I am really slim please tell me balanced and good diet by which I can be healthy I am 18 and my weight is 40kg plese tell me how do I get healthy?

Eat fresh whole foods, and enough of them. Base your diet on eggs, oily fish, fresh meat and chicken, lots of vegetables, fruit, nuts, seeds, dairy and wholegrains. Try to avoid processed food and things with a lot of sugar.

Eat breakfast, lunch and dinner, and if you exercise, have somethiing afterwards which contains protein and carbohydrate.