There is an astonishing story about a sand cat eating a prodigious amount of food which answers the question.
A professor whose name is H. Mendelssohn working at Tel-Aviv University (the sand cat is found in Israel) wanted to find out how much an adult sand cat could eat at one sitting if feed continuously.
He feed the cat laboratory mice weighing 25 grams each. After consuming 15 mice the professor stopped feeding the cat but the cat wanted more. That’s one of the more striking wild cat stories bearing in mind that the sand cat is small, weighing in at 2-3 kilograms (around 5.5 pounds – a small domestic cat size).
Perhaps more typically for sand cats, another captive sand cat ate a 250 gram squirrel each day. This is around the average as under normal circumstances this small wild cat will eat 10% of its own body weight per day.
Humans eat between 3-5 pounds of food daily. A 12 stone man weighs 168 pounds. Therefore he eats 2.4% of his body weight per day, much less the sand cat proportionally. Therefore the sand cat must burn more calories.
The male sand cat will hunt all night and travel up to around 10 kilometres. They attack, kill and eat vipers. And they are unafraid of humans (perhaps they should be afraid).
Source for sand cat: Wild Cats of the World by the Sunquists referring to: 15 mice story: Letter from Mendelssohn H professor of zoology, Tel-Aviv University 1992. Squirrel story: Mammals of the Soviet Union vol 2 part 2 Carnivora (Hyenas and cats) by Heptner wG and AA Sludskii.