Why is it that certain kinds of stress elicit overeating, and others diminish any kind of appetite at all? I try to answer those questions about stress and food here.
‘Flight UA6773 will now be boarding. Ladies and gentleman, please be Ready to board by gate A2′.
And so it was, heavy hearted and almost empty handed (laptop and a few work clothes aside, that is) that I left Madrid. Let’s skip the parts involving security checks, or the part where I always think I have lost my passport, only to realize that I have in fact, forgotten my phone.
…Everything comes secondary to the sheer sense of delight I experienced when I found my place of aerial paradise. It included: an uncomfortable chair, for 7 odd hours. Not a single TV worked, and that 90 degree angle was not going to budge. Now with this ‘chair’. Deep knee thrombosis crossed my mind, as did the kind of ‘thrombosis’ I’d like to apply to the avian industry at that moment.
It’s at this time, that I’ll bring the story back to our present focus. Eating. I hadn’t eaten since about eleven thirty the night before, and now thirteen hours later, with my blood putting acute pressure on my eyeballs, I realized that making people angry (REALLY ANGRY) might offer an excellent solution to the obesity pandemic.
… Yet, for many anger actually provokes eating. Most kinds of small stressors provoke the kinds of ‘reward driven eating’ about which I write so frequently. Choccies and cheese-curls stimulate opioid and anti-stress systems in the brain, which is why we reach so quickly for them when we encounter frustrating or ‘stressful’ situations.
…But what determines stress? And does all stress provoke reward-based eating? What about the times when we’re under so much stress that we cannot bear the thought of eating? And then, what about those hellish deadlines that can only be accompanied by boxes (upon boxes) of sugar-laden cereal, and maybe toss in a few stacks of rice crackers to boot?
In a recent PowerPoint presentation that I dug up on the Internet by Dr. Leigh Gibson, an excellent scientist I have had the pleasure of meeting, a few illuminating points about stress and food are made:
- Obese Swedes with a strong liking for sweet/fatty foods are more anxious (stress vulnerable) (Elfhag & Erlanson-Albertsson, 2006)
- Stress-reactive female ‘binge eaters’ chose more sweet/savory snacks vs. fruit and veg, when stressed (Goldfield et al., 2008)
The key lies in the words, ‘stress-reactive,’
It turns out, that stress-reactive binge eaters are particularly vulnerable to the effects of irritating life events. Interestingly, in the presence of hassles, these types of eaters are likely to eat three times as much as non-stress-reactive binge eaters. The key here being they are both overeaters: just some react by pushing the limits of their stomachs when hampered by frustrating situations – like no TVs on 9 hour flights.
The perception of the degree of the stress is an interesting philosophical paradox. What I see as stressful (a 9 hour flight without any kind of audio visual distraction) and what you do, are two entirely different entities (you may have cleverly thought to bring a few more books or a fully charged iPod). Also, there is a niggling factor that is the fact that ‘chronic stress’ actually encourages both abdominal obesity and overeating.
How would these be linked?
Poorer cardiovascular recovery from acute stress predicts increased abdominal adiposity over 3 years (Steptoe & Wardle, 2005), thus clarifying the fact that individuals with a few extra pounds around the middle will be more inclined to overeat in the presence of ‘daily hassles’. What’s more is that tummy flab is associated with higher levels of cortisol – the hormone that is released when we are under stress.
And another note on cortisol:
It seems that cortisol predicts daily snack intake in women: the greater the number of daily hassles, and the higher the level of cortisol, the more snacking.
Thus, it would seem we have a chain of events that perpetuate food intake (particularly in those who have extra tummy flab, and/or higher levels of cortisol).
…The plot thickens!
Why would increased levels of cortisol lead to overeating?
The short story?
The brain’s stress response is to prioritize energy supply to itself. This includes a drive to eat, and since we know that certain tastes (sweetness being one) sends a very powerful message to the brain that it is being fed – not only is it being fed, but with something where energy is easily accessible – it thus makes sense that psychological stressors provoke appetite – and increased levels of cortisol is a sign of stress. If you were more susceptible to stress, over time, it would seem that the brain reacts acutely by trying to protect itself by sending a message that More Nutrients Are Needed (even if they aren’t).
It would seem, that after three weeks in Margarita Land, my stress reactivity was particularly acute. After being able to do whatever I pleased, confronted with the new reality of not being able to do anything I liked, my brain reacted forcefully by getting stressed to the point where food was not the priority, but finding a way to watch movies for nine hours or so, was.
I was recently quoted in the LA Times about stress and overeating. I used a spectrum that included Being Chased by a Saber Tooth Tiger, and Fear of Famine, as polar opposites for the types of stress that either promote or extinguish eating behavior.
That the fear of living for nine hours without being able to watch HBO’s Mildred Pierce mini series, clearly for me, is not only testament to the excellent entertainment made available by HBO, but confirmation that my life is remarkably stress-free.
By the way: as soon as I got off the plane, after a twenty-minute meet and greet with Homeland Security, and an hour and a half with the Luggage Belt, I moved as quickly towards Starbucks for a latté and muffin as my feet would allow. In other words, I had reached my limit, and medicated the strain with nutrition’s single fastest cure for stress reduction, and also perhaps the the single greatest contributor to adiposity. Oh well. Tomorrow is another day.
XOXO Dr. M