While I was in hospital I found all the ones they gave me were far too sugary. Most of them are made of whey protien which to me tastes foul. Tried the soups,Meritene from Boots, they are about £5 a box for 4 , to me disgusting.
In the end I found some Nine seed bars, just under 10g carb, about 200cals and they have a fair amount of protein in them, its wether you can tolerate nuts and seeds. If you buy them from Amazon in a box for about 50p a bar, so I ate about four a day. Got my husband to by me wafer thin ham and snacked on that, because I am supposed to be lowish fat. I found meat snacking was the easiest way to increase my protien intake. I didn't eat properly for nearly three months so I literally did it a mouthful at a time