Dr. Glenn Flores, a pediatrician at the University of Texas Southwestern Medical Center, said surpassing the 85th percentile for Body Mass Index at 9 months of age is one of the most powerful predictors of severe obesity, which is defined as being above the 99th percentile of average Americans at any given age.
By the time children start kindergarten, 6 percent are already severely obese and on the path to a lifetime of health issues from diabetes to heart disease, Flores said.
"Multiple risk factors associated with obesity play a role, ranging from the sugary drinks children consume to their bedtime habits," Flores said in a statement.
The risk for obesity can start even before birth. If the mother was severely obese just before her pregnancy, it's likely her child also will face weight problems, while being Latino or multiracial is also associated with severe obesity among kindergartners, Flores said.
The first step to reducing the risk of obesity is screening for children who are at high risk. When children are 9 months old, children's BMI and growth curve should be monitored, Flores advised.
Parents can also reduce the risk of having a severely obese child by:
-- Starting at 9 months of age, take the child outside for exercise or play at least a few times a week.
-- Maintain strict bedtime rules because a lack if sleep increases the risk of being overweight.
-- Make sure children eat fruit at least weekly.
-- Avoid consuming sugary drinks.