Key points

Introduction

Childhood obesity is a critical and ongoing public health problem, with almost 25% of children overweight by age 4 years and 35% by adolescence. Once established, childhood obesity is difficult to treat and tracks into adulthood. There is thus an urgent need to prevent and treat childhood obesity, but current prevention and treatment approaches focused on improving diet and physical activity patterns have had limited efficacy. One reason for this may be a lack of focus on the basic mechanisms of behavior change, specifically self-regulation processes that may shape whether recommended health behaviors are adopted. If enhancing self-regulation in childhood could improve health behaviors relevant for obesity prevention, this may lead to new intervention targets and, in turn, better long-term health outcomes.

Self-regulation occurs at many levels (cognitive, emotional, psychological, biological, behavioral) and concerns the ability to control thoughts, emotions, and actions to achieve a desired outcome or goal. Self-regulation can shape health behaviors through multiple pathways. For example, the ability to delay an immediate desired behavioral reward (eg, eating a cookie) in favor of achieving a longer-term goal (eg, weight loss) is a central focus of most weight management approaches. Furthermore, having the cognitive capacity to plan ahead and the mental flexibility that makes it possible to juggle priorities effectively are both likely important in maintaining an exercise routine. Individuals who are cognitively strained, or depleted, may have difficulty engaging in healthy behaviors.

Self-regulation develops during childhood and can set the stage for adult self-regulation capacity. In adults, self-regulation deficits are linked to poor chronic health conditions, including obesity, which often require long-term behavior and lifestyle changes in order to manage. Identifying how self-regulation processes that emerge early in life relate to health behaviors is therefore a critical first step toward interventions that address mechanisms of behavior change. Furthermore, improving self-regulation processes early in the lifespan may provide a novel, prevention-oriented approach to health promotion.

Introduction

Childhood obesity is a critical and ongoing public health problem, with almost 25% of children overweight by age 4 years and 35% by adolescence. Once established, childhood obesity is difficult to treat and tracks into adulthood. There is thus an urgent need to prevent and treat childhood obesity, but current prevention and treatment approaches focused on improving diet and physical activity patterns have had limited efficacy. One reason for this may be a lack of focus on the basic mechanisms of behavior change, specifically self-regulation processes that may shape whether recommended health behaviors are adopted. If enhancing self-regulation in childhood could improve health behaviors relevant for obesity prevention, this may lead to new intervention targets and, in turn, better long-term health outcomes.

Self-regulation occurs at many levels (cognitive, emotional, psychological, biological, behavioral) and concerns the ability to control thoughts, emotions, and actions to achieve a desired outcome or goal. Self-regulation can shape health behaviors through multiple pathways. For example, the ability to delay an immediate desired behavioral reward (eg, eating a cookie) in favor of achieving a longer-term goal (eg, weight loss) is a central focus of most weight management approaches. Furthermore, having the cognitive capacity to plan ahead and the mental flexibility that makes it possible to juggle priorities effectively are both likely important in maintaining an exercise routine. Individuals who are cognitively strained, or depleted, may have difficulty engaging in healthy behaviors.

Self-regulation develops during childhood and can set the stage for adult self-regulation capacity. In adults, self-regulation deficits are linked to poor chronic health conditions, including obesity, which often require long-term behavior and lifestyle changes in order to manage. Identifying how self-regulation processes that emerge early in life relate to health behaviors is therefore a critical first step toward interventions that address mechanisms of behavior change. Furthermore, improving self-regulation processes early in the lifespan may provide a novel, prevention-oriented approach to health promotion.

Executive functioning in children

Executive functioning (EF) is a central aspect of self-regulation. EF refers to a set of interrelated neurocognitive functions that concern attentional, mental flexibility, and self-control capacities. Such skills emerge rapidly during the early childhood years and continue to develop throughout later childhood and into adolescence. EF skills generally include attention shifting, working memory, and inhibition of prepotent responses, or inhibitory control ( Fig. 1 ). These skills function to direct and control cognitive and, to some extent behavioral processes to focus on a task at hand as well as to plan for the future.

