Jeff Hampl, an associate professor of nutrition at Arizona State University, says that if the body doesn't get the proper nutrients during a childhood growth spurt, it may never recover. The growing brain is particularly vulnerable to nutritional deficiencies.
Hampl, who hasn't examined the children, says that if their intelligence hasn't been affected by now, it probably won't be. But behavior problems and attention deficit disorder symptoms could manifest themselves. Sometimes, there is a deficiency in iron in malnutrition cases; iron is needed in the right quantity to carry oxygen to the brain. It's also probable that the kids will be underweight their whole lives, he says.
Many people impose veganism on their children without the kids suffering health problems. In the Parker kids' case, the food was vegan, but there wasn't enough of it.
The number of vegetarians in the United States may range from 1 to 3 percent of the population, but no one really knows how many kids are being raised vegetarian or vegan.
Hampl, a self-described omnivore, says most children start off as vegans, taking breast milk from their mother, then are weaned on whole-grain foods like Cheerios.
Hampl says parents don't need to be experts to raise vegan kids, but they do need common sense.
"You can get into trouble," Hampl says. "But [a vegan diet] can be done safely."
Lana Davis, 27, who recently moved from the Valley to North Carolina with her husband, says her 3-year-old son has never eaten an animal product. She says it's frustrating to hear veganism linked to the Parkers' and similar malnutrition cases in other states.
"Damien is proof that eating vegetables can make you strong, because he's very healthy," Davis says.
But it's not easy, she says of her boy.
"I don't get to crack open a macaroni-and-cheese box and have dinner that way," she says. "Unfortunately with veganism, it's not either cheap or fast when it comes to food."
One troubling aspect of veganism in young children is that parents (the Davises included) usually choose the diet because of concern for animal rights. Good health may be seen only as a side benefit. That can lead to tunnel vision when deciding what's best for kids.
Phil Parmenter, a 45-year-old Fountain Hills resident and IT worker, says he thought about that a lot when he became vegan four years ago and began putting his son, then 5 years old, on the diet.
Already a lacto-ovo vegetarian for 19 years, Parmenter decided he could be objective enough to make the right choices. For instance, he and his son get flu shots even though they are made with eggs. (He says he feels sad for chickens who sit in small boxes, barely able to move, at mass-production farms, but he allows the shots anyway out of concern for his and his son's health.)
"I wish there was another way," he says.
Nine-year-old Arion isn't a pure vegan. Parmenter is divorced, and his ex-wife feeds Arion a diet that includes meat when he's with her.
At one point during his interview with New Times, Parmenter asks the boy if he would rather eat meat.
Arion looks at his father for a long moment, shakes his head and says, "It's disgusting."
Parmenter says he believes he and his son get all the high-quality protein and amino acids they need from non-animal sources. "Some people would disagree with that," he says. "But they're wrong."
Meals at the Parmenter house consist of soy products (he calls them "meat analogs") and legumes, such as beans. Vegetables like spinach and broccoli are important. They eat their veggies fresh or frozen, usually cooking them in the microwave for a few minutes. They take a vegan multivitamin daily.
Asked repeatedly what his favorite vegan food is, Arion says, "I don't know."
His father prompts him what about tofu scramblers?
The boy says they're okay "but they're all flingy and floppy."
Finally, Arion acknowledges he enjoys vegan hamburgers or vegan chicken burgers.
Carol Johnston, another ASU nutrition professor, disagrees with her colleague Hampl on the issue of raising vegan children, though she is a vegetarian. Vegans may give their children food supplements to make up for vitamin or mineral deficiencies but those supplements aren't regulated by the government and may not contain the necessary quantities of nutrients, she says.
It's better to feed kids a wide variety of food, including animal products, to make sure they're getting the right stuff in their growing bodies, she argues.
Humans evolved to eat meat, she says, a fact evident to scientists because of our short colons. Animals that eat more fibrous plant material need a larger colon to digest it.