overweight.
Conclusions: Despite mounting public concern about childhood obesity in Australia, most mothers surveyed were not concerned about their child’s weight, and many mothers did not perceive their overweight children as different from their peers. This may have implications for interventions that rely on acknowledgement of child overweight as a first step to change.