A Review of the Literature Relationship between Psychological Eating Patterns and the Risk of Type 2 Diabetes Mellitus and Metabolic Syndrome

Abstract

Mental health today includes much more than the treatment of psychiatric disorders. More and more interventions aim to bring mental health support closer to people and psychotherapeutic interventions to people with somatic conditions. Since the treatment of people with metabolic syndrome and diabetes mellitus type 2 also requires a change in lifestyle, mental health has a prominent role. This overview paper wants to offer a solution after recognizing the given patterns where psychotherapy certainly has a significant and irreplaceable role. Precisely because of this phenomenon, psychological eating patterns associated with diabetes mellitus and hence metabolic syndrome should be studied, and attempts should be made to uncover patterns in occurrence. The aim of this study is to review the literature and consider the connection among diabetes mellitus, metabolic syndrome, and psychological eating patterns such as emotional and compulsive eating, as well as through the lens of food addiction. Furthermore, we have attempted to uncover the role of psychiatry and psychotherapy in the treatment of diabetes mellitus and metabolic syndrome and delve into the complexity of recognizing these patterns and emphasize the importance of a multidisciplinary approach in the treatment of diabetes mellitus and metabolic syndrome.

1. Introduction

Nearly 80% of psychological eating patterns go undetected which is why it is crucial to better understand them as they can be connected to various other serious medical conditions, such are diabetes mellitus (DM), obesity, and metabolic syndrome (MetS) [1,2]. What is even more problematic is that often people are unaware of the psychological eating patterns, or they are unwilling to accept it, which results in poorer treatment outcomes. Instant solutions rarely lead to good treatment outcomes. Embracing balanced nutrition, considering both physical and mental well-being, is essential. Seeking guidance from healthcare professionals ensures a respectful approach to nutrition, just like how taking control over blood glucose in diabetes can certainly improve treatment outcomes in people with DM and MetS [3,4,5]. Therefore, knowledge about psychological eating patterns could be very helpful for both doctors and patients. One of the first warning signs would be food preoccupation which can offer insights into individuals’ complex relationships with food, hinting at pathological psychological eating patterns. Since obesity is one of the most prevalent risk factors for type 2 diabetes mellitus and serious cardiovascular diseases, it remains one of the biggest public healthcare concerns of our time. Today, we recognize that obesity is but one hallmark of a more complex clinical entity—metabolic syndrome (MetS). MetS is defined as a cluster of abdominal obesity, high blood pressure, high blood sugar, high serum triglycerides, and low serum HDL. Thus, while it is clear that obesity itself represents a significant risk to an individual’s health, the psychological factors that might contribute to it or be significant in these conditions remain less known, recognizable, and universal [6,7,8]. Exploring the psychological mechanisms that induce eating disorders like compulsive overeating or why some patients prefer unhealthy dietary choices while in heightened emotional states might present a new perspective and possibly lead to novel treatment pathways in these patients. In this review, we will examine the current literature on different eating patterns and how these might impact individuals with metabolic syndrome as well as psychiatric patients and ways that psychotherapists may approach treatment in these patients.

2. Materials and Methods

This narrative review aims to examine eating patterns and their association with metabolic syndrome, which is a significant health issue today. To this goal, five authors (F.M., T.G., M.Š., E.P., T.P.) independently identified articles they deemed relevant in this field, which were then collectively reviewed and categorized into thematic units outlined in this article, aiming for a more relevant and contemporary approach to the subtitle’s theme. The analyzed articles were in English, dominantly from the Pubmed/Medline and Google Scholar databases in the period from 2015 onwards, except for papers that were even older, but represent a significant turning point in the profession, as well as capital papers that were still some of the main ones in the field of psychotherapy. The keywords we used were as follows: eating patterns, emotional eating, dietary patterns, binge-eating, metabolic syndrome, diabetes mellitus type 2, obesity, and psychotherapy. Following consultations, primarily via telephone, we extracted and structured the results of studies we considered pivotal into a narrative review format to present them in a more readable and understandable manner.

