To examine weight-related differences in eating behaviors and nutrition of preschool-aged children, the influence of maternal eating behavior on the child's eating behavior, and sex-related differences in the transmission of eating behaviors. A total of 142 mothers of children aged 3–6 years participated. Maternal and child's eating behaviors as well as child's food consumption were assessed using questionnaires completed by mothers. Maternal BMI and child's standardized BMI (BMI-SDS) were also calculated. More than half of the mothers were obese. Multiple regression analysis was used to predict eating behavior of the children by mothers' variables. Overweight children scored higher in external eating, food responsiveness, and speed of eating than normal-weight children, whereas children of overweight mothers showed higher amounts of emotional eating than children of normal-weight mothers. Maternal emotional eating (R2 = 0.19, P < 0.001) and mother's BMI (R2 = 0.07, P < 0.05) positively predicted emotional eating of sons. Maternal emotional eating (R2 = 0.19, P < 0.01) completely mediated the relation between mother's BMI and emotional eating of sons. For mother-daughter dyads, no such relation was found. The tested model shows sex-related differences in the transmission of maternal eating behavior which is discussed as being related to the development and maintenance of obesity.
Obesity in childhood is a growing problem in industrialized countries. In the United States and Western Europe, the prevalence of overweight and obesity among children has dramatically increased over the past years. According to the National Health and Nutrition Examination Survey in 2003–2004, 17.1% of US children and adolescents are overweight (1). In Germany, 9% of the preschool-aged children are overweight and 3% are obese. The prevalence rates of overweight rise up to 16% for overweight and up to 7% for obesity by the time children reach school age (2). Owing to the increased prevalence at primary school age, this age seems to be a sensible period for research exploring risk factors for the development of obesity as well as for prevention activities. For children who are already obese by the time they reach school age, the probability for being obese in adulthood is very high (3).
Children of overweight parents also bear a greater risk to develop overweight themselves (4,5). These familial patterns indicate a genetic predisposition. The increasing prevalence of obesity and overweight in children emphasizes the importance of environmental factors. Obesity occurs when a genetically predisposed person is exposed to certain environmental factors. Influences of imbalanced energy intake and energy expenditure, excess energy intake, and reduced activity levels as well as eating behaviors were discussed in the development of obesity (e.g., 6,7).
Several studies investigated the influence of parental eating and weight characteristics on the child's weight. Familial influences on child's overweight differ according to parent's and child's sex (8,9,10). A few studies found relations between parental and children's weight, for mothers and their daughters only (8,10), whereas Johannsen et al. (9) could show that both boys and girls weight were related to mothers' but not fathers' BMI. Furthermore, the evidence of associations between paternal eating behaviors and children's weight is also inconsistent. The Framingham Children's Study has shown that preschool-aged children whose parents had higher dietary restraint scores prospectively gained more body fat over a period of 6 years. The highest increase in children's body fatness over that period of time was found in children whose parents described high levels of dietary restraint and dietary disinhibition (11). But most cross-sectional studies could not find a significant relationship between parental eating behaviors and children's weight at preschool age (9,10). Cutting et al. (8) showed that the maternal BMI predicts overweight in daughters only, mediated by maternal dietary disinhibition. There is also evidence for overeating eating styles in children of obese parents. Wardle et al. (12) compared children of lean and obese parents and showed that offspring of obese families scored higher on food responsiveness and overeating in response to emotional cues.
Relations between parental and child's eating behavior were also surveyed in laboratory settings. Faith et al. (13) compared eating in the absence of hunger (EAH) of 5-year-old children with high vs. low risk to develop obesity in a laboratory setting. They found a sex-related effect: boys at high risk consumed more than twice amount of energy in the absence of hunger than boys of low risk. The authors assumed that obesity-promoting genes transmit their influence through EAH in boys but not in girls. Franzen and Florin (14) explored the transmission of dietary restraint between mothers and daughters in preadolescence. In a laboratory setting, 7- to 14-year-old daughters of mothers with high dietary restraint ate more in the absence of hunger (after preload) in a free access to food procedure than in the condition without preload. Daughters of mothers with low dietary restraint ate more in the free access to food without preload condition and ate less after preload. High parental dietary disinhibition seems to be associated with child's ability to regulate energy intake in laboratory setting (15).
