Thursday, April 27, 2006

More Restaurants = More Pounds

The more restaurants per capita in a state, the greater the weight gain of the state's population during the past 25 years, finds a study by the National Bureau of Economic Research ("The Super Size of America: An Economic Estimation of Body Mass Index and Obesity in Adults," by Inas Rashad, Michael Grossman, and Shin-Yi Chou). In fact, 54 percent of the increase in Americans' body mass index between 1976 and 2000 can be explained by the increase in restaurants per capita.

How does this work? Here's a theory: As fast food has become part of the daily diet, and as the number of fast-food restaurants has proliferated, Americans eat out more and they eat more when they eat out. The increasingly fierce competition among restaurants has created an arms race of sorts, boosting portion size. When people eat out more, they also consume more calories. Average daily intake grew from 1,854 calories in 1977-78 to 2002 calories in 1994-96, say the NBER authors.

According to a report by the National Center for Health Statistics ("Mean Body Weight, Height, and Body Mass Index, United States 1960-2002"), the average woman gained 19 pounds between 1976-80 and 1999-02. The average man gained 17 pounds. But an examination of weight change within cohorts reveals an even more alarming trend. Boomers have put on much more weight than their older counterparts.

Take a look at what happened to boomers. In 1976-80, the average man aged 20 to 29 (born roughly between 1947 and 1956, this cohort includes most of the oldest boomers) weighed 167.9 pounds. By 1999-02, the same man (now aged 43 to 52) weighed 196.0 pounds. During those years, he gained a whopping 28.1 pounds—63 percent more than the average man. This is a much greater weight gain than experienced by older men. Men aged 40 to 49 in 1976-80 (this cohort was born roughly between 1927 and 1936) gained a smaller 11.8 pounds by 1999-02.

For boomer women, the picture is even uglier. Women aged 20 to 29 in 1976-80 gained an average of 32.5 pounds by 1999-02 (when they were aged 43 to 52)—greater than boomer men's weight gain and more than double the weight gain of their older counterparts. Women aged 40 to 49 in 1976-80 gained only 15.9 pounds by 1999-02.

Why have boomers gained so much more weight than older Americans? One factor could be boomer women's greater labor force participation, which resulted in more restaurant meals. And boomers appear to have passed on those eating habits to their children. The average woman in her twenties today weighs 156.5 pounds. That's 21 pounds more than boomer women weighed at their age. The average man in his twenties weighs 183.4 pounds—15.5 pounds more than their boomer counterparts at the same age. If today's young adults gain weight at the same rate as boomers, then the obesity epidemic has only just begun.


Anonymous said...

Wow. That's alarming. I wonder if women's mortality rates have sky-rocketed during that period to reflect more deaths from heart diesease and diabetes. Cally

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