"When you finish the soup, I will give you the treat," says Kayla's mother.
Kayla takes a spoonful and swallows. The rage returns in an instant.
"It's just nasty," she says in a voice that is both screaming and pleading. "Give me treats, I don't have time for this!"
Matos struggles to hold her ground. Hovering in the background is Matos' bewildered mother and Kayla's grandmother.
"There have been times where I just want to pull out my hair and cry," says Matos. "I don't even know what to do."
There are tears in her eyes.
"I've been trying and trying and trying," she says. "We try to control her weight, we do exercise, she's a very active child and I don't know where this compulsiveness is coming from."
A year ago, after extensive testing, doctors in Chicago determined that there was nothing medically wrong with Kayla and that she was simply eating too much and getting too little exercise.
"I believe that Kayla has been rewarded with food," social worker Sandra Vieyra told ABC News last year, "and I believe that therefore, emotionally she likes her food and she wants more and more of it. … It's easier to prevent her tantrum than it is to really stay firm."
Kayla spots some snacks for her big brother's school lunch and demands some.
Matos goes to the car to hide the snacks in the trunk. While she is outside Kayla's tantrum continues. Her grandmother gives the girl her own lunch.
"No, you can't do this!" says Matos to her mother.
"She gave it to her so she could shut up," says Matos with exasperation, now frustrated by both her mother and her daughter. "I don't want to argue with my mother."
One of the reasons the family moved to Florida was so that Kayla could get exercise year round. They left behind a Chicago apartment for a modest home with a backyard and room to run. Matos works nights, her husband works days. Several times a week mother and daughter go to a children's gym for classes and free play.
As Kayla bounces and run and jumps with the instructors, Matos chats with the other mothers, hoping to pick up pointers.
"You have to stand firm," says Tina Danielson. Her 4-year-old daughter Jordan weighs 42 pounds, 60 pounds less than Kayla. "You can't give in to tantrums."
But with Kayla that is a constant challenge.
At the Publix supermarket, Matos tries to choose foods carefully.
"I don't like that!" screams Kayla as her mother selects a healthy cheese. "Put it back! Put it back!"
When Matos picks up bottles of water and passes by the bottles of juice, Kayla gets furious: "I don't like that water!!!"
Then she hits her mother.
Since moving to Florida, Matos has tried to get more medical help — she has health insurance — but when she called to make an appointment with a specialist in December, she was told the first available date is eight months away — in July.
"I told them 'she's 4 feet tall and she's weighing 105, she's going to be 5 years old in a couple of weeks, can't you do something to get me in sooner?'" Matos says they told her, "'I'm sorry ma'am, it's according [to] the child's health priority.'"
We met with Marie Graf, a pediatric dietitian at St. Joseph's Children's Hospital in Tampa. She has now offered to meet with Kayla.