The boy's Body Mass Index (BMI) reached 41 — more than double a healthy weight for his age — when he was only two and a half years old, and he was suffering from sleep apnea and bowed legs because of his excess weight, the paper published in the International Journal of Surgery Case Reports says.
The child's parents brought him to the doctor when he was two years old and tests ruled out genetics or a brain tumor as the likely cause of his obesity, the study authors Mohammed Al Mohaidly, Ahmed Suliman and Horia Malawi wrote.
But several months after doctors at an obesity clinic prescribed a strict diet to help the boy lose weight, he gained even more weight.
The authors wrote they didn't know if the parents had followed the diet.
In April 2010, he received a type of bariatric surgery called a Laparoscopic Sleeve Gastrectonomy (LSG), becoming the youngest child known to receive the procedure. The authors wrote the boy recovered well after the surgery and his BMI dropped to 24.
The last young child that underwent the irreversible surgery was a five-year-old, also from Saudi Arabia, according to the study.
Australian obesity expert Paul Zimmett told News.com.au the case was "shocking," and researchers know nothing of how the surgery could affect the child as he grows up. Zimmett compared the case to space exploration.
"It's going into unknown territory," he told News.com.au.