Ideas for adding weight on? Healthy

I haven't gone to research your condition and disorder, so take what I say with a grain of salt...please. The weight-gain mechanism of the body is simply one of endocrinology. When we eat, we secrete insulin, but only in response to carbohydrates, weakly to protein, and not at all to fat consumption. What will make you deposit fatty tissue is the insulin. Insulin is a 'storage' hormone' meant to help regulate blood sugar levels. If the blood glucose level gets too high, the body uses insulin to force some of that excess into adipocytes...fat cells. As you store fat, you gain weight.
There is a weak insulinic response to protein. If you want to gain 'healthy' weight, you want muscle growth. The best way to do that is by stimulating another element of the endocrine system, HGH, or human growth hormone. The best way to do that is with HIIT...Hight Intensity Interval Training. It's not for everyone because it is difficult, but if done properly, you can gain muscle weight. The assumption is that you don't have any metabolic or other endocrine defects that might prevent the proper use of any proteins.
Your questions are best posed to an endocrinologist or to a specialist in human kinesiology. If you'd like to investigate HIIT, you can just do a word search on YouTube and watch your fill of videos where people show how it is done, and why it has benefits. One good channel is Mike Muzzle's channel: https://www.youtube.com/watch?v=6xXQU_urTtY

Hello @smartinly
Before starting treatment for DBLC, I lost over 20 pounds and was quite thin. I attended a pre-chemo workshop with the hospital's nutritionist. She mentioned that some of the weight loss is due to loss of muscle along with fat. She recommended a loaded smoothie and nutritious but vegan-friendly options for me. I want to share some easy and tasty ways I picked up 12 pounds a couple of months before chemo.

Before I go into details, have you spoken to the nutritionist at your oncology center? Also, the Leukemia and Lymphoma Society offers a free one-on-one session with a licensed nutritionist—lls.org.

Nutrition
I couldn't keep much solid food down, so I started drinking a "loaded" smoothie, which was about 400 to 500 calories, but I made it taste good. Smoothy Recipe: One scoop of chocolate protein powder (I'm not pushing a brand, but I used Vega One's all-in-one meal replacement 140 calories), one serving of almonds (170 calories), and one serving of mangoes (80 calories). Sometimes, I added another serving of my high-calorie fruit of the day to increase my calorie count or 1/2 cup of cooked brown rice.

Note: I own a Vitamix, which can churn up these ingredients.

The nutritionists recommended eating things like premade, jarred artichoke salad and olives, which are packed with calories and fiber.

Exercise:
I also walked and bounced on a rebounder (mini-trampoline) to build muscle. The mini-trampoline is fun, gentle on the joints, moves lymphatic fluid, and can be made safer with a handlebar. I already owned one. So, it was a matter of getting on and bouncing.

Hi. Thank you for taking time to reply. At this point I haven't talked with a nutritionist. I believe I will need to set one up. I liked that recipe. Thank you. I have a vitamix also. I should have mentioned the appetite is like mental and physical. Times food doesn't sound good but at times when I do eat I get full right away. The damage to my stomach I believe is the cause. So a smoothie packed with those ingredients will help me along the way.

I hope you find a solution. My DBLC (diffused B cell lymphoma) lesion was in my stomach lining. I had that "feeling full" issue until I started treatment. After the smoothie (sometimes 1/2 and finished at another time), I ate about three or four small meals or high-calorie, healthy snacks. OK, sometimes, vegan chocolate made an appearance.:-)

One more thing: Vega One All is One can be quite pricey. You may want to buy a smaller jar to try it out. Also, Amazon often provides a much lower price, or you can choose an Amazon subscription plan (which you can cancel after delivery). I have other savings tricks, but we'll leave it there for now. 🙂

Thx very helpful