Part of this is due to the type of fat. Excessive stomach fat is a sign of visceral fat. Visceral fat differs from other types of fat in that it has greater blood flow and up to four times as many receptors, making the region especially sensitive to the fat accumulating effects of circulating cortisol (a principle stress hormone). In fact, visceral fat responds to circulating cortisol by further increasing in size.

What makes central fat so intriguing to researchers is that they have found a relationship between central fat distribution and adverse psychological states, such as depression and anxiety. In a study entitled Stress and Body Shape, researchers proposed the question, “Does exposure to stress-induced cortisol affect body fat distribution among the general public?” In other words, do women with greater central fat (high WHR) adapt less effectively to repeated stress overtime, both physiologically and psychologically, regardless of Body Mass Index (BMI)?

To conduct this study, 59 healthy women were exposed to three laboratory sessions over 4 consecutive days. In these sessions, cortisol and psychological responses were assessed. The study hypothesized that women with high WHR would demonstrate greater cortisol reactivity (stress response) to a new stressor, would fail to adjust to repeated stressors on subsequent, similar exposures (as evidenced by high cortisol reactivity) and would report psychological traits and stress response indicative of ineffective coping.

Indeed, the sessions demonstrated that lean women with a high WHR showed a lack of adaptation. They secreted higher levels of cortisol when exposed to stressors than lean women with low WHR and similar resting cortisol levels. Furthermore, on the second and third days of testing, when the challenge had become familiar and predictable, women with high WHR continued to show elevated levels of cortisol secretion, demonstrating an inability to habituate to stress triggers.

The next step in the study was to identify whether there were psychological differences in tandem with physical evidence (central body fat distribution) of greater stress. Examining this aspect would verify whether the higher cortisol reactivity of high WHR women was a physical coincidence, simply correlate to greater central fat, or a result of chronic stress. The resulting psychological and cognitive testing responses demonstrated that women with high WHR perceived greater threats, exerted less effort and performed more poorly than those with low WHR. Even at baseline, absent stressors, women with high WHR reported greater chronic stress, higher pessimism, negative affect and passive coping. Women with high WHR reported higher levels of chronic work and financial stress and had lower self-esteem scores.

In conclusion, the study found that central fat distribution is related to greater psychological vulnerability to stress and cortisol reactivity. Lean women with a high WHR may experience greater overall cortisol exposure under stressful conditions due to a greater initial reactivity to stressors and a lack of adaption over time.

A similar study, entitled Mental Distress, Obesity and Body Fat Distribution in Middle-Aged Men examined a group of 1,040 48 year old men with the aim of examining whether psychiatric symptoms are associated with obesity and abdominal distribution of body fat in men, as previous research had suggested was the case for women. The study concluded that high WHR in men -regardless of BMI- is associated with symptoms of depression and anxiety with associated sleep disturbances, as well as psychosomatic symptoms and dissatisfaction. It was hypothesized that the mechanism involved might be increased secretion of cortisol. As in the woman-focused study, WHR showed to be significantly correlated to psychiatric variables, such as a high degree of melancholy and mental depression, both well-known conditions characterized by increased cortisol secretion and a hypersensitive Hypothalamic–Pituitary-Adrenal (HPA) axis (resulting in frequently elevated cortisol secretion). The researchers also speculated that traits of depressive symptoms predispose a person for visceral fat accumulation and a high WHR.

Both studies support the argument for the body shape-stress connection and the need to manage stress levels for a number of life quality and health factors. Relora®, an all-natural dietary supplement, has been strongly supported by the medical community as a supplement that may help to calm the HPA axis while managing stress and potentially alleviating anxiety.