Liam's mom, Brie Heggan says, "He eats no meat at all, his only protein comes from peanut butter and yogurt."
Dr. Katherine Dahlsgaard of Children's hospital says most kids go through a "picky" eating phase, starting as toddlers.
But while "picky" eaters accept more foods over time, "selective" eaters accept fewer.
Dr. Dahlsgaard says, "Selective eaters eat probably less than 20 foods. Mostly, they stay away from fruits and vegetables, and meats."
They tend to like beige or white, very plain foods, such as buttered noodles or plain pancakes.
And they often eat only one brand of a food.
Experts don't yet know what triggers selective eating.
But Dr. Dahlsgaard says some seemingly logical strategies just don't work, such as packing lunches or they'll grow out of it and when they're hungry enough, they'll eat a new food.
"In my experience, we end up with a kid that hasn't eaten for 3 days," said Dr. Dahlsgaard.
Sneaking new food into an old favorite also fails.
Dr. Dahlsgaard added, "My picky eaters pick these things out immediately."
Therapy involving small amounts of a new food every day help some selective eaters increase their range.
But some continue their ways into adulthood.
Brie Heggan recalls she was a very picky child, but is the opposite now.
She hopes Liam will be too, someday.
"He's very normal on scale of weight, height, and everything else, said Brie.
For more information on developing healthy eating habits in kids, click on Feeding Tips for Picky Eaters.