OPINION: At a health psychology conference on Waiheke Island a few years ago, I gave a talk about psychological factors associated with a certain dietary behaviour: why people either consume or abstain from meat and other animal products. I ended the talk with a series of photos of delegates dining during the conference, to invite reflection on their own reasons for eating what they did.
At a recent conference in the same field, hosted in the South Island, the tables were turned. I attended a fantastic food-related talk with a different focus that invited me to reflect on how and what I eat.
I’ve long been a fan of UK-based psychologist Daryl O’Connor’s work, but wasn’t familiar with this particular strand of his research, which focuses on the relationship between stress and “eating styles” in adults and young people.
Hands up if you feel the pull of a bar of chocolate when your days are beset with hassles. Hands up if you eat less healthy food (or, in fact, any food) when you’re feeling stressed. You’re not alone, so don’t allow yourself to be chocolate-shamed – O’Connor and colleagues at Leeds and Cambridge universities have just published a grand mash-up of 54 international studies that shows small but robust decreases in healthy food consumption (vegetables, fruits, etc) when people are stressed, and an increase in eating sugary, fatty snack food.
While many people reduce their food intake when stressed, about a third or more of us increase our consumption.
Regardless of whether you’re the kind of person to eat more or less when stressed, two-thirds of us increase our intake of sugary, fatty foods as our daily hassles go up.
Studies don’t tend to show a consistent gender difference in dietary responses to stress, but where they do find one, it’s usually to show that women are more likely to report stress-related dietary change.
The type of stress also appears important in whether we over- or undereat. O’Connor’s own research shows that troubles that involve interpersonal stress or challenge how we see ourselves appear to trigger greater snacking, whereas physical stressors are more likely to precede decreased eating.
This is a bad combination and at a basic level both these behaviours are affected by a key underlying mechanism – our sympathetic nervous system shutting down less immediately important processes (such as digestion and sexual arousal) to help us beat off immediate threats. Some experts argue that in these situations we’re still attracted to sugary snacks because they represent easily accessible energy for beating off said threat, and also because under stress our brains become more reward-sensitive. Rewards such as yummy food.
O’Connor has a paper coming out in July that addresses a niggle in much of the existing research. He and his colleagues tracked what people ate, their daily hassles, and their levels of cortisol – a hormone that tells the body what to do in the event of a stressor – over two weeks. This is more naturalistic than bringing people into the lab and stressing them out to see if they eat more snacks when the pressure comes off.
This study confirms a lot of what we know from such lab experiments – more daily problems mean more between-meal snacking. People who showed a stronger cortisol reaction and experienced more daily trials snacked more than people with a weaker cortisol response but who reported the same levels of hassle. People who described themselves as emotional eaters also reported more snacking when stressed.
So, if you are someone who reaches for a stress snack, that response is valid. It has a basis in how we’re designed.
But it isn’t inevitable – an ”emotional eating style” is at least partly learned, either because it’s rewarding or has been role-modelled. If this is you, and you feel like it’s a problem well beyond just the occasional chocolate fish, you can always start by visiting your GP.
