By Ellen Feldman, MD
Altru Health System, Grand Forks, ND
- Three main lines of research regarding emotional eating were reviewed: emotional eating as a response to depression; emotional eating associated with shortened night-sleep duration; and genetic factors linked to emotional eating.
- Results suggest that a focus on emotional regulation, sleep improvement, and physical activity may assist with decreasing emotional eating (and subsequently decreasing obesity).
- Genetic studies suggest that there are biological factors affecting vulnerability to emotional eating.
SYNOPSIS: This review of research regarding the link between emotional eating (eating in response to unpleasant emotions) and obesity in adults suggested several factors that contribute to emotional eating and methods for patients to reduce it.
SOURCE: Konttinen H. Emotional eating and obesity in adults: The role of depression, sleep, and genes. Proc Nutr Soc 2020;79:283-289.
Definition of obesity: An abnormal accumulation of body fat to the extent that it may have an effect on health and body mass index (BMI) ≥ 30 kg/m².1 The World Health Organization (WHO) recognized obesity as a disease state in the mid-1900s. By 2000, with the number of obese patients growing worldwide, the WHO recognized obesity as disease of epidemic proportion.2
The prevention and control of obesity is a challenge on multiple levels, starting with an individual, then family and community systems, and, finally, to public health. Medical implications of obesity are far-reaching and include an increased risk of type 2 diabetes, higher vulnerability to specific cancers, development of metabolic syndrome and cardiovascular diseases, gallbladder disease, osteoarthritic conditions, and some pulmonary disorders.2,3
However, even with widespread recognition of the medical consequences of obesity, its prevalence continues to grow worldwide, with rates tripling from 1975 until 2016. WHO statistics from 2016 note a 13% rate of obesity among adults worldwide. Among children, this trend is even more alarming, with a rise from 4% obesity worldwide in 1975 to slightly more than 18% in 2016.4
“Malnutrition in an Obese World,” the 13th European nutritional conference, took place in Dublin in late 2019. At this meeting of nutrition researchers and clinicians, Konttinen presented a review of findings and clinical implications of emotional eating and obesity in adults. Current research investigating emotions and eating have revealed a complex interaction between the experience of emotions and the intake of food. It is clear that some high-intensity emotional states (fear, for example) are linked to physiologic states that reduce eating behaviors.
On the other hand, other emotions are linked to either increased or decreased eating. The pattern of increased eating of high-caloric, high-sugar/fat foods (“energy-dense, highly palatable foods”) in response to negative emotions, such as sadness, disappointment, or anger, is termed “emotional eating.” In most studies, emotional eating has shown an association with weight gain, higher BMI, and higher percentage of body fat.5
Understanding the characteristics of individuals who are more prone to emotional eating, and looking at clinical interventions to modify this behavior, drives much of the research in this field. In this comprehensive review article, Konttinen noted that the research has centered around three general areas in relation to emotional eating: depression, shortened night-sleep duration, and vulnerability.
EMOTIONAL EATING AND DEPRESSION
A change in appetite is a prominent symptom in depression, as noted in the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition description of symptoms of major depressive disorder: “… weight loss when not dieting or weight gain …” and a “… decrease or increase in appetite nearly every day.”6 Konttinen cites studies identifying emotional eating as one factor linking depression to weight gain. One Dutch study associated emotional eating with weight gain independent of depressive symptoms, and a large study following depressed adults for seven years in Finland indicated that the mediator of increased BMI and waist circumference was emotional eating.
A U.S. study with an 18-year follow-up indicated that the association of emotional eating and depression is likely bidirectional. That is, emotional eating is implicated as a factor on the pathway to obesity and subsequent depression as well as on the pathway to develop obesity from preexisting depression. There are some limited data that exercise, or physical activity, can reduce emotional eating in response to stressful emotions.7 For studies looking at physical activity, emotional eating in individuals with a diagnosis of depression may be the next step in this field of research.
SHORTENED SLEEP DURATION AND EMOTIONAL EATING
Shortened night-sleep duration is loosely defined here as a “habitual sleep time of six hours or less.” Three studies are cited as lending evidence of an association between emotional eating and weight gain. A two-year Dutch study found that women with a combination of high emotional eating and short sleep duration had the highest BMI increase. The large seven-year Finnish study in depressed adults noted that sleep durations of more than nine hours nightly seemed protective against the higher BMI and waist circumference found in emotional eaters who slept seven hours or fewer. Finally, a six-year French-Canadian study narrowed the association of short sleep duration and emotional eating with obesity by looking at the level of inhibition. In this study, disinhibited eating refers to an inherent tendency to overeat. Results of this study indicated that the combination of short sleep with high food disinhibition led to an association with weight gain and increased waist circumference.
