A thing to keep in mind is that 1 MWh of raw calories takes much more than 1 MWh to produce (fuel for tractors, inefficiency of meat etc). The GPU energy is also easier to make renewable.

I did an extremely rough calculation recently that the training of GPT-3 is comparable to one transatlantic flight (all passengers combined) in terms of emissions, very depending on the energy mix of course.

That's the entire problem. There's so much more energy that goes into a modern human beyond just what they eat. Beyond physical items you've listed like clothing there's also education and healthcare. Those two institutions are critical in making a modern human and they both have their own dependency chains of physical resource, energy, and the input of even more humans.