Wednesday, October 3, 2012

A Bad Reaction to Research: Why Moderation is Important

CC BY 2.5 anacleaver_2000

When I was getting my Bachelors degree in psychology, I had to take a class called “Biopsychology”. The class was very interesting, focusing mostly on how the structures of the brain influence behavior. One of the gems wedged in the book was a chapter on eating and hunger, called “Why Do Many People Over Eat?” Now, I'm kind of a geek, and I'm very curious about health, eating, and diets. When I saw this chapter, I was really excited about going over it in class. I wanted to know why people would overeat, so that I could apply this knowledge to my own life, and, hopefully, lose weight.
The author of Biopsychology, John J.P. Pinel, makes it very clear that our bodies are designed for storing as much energy as they can, not for giving us the ideal amount of energy as we need it, writing, “you may believe your body is short of energy just before a meal, it is not” (1). Pinel points to the environment that our ancestors had to survive in. He argues that if our bodies were designed for using all energy immediately, our ancient predecessors would have starved during long winters or famines.
Now, I will talk about several studies, but stay with me, there's a method to my madness, or at least, there is this time. Other times...I make no promises.
To illustrate his case that hunger is more than a regulation of energy Pinel writes about R.H., a patient with severe anterograde amnesia. Researchers offered R.H. his favorite meal: veal parmigiana and apple juice. Fifteen minutes after R.H. had finished eating (and had forgotten his previous meal), researchers offered him another meal of veal parmigiana and apple juice. Again, R.H. ate it. They offered it a third time with the same result, and a fourth, at which point, he refused saying “his stomach felt a little tight.” Then, only minutes after R.H. had refused, he announced he was going for a walk and some veal parmigiana (2). The message here is clear, hunger is not motivated by a need for energy, but rather other reasons. In the book, Pinel makes the case the our hunger can be motivated by such things as our schedule, simply having food in front of us (would you say “no” to your favorite plate of food pipping hot and inches away from your face, even if you weren't hungry?) or by habit.
In another study on sham eating, Weingarten H. P., & Kulikovsky cut the esophagi of rats, connecting it with an external tube, so that anything the rats ate would not reach their stomachs. The researchers (whom you might be thinking are mad scientists at this point) had two groups: rats that had previously eaten a specific brand of rat chow (group A) and rats that had never eaten that brand of rat chow (group B). Group A was found to eat similar amounts of rat food as they had previously, even though none of the food was reaching their stomach. Group B, on the other hand, was found to eat more rat chow than group A. When researchers reconnected the rats esophagi to their stomachs, they found that group B ate similar amounts of food to when none of their food was reaching their stomach (3). This suggests that we eat based on experience, not based on how much food we need at that point in time.
After reading about these and other studies done on hunger, the message to me was clear: if you are overweight, it is because you eat too much, and in general, people eat much more than they need.
Now, I have always struggled with my weight, and like most women, I am very sensitive about it. Reading this chapter was like someone bashing me over the head with a large mallet while screaming, “stop eating so damn much!” That is to say, it was very unpleasant. Thus I decided that I would reduce my eating to so-many number of calories in a given meal, and I would not eat anything unnecessary (i.e. snacks, desserts, etc...) and I would lose weight. I would ignore my hunger pangs, after all, “the strong, unpleasant feelings of hunger that you may experience at meal times are not cries from your body for food; they are the sensation of your body's preparations for the expected homeostasis-disturbing meal” (1). Translation: eating a meal is rough on your body.
So I did it. I ignored my hunger pangs, ate relatively little, and was absolutely and completely miserable.
For two whole weeks I was grumpy, irritable, and had a headache that would not go away.
Let me repeat that.
It. Would. Not. Go. Away.
Two weeks.
I was miserable. I couldn't sleep at night because I was so hungry. I wanted more food in a way that mentally talking myself out of it couldn't curb. Yet, the research resounded in my head. I was overweight because I ate too much. I did not need more energy. My body had energy to use in the form of fat. I would not die from this diet, I just wished I would.
One day, I was talking to my sister on the phone. I was going on and on about all the research I had recently read, and how I was trying to incorporate it into my life, and how I felt sick and awful. On and on I went, until finally my sister stopped me. “Katerina, eat when you're hungry, stop when you're not.” Simple. Easy. Non-headache inducing. And like that, I was free from my research malaise.
CC BY 2.5 Marcin Wichary
Now, let me be clear. I am not recommending eating large quantities of food every day all day, or that we should not listen to what research has to say. My point is moderation. Research may suggest that we eat too much, or that by reducing the amount of food we eat, the longer our life will be, but really, who wants to live constantly hungry and obsessing over food?

1. Pinel, J. (2009). Biopsychology. (7th ed.). New York: Custom Publishing.
2. Rozin, P., Dow, S., Moscovitxh, M., & Majaram, S. (1998). What causes humans to being and end a meal? A role for memory for what has been eaten, as evidence by a study of multiple meal eating in amnesic patients. Psychological Science, 9, 392-392.
3. Weingarten H. P., & Kulikovsky, O.T. (1989). Taste-to postingestive consequence conditioning: Is the rise in sham feeding with repeated experience a learning phenomenon? Physiology & Behavior, 45, 471-476

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