After my husband's chemo and radiation treatments he lost about 30 lbs and needs to gain his weight back. The high calorie Boost seems to be helping. We only started this about two weeks ago, so he will weigh in about two weeks from now and we'll see if it has added some much-needed pounds. It has seemed to give him more energy, and he likes all the flavors. Tells me they taste really good. Sometimes I make him a smoothie with ice cream or fruit and use the boost to make the shake. Pretty darn good he says! Has about three a day and it does get a little pricey, but a very good product.