Does Thinking Make You Fatter?

Today's article is a reprint of one I received in today's free newsletter from Dr Joseph Mercola of Mercola.com It's another valuable lesson on the exercise and nutrition we need, and how stress can throw our whole system out of whack!


A research team has demonstrated that intellectual work induces a substantial increase in appetite and calorie intake. This discovery could help to explain, in part, the current obesity epidemic.

The team measured the spontaneous food intake of 14 students after each of three tasks: relaxing in a sitting position, reading and summarizing a text, and completing a series of memory, attention, and vigilance tests on the computer.

Each session of intellectual work required only three calories more than the rest period. However, despite the low energy cost of mental work, the students spontaneously consumed 203 more calories after summarizing a text and 253 more calories after the computer tests than they did after relaxing.

Blood samples taken before, during, and after each session revealed that intellectual work caused bigger fluctuations in glucose and insulin levels -- two critical components in the body's regulatory and energy machinery -- than rest periods.

Jean-Philippe Chaput, the lead author of the study, said that mental work "destabilizes" the levels of insulin and glucose, thus stimulating the appetite, apparently in response to a need to restore the body’s energy balance.

Sources:

ABC News September 10, 2008

Psychosomatic Medicine September 2008 70:797-804

Dr. Mercola's Comments:

After a hard day of mental work, you can be just as physically exhausted as if you had spent the day doing physical work. So it makes sense that thinking hard also increases your appetite. The researchers found mental work “destabilizes” your insulin and glucose levels, and that’s what they suggest is causing the increase in appetite and eating.

For now, it’s safe to assume that many factors can increase your appetite, and of them many are related to your mind.

How Your Mind Makes You Hungry

One of the mental states that leads to more eating is stress (remember, a mental challenge is a form of stress). This is a major one that almost everyone can relate to, and to some extent this is hard-wired into you.

Researchers from the University of California, San Francisco found that when rats are chronically stressed, the release of glucocorticoid steroid hormone (cortisol in humans) leads them to engage in pleasure-seeking behaviors, including eating high-energy foods. When they ate these foods (things like the human-equivalent of greasy pizza or chocolate chip cookies), they developed abdominal obesity, but the negative aspects of chronic stress were blunted.

The researchers concluded that craving, and eating, comfort foods may actually “apply the brakes on a key element of chronic stress.”

Well, relieving stress is good, but not when it’s at the expense of abdominal obesity or “belly fat”, which has been linked to an increased risk of heart attacks, diabetes, strokes and more. Nipping stress in the bud at its root source is a much better option than soothing your nerves with a bowl full of ice cream.

Meanwhile, stress is not the only emotion that leads you to eat. A 2004 study by British researchers found that about half of adults turn to food in times of not only stress but also boredom and loneliness.

Then there are many other, very subtle, reasons why people feel hungrier, such as:

• Seeing food, which makes your body anticipate eating.
• Time of day. Your body is conditioned to eat at certain times.
• Drinking alcohol, which can impair your judgment and make you eat more than normal.
• Eating refined carbs, which generates a rapid rise in blood sugar, followed by a subsequent “crash” that makes you want more food.

• Portion size. Studies show that the larger the portion, the more you’ll eat.
• Eating too fast, which allows you to consume more food before your body has a chance to let you know it’s full (it takes about 20 minutes for this to happen, so you should wait at least 20 minutes before going back for seconds).
• Not sleeping enough, which triggers hormone imbalances that boost your desire to eat.

Does This Mean You’ll be Fat if You do a Lot of Mental Work?

Of course not, but knowing that your appetite may be stimulated after a long meeting or hours at the computer is something to keep in mind. And it’s not as though a stimulated appetite is a bad thing at all.

If you feel hungry, you should listen to your body and eat something. Just make sure it is something that will actually nourish your body, not just keep it going temporarily followed by a major crash. Finding out your nutritional type, and eating accordingly, is really the best way to feel satisfied and give your body the nutrients it needs -- without having to worry about gaining weight.

Now, if you do a lot of mentally challenging tasks it’s a good idea to eat plenty of these foods that are known to nourish your brain:

• Organic eggs
• Leafy vegetables like spinach
• Seeds and nuts (especially walnuts)
• Organic grass-fed beef and chicken
• Green tea
• Omega-3 fats (like krill oil)

That said, some of the worst foods for your brain are refined foods (white sugar, white flour, processed anything), alcohol, and trans fats. So focus on eating whole foods (especially those from the list above) if you do a lot of mental work. And if you’re worried about gaining weight, be sure you’re getting plenty of exercise as well. Not only will the exercise burn calories, it will help to relieve your mental stress and optimize your brain function all at the same time.