Ezra Klein, who’s been expressing doubts about calorie taxes lately, is impressed by a report from the Center for Science in the Public Interest on the projected impact of California’s menu labeling law. The paper finds that reducing calorie intake at chain restaurants by 200 calories or less could cause dramatic reductions in obesity in Los Angeles County.
I don’t have time to dig into the report right now (available here in annoying PDF format), but aside from the fact that its conclusions are based purely on hypothetical impacts rather than on studies of actual outcomes, there’s a key assumption at work in the analysis:
We assumed in the calculations that restaurant patrons who ordered reduced calorie meals would not increase their food and beverage intake at other times during the day. This assumption is supported by research indicating small decrements in caloric intake of the magnitude used in our analysis are not associated with a compensatory increase in caloric intake later in the day or over a period of several days. We also assumed that persons who ordered reduced calorie meals would not alter their physical activity level and that their resting metabolic rate would not change as a result of the small reduction in caloric intake.
In other words, CSPI treats reductions in how many calories people consume at chain restaurants as equivalent to reductions in their entire diets. They say existing research supports this assumption and provide one citation, but I am skeptical given the source. After five years in the hospitality industry I’ve overheard too many customers rationalize their indulgences by mentioning they had a salad for lunch or are going to the gym in the morning. Obviously that’s not scientific data, but I’d really like to see an unbiased review of the literature on the subject. CSPI’s assumption doesn’t strike me as a very realistic.
In any case, the assumption that changing consumption at chain restaurants doesn’t cause partially compensating behavior elsewhere plays such a large role in CSPI’s paper that Klein ought to have included a caveat in his post about it.
Previously:
Too much information
Jacob Grier is a freelance writer, barista, mixologist, and magician in Portland, OR. He writes, eats, and drinks a lot. His articles have appeared in The Washington Post, Reason Online, The Oregonian, and other publications.
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