If You Eat Carbs When You Are in a Bad Mood....

Does eating carbs CAUSE the bad mood?

Posted Sep 28, 2015

Eating a dish of chocolate-sauced ice cream or a large bag of potato chips when feeling sad, angry, tense or worried is pretty standard behavior for people who turn to food rather than alcohol, nicotine or recreational drugs when their moods go south. Women with PMS know all too well the impulse to chow down a bag of chocolate chip cookies or half a sheet cake when the hormones are 'raging,' i.e. the end of the menstrual cycle. 

But few of these eaters would put the blame for their bad moods on the carbohydrates they are inhaling. Rather, they know that a social disaster, financial problem, cranky mother-in-law, their teenager, or even the early sunsets of winter is driving them to food.  Chocolate cravings appear with great regularity among some premenstrual women, along with the feeling that all is wrong with the world. But few who may brave a blizzard to get a chocolate bar would blame their moods on the chocolate. (Of course, if the chocolate were unobtainable, their bad mood might worsen.) But now some scientists, and the carbohydrate overeaters themselves, are suggesting that the trigger to the bad moods is the carbohydrates themselves.

Isn’t it true? After all, what do depressed people eat and overeat? Not celery, kale, cottage cheese and boiled chicken. Not gobs of mayonnaise, lumps of butter or hunks of lard. Carbohydrates, either sweet/gooey or crunchy/salty, are the feel-good foods of choice. And of course, we all know where this type of eating leads: weight gain, obesity, a multitude of medical problems and depression because of the obesity. Certainly someone who looks at the empty quart-sized ice cream container, crumpled bag of potato chips or the crumbs of a depleted box of cookies feels remorse, depression, anger and even helplessness at the eating that just occurred: “Now I am really depressed,” thinks the overeater. “I probably just gained 10 pounds on top of the twenty I already need to lose.  It is all the fault of the carbohydrates. “

But is it? Does eating carbohydrates in association with negative mood mean that eating carbohydrates causes the negative mood states?  When we drink water in association with thirst, do we assume the water causes the thirst?  When we put food in our bodies in association with feeling hungry, do we assume that food causes hunger?  When we take a pain-relieving medication in association with back pain or a headache, do we assume that the medication is causing the pain?

Fortunately, we don’t have to rely on word play to answer this charge.

It is possible to test the carbohydrate-mood link in the laboratory.  The format for such research is to measure the moods of volunteers when they are not in particularly good moods, for example people who get grumpy every afternoon around 4pm or women with PMS. Volunteers fill out self-reports on their mood and then are asked to consume a beverage containing carbohydrate or protein. They don’t know what the beverages contain because the taste and textures are identical. An hour or so later, after the carbohydrate or protein has been digested, the volunteers fill out the same mood reports. We did such an experiments at MIT with people who always ate a carbohydrate snack late in the afternoon when they started to feel irritable, restless, impatient, distractible, tense, and even a little depressed. After they consumed the carbohydrate-containing beverage, their moods improved significantly. But their moods did not get any better after drinking the beverage containing protein.

Several years later we did a similar test with women whose carbohydrate intake (we measured this directly) increased enormously when they were in the throes of their mood-altering PMS symptoms. These women also consumed a carbohydrate or protein-containing beverage and, as in the earlier study, did not know what each beverage contained.  The carbohydrate beverage significantly decreased their anger, depression, tension, confusion, and even fatigue. None of these moods was altered after they drank the beverage containing protein.

There goes the ‘carbohydrates cause depression’ theory.

Was it the taste of the carbohydrates that put them in a better mood? Unlikely. Their moods were measured an hour and more after they finished the drink. Moreover, the drink had a mild fruity taste but would not be a contender for best tasting drink.  The reason for the improvement in mood was due to the increase in the ‘feel-good’ brain chemical, serotonin. The carbohydrates did not produce the serotonin, but their consumption triggered a series of biological events in the blood and brain that caused more serotonin to be made. And that produced a better mood.

What is wonderfully curious is how we know to eat carbohydrates when we are feeling blue, despondent, upset, stressed or anxious. It is not something we are taught and indeed, given the current anti-carbohydrate attitude of self-proclaimed nutrition experts, we have been told to avoid eating those dreadful foods. But (Thank you, Mother Nature!), there must be some sort of signal from the brain, to our emotional self, to our mouth and eyes that says: Now it is time to have some crackers, or an English muffin or a small bowl of oatmeal. I call it a ‘carbohydrate-thirst.’ Indeed, one of our early volunteers said, “My mouth is calling out for carbs.”

Whatever the signal, the outcome is the same. A small amount of carbohydrate, no more than 25 or 30 grams, is enough to perk up our serotonin and take the edge off whatever bad mood we are experiencing. Like thirst, or hunger, or the need for sleep, eventually the carbohydrate hunger will come back when, for a variety of reasons, mood begins to deteriorate.  But for several hours after eating the carbohydrate, we will feel a little less stressed, a little calmer, and even a little happy.  And that, fortunately, is not going to change.