3. The Risk of Type 2 Diabetes Mellitus, Metabolic Syndrome, and Psychological Eating Patterns

3.1. The Connection between Risk and Drive—Sleep and Diet

This interconnection still represents a great challenge, but several types of eating patterns, behaviors, and trends have been researched and looked into to discern common links between them and the development of DM and MetS. Chronically high levels of insulin and insulin resistance, which is more prevalent in obese individuals [9], can impair insulin’s ability to suppress motivational pathways, resulting in higher levels of stress. Individuals in negative affective states have been shown to favor the consumption of hedonically rewarding foods high in sugar and/or fat, whereas intake during happy states favors less palatable dried fruits” [10,11]. Sleep deprivation may contribute to higher levels of stress which puts people at a higher risk of developing metabolic conditions, a bigger abdominal circumference, insulin resistance, and higher blood pressure, which are all closely related to cardiovascular conditions and type II diabetes mellitus [12,13].

Certain diets are associated with a higher risk of developing MetS, including dietary patterns that include meals which are low in fiber but high in calories, cholesterol, saturated fats, sodium, and simple carbohydrates [7,8]. There are studies that observed the effects of skipping meals on the development of certain risk factors associated with the development of MetS [14]. The studies which some authors cite found that the modern lifestyle leads to people skipping meals more often [15,16], the meal most often skipped being breakfast, followed by lunch and dinner [17]. Skipping breakfast is particularly linked to a higher body weight and a higher insulin resistance [18,19]. There are parallels between skipping breakfast and a higher BMI and waist circumference, which are all risk factors associated with MetS [20,21]. The studies also concluded that people who eat multiple meals a day had a lower obesity rate than people who ate fewer than three meals a day. Some authors stated that some studies established a correlation between eating more than six or less than three meals a day and fasting plasma glucose levels [3], but another study found that there is no correlation [4], so this remains unclear. Erratic eating patterns like eating over a longer period per day and eating more than just three meals a day are widespread [5,22,23,24,25,26,27] and are associated with obesity, T2DM, MetS, and CVD [28,29,30,31]. Some studies also found that misalignment between daily rhythms of food consumption and the circadian timing system can contribute to circadian rhythm disruption which results in abnormal metabolic regulation, the disruption of metabolic homeostasis, and increased cardio-metabolic risks [32,33,34,35,36]. These studies presumed that time-restrictive eating (TRE) would help patients with metabolic disorders restore the normality of their circadian rhythms which would positively affect the regulation of their metabolism. The studies they cite concluded that metabolism operates at a higher and more efficient rate in the morning rather than later in the day [33,35,37,38] and that favoring higher energy intakes in the morning and keeping them low in the evening might help with losing weight and keeping glucose and lipid levels in check [39,40]. Although some review articles indicated that TRE strategies might be helpful in addressing cardio-metabolic disorders [28,33,37,41,42,43,44,45], a lot of the cited studies were not conducted on patients with MetS, and some conclusions cannot be made. There is a study that was conducted on animals [10,46,47] and humans [48,49,50] which bore no correlation between stress and the amount of food consumed, because some subjects became hypophagic, while others became hyperphagic. They suspected that this was due to different types of stressors and the duration of the stressful period. Another study suspected that lower amounts of stress induced hyperphagia, while bigger stressors induced hypophagia [51]. They also stated that under stressful situations, animals prefer foods that are high in saturated fats and rich in sugars [52,53,54], while humans prefer hyperpalatable, calorie-rich foods [55,56,57] even though there was no metabolic need for higher energy intake [58]. This effect might be more pronounced in obese individuals [50,59]. Repeated, uncontrolled, and prolonged stress can dysregulate the hypothalamic–pituitary–adrenal (HPA) axis, which is responsible for secreting glucocorticoids such as cortisol, thus influencing energy homeostasis and eating behavior.

