When Did Your Teenage Boy Gain Weight/fill Out?

One of my friends and my SS were always very very tall and lean. They did not "fill out" til they started workouts with weights and got into sports like wrestling and hockey. However, they were not fasting/not eating. SS could eat a horse and go back in the fridge for seconds.

If you think he has an eating disorder, please talk to his pediatrician for guidance. Boys can have eating disorders, too. He doesn't need to lift weights to be a healthy size.

Keep in mind that some people are just skinny. (Wish I was one of them.) We all know some super skinny, adult males. Your son may never "fill out." Try not to worry and remember that he may just be a skinny guy.

hmmmm.....the most worrisome thing that you describe is your son's self-imposed fasting during the day, and then eating a good dinner, but not one that is enough to make up for the lack of calories all day long.

Genetics has a lot to do with when your son will fill out. I have 4 brothers over 6' and they started to fill out, um, in their 40's? Seriously, they are a very athletic, skinny group of guys. Now they are heavy....too heavy.

My son is 14, and is in full on puberty, but he eats and sleeps accordingly. I would never allow my son to go to school on an empty stomach. There's no way. He must eat a healthy breakfast before school/sports. I'm not there to monitor lunch, but I know he eats then too, because I ask, and he's honest.

My concerns are this: a morning green tea and vitamin combo might cause ulcers. Vitamins are worthless without the proper foods for absorption. So he's peeing those right out and they are a total waste of money.

What's his reasoning for not eating all day? No time? Not hungry? How are his grades? Can he focus on an empty stomach? Does he really have the endurance he needs to play a hard game of soccer? If yes, then I suppose it's not a big problem.

Finally, have you taken him to his peds or doctor? They should and will talk to both of you about proper calorie intake. Anorexia is a growing concern amongst boys in America. As a mom, I'd want to rule that possibility out before you chalk it up to the skinny look.

Some of it may just be hereditary. I know plenty of guys who were skinny/slender and never "bulked up" but were tall. I think a bigger issue is that he is skipping multiple meals a day. I'd try to address that. It isn't healthy for a growing teen.

As for lifting weights? My son is 15 and has done martial arts since he was 5. He never bulked up (muscle wise... he did get the prepubescent chub for a short time around age 12 though), even though he had muscle, because it was lean muscle from martial arts and sit ups and pushups type stuff. Not weight training.

He also has access to gym equipment, at home no less. But he had no real interest. Husband uses it daily. Son, not interested.

He began wrestling this summer and the coach encouraged all the wrestlers to sign up for a weight training class (4th block offered during school). Son did and it has turned out to be his favorite class. They offer sound instruction on weight training--not just a free for all to go lift some weight. It is structured and planned out.

He has bulked up quite a bit in just the first 2 months of school due to this mostly. He has always eaten healthy, and eats a LOT. He is 5' 7 1/2" right now and weighs 150 lbs. His body looks very mature and not slim/slender with no form.

I would talk to your family doctor about your concerns (is your son maturing in other physical ways? Is his testosterone production where it typically should be?) and address his eating habits. Why the vitamins and no food for example?

Both my sons were skinny teenagers. One was about 5 ft 10 inches and on a good day, reach 125. He did eat a lot. He stayed that way till a Junior in college.
My other is about an inch shorter and same wt. he started college this yr.
He need something to do and went to their fantastic gym since the last of Aug. He has bulked up but is still thin. I made him eat breakfast in HS, I know, invasive, and made him take a vitamin everyday. He was a pretty picky eater. He now still takes a vitamin everyday and eats a huge breakfast, can't fit lunch in his schedule but eats a good supper. We just loaded him with fruits and snacks and water to go back to college. I also went to Sprouts and got him whey protein to make smoothies in a bullet blender type thing.
I would have worried more about their wt but I knew their dad when we were in HS. Same skinny kid!
I'm saying it will get better. They just happen to get the genes to go with the culture at the right time and played it for all it's worth! Kind of like my straight blond hair when I was young in the 70s! Try not to worry.

My husband was in his early 20's. My oldest son peeked in the 10th grade, my next son (like your son) didn't really start until about the 11th grade, but at 21 is still filling out. It's not unusual for boy/men to continue until about 25.

My youngest always had a skinny build. When he was maybe 16 or 17? I was shocked on day to find that his scrawny body actually had some lovely sinewy muscle on it. He did and does work out some, but I attribute his now more defined build to hormones.

I don't know for sure the science behind this statement, but I think there's a secondary hormone surge in boys' later teens, at 16+ wherein they develop more muscle and some of the less positive qualities associated with hormones. Like acne and a surly attitude.

My son wasn't skinny but he was always small (like his dad.) He didn't actually "fill out" until his first year in college!

Grade 9 during JV baseball season.

My kids are not teenagers yet, but it was not very long ago that my brothers were. 2 of my 3 brothers were rail-thin teenagers and they did not eat much either. In fact, one of them I truly think had some form of anorexia. He is now 30 and seems to pride himself on how little he can eat and how long he can go between meals. He does not look healthy. One of brothers is married now and starting to fill out. My other brother was always a hungry kid and struggles to keep his weight in check (I am the same way).
I am not sure what advice to give you other than vitamins and green tea are obviously not enough! He might always be on the thin side but I would push being healthy. Perhaps mandatory family dinners or breakfasts- not that he has to eat everything that is on his plate but he needs to be there, with you, and healthy food is offered. That meal might be the only healthy thing he eats all day. I do think this is important. I remember as a teenager, breakfasts and lunches were candy bars and cokes from the vending machines, and if my parents had not had normal, healthy food provided at dinner, I would not have eaten anything decent at all.

I am not usually a commenter about weight stuff either. However, his skipping up to two meals a day is a red flag sometimes (and drinking green tea instead is a diuretic with caffeine, often leading to jumping a metabolism rate that he does not need). He COULD have a eating disorder. Boys do. It is not out-of line to address this and may be necessary. He should definitely have filled out a little bit with so much activity (muscle-wise) but with no fuel to build muscle, he will simply burn what is there, leaving him skeletal.

You need to find out whether weight is an issue for him. Does he realize that he is so skinny that people wonder if he is eating? If he thinks that his look is normal then you may have a problem. Also, if he seems to take pride in fitting in the sz. 1 skinny jeans, that is a real sign that size matters in all the wrong ways to him. Good luck!