Obesity has become a global epidemic in developed, as well as developing countries [1
]. In Poland, the prevalence of obesity is worryingly high [3
]. A recent study showed that the prevalence of obesity (with 95% CI) in the 7–18 age group was 4.3–8.8% among boys and 2.7–4.2% among girls [3
Obesity is considered a multi-factorial disease, and multi-component interventions are more effective than single-component interventions in reducing body weight [1
]. It is therefore important to consider obesity from an interdisciplinary theory- and evidence-based perspective. One such approach is the Homeostatic Theory of Obesity [5
]. This model was created by Marks [5
] and is based on a homeostatic theory of physical and mental health and illness. Marks [5
] assumes that obesity is at least in part an effect of homeostatic imbalance in psychological functioning. By providing considerable scientific evidence, Marks created the Homeostatic Theory of Obesity, in which the Circle of Discontent (COD) is considered particularly important. This vicious circle describes the relationship between obesity, high-energy consumption, negative affect and body dissatisfaction. One of the variables listed in the model, related to the Circle of Discontent, is restraint (identified by restrictive eating). All these interrelationships have been widely researched in many studies [5
]. Based on these new outcomes [6
], a new variable (uncontrolled eating) and new relationships (between uncontrolled and restrictive eating and other variables) were added to the model (Figure 1
). These studies show that body mass index (BMI) [7
] and high-energy consumption [6
] increase as uncontrolled eating increases. Moreover, a high level of restrictive eating is accompanied by a low level of uncontrolled eating [13
] and a high level of body dissatisfaction [8
Based on Marks’ theory [5
] and the other studies mentioned above, it was assumed that all relations (except for restrictive eating and uncontrolled eating as well as restrictive eating and high-energy consumption) are positive.
To the best of our knowledge, the model has not yet been empirically verified in research. Therefore, the purpose of the present study was to provide an empirical verification of the Circle of Discontent with an assessment of its relationship to restrained and uncontrolled eating among children and adolescents. This study examined whether our results confirm a new hypothesized model.
In the present study, we empirically verified the Circle of Discontent with an assessment of its relationship to restrained and uncontrolled eating among children and adolescents. To our knowledge, our evaluation is the first assessment of the relations assumed in the Homeostatic Theory of Obesity using structural equation modelling. Several key findings were revealed in the present work. Most of the relationships described in the hypothesized model are significant and consistent with the assumed direction.
Being obese co-occurs with experiencing body dissatisfaction and maladaptive eating behaviors in the form of uncontrolled and restrictive eating. Moreover, the association between restrictive eating and uncontrolled eating is significant and negative. The current findings are in line with previous studies demonstrating significant relationships between the above-mentioned variables [5
]. A possible explanation for our outcomes is the current ideal of beauty. Numerous studies presented in Marks’ article [5
] indicate that the current ideal of beauty is associated with having a thin silhouette [25
]. Therefore, if there is a discrepancy between the current body weight and the ideal, there may be social pressure to change the appearance and strong body dissatisfaction. As a consequence, behaviors are undertaken to reduce body weight (e.g., restrictive eating) [5
]. On the one hand, as everyone knows, these behaviors often do not have the desired effect because a restrictive diet often increases the risk of overeating (e.g., “masking hypothesis”) [5
]. On the other hand, not all studies confirm the negative impact of restrictions on overeating [28
] or show that this relationship is negative [13
]. Therefore, further research into these relationships is necessary.
Consistent with previous findings [5
], our findings indicate that the subsequent relationships between body dissatisfaction, negative affect and restrictive eating, as well as that between uncontrolled eating and high-energy consumption, are significant and positive. Therefore, as predicted by Marks [5
], a high level of body dissatisfaction is associated with the experience of a high intensity of negative affect, and the source of these emotions can be difficulty in controlling eating behavior, a large discrepancy between current and ideal body weight, and discrimination on the basis of physical appearance and body weight. Negative affect can trigger emotional eating, which, if it becomes a constant way of regulating emotions, may lead to weight gain [5
]. Therefore, people often use dietary restraint to prevent weight gain and reduce the level of body dissatisfaction, negative affect and uncontrolled eating [5
]. Dietary restrictions are a particularly important method of weight control for people with a high level of uncontrolled eating because they often consume more total energy, snacks and desserts than controlled eaters [9
]. This is because a tendency towards uncontrolled eating is associated with the consumption of high-calorie foods (e.g., sweets, chocolate, fast food), which can also lead to weight gain [32
Other relationships have not been confirmed. Obesity is not associated with the experience of negative affect and high-energy consumption. In addition, the analysis shows that body dissatisfaction is not significantly related to high-energy consumption, nor is high-energy consumption associated with negative affect and restrictive eating. Interestingly, Marks [5
] assumes that all these relationships are significant and positive (except for restrictive eating and high-energy consumption). However, we can find studies both confirming these assumptions [32
], and contradicting them or showing that the relationship among the variables is weak [38
]. Still, other studies indicate the need to include moderators and mediators (e.g., sex, stress, size of image on food packaging targeting children) of the relationships we analyze [40
It should be noted here that almost all relationships between high-energy consumption and other variables are non-significant. Consideration should therefore be given to conducting a future study using a different questionnaire that will more validly and reliably assess high-energy consumption (more information is provided in the paragraph on limitations). Moreover, many of the studies presented in this article have been conducted in the adult population (and not among children and adolescents). Therefore, caution should be exercised in drawing conclusions. Future research can help clarify current inconsistencies in the literature.