Potential pathways of association between poor EF and obesity in childhood.

EF has both cool and hot components that are activated under conditions that vary in motivational salience. That is, cool features of EF reflect the child’s capacity to control attention and make choices in a situation that does not involve emotional challenge or high-stakes decision making, whereas hot EF skills are important when the child needs to make decisions that are motivationally salient. Cool components of EF thus include working memory and attentional capacity, whereas inhibitory control is considered a hotter EF skill. Cooler EF skills have been associated with the lateral prefrontal cortex, which shapes complex cognitive skills such as planning and attentional flexibility, whereas hotter EF skills have been associated with the orbitofrontal cortex, which is hypothesized to be involved in more affectively salient decision making. However, the mapping of EF skills to specific brain structures is still emerging, and the developmental trajectories of cool and hot EF skills are still not fully understood.

EF skills have been found to underlie functioning in many domains, including academic achievement (particularly cool EF ) and emotion regulation (particularly hot EF ) as of early childhood. Both cool and hot components of EF may also have implications for health behaviors, but EF skills have rarely been examined with regard to health-related behaviors in children.

Determinants of executive functioning in children

Understanding the determinants of EF is important in order to identify opportunities for intervention to enhance EF. The preschool to early school years are a critical period for the development of EF. Deficits in EF may arise as a result of toxic stress exposure during early life, which can occur in the context of poverty and is known to have long-lasting effects on brain development and organization. Research has identified both genetic factors and early behavioral precursors of EF, including infant and toddler attention skills, emotional reactivity, and sleep. Social-contextual features have been consistently associated with EF capacities, and the importance of parenting has recently been highlighted. Children who are born into poverty, experience intrusive parenting, or have parents with low EF themselves display reduced EF skills even as early as the preschool years. In contrast, positive caregiving and secure attachment are associated with better early EF skills and preschool curricula that provide highly scaffolded, play-based, and predictable social environments can have beneficial effects on EF. As with other developmental phenomena, EF skills are most likely a result of the interplay between genetic and other biological factors and the child’s caregiving environment.

Development of executive functioning

Taking a developmental perspective is essential in order to understand how EF could shape health behavior. Early childhood is a period of rapid brain growth with constant remodeling of neural architecture and synaptic pruning; EF skills thus develop rapidly during this time and there is evidence of malleability. EF skills continue to develop across the first 2 decades of life, generally in conjunction with brain maturation. Importantly, not only brain structures but also neural organization and functional connectivity among brain regions change and develop over this time. Certain cooler EF skills, such as working memory, may develop earlier than hot EF skills, such as behavioral inhibition, which continue to develop into preadolescence and beyond.

Importantly when considering implications for health behavior, demands on EF also change across development as a function of social context. For example, the temptation for adolescents to engage in high-risk activities can increase when with friends, even if the adolescent is cognitively aware of potential negative consequences. Therefore, although adolescents generally possess more developed EF skills than younger children, they are also required to negotiate more complex contexts that test such skills to a greater degree; the failure of EF skills in such settings may therefore be particularly costly to an adolescent’s health.

Poor executive function is associated with childhood obesity

Obesity and overweight during childhood and adolescence are associated with a wide range of cognitive skill deficits; over the past decade there has been a dramatic increase in the number of articles reporting on the association. However, given that few studies have used overlapping measures or assessed the same aspects of EF in similar populations, the precise nature of association between different EF components and weight remains unclear. Among young children (<6 years of age), deficits in hot behavioral inhibition skills have been consistently associated with higher body mass index (BMI) and overweight as assessed using behavioral delay of gratification tasks as well as cognitively focused EF tasks. Less is known about cool EF skills in relation to weight in children younger than school age. Among older children and adolescents, reduced EF skills in the areas of inhibitory control, attention, and working memory, as well as differences in brain activation in cortical regions associated with reward, have been found in association with overweight and obesity. Using longitudinal designs to study associations between EF components and weight across different developmental periods can help identify which aspects of EF are uniquely associated with weight (or other adiposity indicators) and when such associations emerge.

