I have recently bought Whey protein supplement.
I not fond of eating much. I wish to know what kinds food should I consume regularily to gain weight?
Is Whey protein helpful in gaining weight? I also eat eggs, but those propeins are different than Whey proteins? Which proteins would be helpful in gaining weight?
What other foods need to be eaten in what proportion to gain weight?
I am 5 foot 5 inches tall and I weigh 50 KG.
If you're not fond of eating much, it's going to be hard to gain weight. Period. You're going to have to get over that.
Whey is no better than other kinds of protein at gaining weight. Whey is fine. Eggs are fine. But you should be focusing on eating large amounts of actual food rather than trying to solve your problems with supplements.
You should eat food. Food that is proteiny: meat, eggs, milk, yogurt, kefir, eggs, lentils. Food that is carby: potatoes, rice, lentils. Food with good fats: olive oil, avocado, coconut. You should be eating a lot of all these things and lifting heavy weights too.
Thinking about what proportion of food you should be eating is fine tuning. How to gain weight? Put butter on everything and fast food. I find consuming simple sugars (soda or tang or juice) will help me keep my appetite up.
The real problem is your lack of appetite. Are you hungry a couple hour or so after you work out? If you are not you might not be lifting heavy enough. Is stress killing your appetite? You need to not be stressed.
For general tips on nutrition and gaining weight, see e.g. What can I do to start gaining weight? or I am underweight. How do I gain weight and muscle? or have a look at a sample workout/nutrition plan.
There is some evidence that Whey protein may be more potent than others(you can google for a paper entitled "Ingestion of whey hydrolysate, casein, or soy protein isolate: effects on mixed muscle protein synthesis at rest and following resistance exercise in young men", unfortunately i can only post a limited number of links)
Your BMI (18.3) suggests you are slightly underweight and should indeed eat more. Nutrition supplements like Whey and other protein shakes (By the way, Nutritional supplements specifically designed for gaining weigth are called weight gainers) can help you gain weight, but they alone will not suffice.
My suggestion: Read up on the links above, but take it from me as someone who for years has had a BMI of 17.3: If you are not already doing so, you need to start working out and do some kind of physical activity. Monitor your weight and fat gain closely, make sure you gain (mostly) in muscle, not in fat.
TL;DR: Start eating (more and healthy!) and lifting ;-)