Research activities predominantly focused on the relationship between parental eating behaviors and children's body fatness and weight, but little is known about the eating behaviors of children at preschool age which might be an important factor in the familial transmission of obesity. Therefore, we investigated the relationship between eating behaviors and weight status in this age group. The aim of this study was to examine weight-related differences in the eating behaviors and nutrition of preschool-aged children. We expected offspring of overweight mothers to score higher in emotional and external eating behaviors as well as problematic food intake than children of normal-weight mothers. Furthermore, we analyzed the influence of maternal eating behaviors on the child's eating behaviors. We also surveyed sex-related differences in the transmission of eating behaviors.
Methods and Procedures
This cross-sectional study involved 142 mothers of preschool-aged children. All mothers were recruited in clinics where they either escorted their chronically ill child (e.g., child's asthma) or received treatment themselves (e.g., maternal depression, weight reduction). Mothers were asked by the clinic staff (physicians or psychologists) to fill in a set of questionnaires in case they fulfilled the defined inclusion criteria (preschool-aged child; maternal or child overweight; low socioeconomic status). The mothers came from different parts of Germany. The clinics mainly recruited mothers with lower socioeconomic background. The participation was voluntary. The research was granted prior approval by the Ethics Board of our institution.
Mothers were asked for weights and heights to calculate their BMIs (in kg/m2). A subsample of mothers were also measured for weight and height data by doctors (N = 89). The objective data for this subsample did not differ significantly from self-reported data (T = −0.47; P = 0.64). Therefore, the self-reported data were used in all analyses.
Maternal eating behaviors were assessed using the Dutch Eating Behaviour Questionnaire (DEBQ) (16). The DEBQ is a 30-item self-report measure that includes three subscales: emotional eating, external eating, and restrained eating. The DEBQ has good reliability and validity. Several studies showed high Cronbach's α of the scales (α = 0.82–0.93) (e.g., refs. 17,18).
Child's body weight was measured in light clothing to the nearest 0.1 kg using a calibrated scale. Height was measured without shoes to the nearest 0.1 cm using a vertical ruler. BMI was then calculated as weight (kg)/square meters. In order to adjust data to age and sex, we calculated the standardized BMI (BMI-SDS) on the basis of percentiles (19). Overweight was defined as BMI scores at or above the 90th percentile for age and gender, obesity at or above the 97th percentile (19).
To evaluate the child's eating behaviors, all questionnaires were adapted asking mothers to evaluate the eating and nutritional behaviors of their children.
We assessed children's eating behaviors using the DEBQ for children (20). The DEBQ for children was adapted on the basis of the DEBQ (16,17) in order to evaluate eating behavior in children. We used the subscales emotional and external eating. With respect to the age of the children, we excluded the restrained eating scale. In their original version, these subscales showed good reliability with Cronbach's α = 0.74–0.95 and satisfactory correlations with other measures (21,22). Both scales were positively associated with spending time in front of television and computer and parental pressure. External eating was positively associated with more frequent consumption of sweet and snack-food (22).
The speed of eating was measured by four items concerning negative eating behaviors (e.g., my child eats his or her food without any breaks). In addition, we used the subscale food responsiveness (Child Eating Behavior Questionnaire) (23) to examine child's craving for food. This subscale showed good reliability with Cronbach's α = 0.80–0.82 and test-retest-reliability r = 0.83 (23). No other subscales of Child Eating Behavior Questionnaire were used.
For the child's food intake, we asked mothers to rate the consumption of problematic food (sweets, fast food, soft drinks, and unhealthy snacks) as well as the consumption of fruits and vegetables of their children on a six-point scale. High values represent a more frequent consumption (see Figure 1). We created these scales in a criteria-orientated assessment. According to the recommendation of nutrition experts, we included relevant food for the analyzed age group and classified in problematic food and unproblematic food (fruits and vegetables). In a previous study in 1- to 9-year-old children (N = 556), the scales showed moderate reliability: problematic food: α = 0.62; fruits and vegetables: α = 0.73.
A total of 142 mothers of preschool-aged children aged 3–6 years participated. Maternal mean age was 34.7 years (s.d. = 5.4). Children's mean age was 4.2 years (s.d. = 1.0) with 64% being boys. Families were predominantly German (96%) and intact (86% married or marital status). Of the 142 mothers, 22.3% had attended a maximum of 9 years of school or had no school leaving certificate, 61.2% attended school for 10 years, and 16.5% had Abitur (university entrance diploma) with school attendance for 12 or 13 years. Thirty-one percent of the families were defined as living below the national poverty threshold. More than half of the mothers were overweight or obese (28.6% BMI ≥ 25 vs. 32.8% BMI ≥ 30). Regarding national cutoffs (19), 12% of the children were overweight, and 7% were already obese (see Table 1). According to the International Obesity Task Force criteria, the prevalence for overweight (>85th <95th percentile) was 12.7% whereas, the prevalence for obesity (>95th percentile) was 10.6%. Table 2 shows children's scores on eating behavior and nutrition scales.
