Rates of obesity among children in the United States⁴ have motivated extensive research to understand influences on body weight, as well as interventions to prevent excess weight gain in childhood.⁵ An array of factors contributes to obesity among this population at the individual, familial, school, and governmental levels.^5,6 These contributors may both include, and can influence, dietary behavior. Understanding dietary behaviors, their associations with other factors related to obesity, and how these behaviors are influenced by interventions is thus an important piece of the puzzle in our efforts to advance childhood obesity prevention efforts. For example, there has been attention to how diet quality, fast food consumption, and intake of sugar-sweetened beverages relate to weight gain among children, as well as the extent to which interventions can shift these dietary behaviors and associated weight-related outcomes. There has also been attention to whether differences in eating patterns might contribute to disparities in obesity among different racial and ethnic groups and geographical areas.⁷

Dietary behaviors salient to obesity are relevant beginning in infancy; for example, breastfeeding has been shown to be a protective behavior against weight gain in childhood.⁸ Researchers also have paid attention to the role of timing of introduction of solid foods and subsequent development of obesity. However, this relationship remains unclear, with a recent study by researchers at the Centers for Disease Control and Prevention finding no association between timing of introduction and obesity at age 6 years.⁹ In toddlers, low fruit and vegetable consumption and high consumption of energy-dense foods^10–13 are predictors of weight status in later childhood stages.

The dietary behaviors associated with overweight and obesity among school-age children are similar to those observed in toddlers,^14,15 in addition to frequent consumption of energy-dense foods, predominantly those high in fat, sugar, and/or salt¹⁶ as well as sugar-sweetened beverages. Recent research has focused on consumption of sugar-sweetened beverages in particular, as they are a primary source of added sugars among youth, and evidence suggests that these beverages significantly contribute to weight gain.¹⁷ Low intake of fruits and vegetables, which is influenced by food-related attitudes and taste preferences,^18,19 also correlates with the consumption of highly-processed, energy-dense fast foods among this age group.²⁰

Dietary behaviors, attitudes, and related factors play a larger role in dietary intake and obesity risk as children reach adolescence. Diet-related behaviors, such as excessive snacking, frequent eating at restaurants, and intentional diet restrictions for weight loss purposes are associated with increased risk of weight gain.^21–23 Dietary intake, related behaviors, and attitudes are often interlinked and influence one another, with a possible overall impact on weight. For example, an adolescent trying to lose weight may intentionally restrict food choices, which is associated with an increased likelihood of consuming a poor diet and eventual weight gain.²²

A wide array of influences affect dietary behavior, as conceptualized by social-ecological models of behavior.^24,25 Ecological models aim to describe human behavior at multiple levels, including the intrapersonal, interpersonal, organization, community, and policy levels.²⁶ For example, dietary behavior at the individual level is influenced by federal, state, and local governments, industry and media, health care professionals and resources, community organizations, schools, and peers, parents, and families.⁵ Most models focus on the interplay of multiple factors at multiple levels that influence individual behavior, with potential for overlap or interaction across levels,²⁷ postulating that changes at both individual and broader societal levels are needed to enable individuals to successfully enact and sustain behavior change. The social-ecological model can be applied to conceptualize the role of dietary behavior in the context of childhood obesity, helping researchers and practitioners to consider multiple levels of influence on individual dietary behaviors among children and youth when designing studies to better understand these influences, as well as interventions to address them.^28,29 The inherent complexity of dietary behaviors and obesity suggests the need for comprehensive approaches to measurement, taking a systems perspective³⁰ to consider, for example, how an intervention targeting a specific component such as sugar-sweetened beverages affects other aspects of the diet. This has implications in terms of the capacity of measures to capture the total diet broadly, an issue discussed in Section 5.