Food and Your Mood

Why moods can tempt you to indulge -- and what to do about it

Medically Reviewed by Kathleen M. Zelman, RD, LD, MPH on August 31, 2004
6 min read

It's one of those days. Deadlines looming. Meetings all morning. The boss on a rampage. Your assistant out sick. Your inbox overflowing. And it's only Monday afternoon!

You're overwhelmed and exhausted, and all you can think about is that candy bar stashed in your desk drawer. You reach for it, your mouth watering in anticipation. You're sure it's just the thing to boost your energy and calm your nerves.

But is it really? Not according to Robert Thayer, PhD, professor of psychology at California State University in Long Beach and author of Calm Energy: How People Regulate Mood with Food and Exercise. Thayer's research has shown that the boost in mood people get from sweet snacks like your candy bar is short lived at best.

"In fact, in one study, we found that people were more tense and tired an hour after they had eaten a candy bar than before it," says Thayer.

So why do we crave sweet snacks at times of stress? For one, they taste great. OK, that's a no-brainer, but a megadose of sugar does more than tickle your taste buds. It actually stimulates your brain's pleasure center while temporarily lowering your body's sensitivity to pain. Healthcare professionals who work with newborns often take advantage of this by putting sugar drops on an infant's tongue to ease the distress caused by medical procedures.

It isn't just the sugar, though. High-fat content in food also creates pleasurable sensations and lessens pain. In a 1997 study in Britain, volunteers who ate high-fat pancakes an hour and a half before dunking their hands into ice-cold water reported less discomfort than others who had eaten equally caloric, but low-fat, pancakes.

The other draw of the sugary, high-fat snack is the fuel it provides. "When people are experiencing negative moods, and also when they are experiencing stress, they need energy," says Thayer. "And food is a very elemental form of energy."

Of course, most of us don't settle for any old food when we feel run down. We go for the gold: sugary, energy-dense treats such as ice cream, cookies, and chocolate. These foods are crammed with easily digested carbohydrates, which the body converts into glucose -- the simple sugar that circulates in the blood to fuel our cells.

Unfortunately, the quick fix that sweet snacks provide is all too fleeting. People often end up eating still more carbohydrates in an attempt to revive their energy levels after the rush wears off.

Why do it, then? Thayer says it is because people are more or less hardwired to respond to instant gratification.

"You may know that you will be feeling bad in 10 minutes or 15 minutes or an hour, but it is the immediate effect that controls your behavior," he says.

There's still more bad news about sugary foods. Larry Christensen, PhD, chairman of the department of psychology at the University of South Alabama, believes that eating sucrose-containing (sugar-containing) foods may actually cause depression in some people. In his studies, he eliminated sugar from the diets of depressed people and found that about 25% saw a significant improvement in mood.

"For some people, taking sugar out of the diet and adding it back in can turn their depression off and on like a faucet," says Christensen. "It can take a week or two weeks to have an effect, but most people will feel better in a week." It's not clear why sugar has such a profound effect on mood, but it may be linked to exhaustion. "Sugar boosts energy initially, but then it has the paradoxical effect of inducing fatigue," explains Christensen. "And if an individual is constantly fatigued, things are hard to do, and it's easy to become very pessimistic."

But before you throw out that secret stash of extra Halloween candy, remember this: You may not be one of those people who is especially sensitive to sugar, and as long as you partake of sweets in moderation, they probably won't do you any harm.

Also, according to one recent study, there may be a good reason for craving comfort food during tough times. When researchers at the University of California in San Francisco subjected rats to chronic stress over a few days, they found that the rodents preferred to eat sugar and fat.

"Not the ordinary, everyday boring food, not the regular rat chow," says Mary F. Dallman, professor of physiology at the University of California, San Francisco, and the chief investigator on the study. "They went for sucrose and fat."

And when the rats ate these foods, their brains produced less of the stress-related hormones that normally trigger the fight-or-flight response. "To me, this is enormously exciting," says Dallman. "I think this is the first data that show that there might be something good about eating comfort food."

The study also uncovered another interesting wrinkle: Rats who build up more abdominal fat -- the rodent equivalent of a spare tire -- also have a lower response to stress. "It's like what your grandma told you: the happy fat man; the mean lean. It's like a folk tale," says Dallman.

She and her colleagues haven't figured out how abdominal fat signals the brain, but they are working on it. In the meantime, she cautions that people should not get carried away by the benefits of a big belly.

"Abdominal obesity is specifically associated with type 2 diabetes, cardiovascular disease, and stroke," she says. "If you don't exercise it off, you've got big, bad problems."

So don't dive for the doughnuts whenever you're in distress. It's a sure path to weight gain. In fact, according to Thayer, the current epidemic of obesity in the U.S. may stem from stress-induced eating.

"Over the past two decades or so, there's been a steady ramping up of stress and also depression in society, and I think what's happening is that people are trying to self-regulate with food," Thayer says. "I think it is a very likely explanation for the changes in weight and obesity that are being observed nowadays."

Thayer has a much better way to deal with negative emotions: Take a brisk 10-minute walk.

Yes, it's that easy. Thayer says people tend to crave sugary, fatty foods when they are anxious but also low in energy, a state he calls "tense tiredness." This hits most people about 4:30 in the afternoon and again in the evening. Though a sweet snack may temporarily revive you, Thayer's research has shown that a brief bout of moderate exercise is a much more effective and longer-lasting solution.

Unfortunately, most people have a hard time motivating themselves to exercise even at the best of times. When you feel exhausted and stressed, it's even tougher. So Thayer suggests that you start small.

"Don't think about going out and exercising for an hour, but think about getting up and walking down the block -- or ten steps or 100 steps. Once you do that, your body becomes a bit activated, and that in turn makes it easier to go on and do more."

If the weather's nasty, or there isn't a good place to stride outside your home or workplace, climb up and down the stairs, do some jumping jacks, or turn on the radio and dance to a couple of songs (you might want to close your office door).

You can also try stretching exercises, yoga, or meditation because they will help relieve the muscle tension associated with the tense-tired state.

Here are a few more tips for mood-food management:

  • Discover your own daily energy and tension cycle. During three typical days, write down your energy level and tension level once an hour. Use a 7-point scale for each measure (1=least; 7=most). Chart the results.
  • Beware of your tense-tired times. Note the hours when your anxiety is highest and your energy lowest. Avoid food temptations and big decisions during these times. Try a brisk walk instead.
  • Use your best moods to advantage. Schedule challenging activities for the hours when you feel most revved and least stressed (mid-morning for many people).
  • Snack well. Avoid the sugary, fatty stuff, but if you're really hungry, munch on fresh fruits, veggies, yogurt, nuts, low-fat cheeses, or other healthy options.
  • Eat breakfast. Studies show that eating a morning meal improves mood and memory and increases energy. Also, people who regularly eat breakfast are less likely to become obese.
  • Finally, don't let your bad moods get you down. They will pass.

Thayer explains: "If you think about a personal problem late at night when your energy is low and your tension is high, it seems horrendous. But the same problem considered the next morning may seem like nothing at all."