Table 1. Weight characteristics of children and mothers (N = 142)
Table 2. Children's scores on eating behavior and nutrition scales
All variables were rated using five- or six-point Likert scale. For better comparability, all scales were transformed to range from 0 to 100. Therefore, scale means of all variables were divided by their number of scale points and multiplied by 100. Higher scores indicate greater presence of the factor. Data are presented as means (M) ± s.d. Significance is determined by P < 0.05. A two (child's weight status: overweight/obese vs. normal weight/underweight) × two (maternal weight status: obese/overweight vs. normal weight) multivariate ANOVA was conducted to examine differences in child's eating behaviors depending on child's and maternal weight status. We expected higher external and emotional eating, speed of eating, food responsiveness, and problematic food intake in overweight children and children of overweight mothers. Correlational relationships between eating behaviors and BMI of mothers and their children were tested. Multiple regression analysis was used to predict eating behaviors of the children by mothers' variables. We expected a significant influence of maternal BMI and maternal eating behavior on children's eating behavior whereas the influence of maternal BMI was supposed to be mediated by maternal eating behavior. Therefore, we independently analyzed the influence of mothers' BMI and eating behavior on children's eating behavior as well as the prediction of maternal eating behavior by mothers' BMI. In addition, the mediation of maternal BMI and maternal emotional eating was tested by entering both predictors. All analyses were performed using SPSS 14.0 (SPSS, Chicago, IL).
Weight-related differences in child's eating behaviors
We compared children's eating and nutrition-related behaviors depending on their weight status. As Figure 2 shows, overweight and obese children score higher on external eating (F = 6.56; P = 0.01, food responsiveness (F = 12.42; P = 0.001), and speed of eating (F = 5.41; P = 0.02). Unexpectedly, children with higher weight status eat less problematic food (F = 8.09; P = 0.005).
Differences in child's eating behaviors depending on maternal weight status were also analyzed. The results shown in Figure 3 imply that children of overweight or obese mothers show higher amounts of emotional eating (F = 7.27; P = 0.008) than children of normal-weight mothers. There was no significant interaction between mother's and child's weight status regarding the eating behaviors of the children (emotional eating: F = 0.99; P = 0.32; external eating: F = 0.31; P = 0.58; food responsiveness: F = 0.15; P = 0.70; speed of eating: F = 0.29; P = 0.59; problematic food: F = 0.01; P = 0.93; fruits and vegetables: F = 0.27; P = 0.43).
Children do not differ in their BMI-SDS (F = 0.14; P = 0.71) or in their eating behavior (emotional eating: F = 0.07; P = 0.79; external eating: F = 1.87; P = 0.17; food responsiveness: F = 0.08; P = 0.78; speed of eating: F = 0.13; P = 0.72; problematic food: F = 0.01; P = 0.93; fruits and vegetables: F = 3.92; P = 0.06) depending on maternal socioeconomic status.
Relations in eating behaviors and weight between mother and child
To analyze sex differences with respect to maternal eating behaviors, BMI and children's eating behaviors and BMI-SDS, separate correlations for boys and girls were tested. Boys and girls did not differ in age, BMI-SDS or socioeconomic status. As shown in Table 3, emotional eating is merely correlated between mothers and their sons. Additionally, boys' emotional eating is moderately associated with maternal BMI. For mothers and their daughters, no such relation was found. Maternal external eating is related to external eating of daughters and sons.
Table 3. Correlations (r) between eating behaviors and BMI of the mothers and eating behaviors and BMI-SDS in daughters and sons significant correlations are marked bold; (*P < 0.05; **P < 0.01)
The correlations in Table 3 only show a significant relation between emotional eating in children and maternal BMI for boys but not for girls. To determine the prediction of emotional eating in boys, we independently analyzed the influence of mothers' BMI and emotional eating. Mothers' BMI (R2 = 0.07, P < 0.05) and maternal emotional eating (R2 = 0.19, P < 0.001) independently predicted emotional eating of their sons. Mothers' BMI (R2 = 0.30, P < 0.001) significantly predicted maternal emotional eating. Furthermore, we tested the mediation of maternal BMI and maternal emotional eating by entering both predictors. As Table 4 indicates, maternal BMI was no longer a significant predictor of emotional eating of their sons but maternal emotional eating (R2 = 0.19, P < 0.01) mediates the relation between mothers' BMI and the emotional eating of their sons. The Sobel test (T = 3.55; P < 0.01) confirmed this mediation. Models involving mothers and their daughters do not show a significant relation (see Table 5). We could not find a significant relation between maternal BMI and child's external eating.
