Well to bulk up you have to ask yourself a few questions?
How old are you?
Do you have any hobby's that are aerobic in nature? example: Running, biking?
Do you lift weights anaerobic workouts?
If so how long are your workouts and what is the frequency?
How many times a day do you eat?
What times of the day do you eat?
What foods do you eat mainly?
The reason I ask is I was once in the same boat 6'2 and 125 pounds. I was real frustrating to say the least. Matter in fact that was one of the reason I went into the Marines. In bootcamp (12 weeks I went from 125 to 163 lbs. That was 15 years ago and today I weigh 190 lbs. It's the opposite now I now have to eat less to maintain my weight. You have been gifted with a fast metabolism which is a good thing. You just need to adjust your lifestyle a bit to start gaining weight.
If you want to put on weight you need to first up your calorie intake to say 3000-3500 calories a day.
Second cut back on the aerobic exercise.
Third eat fewer meals a day. Suggest 3 versus 6 and eat supper two hours before bed.
Fourth eat high carb foods: Baked Potatoes, Rice, Pasta, Bread, Waffles,
Eat high glycimic idex foods: Bananas, watermelon, canned apricots, fruit ****tail.
Eat less fiber....
Fifth weight lifting, keep the weights heavy and the reps around 8-10 no more than 3 sets.
Sixth the secret weapon is to wake up about 2:30 in the morning from bed and drink a carb/protein loaded shake.
This should start you on your way onto gaining weight.. ...
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