Your malnutrition is as you states is a poor diet that does not contain the right amount of nutrients you have.
As I had 2 years Helicobacteria Pyrl that was untreated that time, I become very weak and had bad apetite and as you said malnutrition, as myself doing dieting alot, I do eat very less as boiled chicken, and fish as in oven to grill it, I don't eat much as fruits because most of them containts to much acid, I do eat apple and carrots, Celery. I am very weak as myself a lot and I am trying not to take PPI as I have test for to come soon and I do not want to take it in future if I want to heal it by strengthening my stomach as slim as hard that would eliminate acid reflux as completely. If you need any help with weight loss as to slim your stomach, I can try to help you with specefic methods for exercise, even at home.
Listen this might be occurred and confusing for you and a challenging, but you can try methods that would help you for acid reflux, but for me I can't have those things because of 24h monitor I need to do, when I finishe I will start as myself.
First: Green Cabbage juice is good thing for two treatmens is: stomach ulcer as also known as gastric ulcers, that is develop on the lining of the stomach. This also helps with Acid Reflux as serious reflux problems that people have and many people don't even have it anymore. But remember to have less as 100ml as twice a day as everyda, but remember to mix Green Cabbage juice with carrots and celery: Do not drink Green Cabbage juice only, it needs to be mixed with other stuff as I mentioned there.
Second: Potato Juice: I know you are shocked and surprised of it but Potato Juice helps to heal Gerd. Its good to have in early morning only before you have your breakfast. Remember its up to you if you want to mix it with carrots and celery and apple as all juices, but you can also have it Potato Juice only, its because of the taste is different.
Here is how to make Potato Juice as it shows in youtube: http://www.youtube.co/watch?v=PwD9hrNzGBc
Please, Please, watch it carefully that how he is making it and what is the instructions of what to avoid.
also a little different way to clean it that I got from this site as Instructions: http://www.ehow.com/how_8374594_juice-potato.html