Gary,
have you tried "Prosure", a new nutritional formula especially made for cancer patients struggeling with excess weight loss?
It has been on the market for about a month or so, and comes in vanilla and banana. I haven't tried it myself, but it can't be worse than Ensure and Boost, and has more calories, as well as 16 g of protein, 5 g of fiber, 1 g of omega-3, 48 g of carbs, but only 6 g of fat, and 8 g of sugar.