Too many children and adolescents make unhealthy food choices, are not sufficiently physically active and spend too much time in sedentary behaviors [1
]. Research has shown that these behaviors, referred to as energy balance-related behaviors (EBRBs) [4
], are associated with negative effects on health and well-being [5
], as they have been associated with weight gain and the development of overweight and obesity. Since unhealthy lifestyle habits often track into adulthood [11
], it is important that healthy lifestyle habits are established at a young age.
It is well-known that individuals’ healthy lifestyles are determined by a multitude of influences, including individual as well as social and physical environment factors and their interplay. In this paper, we address the relevance of the family microsystem. The family is the basic social context where healthy or unhealthy behavior patterns develop and are maintained [12
]. It serves as a reference point for the development of behavioral habits. Family life implies a large number of health-related cues, as daily family routines, such as family meals, choice and preparation of food and communication, are an inherent part of family life [12
]. Furthermore, specific formal or informal rules may develop, which stimulate individuals’ eating or activity and inactivity patterns [12
]. The family is an instance of control and organization which provides socio-emotional support [14
], and internalized concepts of health and well-being, values, attitudes and self-perception of competences are formed within the family [15
]. The majority of studies in the field of child EBRBs have focused on the influence of parents on their children. However, the family is more than interactions between parent and child. Family-level socialization dynamics (arising for example from family functioning, cohesion within the family, communication patterns between family members, shared values and attitudes) may affect the development of a healthy lifestyle beyond the impact of parenting behaviors. The current paper aims to synthesize theoretical and empirical literature on different types and levels of family influences and to describe their assumed interrelationships by developing a framework called Levels of Interacting Family Environmental Subsystems (LIFES). LIFES aims to organize the variety of different family environmental factors and environment—behavior pathways in youth. It helps to advance the research field as it supports researchers to derive specific hypotheses regarding underlying mechanisms of family environmental influences on individual’s behaviors. LIFES-based research might inform future interventions as it reveals processes that impede or support individual behavior change. It could also help to find answers for example regarding the question how the family environment should be integrated in intervention programs in order to increase sustained effects on children’s and adolescents’ EBRBs.
Family and EBRBs of Children
There is a large body of research showing the relevance of the family environment for children’s and adolescents’ EBRBs. Research into different forms of parental influences on children’s and adolescents’ behavior has shown that parents play an important role in the development of a healthy lifestyle [17
]. Parents are “gate keepers” of healthful eating and engaging in physical activities [19
]. Mechanisms that have been studied include parenting practices such as modeling, monitoring, and encouragement [21
] and more general concepts such as parenting styles or general parenting [27
]. Overall, these studies reflect the important role of the parents in the development of a healthy lifestyle by children and adolescents.
The traditional approach to investigating family influences on children’s health or health-related behavior is unidirectional. Studies on parental influences often assign a passive role to children, seeing children mostly as recipients of parenting behaviors. However, recent studies also provide evidence that parenting behaviors occur in response to the child-level factors and children’s behavior. These studies showed that parent’s choices regarding food parenting are influenced by the child’s weight status and behaviors [31
]. Despite such findings, the literature is still dominated by studies characterizing parents as the agents acting upon the child, without taking reciprocal processes or feedback loops into account.
The majority of studies in this field have focused on the parent-child subsystem [20
]. However, in this paper we will argue that the family is more than the interactions between parent and child. We assume that family-level socialization dynamics [38
] affect the development and maintenance of a healthy lifestyle [37
], beyond the impact of parenting behaviors. For example, interpersonal behaviors that occur at the family level, such as family meals, might have an influence on EBRBs [36
]. Research has consistently shown that having frequent family meals is associated with a number of health benefits for children e.g., lower BMI and healthy dietary intake [36
]. Another example is family functioning, which comprises structural and organizational properties of the family and interpersonal interactions. Family functioning is reflected in aspects like communication patterns, role fulfillment, adaptability, management of conflicts, involvement, warmth/closeness, and behavior control. This topic has been addressed by a small number of studies, which found that family functioning may be a relevant correlate of EBRBs [36
Gaining knowledge about the interplay of family environmental factors is crucial to understand the development and maintenance of children’s and adolescents’ ERBRs [37
]. It should be noted that although the family environment is important for both children and adolescents, the relevance of specific family environmental factors will depend on the age of the child. Therefore, these age groups should be studied separately, or, at least age should be incorporated not only as a confounder but also as a potential moderator. In the current paper, we seek to bring together findings reported in theoretical as well as empirical literature on different types and levels of family influences, and we describe their assumed interrelationships. Since there is currently no framework that addresses such a “bigger picture” of family environmental influences, we have developed a framework, called Levels of Interacting Family Environmental Systems (LIFES) with the aim of (1) illustrating that the family is more than parent-child interactions, (2) assisting researchers in putting their study in the context of the family environment, (3) stimulating research that includes higher level (upstream) influences, and (4) identifying areas of research that are in need of empirical research.
