I found several human studies published in various journals that appear to confirm the study from Brain, Behavior and Immunity (BBI) discussed previously.
The first, published in Physiology & Behavior in 1999, is a study detailing the self-reported effects of stress on eating behavior. The researchers had the subjects (a group of 212 undergraduate studentsâ€”63 male, 149 female) fill out a questionnaire about their eating habits while under stress. The analysis showed that the subjects not trying to lose weight, the so-called nonrestrained eaters, tended to eat less under stress while the subjects who were dieting, the restrained eaters, ate more high-sugar, high-fat snacks during times of stress. If one makes the assumption that the dieters were overweight (not a large leap of logic), the study data takes an interesting turn because if the dieters are overweight that means they are probably insulin resistant and hyperinsulinemic (as almost all overweight people are). The BBI study indicates that insulin potentiates the CRF-ATCH-cortisol driven motivation to increase comfort food intake in an effort to hasten abdominal fat stores to shut down the stress hormone response.
The second study I reviewed was a little more of a “real world” type study, that basically showed the same thing, i.e., under stress people tend to eat more fatty, sugary snacks, especially those who are dieting. In this study published in the Journal of Psychosomatic Research researchers evaluated workers in a large department store who worked during both high-stress and low-stress periods as part of their employment. The high-stress periods were those times in which the subjects were under some sort of deadline, the low-stress periods were normal non-deadline work situations. During the deadline periods people worked longer hours, and those people who were restrained eaters consumed more comfort foods.
The third study, published in Psychosomatic Medicine, was a controlled study in laboratory conditions. The researchers recruited subjects, divided them into a control group and a study group, then had the members of the study group prepare a 4-minute speech that was to be filmed and graded. The subjects prepared their speeches, then had lunch served them right before they were to give the speeches. The control group listened to a passage of text before lunch while the study group subjects ere preparing their speeches. The researchers knew that public speaking is a terrifying, stressful activity for most people, so they figured that the study group, facing the prospect of not just giving a speech, but having it filmed right after lunch would make them maximally stressed during the meal. The control group had no such prospects after lunch, so were able to enjoy their lunch pretty much stress free. The stressed subjects consumed more fatty, sugary foods than did their non-stressed counterparts. In this studyâ€”which looked at acute stressâ€”there was no difference between the restrained and nonrestrained eaters. Both dieters and non dieters in the study group were face down in the cake and chocolate biscuits.
It’s pretty clear to me that stress drives us to seek sugary, fatty foods to offset the discomfort we experience from the raging stress hormones. Back in college a hundred and fifty years ago during my only psychology course I became intrigued by the work of a (then) famous Italian psychologist (whose name I can’t recall right now) who theorized that if instead of viewing urges, feelings, and compulsions that come on us unbidden as inner generated, that we should view them as forces from without seeking to cause us harm. He seemed to thinkâ€”and I believe he’s right to a great extentâ€”that it is much easier to ward off or resist invaders from without than it is to resist invaders from within. I, myself, have an easier time controlling urges if I think of them as outside influences. And I also have an easier time of it if I know there is some kind of physiological underpinning for the drive and know in advance when to expect it. It may not work for everyone, but if you’re having trouble keeping cravings for fatty, sugary food at bay during times of stress, it’s probably worth a try.
On another post at another time I’ll get into Dr. William Glasser’s Control Theory approach to life in general, which can certainly be applied successfully to diet.
Fat and happy II