That's true, but only with children under 4 years old, which isn't tremendously meaningful. Few three year olds are allowed to make their own food choices, and

That's true, but only with children under 4 years old, which isn't tremendously meaningful. Few three year olds are allowed to make their own food choices, and thus may be restricted in weight despite innate hunger due to the fact that adults are limiting their food intake. Not to mention that the US CDC measures childhood obesity as weighing above a percentile of the population, an even more tenuous measure than BMI.