The importance of the family environment for children’s and adolescents’ EBRBs has been addressed in a large number of studies. Different types of influences of the family environment have been examined. Based on these studies and on theoretical approaches such as Family Systems Theories, the purpose of this paper was to describe the development of an overarching framework. The aims were (a) to bring together the different types and levels of influences in one framework, (b) to relate them to each other and (c) to postulate potential mechanisms and paths of influence. The core message is that family environmental influences arise from interactions between the individuals within the family, the parent-child subsystem and the family as whole. Furthermore, the influences can be differentiating according to their proximity to EBRBs (immediate, proximal and distal level). The LIFES framework covers the notion of the “family as a system” in that individuals’ behavior cannot be understood in isolation from the rest of the system. It takes into account children’s personal factors, parents’ individual factors, parent-child factors and factors at the overarching family level. The framework seeks to simplify the complexity of family influences on children’s EBRBs and illustrates which influences could (and should) be considered, where those influences are located, and how they are interrelated with other influences arising from the family. Potential direct and mediated links as well as moderators could be derived from this framework and be transmitted into distinct research models and testable hypotheses.
Researchers could focus on the interrelationship between factors within one sector (e.g., interaction between mother-child and father-child factors such as parenting styles, parental beliefs, parenting practices) and the relationships to children’s outcome variables. Furthermore, they could address how those factors are related to children’s EBRBs (e.g., mediators such as children’s motivation) and under what circumstances they are related (e.g., moderators such as family structure, family functioning).
While the importance of different family environmental influences for children’s and adolescents’ EBRBs has been shown in a large number of studies, overall there is a lack of studies focusing on the interplay between these different influences. Examining this interplay and considering mediation and moderation effects is crucial for a better understanding of the development and maintenance of healthy or unhealthy life styles.
For example, the model illustrates that small associations between distal variables (e.g., family functioning) and children’s EBRBs (e.g., [30
]) should not be interpreted as irrelevant but as potentially important upstream factors that influence children’s behavior via mediated paths and as higher level moderators (e.g., [109
]). For example, Kimiecik and Horn [125
] concluded in their study, that parenting styles may reflect parent-child interaction patterns that impact the development of children’s physical activity beliefs, such as value and competence. A better understanding of the influences of different factors on children’s and adolescents’ EBRB and the integration of distal variables of different subsystems might be crucial for planning interventions, for example regarding the question how to involve parents and families in intervention programs [126
]. Therefore, incorporating LIFES in the development of intervention programs could improve their effect on children’s EBRBs.
Recent studies have recommended considering the overarching family context [39
]. It is especially the immediate and proximal levels within the family subsystem which have rarely been addressed. Even though several studies have addressed family meals, studies examining other family practices in the context of eating behavior, as well as studies addressing the context of physical activity and sedentary behavior, are lacking. A qualitative study revealed that “family activities” are deemed to be very important by families. Parents stated that these activities relate to family functioning and to benefits for children, e.g., development of health lifestyles [128
]. As far as we know, the Family Health Climate is to date the only empirically investigated factor at the proximal level, in relation to children’s and adolescents’ EBRBs [104
]. We suggest investigating variables that reflect the family subsystem at the immediate and proximal levels and especially regarding family practices related to physical activity (e.g., joint physical activities) and sedentary behavior (e.g., watching TV as a family).
Examining the interplay of different family environmental influences and taking into account influences from different levels and subsystems requires a consistent use of terminology. As Vaughn and colleagues [25
] stated, the research field would benefit from solving inconsistencies in terminology and definitions. This becomes evident when factors from the parent-child subsystem and the family subsystem are addressed simultaneously. Factors from these two subsystems have to be clearly distinguished. An example are “family meals”, which are often described in terms of parenting practices even though they are actually a factor of the family subsystem (e.g., [36
]). Therefore, it might help the field moving forward if researchers strive to find a consensus in terminology and definitions for example via establishing an expert group, implementing expert symposia and publishing the results (for example, see [129
Strictly speaking, the parent-child subsystem refers to the mother-child and father-child subsystems. It should be noted that the evidence regarding the important role parents play refers mainly to the mother-child subsystem [130
]. Although fathers undoubtedly play an important role, it remains poorly understood what exactly this role looks like, if there are behavior-specific differences (in terms of physical activity, diet, sedentary behavior) or gender-specific differences (daughters vs. sons), how the father’s role differs from mother’s role, how mothers’ and fathers’ interact (e.g., co-parenting) and how this interaction affects child’s EBRBs [131
]. It should be noted, that the term “parent” in the framework is not limited to natural parents. It could be applied to caregiving members within the family system including step-parents but also grandparents if applicable. Furthermore, family is a heterogeneous social context. Therefore, underlying family characteristics, such as single- and double-parent families, blended families or multi-generational families should be taken into account. Furthermore, the social and physical context the family is living in might influence family dynamics as higher-level moderators. However, to date, both empirical data and theoretical approaches are lacking to incorporate these issues in LIFES at this point. We encourage research regarding these questions.
LIFES seeks to cover different behaviors, in particular regarding physical activity, eating and sedentary behavior. The framework is the same, but the importance of specific factors and their interrelationships are supposed to differ depending on the behavior. The same applies to the age and gender of the children and adolescents. The relevance of specific factors might differ for children and adolescents and for boys and girls. For example, Haines and colleagues [40
] showed gender differences in the association between family functioning and weight status. While a higher level of family functioning was associated with decreased likelihood of being overweight among girls, this was not the case for boys.
LIFES zooms in on the family context. This does not mean, however, that we would disagree with scholars advocating a more holistic view of environmental influences on EBRBs, for example by including the school environment [132
] or by focusing on interactions between multiple microsystems in the mesosystem [133
]. Indeed, taking into account other contexts is important; nevertheless, we have to gain knowledge how the specific setting or system, in this case the family, works and how interventions could be effectively implemented within this system. This could serve as a valuable precondition for realizing more effective upstream ecological approaches. However, in the end, the research question will determine which focus is most suitable.