My husband had chemo and radiation for tongue cancer last year. First off document everything he puts in his mouth. You'd be suprised how few calories he takes in if you're not keeping track. He ate alot of the Jimmy Dean Breakfast Bowls,canned soups, Mac n cheese, yogurt. I would put 7 16 Oz bottles of water on the table everyday so we knew how much he was drinking. Supplement with Ensure,etc .and a milkshake several times a week. Keep a calorie total daily ! This too shall pass!!