3.2. Hormonal Basis of Relationship between Diet and Reward in MetS and Obesity

The chronic activation of the HPA axis has an effect on glucose metabolism, promoting insulin resistance and altering some appetite-related hormones [9]. The prolonged secretion of glucocorticoids promotes fat accumulation in the abdominal region which is one of the risk factors for MetS. Those under chronic stress eat hyperpalatable, energy-dense, high-fat foods more often during acute stress episodes [60]. HPA activation is linked with the activation of the reward system. A diet rich in high-fat foods sensitizes the reward system which can promote cravings and a higher intake of said foods [61]. The continued stimulation of these reward pathways progressively promotes more compulsive behavior [62]. Obese individuals have shown a stronger activation of the reward system when exposed to food while under stress compared to lean individuals [59]. Animal models demonstrated that obesity often has an effect on adipose receptors [63] which are important for the negative feedback loop and the cessation of eating. People with higher BMI scores have an increased probability of weight gain while under chronic stress compared to individuals under the same amount of stress but who have lower BMI scores [50]. Yoshida et al. [21] found that there is a significant correlation between both individuals who eat snacks after dinner and those who eat dinner before bed and a higher BMI score, higher LDL cholesterol, and abdominal circumference, while those who exhibit both behaviors have an even higher chance of presenting with the same afflictions. In some patients with MetS, we find comorbid binge eating disorder, where a person has the urge to consume enormous amounts of food at once just to satisfy an unbearable need rooted in the experience of stress and anxiety that overwhelms the person. After such binge eating episodes, patients feel temporary relief and a reduction in stress, which over time may become a compulsive pattern of behavior. This form of release represents a kind of acting out, after which an aggressive impulse is discharged, which shows that personality traits like impulsivity can also play a significant role in pathological eating patterns. Considering a person’s circadian rhythm and the tendency of individuals prone to anxiety and depressive moods to be more overwhelmed with negative thoughts and feelings towards the end of the day, just before usual bedtime, it is not surprising that this phenomenon is often found in a modified form known as night eating syndrome [64]. These eating patterns play a significant role in the lives of these individuals, contributing to weight gain and obesity. Furthermore, Yoshida et al. [21] studied night eating habits and found that they are associated with dyslipidemia in both men and women. Therefore, besides addressing internal medical conditions, mental health plays an extremely important role and should be central to health. In accordance with this, treatment interventions should focus on improving the mental health of individuals with metabolic syndrome, especially those linked with compulsive overeating, as this is currently undervalued in the treatment of these patients. Thus, treatment should encompass complex psychopharmacological and non-pharmacological/psychotherapeutic interventions. Some possible pharmacological approaches include antidepressants, particularly selective serotonin reuptake inhibitors, and newer psychopharmaceuticals like Lisdexamphetamine [64].

4. Adopting Healthier Psychological Eating Patterns as Part of Treatment of Diabetes Mellitus and Metabolic Syndrome

4.1. Better Mental Health and a Healthier Lifestyle as the Root Cause of Changes in MetS and DM Type 2

The definition of MetS includes a cluster of factors such as abdominal obesity, insulin resistance, dyslipidemia, and elevated blood pressure [65]. Considering MetS a complication of obesity, losing body weight is crucial in reducing the risk of obesity-related diseases [66]. According to one study, obesity is seen as a multi-factorial disease where lifestyle traits are the most important pathogenic factors, as well as a combination of genetic, epigenetic, biological, and psychological factors that cause weight gain and disable the reduction in and retention of a healthy body weight [67]. First of all, when thinking in terms of psychiatric medications, the clinical use of psychopharmacological agents necessitates the recognition, monitoring, and management of potential adverse metabolic impacts. Switching to medications with a reduced risk of weight gain and associated metabolic issues is recommended [68]. An elevated incidence of MetS has been noticed in some groups of psychiatric patients. As de Almeida et al. [69] stressed, patients with bipolar disorder have higher rates of MetS. Other than the adverse effects of psychotropic drugs, unhealthy lifestyle choices, shared neuroendocrine and immunoinflammatory disorders, and genetic predispositions are also contributing factors. A significant neuroendocrine anomaly, the hyperactivity of the hypothalamic–pituitary–adrenal axis, predominantly associated with major depression, is implicated in the neurobiological mechanisms governing the switch processes in bipolar disorder. Moreira et al. [70] found that subjects with depression and anhedonia exhibit elevated levels of glucose, triglycerides, total cholesterol, and LDL cholesterol, alongside reductions in HDL cholesterol levels, which indicates a higher prevalence of MetS among those individuals. As suggested by Räikkönen et al. [71], psychosocial factors are predictive of the risk for developing MetS across various definitions, suggesting a potential causal role in the etiological pathway leading to MetS. Women experiencing high levels of depressive symptoms coupled with significant stressful life events at the outset of a longitudinal study demonstrated an elevated risk for developing MetS over an average follow-up period of 15 years. According to Pigsborg et al. [72], the success of weight loss interventions is influenced not only by genetics and biological processes but also by psychological and behavioral constructs. Factors related to eating behavior, societal norms, and personal psychological aspects like motivation, self-efficacy, locus of control, and self-concept play significant roles, as well as major life events [72,73,74]. Curis et al. [74] emphasized that the ingestion of food not only fulfills the basic need for nutrient and energy intake but also serves as a source of pleasure. Emotional instability is frequently linked to unhealthy behaviors and irrational cognitions regarding eating habits often resulting in a cascade which leads to obesity [67,74]. According to Conti et al., alexithymia, a personality trait with difficulties in recognizing and processing emotions, may also contribute to the development of MetS through binge eating and psychological distress [67,75]. Conti et al. [75] found that individuals with MetS are older, have a higher body mass index, have had obesity for a longer duration, and scored higher on scales measuring alexithymia like TAS-20, suggesting that binge eating might play a mediating role between alexithymia and metabolic syndrome.

