Tips for gaining weight?

[Anthropos]

I would recommend fat and salty food.

Pizza for example is very nutritious, especially with good toppings. Lasagna another good one. Pasta and cheese or cheese sauce. Fat fish with 40% fat creme fraiche and a choice of carbohydrates. Pork chops with potato pancakes (pancake with grated potato in it) and lingon jam. Bacon and eggs. Shrimp omelette. Crepes.

I have heard that carbohydrates are supposed to be the most fattening, but there are too many negative effects of excessive carbohydrate consumption, some of which are psychological. I therefore think that a more balanced diet is better, as long as it's rich in fat and proteines. Fat has many calories and proteines and cholesterol help build new cells.

Fat food is good for the appetite; one doesn't get tired of it easily. Some even say that it increases the appetite for more fat food.

If you are on medications it may not be an option but a glass of wine or two also could help.

I would also recommend home cooked meals. A lot of premade stuff is low fat to fit the typical stressed out crowd which doesn't want to be fat.

[Era]

Take walks in a park and have red meats at least 3 times a week , cook it yourself preferably, a nice steak make it soft and juicy. Have you checked your blood stats? And yes fruits and vegetables. You don't need to go for the fried foods imo.

[Highlands]

Were the antibiotics taken orally? Antibiotics are in general a big gamble.

Yes, I take antibiotics orally. (It was the only option).

Thanks everyone. I value each and every post.
I will devise a daily food plan and keep track of my calory intake. If you would like to do the same, this website is a good tool: https://www.supertracker.usda.gov/myplan.aspx.

[Catkin]

Sorry you've been suffering, hope you're feeling a little better soon. My grandmother was very thin and struggled to keep at a healthy weight. Her doctor told her to eat a small slice of chocolate cake every day. Not particularly healthy, but it did seem to help a bit, and hey it was doctor prescribed! I think I took all my genes from the other side of the family.