700 kilocalories for the small guys
50'000 to 60'000 kilocalories for the big guys
Usig the Katch-MCArdle formula it comes out to be around 500-700 kilocalories per day for very active humans that are around the weight of 0.8kg to 1kg at the height you specified, could probably be to the lower ends of 500 kilocalories for very sedentary small people.
700kilocalories seem a lot for someone this small and short, but smaller animals eat more because they lose a lot of heat and maintaing temperature costs a lot of energy.
While your giants will weight something around 5,248.7 lbs or 2380kg(those are skinny giants, because humans struggle not collapsing on their own weight after surpassing certain height to weight ratios), will need around 50 to 60k kilocalories per day, which doesn't seem like a lot.... normal human bodybuilders, strongmen and athletes eat this ammount of food in 6-8 days.
but remember that bigger people lose less heat, therefore they waste less energy maintaing their body temperature.
So in proportion the giant guys aren't gonna be big eaters.
For more bulky and muscular giants, give them a diet of around 110 to 128k kilocalories per day, but keep in mind that in any realistic gravity they would collapse onto themselves and be crushed by gravity, the human spine is not made to handle this size.
You can make the spinal muscles as big and strong as you want, but the human body is just not made to handle this much weight vertically.
world-level athletes seem to die or collpase when their spine is holding or moving straight perpedicular weights around 6 to 7 times their size.
if a 120kg athlete faints while holding 720kg in their hands for a few seconds, don't expect your giant's spine to be able to hold any remarkable weight, also given the fact that bigger animals have a less size to strength ratio. So go and make your giants skinny like oversized giraffes.
if you make your giants be more like gorillas and less like humans, then you could maybe make them heavier than two tons.