I really don't know if that is a true sign of decline. However, when my dh was on Hospice they told me that one of the criteria for renewing their stay was a loss of 10% of their body weight within 6 mos. I think I remember that right. And, within weeks of them saying that to me he lost 10 pounds within a couple of weeks and never lost any more weight until he was closer to passing when he didn't want to eat and couldn't eat.
Have you had a Hospice evaluation of him and what does your doctor tell you? Others may be able to answer your question concerning their experience and remember each person is different.
Lloyd started out at 155 lbs. He probably weighs around 117 now. When he had his first seizure in April 2011, he ended up in ICU for a week. They would not feed him anything by mouth because he had forgotten what to do with food. He got down to 116. I have given him Ensure 3 times a day, but it has not gotten the weight back on. The only thing that got him back to 131 lbs. was Marinol (the synthetic marijuana pill). It was amazing, but too expensive and not covered by insurance. The 2.5mg 2x per day cost us about $250 per month. When he needed the 5mg. the cost doubled and we just could not afford it. Lloyd is "end stage" now and while he eats alright, he also paces constantly. It is the pacing that keeps the weight off. I know Lloyd is declining more rapidly since cold weather has set in, but no 2 cases of this rotten disease are the same. The saying is "If you've seen one person with Alzheimer's, you've seen one person with Alzheimer's". If you can get your insurance to cover Marinol, you would be AMAZED! It was worth it to know that it did work, but sad because we could not afford to continue it. I was told by the insurance company that Marinol was only approved by the FDA for treating nausea caused by chemo in cancer patients. Good old federal gov't calling the shots, controlling the population, and sticking it to us one last time! I do need to say that some people here have been able to get it covered by their insurance. Maybe check it out.
My 'DH was losing wt as his eating habits changed. Worse his PCP doc kept at him to lose wt..He did need to drop some but.....now he is stable at his near normal wt. He still has eating issues, and control of his glucose is not easy.
My wife has gained 30+ pounds since diagnosis nearly 4 years ago. She has 'no appetite' for eating many of the foods she used to enjoy,and every fre months she stops eating foods she used to like. But ... but she always has an appetite for 'junk foods' and that is what she now eats all the time. These junk foods also change every few months. In Oct/Nov, it was Hershey bars, chocolate anything, pistachio nuts and chocolate chip cookies along with many cans of diet caffeine free Coke. In Dec and this month, it's still those same chocolate chip cookies, but now it's cashew nuts (won't touch pistachio nuts anymore) and only occasionally a Hershey bar along with her many cans of soda. When we go out to eat, she eats fine. Chinese/Greek/Italian food, anything at fast food restaurants and diners ... she eats fine. But bring that same food home ... no. And whatever I used to make for her at home ... she still says she wants me to make it for her, but then she doesn't eat any of it, always saying she's not hungry!
My DH is also gaining weight because of the junk food. He will eat what I cook if it is chicken or hamburger, but no fish, steak, shrimp, barbequed ribs and lots of other things he used to like. He will eat peanut butter on bread several times a day, Entenmann's donuts, yougurt and ice cream between meals.