Because the dramatic increases in childhood overweight cannot be attributed to changes in the gene pool and hence genetic factors alone, there is a need to identify both contributing environmental factors and behavioral phenotypes for childhood overweight. The findings of the present research provide the first evidence that young girls’ eating when exposed to large portions of palatable foods in the absence of hunger represents a stable behavioral risk factor for overweight. The parents’ use of restrictive feeding practices when the girls were 5 y of age predicted eating in the absence of hunger at age 7 y, providing additional evidence for environmental effects on the developing controls of food intake in girls. In particular, these findings extend previous experimental and cross-sectional research that indicates that parents’ use of restrictive feeding practices is not effective in limiting children’s food intake and can actually promote children’s consumption of the restricted foods, even in the absence of hunger.
Infants and children are responsive to the energy density of the foods they consume, illustrating the importance of internal hunger and fullness cues to self-regulate energy intake (20
). However, environmental factors play an increasingly important role in the development of eating behaviors throughout early childhood (7
). For instance, preschool-aged children learned to initiate eating in a setting where they had become accustomed to eating, even in the absence of hunger (25
). In another study, young children’s ability to regulate energy intake was disrupted by focusing their attention on environmental cues, including the use of food rewards and drawing attention to the amount of food remaining on the plate (26
). Similarly, a recent study by Rolls et al (6
) found that although 2–3-y-old children’s eating was not affected by increasing the portion size served at a meal, 4–5-y-olds increased their intake as portion size increased.
The findings of the present study are consistent with previous findings; the girls’ mean snack food intakes at 5 [522 ± 390 kJ (125 ± 93 kcal)] and 7 [709 ± 473 kJ (169 ± 113 kcal)] y of age indicated that most girls ate something when presented with large portions of palatable foods, even though they had just indicated that they were not hungry. This research extends previous findings, however, by providing evidence that eating large amounts of food in the absence of hunger can be distinguished from a more normative tendency to show some responsiveness to environmental cues. In this study, girls who ate relatively large amounts of food in the absence of hunger at age 5 y were almost 4 times as likely to eat large amounts of food at age 7 y as girls who ate little in the absence of hunger at age 5 y. The girls who ate relatively large amounts of food in the absence of hunger at both ages were at increased risk of being overweight at both ages.
The fact that girls’ eating in the absence of hunger was associated with overweight is noteworthy given that “supersize” food portions have become increasingly abundant in restaurants, supermarkets, and movie theaters. For instance, Young and Nestle (27
) noted that movie sodas have increased from 360 mL (12 oz) to 600 mL (20 oz) in the past decade, and the largest adult size of soda has increased from 960 mL (32 oz) to 1320 mL (44 oz). The findings of the present study indicate, however, that “obesigenic” eating environments in which large portion sizes of energy-dense foods are present are necessary but not sufficient to promote overweight. Rather, the manner in which children initiate and terminate eating in such “obesigenic” environments may indicate a behavioral phenotype of girls who are highly susceptible to problems of energy balance.
From a developmental perspective, girls’ eating in the absence of hunger may be problematic because it resembles disinhibited eating patterns observed among adults (10
). Disinhibited eating has been characterized as eating that occurs in response to factors other than hunger and satiety, such as the presence and smell of palatable foods or emotional states (eg, sadness or anxiety). This problematic eating behavior is associated with weight status and gain (28
), weight fluctuations (30
), and binge eating in adults (31
) and is thought to be produced, in part, by self-imposed rigid restrictions placed on eating (32
). In the present study, young girls’ eating in the absence of hunger was associated with both overweight among the girls and parent-imposed restrictions on their eating.
The relation between parents’ use of restriction and girls’ eating in the absence of hunger extends experimental (12
) and cross-sectional observational (11
) research indicating that restriction draws children’s attention to restricted foods, increases selection and intake of restricted foods, and may even generate negative self-evaluation about eating restricted foods in young girls (9
). In this sense, restrictive child-feeding practices may serve to establish young girls’ responsiveness to external cues as controls of food intake, favoring the development of overweight (7
). It is likely, however, that the relation between parents’ use of restriction and child weight status is bidirectional (34
); parents may impose restriction in response to the child’s eating behaviors or weight status, and restriction may, in turn, promote behaviors that contribute to overweight among children.
One recent study by Johnson (38
) offers promising evidence that the extent to which children’s eating is regulated by environmental factors, such as parents’ restrictive feeding practices or the presence of palatable food, can be modified. In a pre-post test design of 25 preschool-aged children, Johnson found that children’s ability to regulate energy intake was improved after 6 wk of training sessions in which children were focused on their own internal hunger and fullness cues during eating. Furthermore, although poor intake regulation was associated with their greater weight status and higher levels of problematic maternal eating behavior at the beginning of the study, these relations were not evident after the training-related improvements in children’s intake regulation. Such work indicates that successful preventive and interventional efforts are contingent on identifying problematic eating behaviors of susceptible individuals and understanding the causes of those behaviors, particularly within the context of the family eating environment.
The findings of the present study provide evidence for environmental effects on child overweight, resulting from a heightened responsiveness to an “obesigenic” food environment in which a wide variety of energy-dense foods are readily available in large portions. In this study individual differences in young girls’ eating in response to palatable foods in the absence of hunger were 1) stable across time, 2) associated with an increased risk of overweight, and 3) predicted by parents’ reports of restrictive feeding practices. This research also adds to a growing body of research indicating that restricting young children’s access to food does not promote moderate intake of restricted foods. That overly restrictive feeding practices may not be effective, however, does not mean that structure in child feeding should be abandoned. Limit setting is an important part of child feeding and should be a focus of anticipatory guidance for parents. Alternatives to overly restrictive approaches, however, should be suggested. These include fostering dietary variety by offering children an array of healthy foods to reduce neophobia and promote acceptance, offering children portion sizes appropriate to their needs, and giving children structured choices regarding the types of foods consumed. Children should be encouraged to focus on their own hunger and fullness as a guide to when eating begins and ends.