Kiev will not run out of food. Too many ways to get food in. It’s more likely that the Russians will run out of food. Their logistical train is much easier to disrupt.
Those 140,000 Russian troops not sent in are likely mostly support troops. If not, Russia has a huge problem.
There is already one video of Russian soldiers running with bags of looted food.
Proof that Russia can’t feed its own military. They won’t find it so easy in the future. They might find themselves getting killed in ambushes while trying to steal food in the future.
Like I posted earlier, I think the 140,000 Russian soldiers who did not go in on the initial invasion are likely support troops. There are likely ill-trained in combat and would have no chance of survival, even against civilian partisans who know the territory.