Stress and eating behaviour
03 September 2005
You are preparing for an important public speaking engagement; do you reach for the biscuit tin or go right off the whole idea of food? Stress affects people’s eating behaviour in different ways, read on to find out why.
We experience stress when something happens within ourselves, or in our environment, that challenges our status quo. We then employ tactics to deal with the stressor and return to our balanced unstressed state. Stress can be internal like worrying about something or getting upset, or external like taking an exam or dealing with social situations. As stress is an integral part of daily life, how we eat in response to stress can have an impact on our overall diet and health.
Fight or flight
When threatened, the body automatically engages the fight or flight response. A rush of adrenaline drives blood to the brain, heart and muscles and away from the digestive system in preparation to run or to fight. It is believed that we still experience this type of reaction even when the threat or stressor is psychological or emotional rather than physical. This aroused state should make people unable to eat and even make them feel sick (1). But it has been found that for some people stress is a major trigger to eat and that they actually eat more when they are stressed, not less (1), so what is going on?
Dieters tend to eat more under stress
Many people these days are on slimming diets or “watching their weight”. This usually involves controlling the type and amount of food consumed. Dieters must also override their hunger signals in order to eat less than they really want to. In other words they exercise restraint over their eating. People who eat according to their appetite eat in an unrestrained way. Studies have repeatedly shown that restrained eaters tend to eat more in response to stress whereas unrestrained eaters tend to eat less (2), (3).
Stress can lead to binge eating in restrained eaters
Dr Paul Lattimore, an expert on eating behaviour from Liverpool John Moores University, offers an explanation about why dieters eat more under stress. “When people are dieting they spend so much energy controlling their biology, that there are only limited resources left to deal with daily hassles. So when they get stressed they lose control, and if food is available, they will eat it. Not only that but they are so used to overriding their biology that they ignore or misinterpret the body’s fight or flight signals.”
A recent large scale study in Finland found that body mass index (a measure of weight relative to height) was highest in stress-driven eaters and that they tended to eat more foods like sausages, hamburgers, chocolate and pizza, compared to others (4). So if stress related eating is constantly undermining someone’s attempt at weight control, what can be done to help? Dr Lattimore who has been working in obesity prevention, gives some advice. “Firstly the individual must identify which particular situations trigger overeating for them and then they must devise alternative ways to cope with the stress. An ideal strategy would be to go for a walk as this will make us think of something else while using calories too."
People who eat when they are hungry and stop when they are full are tuned in to their biological signals. These are the people who do not feel like eating food when they are stressed. Those people who override their biological signals need to be aware of the emotional and psychological triggers that drive them straight to the fridge - and instigate diversion tactics. Response to stress underlines the importance of approaches to weight control that reduce dietary restraint and emphasize high intakes of low calorie, nutrient-rich fruit and vegetables. These foods have the ability to dilute the calorie load from binge-eating episodes.
- Greeno CG &Wing RR (1994) Stress-induced eating. Psychological Bulletin 115: 444-464
- Lattimore P & Caswell N (2004) Differential effects of active and passive stress on food intake in restrained and unrestrained eaters. Appetite 42: 167-173
- Polivy J and Herman CP (1999) Distress and dieting: why do dieters overeat? International Journal of Eating Disorder 25: 153-164
- Laitinen J & Sovio U (2002) Stress-related eating and drinking behaviour and body mass index and predictors of this behaviour. Preventive Medicine 34: 29-39