The longer away your units are from capital the greater is this effect, for example if your units need 270 fuel and they are an average of 30 provinces away the entire network need 8100 fuel to be "filled" and start delivering to the units. If your units are on low fuel they will start requesting twice that amount. Since fuel (and supplies) only move one province a day all provinces between the unit and their source needs at least the daily consumption to deliver to the next one.
Temporary fluctuations are normal with the current supply-system, and they should normalize back to your 270 needed according the statistics within a few days. Also your not actually losing the fuel, just sending it into the network.
To prevent this from happening you should be careful and try to not strategically redeploying to much armour and air-force at once. (Since this will reset their supply-path and start over)