while meal replacements can be a boost for anyone with appetite issues (or unable to cook, or even energy to eat a full meal), I really do encourage people to try to eat some fresh healthy food (not processed, or meal replacements).
Spend a short while on the internet & find the top 20 foods high in nutrition & anti-oxidents. See if you can manage to eat the majority within a week. (my diet is based around them, but I can't eat oats because I get hives).
Secondly, instead of trying to eat lots of food, or different varieties, or large servings, or even looking for great recipes, try getting used to only eating 10-12 fresh foods.
I find I lose interest in food when I try to cook recipes, or eat a varied menu. I'm too tired at the end of the work day.
If I have the very basics of good food, I don't have to think so hard.
Cook or eat different coloured foods & serve on an attractive plate. Makes all the difference if your plate of food looks bright & cheerful. Believe me, it really does.
Also, cook small quantities & serve on a small plate (like an entree). I once saw an English friend serve her small children a mountain of bland, colourless, overcooked vegetables that would have scared anyone away. A third of what she served would have been plenty for a small child. And the broccoli was cooked to grey mush, instead of bright green, al dente cooked broccoli.
I even drink my water out of an attractive glass. Serve vegie juice in a wine glass. I eat from blue or green plates most of the time.
And in the very hot weather, try just cutting up a plate of raw vegies & fruit, with an organic, free range boiled egg or cheese for some protein. Or a can of baked beans on toast with some steamed broccoli. I can't eat beans, but they are a useful protein when combined with bread or pasta (which I don't eat either, but that doesn't stop it from being good for you).
I tried a meal replacement about 17 years ago (to lose weight). Never, ever again.
The most boring, bland thing imaginable (or another one I tried was loaded with artificial flavourings or sweeteners).
Try eating 6 tiny meals a day if you have a poor apetite. If you're house bound, try sitting outside in fresh air for a few hours each day (if weather & pollution permits).
If you haven't got somewhere outside to sit, try opening the windows wide. If it's cold, wrap yourself in a warm blanket, so you don't get chilled.
If you can manage a walk, trying a 10 minute walk morning & night. Don't go too far, in case you're too tired to walk home.
They say fresh air is good for the appetite.
Please do try to eat fresh food.