Lol. Didn't he only have £10 in that jacket pocket? The best that would get you is Dominoes Full house 9.5 inch at £9.15 (they don't deliver under £8.95. He could have called a smaller pizza place and done two-for-one, but they would have levied a delivery charge so not really. Fair play though, he could have eaten the delivery bloke, and the cable guy. I know that one person (average male) feeds 70 people at banquet size portions, but he could have stretched it being on rations. Lets say 3rd size rations, thats 420 meals and the pizza, so about 140 days food, ( boil the bones for marrow as broth snacks). He'd need a lot of water though beacuse the blood would be salty, and the meat tough. I guess he should set up a solar still, or rain catcher..because he was cut off from mains. There is always the inherant risk of CJD if you eat brain so he should leave that alone for a start. Best off eating the liver. Packed with energy.
It's not hard to establish a colony of rats in your house, which will provide plenty of food for one man. Twinned with killing garden birds. I reckon i could have survived ages...