Directly. Energy is consumed by humans over time.
That time may be spent on doing tasks. Spending that time doing task increases energy consumption over baseline (though humans have substantial energy storage, so, for tasks shorter than couple hours, the cost is usually paid after such tasks).
> The caloric needs of a human are minuscule compared to the electricity converted to waste heat to train and operate an LLM.
The costs of operating: not really, and that's the whole point of comparison. Sure, humans are energy-efficient in some aspects - but the brains can only do so much. There's plenty of work that LLMs do faster and better than humans, so much better that no human can match them. And speed means more tasks, so energy use per task is lower.
Also, if you're talking about cost of operating LLMs in general - i.e. keeping them running and doing arbitrary work, you really need to compare it against costs of keeping a human alive and available to do the work. So it's not just food, but also hygiene - including e.g. delivering water, heating water for laundry and showers, etc. - and similar consumables.
As for training costs, that must be a joke. Do you know how much it costs to train a human? Energy or otherwise? As a parent of three kids I'll tell you: a lot.
If you include the energy a human uses from birth to ~18, and then energy used while they're trained for whatever jobs you want to compare against AI, then the comparison gets even worse for humans.