Brief Answer:
First,find out the causes to non-gaining weight...
Detailed Answer:
Hi,
I have gone through your query carefully and understood your concerns.
To understand that you have a normal weight according to your height, you should look at the weight-height chart:
http://www.rush.edu/rumc/page-0000.html
So, for your height 6'0, the weight 165 falls within the ideal range. That's why your doctors has assured that there is nothing you should be worried about.
Next, you are at the age of 24, with highest
metabolism rate, which also explains why you are not gaining the weight you aim to.
By passing of time, after 30s, as the rate of metabolism will be reduced, you will gain more weight.
Next, being physically active is also another factor contributing to burning all the calories you get all the day.
I also suggest to check for your
thyroid function as might interfere with gaining weight. The main aim is to find out what is causing you not to gain weight, then, should think over how to gain weight (by fighting those causes or changing diet and lifestyle strategies).
When it comes to gaining weight, I advise my patients to have regular meals (5 times/day) and increased calories for each meal. Once again, your weight is ideally accepted for your age, and to my opinion, you should not worry about gaining more weight, but to keep healthy and fit.
Hope it was of help!
Feel free to ask me other questions you might have!
Dr.Albana