Table 4. Linear regression analysis predicting emotional eating in boys (N = 91)
Table 5. Linear regression analysis predicting emotional eating in girls (N = 51)
Children who are already overweight at preschool age bear a high risk to be obese at school-age. The probability for being obese in adulthood is very high for obese children (3). In this study, 19% of the children were already overweight or obese. Research activities predominantly focused on the relationship between parental eating behaviors and children's body fatness and weight, but little is known about the eating behaviors of children at preschool age which might be an important factor in the familial transmission of obesity. It is known that children of obese families tend to overeat in response to emotional cues (12). In the past years, several studies examined the influence of parental eating and weight characteristics as well as feeding practices on children's body fatness and weight. The familial influences on child overweight differ according to parent's and child's sex (8,10,11,14). Whereas Hood et al. (11) showed higher gain in weight of children whose parents report higher dietary restraint and dietary disinhibition, Cutting et al. (8) found this effect only for mothers and their daughters. In this study, we were not able to find any relations between maternal eating behaviors and child's BMI-SDS. We assume that the relation between parental eating behaviors and child's weight is very small in the preschool age. We rather suppose the familial transmission of weight-related eating behaviors as an essential factor in the onset of obesity. Eating behaviors triggered by emotional and external stimuli contribute to the development and maintenance of obesity. Our results are consistent with this finding as we could show that overweight children scored higher on external eating behavior, food responsiveness, speed of eating, and offspring of overweight mothers scored higher on emotional eating than children of normal-weight mothers.
Little is known about the influence of parental eating behaviors on child's eating behaviors in preschool age. Research activities on this topic in laboratory settings or in older childhood or adolescence suggest a familial transmission of eating habits (14,15). Our research implies the maternal transmission of emotional eating behavior in sons but not in daughters. This result corresponds with Faith et al. (13) who also found a limited effect in boys. Boys at high risk to develop obesity consumed more than twice amount of energy in the absence of hunger (EAH) than boys with low risk. The authors assumed that obesity-promoting genes transmit their influence through EAH in boys but not in girls. Recent studies have revealed sex-related transmission in eating behaviors with maternal disinhibition independently predicting daughters' free access intakes and daughters' overweight but not for boys (8). Faith et al. (13) assumed that parental restriction of child food intake may lead to the development of EAH especially in daughters being less relevant in sons.
Owing to the cross-sectional nature of our study, the interpretation of the results is limited. Beyond, we used mother's evaluation to assess the eating behavior of the preschool-aged children. This could influence the results, as mothers rated their own eating behavior as well as the eating behavior of their children. Furthermore, the assessment of eating behavior is a very sensitive topic; hence, self-serving biases cannot be excluded. The assessment of father's influence in the transmission of eating behavior was not realized due to the low readiness of fathers to participate in our study. Our research suggests that the familial transmission of emotional eating behavior may lead to eating and weight disorders. Prospective studies are necessary to analyze whether high emotional and external eating in children causes obesity or whether obesity leads to the changes in the eating behaviors. Nevertheless, our findings emphasize to integrate the transmission of eating behaviors as an important topic in programs to prevent childhood obesity.
This study was supported by BMBF/DLR, Förderkennzeichen GFELO 1054304 (to P.W.). We thank all mothers and children who participated in our study as well as the following clinics for their support (in alphabetical order): DRK-Mutter-Kind-Kurzentrum Carolinensiel, Ms Menzel; Inselklinik Sylt, Ms Kötter; Klinik “Nordseedeich,” Ms Petry; Klinik “Santa Maria,” Mr Gulyas; Klinik “Sonnenalm,” Mr Polan; Klinik “Waldfrieden,” Ms Patzwall; Klinik “Werraland,” Ms Hasselmann; Ostseeklinik Königshörn, Mr Schlichting; Südstrandklinik Fehmarn, Mr Bräter and Ms Groos. Special thanks to Ms Kröller, Ms Richter, and Ms Berger for their helpful advice.