Thank you all again. I spoke to my mother last night and my dad only lost one pound in the past week and the doctor isn't upset so she has calmed down a lot. (My question was as much for her as it was for him.) Only 2 more weeks to go. It should get worse before it gets better :( but then he'll be done and can get his taste buds back. We'll be there Christmas weekend and I'll show them this thread. Thanks and hugs to all of you.

I'm sending hugs and a link for some ideas.
http://www.livestrong.com/article/288431-high-calorie-liquid-diet/

shame! We had a house guest who was with us for a while recovering from having a tumour surgically removed from her throat. As hardlikearmour says, there are different liquid meals available and I'd suggest you ask a decent pharmacist for advice. You might find there's something more suitable available. You might also consult a nutritionist.

What feels better, hot or cold? If cold works, you could try smoothies like I did for my wife when she was pregnant. I used frozen fruit blended with milk. I was going for a calcium boost, so I used skim milk and added skim milk powder with some molasses for an extra boost. However, I'd think you'd find you could add just about any kind of powdered nutritional supplement and still have a pretty thin drink if you blend it enough. There are all kinds of supplements out there, often designed for weightlifters and fitness junkies, with massive amounts of protein in them, but again, before going that route I'd talk with a nutritionist to get the right balance of what he needs.

good luck!

Thank you all for these wonderful suggestions! This is what i love about Food52--this supportive community! Thanks so much!

drbabs - just had a crazy thought - might using a straw help at all?

You can get higher calorie meal replacement drinks than the Boost. Carnation Instant Breakfast VHC is 560 cal per 8 oz serving. Nestle also makes one called Resource 2.0 which has 475 cal per 8 oz serving. They also have more protein that the boost, which is needed for tissue healing. You may also be able to add some protein powder to the boost w/o too much thickening. There's one called Beneprotein that is supposed to be tasteless and not change the texture. You can order the CIB and the Beneprotein from Amazon.
Good luck!

drbabs - so sorry to hear of your father's illness and do hope that once the chemo is over he'll be more comfortable eating and drinking again. I don't know anything about throat cancer but I do know that my father existed on a Boost type drink for quite a while while he had chemo for prostate cancer. I think he might have also eaten Jello. I wonder if a chat with the MD might produce some ideas - possibly even an IV if he continues to be unable to eat and drink. Though I guess an additional needle stick might not be welcome. Sending wishes for a speedy and full recovery for your Dad.

You can make pudding, with eggs, and dilute it. My daughter underwent chemo when she was a baby and had severe mouth sores from it, The thin pudding was about all she could get past her poor little mouth. Even creme anglaise might be good to mix in with the boost, it has plenty of egg protein and it's cooked so it shouldn't be a potential bacteria carrier. Maybe whip a mashed banana in it? Drink water after to rinse away any residue, Check with his doctor or dietician for advice before trying something new.

I'm sorry I don't have any good suggestions for you. I do know this frustration from experience with family members, and I do want to offer encouragement and all best wishes.

Oh Dr Babs I am so sorry to hear this - my brother in law also lost a ton of weight during radiation, he also drank Boost (grudgingly) but the good news is that once the radiation was done he was able to start eating again and gained weight back ... the only thing I can think of is maybe adding whole milk and maybe honey or molasses to increase calories. Also warm milk and honey might be easier to swallow ... soothing to the throat. Honey has 64 calories / tbs ...