Grant: Master's Award: Canada Graduate Scholarships

Obesity rates are at a record high in Canada and continue to escalate. Currently, an estimated one in four Canadian adults are obese and there is an urgent need to address the factors contributing to this epidemic. A recent study found that chronic stress is associated with a heightened risk of obesity among Canadian adults, and stress-induced eating is one of the key factors contributing to this relationship. A recent national survey in the United States found that 43% of individuals report using food to cope with stress.4 Stress-induced eating typically involves indulging in highly palatable or “comfort foods”, which are typically high in sugar and fat. Previous laboratory studies have found that acute stressors can increase subsequent indulgence in “comfort foods”, or eating in the absence of hunger, and this relationship is especially true for women and individuals with a history of dietary restraint. There is a large body of literature demonstrating the stress-buffering effects of social support. In addition to actual received support, perceived availability of support has been found to reduce psychological and physiological reactivity to stress. For example, simply writing about supportive ties can reduce blood pressure and heart rate in response to a stressful task. However, surprisingly very little attention has been paid to considering support from others as a potential moderator of stress-induced eating, and no existing studies in the literature have tested the extent to which social support following an acute laboratory stress task may influence subsequent eating behaviour. The proposed research has two objectives: (1) to examine whether individuals who receive support or who merely think about their support system after an acute stress task are less likely to engage in stress-induced eating compared to a control group, and (2) to determine whether individuals who are generally higher perceived support are less likely to engage in stress-induced eating in the first place. The study will use the well-validated Trier Social Stress Test (TSST), which involves giving a 5-minute speech and completing a 5-minute counting task in front of an audience. This test has been used in a number of previous studies examining stress and eating behaviour. Participants will be randomly assigned to one of three conditions: (1) TSST followed by social support from a close friend, (2) TSST followed by mental activation of social ties (writing about a supportive relationship), or (3) TSST followed by watching a neutral film (control group). Next, participants will be left alone to complete follow-up paperwork and will be encouraged to help themselves to a variety of available snacks, including comfort food, unaware that their food intake will be measured. It is hypothesized that individuals who are high in perceived support will consume less comfort food, across all three conditions, and that individuals in the support conditions will consume less comfort food than individuals in the control group. The findings from this project have the potential to inform future interventions for individuals who exhibit stress-induced eating behaviour. In particular, results may indicate the benefits of seeking social support or simply activating perceptions of support in response to stress, as this support may buffer the desire to indulge in unhealthy food choices. An improved understanding of the intricate relationship between stress and eating behaviour will ultimately contribute to combating current trends in obesity and associated diseases such as heart disease, diabetes, cancer, and stroke.