My Dd ate a kilogram - 2.2 pounds of food a day when she was weaning (ages 6 months to one year). that was 10 little 100g pots of whatever I had ground up for her every day. She ate a HUGE amount, and grew and grew.
She was breast fed on demand also till 9 months, when she self weaned and then had 5ooml (16 oz)2X8oz) formula every day, along with her kilo of pureé. I used to run to the kitchen and get another homemade frozen leek and chicken or vegetable pureé dinner out of the freezer for her.
For a bit of variation and if we were out and about, I used to feed her Heinz organic, just natural vegetable, parsnip and pea pureé and fruit pureés, to top her up.
Now, at 4 she eats a reasonable amount,(as much as me really) an egg with toast soldiers for brekkie, her fist size of potatoes / pasta / rice and her fist of salad / veges and her fist of protein for lunch and a few spuds and a 100g - 150g salmon steak for dinner, with salad and ice cream for desert...
She's really tall for her age (3.5 foot) and very very active. She's slim and we need belts for all her age 6 to 7 jeans for her.
She drinks a lot of water also. Glasses of the stuff throughout the day - she gets them herself now which is great..
My Dh is tall and slim, as are all of his family. His sister is 5'11" and I would say DD is headed up in that direction.
I've never forced my DD to eat, and she knows where the fruit bowl is if she wants a snack. We also have rice cakes, carrots and nuts on demand also.
Don't worry if your DS is eating you out of house and home before they are one, after my DD turned one she slowed down her growth and intake, and now eats as much as me.
It is a bit frightening when you're just feeding lots at high speed and the little mouth opens up again again for the little spoon. I used to stand back sometimes and wait for DD to explode but she never did.
She'd turn away eventually and that was it! Meal over, Finito.
HTH