Thus, mildly challenging stimuli limited in duration can be “good stress” or “eustress” and may increase motivation to achieve goal-direct outcomes and homeostasis – this can result in a sense of mastery and accomplishment, and can be perceived as positive and exciting 15. Acute stress activates adaptive responses, but prolonged stress leads to “wear-and-tear” (allostatic load) of the regulatory systems, resulting in biological alterations that weaken stress-related adaptive processes and increase disease susceptibility 14.

In addition, regular and binge use of addictive substances may serve as pharmacological stressors. Stress experiences can be emotionally (e.g., interpersonal conflict, loss of loved ones, unemployment) or physiologically (e.g., food deprivation, illness, drug withdrawal states) challenging. The term “stress” refers to processes involving perception, appraisal, and response to noxious events or stimuli 13. However, few studies have reviewed links between stress and food intake, particularly of hyperpalable or “comfort” foods that may be consumed to reduce stress. Stress has long been considered a critical risk factor in the development of addictive disorders and relapse to addictive behaviors 11, 12. One conceptualization supported by recent research in the addiction and nutrition fields is that foods, particularly highly palatable and energy-dense ones, may be “addictive” in ways similar to drugs of abuse 9 these findings have consequently led to the conceptualization of ‘foods as drugs’ 10. The difficulty in treating and decreasing the prevalence of obesity may reflect the heterogeneity of obesity as a condition. There have been multiple and diverse attempts to provide mechanisms for individuals to lose weight and maintain a healthy body weight however, most have failed to sustain lasting effects, with patients often regaining their lost weight within 5 years 6- 8. Obesity represents an important risk factor for potentially life-threatening health problems including cardiovascular diseases, type II diabetes, osteoarthritis, and certain cancers 3- 5. Globally, estimates from 2008 suggest that 1.4 billion adults globally were overweight (BMI ≥25 kg/m 2), and that at least 200 million men and 300 million women were obese 1. In the United States, 35.7% of adults are obese (body mass index ≥30 kg/m 2) 2.

Understanding the associations and interactions between stress, neurobiological adaptations, and obesity is important in the development of effective prevention and treatment strategies for obesity and related metabolic diseases.ĭefined as “abnormal or excessive fat accumulation that may impair health” 1, obesity is a condition that is increasingly common. Individual differences in susceptibility to obesity and types of stressors may further moderate this process. Together, these may synergistically potentiate reward sensitivity, food preference, and the wanting and seeking of hyperpalatable foods, as well as induce metabolic changes that promote weight and body fat mass. At a neurocircuitry level, chronic stress may affect the mesolimbic dopaminergic system and other brain regions involved in stress/motivation circuits.

This association may be mediated by alterations in the hypothalamic-pituitary-adrenal (HPA) axis, glucose metabolism, insulin sensitivity, and other appetite-related hormones and hypothalamic neuropeptides. Uncontrollable stress changes eating patterns and the salience and consumption of hyperpalatable foods over time, this could lead to changes in allostatic load and trigger neurobiological adaptations that promote increasingly compulsively behavior. Stress is an important factor in the development of addiction and in addiction relapse, and may contribute to an increased risk for obesity and other metabolic diseases. One conceptualization gaining media and research attention in recent years is that foods, particularly hyperpalatable (e.g., high-fat, high sugar) ones, may possess addictive qualities. Obesity is a heterogeneous construct that, despite multiple and diverse attempts, has been difficult to treat.

Hedonic glands