Final answer:
The specific percentage of U.S. children between 2 and 19 years who are overweight or obese is not directly provided, but with adult obesity rates at nearly 36% and overweight rates at 33%, and the rising trends in childhood obesity, it's indicated that a significant portion of children is affected.
Step-by-step explanation:
The student has asked about the percentage of U.S. children between 2 and 19 years of age who are either overweight or obese. Looking at the provided statistics and focusing on childhood obesity, it is indicated that the level of obesity among children is rising, which is a trend paralleling that of adults. The specific percentage of children affected was not directly provided in the provided material, but with the recognition of obesity as a serious public health concern and data on adults indicating that 36 percent were obese and 33 percent were overweight, we can infer that a substantial portion of the child population is likely affected as well. It's important to note that obesity in children is diagnosed using BMI reference values, comparing a child's BMI with that of large samples of children of the same age.