GENETIC FACTORS AND OBESITY
Genetic factors influencing obesity have been investigated via twin studies looking at variations in BMI. In one large study (140,000 subjects), the contribution of genes to BMI appeared to change with age but have a substantial contribution (from 60% to 80%). Current investigations have centered on genetic influences on underlying eating behaviors.
Four studies are cited — two from Finland, and one each from France and the United Kingdom — where there appears to be an association between genetic risk of obesity and emotional eating. In these studies, there seem to be at least a partial mediating effect from emotional eating on the development of obesity in individuals with genetic risk. Several North American studies suggested similar findings, but the association was not as strong. Studies that looked at behaviors other than eating habits pointed to physical activity levels and noted the increased genetic susceptibility to obesity in less physically active individuals (vs. more active individuals). It appears there may be genetic influences on obesity that involve not only eating behaviors but also other factors, including level of physical activity. The interplay between all of these factors may be the key to understanding this complex relationship.
It is important to note all of these relationships are associations, and causation cannot be assumed or
extrapolated. For example, Kontitinen notes that it while it may be that obesity develops in part because of emotional eating, reverse causation also should be considered. That is, a gain in body fat may directly or indirectly cause a change in hunger sensations and lead to a deficit in control of eating.
Although many questions remain unanswered in the realm of emotional eating and obesity, it is clear that our current understanding can be transformed into meaningful clinical interventions.
- Ask patients with depression and weight gain about emotional eating. Consider recommending therapies that address emotional regulation to address the tolerance of difficult emotions (e.g., mindfulness interventions).8
- In patients with unwanted weight gain, ask about length of sleep and any connection to emotional eating. Consider interventions that target improved nighttime sleep duration.
- Acknowledge that genetic factors will play a role in weight gain and, potentially, in emotional eating. With this knowledge, patients may want to take steps to limit the availability or easy access to high-caloric, high-sugar/high-fat foods.9
Notably, these specific interventions are extrapolations from the current research and have not been subject to rigorous, well-controlled investigations. However, even if weight is not affected significantly, the potential health benefits of improved emotional regulation and longer nighttime sleep are numerous, and the risks are limited, at best.
The most practical take-home message from this study for the primary care provider may be that, when working with patients with weight gain concerns, think about eating and sleep patterns, adopt a nonjudgmental stance, and ask patients opened-ended questions about emotional eating. Although some patients may be reluctant to mention this eating pattern spontaneously, appropriate queries from a trusted provider can be helpful in understanding a fuller picture and creating a meaningful wellness plan.
- World Health Organization. Obesity. https://www.who.int/health-topics/obesity#tab=tab_1
- [No authors listed]. Obesity: Preventing and managing the global epidemic. Report of a WHO consultation. World Health Organ Tech Rep Ser 2000;894:i-xii, 1-253.
- Park A. Pathophysiology and aetiology and medical consequences of obesity. Medicine 2019;47:169-174.
- World Health Organization. Obesity and overweight. Updated June 9, 2021. https://www.who.int/news-room/fact-sheets/detail/obesity-and-overweight
- Konttinen H, van Strien T, Männistö C, et al. Depression, emotional eating and long-term weight changes: A population-based prospective study. Int J Behav Nutr Phys Act 2019;16:28.
- Halverson JL. What are the DSM-5 criteria for diagnosis of major depressive disorder (clinical depression)? Updated Oct. 7, 2019. https://www.medscape.com/answers/286759-14692/what-are-the-dsm-5-criteria-for-diagnosis-of-major-depressive-disorder-clinical-depression
- Leow S, Jackson B, Alderson JA, et al. A role for exercise in attenuating unhealthy food consumption in response to stress. Nutrients 2018;10:176.
- Mason AE, Epel ES, Aschbacher K, et al. Reduced reward-driven eating accounts for the impact of a mindfulness-based diet and exercise intervention on weight loss: Data from the SHINE randomized controlled trial. Appetite 2016;100:86-93.
- Centers for Disease Control and Prevention. Improving your eating habits. Updated Aug. 17, 2020. https://www.cdc.gov/healthyweight/losing_weight/eating_habits.html