There have been a number of articles about obesity and children, and frequently there are words used such as “surge,” “epidemic,” and “growing problem.” Let’s take a look at what the issues are.
Obesity has a popular meaning (just plain fat – we know it when we see it) and a technical meaning. Overweight (chubby) is the same. And here comes the interesting thing: official technical meanings of these two words have changed. They deal with the body mass index, or BMI, which is the ratio of weight to height, and is arrived at by the following method: multiply the weight in pounds by 703, then multiply the height in inches by height in inches, then divide the first number by the second. If using the metric system, the numbers are weight in kg divided by the square of height in meters.
Before 1998, a BMI of 27 or more was considered overweight. But in June 1998, new cut-off weights were implemented. The BMI for overweight became 25 to 30, and anything over 30 became obese. Thus, overnight a lot of people became overweight who were considered normal the day before.