Im going to share my exprence and diet first if you want you gain healthy waight gai  you need to stop eating jung food all you need to eat healthy and good food carbs fish chicken and vegetables 

In morning breakfast 5 egg and 30 gram oat's one cup milk with banana and some nut's and in lunch you need to eat rice and 1 chicken breas and after 2 hours you need to eat some snaks like kidne bens or rajma and you have to heavy workout ypu need to focuse on chest shoulder and back workout like pullup and pushup like on chest workout do bench press 8 rep

And shoulder workout: dumble press amd dumble cul.

And in back workout do some bar pullups

And befour workout you drink shake like 2 banana i low fat milk or 5 almound and nut's

Do 50 min workout follow this diet and workout 2 week.

After 2 week change your workout like 

Diet in break fast you eat oat's and banana shake 

In lunch 2 cup rice and eat meet if you are vegetrean and soya bean and drink 6 liter water every day 

Eat some frut's like avacado,banana, apple, 

And befour workout drink banan shike and and in dinner eat fish carry in diet 3 week .

After 3 week chinge diet and wortout 

In breakfast in raguler oats and 6 eggs 

In lunch rice and meet or chicken or bole ckicken with black papper 

Befour workout brink banana shake after workout eat boil chicken and fish it's help to recover fast your body and every 2 week take full body massage with oil its help 

And do abs workout every week end 

And in 4 week you need you eat more like 60 gram oat's amd 9 egge 2 hole eggs and 6 white and in lunch eat 3 cup rice and 2 chapti and fish or chicken your choise and if you are vegetrean eat potato and sweet potato soya been mashroom and carot and eat fiuts apple orange avacado and befour workout drink 5 banana 1 apple and 1 cup low fat milk shake and after workout eat 3 chicken breast and 4 fish do this and you feel changes in your body and keep doing workout and don't eat junk food.

I hope you like it and its help you