Suddenly, the rules have changed for 6-year-old Jesús Emilio Adame.
His grandparents used to let him eat whatever he craved, despite his growing waistline.
Now Jesús ponders food portions and restrictions after a pediatrician warned his grandparents that he was at risk of becoming diabetic.
"It breaks my heart," his grandmother Elisa Ramos, 62 says. "To me, he's just a baby and I feel awful not being able to give him whatever he wants."
She and her husband, Gilberto, 67, are raising Jesús, whose parents were killed in a car wreck five years ago.
The couple are diabetic and both have multiple related ailments. They want to spare Jesús from the same fate.
Changing the first-grader's eating habits is a daily tussle.
He loves tortillas, pizza, hamburgers, bread, macaroni and cheese - heavy on the starch and carbs, low on protein and vitamins.
The couple's fixed income won't budge for club sports memberships. Jesús' school offers PE only once a week. There is no nearby park. And the family's south-side neighborhood is not safe for Jesús to run and play outside.
"Sometimes we go to Reid Park to see the ducks," Gilberto says.
The grandparents have splurged on a Wii video game to encourage Jesús to exercise indoors. He says one of his favorite games is tennis, and he dreams of playing the real game someday.
Because he's on AHCCCS, Arizona's health-care program for the state's poorest residents, Jesús sees different doctors. Some have said he should be allowed to eat whatever he wants, but "just a little."
"When I tell him he shouldn't eat something, he gets upset and reminds me the doctor said yes," Elisa says with a sigh.
Jesús has started shedding pounds, but Elisa says purchasing "good" food with the $260 a month the family receives in food stamps is a chore.
On a recent shopping trip, Elisa visits the deli, where she picks up chicken sausages and light cream cheese. Then she goes to the produce section and gets bananas, apples and romaine lettuce.
"No, this is not enough to afford a healthy diet. I make the most out of our money," says Elisa, who makes wheat tortillas to save.
"We don't eat out," she says, "and we only buy pizza and burgers for him once a month."
Back home, Jesús rushes into the kitchen after school to show off a green Saint Patrick's Day necklace he received from his PE teacher.
"I ate my veggies. That's why they gave it to me," he announces.
A couple of weeks ago, Jesús had his medical checkup.
"The doctor said he is doing good ," Elisa says. "Now he is again wearing clothes that didn't fit because he was very heavy."
She hasn't declared victory. Instead, Elisa says she is collecting information and advice to continue the battle.
How much exercise do children need?
Children and adolescents should do one hour or more of physical activity each day, the U.S. Centers for Disease Control and Prevention says. Most of that activity should be moderate aerobic, such as brisk walking, or a vigorous activity such as running. The CDC says it's important to include "vigorous-intensity" aerobic activity at least three days per week. Vigorous-intensity means the child's heart will beat much faster than normal and the child will breathe much harder than normal. Nearly 70 percent of Arizona children between 6 and 17 are not meeting the CDC's recommendation for physical activity, the nonprofit Trust for America's Health says.