Given the high costs of obesity and comorbidities in terms of healthcare expenditure, prevention strategies are much needed [43
]. When planning actions, keep in mind that childhood obesity is a complex issue [4
]. Interestingly, one of the reports of the World Health Organization on obesity among Polish children indicates the need to carry out activities directed at improving the mental functioning of obese children [4
]. Therefore, for the effectiveness of such activities to be as high as possible, it is necessary to integrate knowledge from many disciplines (including medicine, dietetics, physiotherapy, psychology) [4
To eliminate the impact of a subjective assessment of obesity, children and adolescents with a diagnosis of obesity confirmed by a doctor and/or dietitian participated in the study. First empirical verification of the relations assumed in the Homeostatic Theory of Obesity, an evaluation of obesity as a complex issue and knowledge that can be helpful in a multidisciplinary approach to obesity are the strong points of this study.
Our study has some limitations that should be taken into consideration in interpreting outcomes and planning further studies. First, due to the cross-sectional design of the study, causality cannot be inferred, and longitudinal studies are required. Second, the size of the sample in the present study (based on the standards for structural equation modelling; [24
]) is relatively small. Third, our analysis assesses only a selected fragment of relations assumed in the Homeostatic Theory of Obesity (the Circle of Discontent) together with an assessment of the relationship to restrained and uncontrolled eating among children and adolescents. Fourth, the study does not include emotional eating, which, as it turned out, could be important for interpreting the relationship between negative affect and restrictive eating. Therefore, we plan (in the third stage of our research, no. 2017/25/N/HS6/00004) to evaluate all relationships between the variables described in the Homeostatic Theory of Obesity, taking into account both the new relationships presented in this study and a much larger number of participants as well as incorporating emotional eating into the model. Fifth, we used a measure of high-energy consumption based on a single item about the frequency of eating high-calorie snacks during the day. In the future, a valid and reliable questionnaire (e.g., Food Frequency Questionnaire) may be used. This will provide information on the frequency and/or portion size of different types of food and beverages (typically over the past month or year). Sixth and last, because in our study BMI was calculated based on self-reported data, it would be worth applying an objective assessment of weight and height to all participants using bioelectrical impedance analysis to estimate body composition.
Most of the relationships established in the Circle of Discontent, as well as relationships of restrained and uncontrolled eating with variables described in the circle, are confirmed among children and adolescents. The following relationships are significant and consistent with our assumptions: (a) positive relationships: (1) obesity and body dissatisfaction, (2) obesity and uncontrolled eating, (3) obesity and restrictive eating, (4) body dissatisfaction and negative affect, (5) body dissatisfaction and restrictive eating, (6) negative affect and restrictive eating, (7) uncontrolled eating and high-energy consumption; and (b) negative relationship: (1) uncontrolled eating and restrictive eating. As suggested in the Discussion and Limitations sections, the main findings of our research and all limitations should be included in the next stages of the study.
Based on our research, we might create prevention strategies and psychological interventions that involve: (a) decreasing body dissatisfaction; (b) reducing high-energy consumption and maladaptive eating styles (uncontrolled and/or restrictive eating); (c) decreasing negative emotions and increasing adaptive emotional regulation. This information can be combined with knowledge already available in the fields of medicine, dietetics and related disciplines. In the light of these and other findings, there can be little doubt that the addition of psychological components to interventions would lead to improvements in the functioning of children and adolescents with obesity. These proposed interventions can help to slow the obesity epidemic.
The mechanism of obesity development is still being explored [1
]. A biopsychosocial approach is based on the belief that the causes of obesity are attributable to genetic, nutritional and environmental factors [4
]. Our and previous research shows that an increased body mass index can also be associated with psychological factors (e.g., increased body dissatisfaction, restrictive eating and uncontrolled eating) [6
]. The above-mentioned factors often form a vicious circle that hinders effective behavioral control and weight loss [4
]. It is therefore necessary to create prevention strategies and psychological interventions that take this information into account.