paulflexes saidIt's not metabolism. You just don't eat as much as you think you do. Thin people actually have a SLOWER metabolism, because the lower weight requires less calories to sustain itself.
Get a calculator, read labels, and do the math. You'll be surprised.
Yep, this is how I started making gains. I thought I ate a lot of food! When in reality, compared to bodybuilders, I don't eat nearly enough. Compared to my family, however, they think I'm a food fiend.
Keep track of what I ate on a spreadsheet, I was only getting 50-70g of protein a day and eating around 1500-2100 calories. Not going to make much gains on that intake. Occasionally I would eat more, but not consistently.
Bought protein powder just as a supplement, but mostly just buy tons of food and try to eat it all, and never be in a position where there is not good high protein balanced food available.
Sure enough, I started seeing gains for the first time in years. I'm approaching 170 lbs after being stuck at 155-160. However, really is a chore to shovel the food in!