Watching bodies

Kevin Lewis

November 18, 2017

Increased Physical Activity Associated with Less Weight Regain Six Years After “The Biggest Loser” Competition
Jennifer Kerns et al.
Obesity, November 2017, Pages 1838–1843

Objective: The aim of this study was to explore how physical activity (PA) and energy intake (EI) changes were related to weight loss and regain following “The Biggest Loser” competition.

Methods: At baseline, week 6 and week 30 of the competition, and 6 years after the competition, body composition was measured via dual-energy x-ray absorptiometry, resting energy expenditure was measured by using indirect calorimetry, and EI and PA were measured by using doubly labeled water.

Results: Six years after the competition, median weight loss in 14 of “The Biggest Loser” participants was 13%, with those maintaining a greater weight loss (mean ± SE) of 24.9% ± 3.8% having increased PA by 160% ± 23%, compared with a PA increase of 34% ± 25% (P = 0.0033) in the weight regainers who were 1.1% ± 4.0% heavier than the precompetition baseline. EI changes were similar between weight loss maintainers and regainers (−8.7% ± 5.6% vs. −7.4% ± 2.7%, respectively; P = 0.83). Weight regain was inversely associated with absolute changes in PA (r = −0.82; P = 0.0003) but not with changes in EI (r = −0.15; P = 0.61). EI and PA changes explained 93% of the individual weight loss variability at 6 years.

On the Distributional and Evolutionary Nature of the Obesity Wage Penalty
Christian Brown & Wesley Routon
Economics & Human Biology, forthcoming


The economics literature supports a link between labor market measures, such as earnings, and health conditions, such as obesity. There is reason to believe the effects of obesity on wages may vary for high- and low-earning individuals and that obesity wage effects may evolve over a lifecycle or from generation to generation. Drawing on data from two longitudinal surveys, we estimate quantile and fixed effect quantile regressions, among others, to further examine the obesity wage effect. Results suggest an increasingly severe penalty across the wage distribution for females. Specifically, the highest-earning women may be penalized as much as five times that of the lowest earners. Results for males suggest that penalties may be present at select wage levels, while prior research has generally found no male obesity penalty. We also provide evidence that the obesity penalty has increased across generations and limited evidence that it may slow earnings growth over one’s lifetime.

The Effect of Neighborhood Fast Food on Children’s BMI: Evidence from a Sample of Movers
Yiwei Qian et al.
B.E. Journal of Economic Analysis & Policy, August 2017


We use a statewide panel dataset and an instrumental variable strategy to identify the effect of neighborhood fast food on the BMI z-scores of Arkansas public schoolchildren. As in earlier studies, we use distance from the child’s residence to the nearest major highway as an instrument for the density of fast-food restaurants. The sample is limited to children who moved at least once during the study period to ensure temporal variation in our instrument. Neighborhood fast food does have significant and positive effects on their BMI z-scores. The effect is disproportionately large for children who are rural, non-minority and female.

Selection Effects and Heterogeneous Demand Responses to the Berkeley Soda Tax Vote
Jakina Debnam
American Journal of Agricultural Economics, October 2017, Pages 1172–1187


Early evidence from household-level surveys suggests that the one-cent-per-ounce tax on sugar-sweetened beverages that took effect on March 1, 2015, in Berkeley, California, has decreased consumption of sugar-sweetened beverages dramatically. Even if these findings are robust, the public policy implications of expanding the Berkeley soda tax policy to a national level are complicated by selection effects inherent in the populations of both voters and consumers. We find that consumption responses related to the tax interact nontrivially with consumer heterogeneity. Some of these responses directly counter the public policy goals of a soda tax. For example, high-consuming households are less price sensitive and therefore less responsive to price changes following a tax. Further, “reactance” among high-consuming populations led to increases in soda consumption immediately following the passage of the tax, partially mitigating reductions in soda consumption.

Do Taxes for Soda and Sugary Drinks Work? Scanner Data Evidence from Berkeley and Washington
Christian Rojas & Emily Yucai Wang
UMass Amherst Working Paper, September 2017


Curbing obesity through taxation of certain beverage products has been a priority in the policy agenda across many U.S. jurisdictions. We assess the effectiveness of this highly debated policy instrument through two measures of its impact: the pass-through rate (the extent to which the tax actually translates into a retail price increase) and the impact on consumption (volume sales). We evaluate the actual effect of two excise taxes on the beverages market: the sugar-sweetened-beverages (SSB) tax of 1¢ per ounce in the city of Berkeley that has been effect since 2015 and the tax of 1/6¢ per ounce on carbonated drinks (soda) that the state of Washington imposed from July through December of 2010. We carry out the analysis with a barcode-level dataset containing price and volume sales information from a large number of retail outlets. Our identification relies on sales data from stores located in taxed areas as well as from stores in nearby localities. We find differences across the two tax events on pass-through: retail prices in Washington reacted sharply (by a larger magnitude than the tax) and promptly whereas in Berkeley retail prices reacted only marginally (by less than 30% the magnitude of the tax). In terms of volume sales, we find a 5% volume reduction in Washington but fail to find any evidence of an effect in Berkeley.

Projecting the impact of a nationwide school plain water access intervention on childhood obesity: A cost–benefit analysis
Ruopeng An et al.
Pediatric Obesity, forthcoming

Objective: This study aimed to project the societal cost and benefit of an expansion of a water access intervention that promotes lunchtime plain water consumption by placing water dispensers in New York school cafeterias to all schools nationwide.

Methods: A decision model was constructed to simulate two events under Markov chain processes – placing water dispensers at lunchtimes in school cafeterias nationwide vs. no action. The incremental cost pertained to water dispenser purchase and maintenance, whereas the incremental benefit was resulted from cases of childhood overweight/obesity prevented and corresponding lifetime direct (medical) and indirect costs saved.

Results: Based on the decision model, the estimated incremental cost of the school-based water access intervention is $18 per student, and the corresponding incremental benefit is $192, resulting in a net benefit of $174 per student. Subgroup analysis estimates the net benefit per student to be $199 and $149 among boys and girls, respectively. Nationwide adoption of the intervention would prevent 0.57 million cases of childhood overweight, resulting in a lifetime cost saving totalling $13.1 billion. The estimated total cost saved per dollar spent was $14.5.

to your National Affairs subscriber account.

Already a subscriber? Activate your account.


Unlimited access to intelligent essays on the nation’s affairs.

Subscribe to National Affairs.