In my case I am allergic to soy & whey so the weight gaining drinks can't work. They also have lots of sugar which is the #1 no no for the diet. For others they sit very heavy and don't work on a gentle stomach.
Just recently by the grace of God I was pointed toward a wonderful product called Benecalorie. Each one ounce serving cup has 330 calories. You can easily put it in a smoothie and instantly make it 600 calories. Half a days worth of food. It mixes into anything. Mashed potatoes, pudding, any other food really. It's made up of made different fats. No whey, no gluten, no sugar, no soy, nothing that could cause allergy & super versatile.
I had searched for supplemental nutrition for years & I have no idea how I just NOW found it, but I credit God. So I wanted to share this with anyone else who is struggling with an illness or Lyme that needs healthy calories in small servings. It's been a life saver for me.