4.2. Emotional Regulation and Psychotherapy as Significant Aids in Treatment

In our previous research, we investigated the association between alexithymia, obesity, and diabetes mellitus type 2. The paper demonstrated that recognizing and raising awareness of alexithymia, along with psychotherapy, particularly of a psychodynamic nature, could have a significant impact on improving the quality of an individual’s relationships and insight into their own personality. Consequently, this may have repercussions for better diabetes mellitus control. Similarly, in the case of metabolic syndrome, it is expected that better insight and recognition of certain intrapsychic phenomena will positively affect cooperation in the treatment process [76]. Camacho-Barcia et al. [77] suggested that the excessive consumption of energy-dense foods is driven by heightened food reward sensitivity, problems with self-control, or emotional states. Implementing individual-specific psychological strategies is crucial for ensuring and sustaining weight loss. High reward sensitivity, preference for unhealthy foods, and overeating in patients with binge eating disorder and obesity underscore the need for interventions that strengthen self-control and conscientiousness, as well as developing emotion regulation skills. Furthermore, non-invasive deep magnetic brain stimulation has shown promise in reducing impulse-related behaviors linked to obesity. Mindfulness-based interventions have demonstrated positive outcomes in treating obesity by altering eating behaviors leading to mindful eating [77,78]. According to many studies, cognitive behavioral weight management treatment leads to improvements in measures of self-regulation, self-efficacy, and mood with the development of abilities to redirect attention and the management of the physiological consequences of emotions [77,79,80,81,82]. As Slabá et al. [80] mentioned, the most common character traits of obese patients predominantly include neuroticism, which manifests as anxiety, depression, impulsiveness, anger, and hostility. Marčinko et al. stressed the significant role of the spectrum of the “master emotion” of shame, as well as the importance of psychodynamic psychotherapy in the management of obesity [80,83]. Other studies recommend different psychotherapeutic approaches, such as existential therapy [80] and acceptance and commitment therapy which was found to be effective in improving weight loss in terms of BMI, psychological flexibility, and weight-related stigma [84]. In summary, the interplay of psychological, emotional, and lifestyle factors plays a significant role in the etiology and management of obesity and MetS, emphasizing the need for integrated and multifaceted therapeutic approaches [85].

