I'm happier giving you an answer for Virginia, although, I think it would roughly apply to most of the colonies with some regional differences.

Most people ate a lot of corn and pork, especially in the winter. The corn was in the form of meal mostly. Most of the time it was probably corncakes, (Pancake like things made with cornmeal, water and maybe an egg) not the cornbread we are more familiar with. The pork was almost always preserved in some form. There were a lot of pigs in colonial 19th century America. They were usually let loose to roam around in the spring and summer and rounded up in the fall when many of them would be slaughtered. People would preserve that pork to make bacon, salt pork and the like and would eat it throughout the year. You might supplement that with game, depending on where you were, maybe even in the winter. Perhaps the occasional vegetable or green might enter into the diet, although that gets tough in winter, but the corn and pork were the mainstays.

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In general, most people got enough food. There is some evidence that people living in the colonies and then the United States in the 19th century were significantly taller than Europeans, probably because they got more protein and generally were able to eat more. If you're interested in some of this, I'd recommend the The Alcoholic Republic, which discusses diet as well as alcohol intake. Most people barely drunk any water at all and drunk huge amounts of cider and rum.