: What can I do to start gaining weight? I am 6 ft tall 20year old boy. I currently weigh 60Kgs. I take regular diet which consists of morning breakfast, milk, day lunch, evening snacks, dinner and half liter milk in night

Eat more than you burn, e.g. Michael Phelps eats mad amounts of food but he isn't overweight because he burns mad amounts of calories.

Calculate your daily calorie intake and estimate how much you burn through manual work, walking, exercise and sports, etc.

If comparison of the two does not result in substantial excess of calories you will not be gaining weight.
However, if the math does add up then I'd agree with @Madhuri Sathe's suggestion about medical examination.

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You might have a fast metabolism but it would be very useful if you shared an example of your daily intake so we can see how much and what you eat.

You should eat a lot of proteins and the right ammount of carbs and have enough sleep (at least 8 hours a day) in order to gain quality weight.

When I started to train I went to the gym 4 times a week, each time exercising 2 muscle groups and abs and used the following diet:

Morning:

3 egg whites

1 cup of cereals with low-fat milk

Snack:

sanwich with integral bread and turkey ham

low-fat yogurt

Lunch:

pasta or rice

300g of meat (turkey, chicken, horse or fish)

vegetables

Snack:

2 apples

Dinner:

300g of meat

vegetables

If you are a healthy person, eat the right ammount of quality food, exercise well and sleep enough sooner or later you will get the right results. Many people complain about not being able to gain weight but in most cases it is not because of metabolism or health issues but the matter of incorrect daily habits.

Hope it helps!

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If you are not gaining weight in spite of eating high calorie, high protein foods at regular intervals of 2-3 hour:

Before thinking of weight gain by diet way, check other medical problems.
Blood examination to check-hyperthyroidism or any other disease condition.
Stool examination for any worms problem etc.
For this consult a Doctor (general physician), confirm you don’t have any medical problem. If you have any medical problem then start the treatment with proper therapeutic diet. Your weight gain problem will get solved.
If you don’t have any medical problems then go to a dietitian for weight gain because weight gain is not that easy to do on your own.

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