Emotionally, shifts in body weight exacerbate self-esteem and body image concerns. Distorted body image perceptions, societal pressures, and underlying emotional issues drive the desire for rapid weight changes. Such fluctuations can lead to nutritional deficiencies, weakened immunity, and cardiovascular problems with rapid weight loss, while weight gain may result in metabolic issues and chronic illnesses. Achieving lasting recovery entails addressing body image and self-esteem issues alongside physical healing. Cultivating self-acceptance and self-love is crucial in this journey, supported by empathy and understanding. It is a holistic approach that fosters enduring healing by acknowledging and confronting the root causes of negative body image. The pursuit of control, which usually manifests as a constant preoccupation with food, weight, and appearance, serves as a coping mechanism in times of stress and anxiety, intertwining self-esteem with body image. Another thing to consider is the fact that studies have shown that about 50% of preadolescent girls and 30% of preadolescent boys dislike their body which shows the severity of this issue [86,87]. These behaviors disrupt daily life, elevating stress levels and affecting decision-making. This focus can strain social interactions and contribute to feelings of isolation. Other warning signs include frequent body checking, comparison with others, seeking affirmation, clothing insecurity, avoidance of social situations, and negative self-talk. Effective treatment requires a multidimensional approach, including therapy and support groups, to address underlying emotional and psychological factors. These interventions foster healthier relationships with food, body image, and self-esteem. Another important aspect to consider is the individuals’ relationship with exercising. Balancing a healthy fitness routine with potential obsession is challenging. A growth-positive routine involves regular exercise for physical and mental well-being, with flexibility and joy in activities. Recognizing this balance requires understanding emotional and psychological factors. Guiding towards a balanced approach, incorporating rest and diverse activities, and nurturing positive body image are crucial for a healthy fitness routine as well as the regular control of blood glucose in the case of DM.

5. The Limitations of the Current Literature and Future Considerations

This review of the literature is predominantly narrative, although the authors have tried to select studies that they consider relevant in the field. However, this literature review was not conducted in a systematic way. Therefore, some future reviews in this area that would look at variables in a systematic way, as well as a meta-analysis of these variables, would certainly be welcome. On the other hand, psychotherapeutic phenomena are more difficult to quantify and measure than some other variables, but this does not mean that psychotherapeutic support and psychotherapeutic techniques do not have an important role in clinical work with patients. The way in which this can be examined is by providing psychotherapeutic support and comparing patients who had psychotherapeutic support with those patients who did not have it, that is, who were treated with treatment as usual, which is still dominantly present due to the stigma against psychological interventions, but today, however, it is less present than before.

6. Conclusions

It is necessary to examine the complexity of the disorder itself and with an understanding of psychological eating patterns and to be aware of these phenomena in people with DM and MetS. The complex dynamic among control of blood sugar, psychological eating patterns, pathologic behaviors, and the development of DM and MetS highlights the critical need for a holistic approach to managing this condition. While the consumption of food high in calories, cholesterol, saturated fats, and carbohydrates has been linked to a higher risk of DM and MetS, this is exacerbated by meal skipping, contributing to higher body weight and insulin resistance. We highlight the interplay of food intake with circadian rhythms and the potential benefits of time-restricted eating in metabolic regulation. The interplay between psychological well-being and metabolic health is particularly significant. Chronic stress and poor mental health can lead to maladaptive eating behaviors, further compounding the risk of DM and MetS. Effective treatment strategies must therefore include robust mental health support in addition to lifestyle interventions. Addressing emotional issues and implementing psychotherapeutic approaches are essential for the holistic care of MetS. Furthermore, recognizing and addressing unhealthy eating patterns early on are crucial. Warning signs such as extreme dietary restrictions, compulsive exercise, and rapid weight fluctuations should be recognized, and timely interventions should be implemented. Understanding eating patterns enables more effective treatment, addressing root causes and preventing escalation. Awareness helps dismantle the stigma surrounding eating disorders and obesity, encouraging open conversations and improving understanding. Creating a safe environment for individuals to express their struggles fosters empathy and promotes well-being, both mentally and emotionally, extending beyond physical health. In this aspect, psychiatrists and psychotherapists step in as indispensable components in treating patients with DM and MetS, especially in cases where there is suspicion or confirmation of disordered eating patterns. Ultimately, reducing the prevalence and impact of DM and MetS requires a multifaceted approach that integrates medical, psychological, and lifestyle interventions. By prioritizing both physical and mental health, we can better support individuals in achieving sustainable improvements in their overall well-being. Further research is essential to refine these strategies and ensure they are effective for diverse populations, paving the way for a healthier future.