My high school son is very lean at 4% body fat. He's an athlete (soccer & lacrosse, which is very high cardio)...trying to get him to eat as much as possible (including carbs in his case)...he's a handsome young man, just needs to fill out.
When he eats he gets full...although he needs more calories.
Ideas? Serious question. I'm not sure what is best. He was off the growth curve as a baby and I don't think has a usual number of fat cells. His appetite was never very high even very young.
I don't think he will ever be obese...but to help him bulk up a bit would be great. He is 5'8" and might weigh 120 on a good day at almost 17.
I used to be around the same weight at that age. Probably around 130-135 lbs. Had about the same level of appetite as well my entire childhood. When I joined the military at 20, I was 126 lbs. After basic training, 14 weeks of it, I weighed 151 lbs. Haven't gone back down below that since. Nowadays, I weigh around 165 lbs. During training, my appetite had to increase to match the energy I was burning. Cram down as much food as possible. But I don't think I overate in that instance. It was more than I ate before, but not to an extreme state. Just followed my appetite.
Obviously your son doesn't need to join to bulk up, but I think the types of training might reveal some insight into it. I would say the physical intensity was the better trigger for the growth, rather than simply eating more. Legs probably was the main factor for growth (although upper body came into shape as well) - I've read that working out bigger muscle groups (such as quads) causes more overall muscle growth for your whole body (more testosterone, etc.). Here's a random site (
link here) that supports that, seen others too while quickly searching on it.
In terms of training, trying to bulk up - I recommend generally for him to focus on increasing total weight lifted rather than more reps/cardio. Around 6-8 reps is good for strength. Bench press/chinups/squats are the three main exercises I think are great to incorporate into any workout (but especially for mass building). If he's into outdoors, hiking uphill with weight in a backpack does quite a bit for legs. Sprinting uphill (no weight) is something I'd recommend for muscle building, good for explosiveness and speed as well (for his soccer/lacrosse).
I agree with marmel about the protein shakes. I do 1 shake immediately after a workout, to give the body something to work with. You can do more than one shake a day, but I don't think it's especially necessary - 1 shake during off workout days can help. I stick with knowing 1g per pound of body weight is the 'max' for simplicity, but the numbers he's said are more correct for actual limits. Also note the timeframe is important (spread out over day vs all in one sitting). There's two main protein types as well (for powder) - whey and casein. Whey is good for right after the workout, due to being absorbed quickly. Casein takes longer to digest, so spreads the protein supplying out (good to take between workouts). Milk has about 80% casein, so can drink that if preferred.
Anyway, hope that helps out some, and gives some ideas towards all of it.
