Americans are fat. The latest obesity estimates reach as high as 30% of the population; and the future looks worse. There’s been much hand wringing over the years, with a new television show sprouting up every season imploring the obese to lose weight.
A new paper by researchers Charles Baum and Shin-Yi Chou provides a detailed look at the leading indicators of weight, using the National Longitudinal Survey of Youth from 1979 and 1997 to compare the habits, similarities and differences between people of the same age – just a quarter century apart.
The results aren’t pleasant: the largest effect on our recent weight gain? The decline in cigarette smoking.
Here’s the abstract:
We simultaneously estimate the effects of the various socio-economic factors on weight status, considering in our analysis many of the socio-economic factors that have been identified by other researchers as important influences on caloric imbalance: employment, physical activity at work, food prices, the prevalence of restaurants, cigarette smoking, cigarette prices and taxes, food stamp receipt, and urbanization. We use 1979- and 1997-cohort National Longitudinal Survey of Youth (NLSY) data, which allows us to compare the prevalence of obesity between cohorts surveyed roughly 25 years apart. Using the traditional Blinder-Oaxaca decomposition technique, we find that cigarette smoking has the largest effect: the decline in cigarette smoking explains about 2% of the increase in the weight measures. The other significant factors explain less.
The researchers examined differences in employment, physical activity at work, food prices, prevalence of restaurants, cigarette smoking, cigarette pricing, food stamp receipts and the prevalence of urban sprawl.
They found that: “(i) occupational fitness and strength demands significantly affect weight, (ii) cigarette smoking (and being a cigarette smoker) significantly decreases weight, (iii) food stamp receipt significantly increases weight, and (iv) urban sprawl significantly increases weight.” The decline in cigarette smoking, however, only makes up about 2% of weight increase, and the authors saw their criteria show only small percentage changes in weight measures as a whole, as opposed to other studies with much higher numbers.
The authors write: “Ultimately, the socio-economic and demographic factors examined in this analysis, whether considered individually or collectively, explain a minority of the increase in BMI, overweight, and obesity.”