Weight gain in the American population 1960-2000 [View all]

[eridani]

http://www.cdc.gov/nchs/data/ad/ad347.pdf

The definitive data are in the above paper. I used the Excel chart function to see how the numbers came out visually. What really jumped out at me was that the crucial dividing year was 1980. Any discussion of possible causes must use this year as a reference. The internet was not in widespread use until the late 90s, so that isn't it. What about HCFS? Was 1980 a turning point of some sort nutritionally? One obvious point to make is that that year is the start of the destruction of the American middle class.

The NHANES studiess are by decade--1960, 1970, 1980, 1990 and 2000. Do a linear regression on 1960, 1970 and 1980, and then on 1980, 1990, and 2000. You get pretty straight lines as indicated by the correlation coefficients. The slopes are an indication of the rate of increase in average weight gain.

Men 1960-1980
Slope = 3.75
R2 = 0.7899

Women 1960-1980
Slope = 2.56
R2 = 0.9204

Men 1980-2000
Slope = 8.6
R2 = 1.000

Women 1980-2000
Slope = 9.4
R2 = 0.9976

For men, after 1980 the rate of increase increased by a factor of 2.3 times.
For women, after 1980 the rate of increase increased by a factor of 3.6 times.