Your brain uses lots of energy. Can thinking make you lose weight?

Can thinking help you lose weight? (TL:DR...No, but the brain IS an energy-guzzler)

November 29, 2019 

Weight loss is simple math

For all of the agony, and the diets, and the money spent on weight loss products, losing weight is really pretty simple. If the body burns more calories than it takes in, the body will lose weight. And there’s good news on that burning calorie front.

It turns out that when the body is resting—not doing anything besides the requirements of basic living such as breathing, digesting food, maintaining body temperature and keeping the blood flowing—the body burns about 20-to-25 percent of its overall energy simply coordinating those activities. That’s right, the BRAIN uses up 350-450 calories per day, mainly in the form of glucose, just to keep the body going.

Children use even more brain energy as their brains develop. That makes the glucose guzzling brain the most intensive energy usage organ in the body, despite the fact it is only 2 percent of the body’s overall weight.

“The brain may not weigh a lot, but it is relatively large compared to the rest of the body,” explains Doug Boyer, Ph.D., an associate professor of evolutionary anthropology at Duke University. He told Live Science “If you have a really big brain relative to your body size, it’s going to be more expensive metabolically.”

More brain activity, more weight loss?

So… since the brain is such a big energy-guzzler, is it possible to burn more calories by using the brain more? In other words, if you perform a lot of “brain heavy activity” such as learning a musical instrument or playing intense strategy games, would you burn more calories and possibly lose weight?

Theoretically, yes. As you train to learn something new, your brain uses more energy in whatever regions of the brain are activated by the training. Learned a new language? The part of the brain that powers and coordinates our communications skills is fired up. Learning to dance? The brain that controls coordination and movement is taxed. As you get better at performing whatever new skill you were learning less energy is needed, but in those early stages there’s a lot more energy required.

“Most of the brain’s energy is devoted to enabling neurons in the brain to communicate with each other via chemical signals transmitted across cell structures call synapses,” said Arianna Harrington, a graduate student in evolutionary anthropology at Duke. “A lot of the energy goes into firing a synapse, which involves moving ions across membranes.”

It follows then that heavy thinking could help lose weight, right? Well, no. Unfortunately, while the brain uses a lot of energy, the additional energy to think harder is comparatively small. And the brain actually adjusts to “heavy thinking.”

“The brain diverts blood and energy to particular regions that are especially active so the overall energy availability in the brain is pretty constant,” Harrington told Live Science. “So, while there may be significant spikes in energy use at specific regions of the brain where cognitive tasks are performed, the brain’s energy budget isn’t changed. Sadly, that’s something to think about. Thinking alone won’t make us slim.

—Frank Graff 

 Frank Graff is a producer/reporter with UNC-TV, focusing on Sci NC, a broadcast and online science series.