I don't know how you did that math, but you cannot convert kcal to mAh, you need a unit of energy like watt hour

2000 kcal * 4184 (J/kcal) / 3600 (seconds) ~= 2324 Wh

which is... a lot of batteries (a large laptop battery is around 100 Wh)

A human at rest uses around 100W, which is easier to remember.

2.3kWh is about 10kg of battery (more if LFP, less if NMC).

2000 kcal is equivalent to 470 mAh at like 4946V.

This is not how unit conversions work.