Comparing Body Mass Index in the 1970s to 1980s.

Comments and Key points about this article on the range of body mass index values

This article shows tables of data comparing American’s Body Mass Index (BMI) in 1976-80 versus 1988-94. The data is ‘late 70s’ compared to ‘late 80s’:

Median BMI	Men		Women
	1976-80	1988-94	1976-80	1988-94
Age 20 to 29	23.7	24.3	22.0	22.7
Age 30 to 39	25.1	25.7	23.1	24.4
Age 40 to 49	25.9	26.3	24.1	25.4
Age 50 to 59	25.8	27.2	25.3	27.1
Age 60 to 69	25.7	27.1	25.6	26.6
Age 70 to 74	25.2	26.1	25.9	26.3

Are these average body mass index?

Yes. You can see how everyone got heavier from 1980 to 1990.

And the average BMI changed according to how old you were.

The article also shows children’s data, comparing 1963-70 versus 1988-94.

Median BMI	Boys		Girls
Age	1963-70	1988-94	1963-70	1988-94
6	15.4	15.7	15.2	15.3
7	15.6	15.8	15.5	15.8
8	15.9	16.3	16.0	16.6
9	16.2	17.0	16.3	16.6
10	16.5	17.7	16.9	17.3
11	17.2	18.3	17.5	18.5
12	17.7	19.0	18.5	19.4
13	18.7	19.5	19.3	20.5
14	19.6	20.8	20.2	21.1
15	20.3	20.9	20.6	21.1
16	20.7	21.1	21.0	21.2
17	21.4	21.8	21.0	22.2

Children’s average body mass index also got a little heavier too, between 1980 and 1990.

Yeah, a little bit.

When this data is graphed, you can see the pattern, that children and adults are heavier (probably fatter), recently in the 1988-1994 survey.

Changing BMI of the USA population

That’s it. This actual article managed to show 11 pages of description, analysis, hypotheses and discussion. But I have summarized the bottom line.

Eleven pages, summarized into dots on one chart.

These NHANES studies are the 800-pound gorilla in the room, by which I mean, an incredible resource of good data that is trustworthy.

Now lets add a little more talky talk into this little article. One thing I noticed, is that if you just use the NHANES data purely, like this study did, then the childrens values and the adult values are nicely lined up with each other. My charts show a little artificial gap between childrens and adults data, but if you ignore that whitespace, the pink and orange square dots, and the blue and green diamonds, seem to flow nicely together, as they should. In contrast however, later in the history of the CDC setting growth charts, they created a noticable problem by compressing childrens values into a data range that they were hoping for, causing childrens and adults data to no-longer flow nicely together.