Discussion
Our study was unique in its focus on the differences in a child's weight during a parental weight gain or loss. It specifically investigated the weight change of both parents in relation to their child's weight change. A father's weight gain or weight loss was correlated to the weight of school-aged daughters but not associated with the weight of school-aged sons. A mother's weight gain or weight loss was correlated to the weight of school-aged sons and school-aged daughters. A mother's positive weight change also increased the chance of a positive weight change in pre-schoolers and school-aged children. As mothers tend to be the primary caregivers, they are perhaps a child's role models, predominantly responsible for feeding their children, and monitoring the food intake of their children. They also likely eat with their children more frequently and are more dissatisfied with their bodies than fathers. Mothers might be more likely to use feeding-based strategies that have been suggested to teach children emotional and disinhibited eating. They might also be more likely than fathers to employ authoritative and encourage compliance in their children. Most researchers have assumed that fathers do not have as much influence on a child's development as do mothers. However our study unearthed something new: parental weight gain or weight loss did not seem to be related to the weight of adolescent daughters. We found no associations between a parent's positive weight change and the child's positive weight change for children ranging from the age groups of "school-aged" to "adolescence" in the third transition. Our explanation is that the cognitive, physical, social, and lifestyle changes during adolescence can create profound changes in a child's eating patterns. Teens tend to snack, miss meals, eat away from home, consume fast food, and start diets (especially true for females) more frequently than younger children. Adolescents gave several reasons for not having family meals, including schedules differences, the desire for autonomy, and dissatisfaction with family relations. The most frequently mentioned reasons among parents were conflicting schedules due to work and activities such as sports.
The results of this study showed that parent weight change is a significant predictor and a key contributor to child weight change, a conclusion consistent with other research. Parental changes in eating and activity can act as models for changes in child behavior. A mother's positive weight change increased the chance of a positive weight change in pre-schoolers and school-aged children but not in adolescents. However, during each transition, we found no associations between the father's positive weight change and the child's positive weight change, suggesting that the mechanisms affecting the child's acquisition and maintenance of eating and exercise behaviors differ for each parent. Further studies might identify the exact mechanisms determining differences in the positive and negative weight changes in father-child and in mother-child pairings.
Whereas a parent's self-control might weaken over time, child behavior can be maintained by consistent parental support or through child self-regulation. Garn and Clark suggested that childhood eating and exercise patterns are modeled after parental behaviors. Experimental research has indeed suggested that parental modeling can influence and alter children's eating and exercise behavior. Bandura has argued that reciprocally reinforcing relationships among family members is important for acquiring and maintaining new behaviors. The family provides an ideal environment for the improvement of health-related behaviors, including eating and physical activity. Parental weight change might influence child weight change through the modification of the shared family environment, thereby facilitating weight changes in parents and their children.
Highly educated parents overweight or obese parents (BMI ≥25 kg/m ), and parents living in urban areas were more likely to have positive weight change. Having a post-graduate degree may result in better knowledge and understanding of healthy weight and weight control practices, including a healthy diet and adequate exercise. In addition, parents with higher education may increase access to healthy foods and the ability to maintain physical fitness. Parental overweight or obesity probably contributes both genetic and family environmental influences for childhood overweight. Overweight parents tend to overcontrol the child's feeding behaviours, food preferences and energy intake, such as restricting the total amount of food and pressuring children to eat healthy foods, possibly because they were more aware of acknowledging the problem and health consequences of obesity. These facts could perhaps be used to help their children, who are already overweight or obese, lead healthy lives. Parents' restrictive eating behavior affects child's weight, which in turn imposes positive weight change. Though it has been estimated that overweight or obesity was observed to be more widespread in urban areas, their awareness of the health threats that obesity poses is also increasing. A previous study shows that children in urban schools had more exercise equipment available at home, and were more frequently transported to places where they could be physically active. In addition, a more competitive workplace environment in urban area and the insecurities associated with being discriminated and prejudiced both in their personal and professional lives often motivates urban adults who are overweight to make an effort to lose weight. Our study has its strengths and weaknesses. This study adds to a small body of literature that supports the incremental effects of parental weight change on child weight change. Our dataset uses a rigorous sampling design that selects a large sample of a representative group of children and their parents among multiple time periods. The number of participants included in this study was larger than those of other studies. Additionally, this study includes repeated measures of a moderately sized cohort of parents and their children. Data from the same individuals over multiple points in time provides uniquely rich longitudinal data. The consecutive study (14-years) allowed us to identify developmental sequences for stability and continuity over time, thereby benefitting the quality of our assessment of the temporal generality of important key predictors of child weight change.
However, this study was limited by its use of BMI as a measure of weight status, a fact that might introduce misclassification problems and result in an estimation bias for the effects related to the relationship between parental and child changes. Another limitation is the likely existence other unmeasured parenting variables that contribute to child weight change, such as changes in the mood surrounding and discussions about eating and physical activity in the home. The impact of variables such as these deserves further research.