Anything unatural shouldn't be considered safe. You can give him "Gain powder" but i suggest you visit your MD before doing so.
no
You will gain weight if the amount of energy you take in is more than the amount you use.
Steroids
yes, each year you should gain about 8-10 pounds, 12 year olds are growing so they will gain weight which is perfectly natural.
The average weight gain for a one year boy is to triple their birth weight. Most children that are one year old have grown by 50 percent and have gained 9 to 11 inches since birth.
yes
6
Thats whats happening to me i weight 155 i gain pounds from out of no were
A 97 pound 18 year old could gain weight by exercising and adding protein to his or her diet. This person could work with a nutritionist to find the best diet for weight gain or try adding calories using protein shakes.
Eat protein and carbohydrates. If you consume more calories than you burn then you'll gain weight that way too.
Yes.