system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: If your brain uses 20% of your calorie intake, and your brain uses more energy when used intensely, does this mean you can lose weight from using your brain more intensely on a regular basis?
gpt
Most of what your brain does has nothing to do with "thinking hard".  Rather, the energy is primarily going towards just keeping all the systems operational.  While it would no doubt be possible to measure some small difference in energy consumption based on use, this difference probably wouldn't favor the sort of thinking you're considering.  It's a much more difficult computational chore for your brain to play a game of racquetball than it is for your to lie dead still and philosophize about how much energy you can burn with pure thought.