Possible pathways of association in children

Beyond simply identifying associations between weight and EF, it is important to understand the complex pathways through which EF deficits and obesity become established during childhood in order to recommend intervention approaches. Fig. 1 presents an overview of EF-obesity pathways that are supported by research evidence to date (note that neither all possible pathways nor all bidirectional arrows are represented). In children, poor EF has been associated with obesity-promoting behaviors, including obesogenic eating, lack of physical activity, emotion regulation difficulties, and poor sleep, although in some cases such behaviors may be driving poor EF performance and/or the associations may be bidirectional (eg, sleep, physical activity, emotion regulation ).

Deficits in hot EF skills such as behavioral inhibition have been associated with poorer emotion regulation as well as obesogenic eating behaviors such as emotional overeating, reduced self-regulation of eating, and intake of high-calorie snack foods in preschool and school-aged children, although findings are not consistent, particularly in younger children. Difficulty delaying immediate gratification in favor of long-term goals may be responsible for self-regulation failures in the context of emotional distress or in the presence of tempting foods, which may increase the level of self-regulatory effort involved to delay gratification and therefore the likelihood that a child’s capacity to self-regulate will be depleted rapidly. In particular, individuals who are higher in food reward sensitivity or who eat to calm themselves when upset may be highly susceptible to such failures and thereby more prone to obesity. However, this possibility has rarely been considered in children; thus, research examining the inhibitory control aspect of EF with regard to food reward and emotion regulation capacity in young children is needed in order to clarify these processes.

Compared with immediate delay of gratification, a hot EF skill, cooler EF capacities such as working memory and planning may operate through a longer-term pathway wherein limited capacities to plan ahead to eat healthfully or exercise, or a lack of focus on future goals, could increase obesity over time. Evidence for this pathway in children is limited, particularly in young children. One study of school-aged children found that cool, but not hot, EF was associated with parent-reported obesogenic eating behavior, and another study found that children who reported more sedentary behavior and high snack food intake showed EF deficits in the areas of working memory and organization, whereas lower-risk children did not show such patterns. Findings based on adolescent samples have shown that poor planning ability was associated with increased binge eating in overweight children, and that binge eating mediated longitudinal EF-BMI associations in girls. The implications of cooler versus hotter EF skills for obesity risk may thus change with development. Because adolescents are known to follow peer influences with regard to eating and health behaviors, deficits in either cool EF skills such as planning or hot EF skills driving affectively loaded decision making could increase risk as a function of the peer group.

Regarding other behavioral risk factors for obesity, both cool and hot EF skills have been associated with greater physical activity, but most studies in this area focus on how physical activity may improve EF as a pathway for intervention rather than on the role of EF in promoting physical activity. Thus, future work that distinguishes the potentially unique roles of cool and hot EF skills in relation to different obesity-promoting behaviors over the short and long term may allow clinicians to tailor developmentally sensitive interventions to reduce obesity risk based on EF as well as obesity risk behavior profiles.

Mechanisms of executive functioning–pediatric obesity association are poorly understood

Although EF-obesity associations are increasingly recognized, the underlying mechanisms are not yet well delineated and the causal direction of association is debated. Poor EF may contribute to obesity risk by reducing self-regulation capacity, but the association could be bidirectional. Experimental studies in adults have shown that EF skills, particularly working memory, can improve after dietary changes and surgically induced weight loss. It is difficult to extrapolate from these studies directly to the pediatric context, because most such work has been conducted in older adults who have been overweight for years or in animal models that can identify mechanisms but only approximate human development. However, obesity-related biology has been proposed to contribute to reduced cognitive function through inflammatory and appetite-regulating hormone–mediated pathways (indicated by the dashed line in Fig. 1 ). Mechanistic and experimental work is needed in children in order to determine the direction of association and inform intervention strategies. For example, intervening to enhance EF may change behavioral pathways leading from poor EF to obesity, whereas reducing adiposity-related factors that impair cognitive skills (eg, through physical activity or surgical interventions) could interrupt the harmful effects of obesity on EF.