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Ask Dr. Nandi: Does thinking burn calories? Here's what the science says

Posted at 6:25 PM, Sep 24, 2018
and last updated 2018-09-25 08:04:47-04

Is it possible to burn calories just by thinking really, really hard? Could a mental workout actually pay off?  

The answer is yes according to science.

If you’ve just spent your weekend lounging on the couch binge-watching TV, you’ve likely not used much brainpower. And to actually burn calories using your mind, you need to engage it.

Our brains run on glucose. And glucose is a specific type of sugar you get from foods, mainly from carbohydrates like fruit, bread, and potatoes.  

It helps nerve cells and chemical messengers process information.  

Now scientists who have studied how the brain uses energy say tough mental tasks like solving a math problem or learning a new instrument requires the brain to burn more glucose than it would if you were surfing social media.  

But don’t think that engaging in cognitively challenging work is going to help you slim down, because, after 8 hours of intense thinking, you’d only burn roughly 100 calories more than someone who was spent that time vegging on the couch.  

As your brain gets low on glucose, you get mentally groggy and tired. So then you need to eat, and that means more calories that you likely aren’t going to burn off by thinking alone.  

If you’re looking to burn calories the easy way, here are my prescriptions:

  1. Clean the yard. With the leaves starting to fall you can easily burn some calories raking and bagging them. 
  2. Try easy activities like dancing, walking, swimming, or cycling. Just 10 minutes of moderate exercise can rev up your metabolism.
  3. Get fidgety by moving body parts like tapping your toes or bouncing your knee. Research suggests you could burn 350 calories a day compared to those who are non-fidgeters.
  4. Do some strength training. You’ll build muscle mass, and that will help you burn more calories even if you’re watching TV.

But if you’re someone that has a job where you're engaged in plenty of mind-challenging work, day after day, then there is a possibility you might just benefit physically from it. But it could take 50 or so years.

I’d recommend that everyone make movement a part of your every day life. And you’ll reap plenty of health benefits just from doing that.