Genotype May Help Predict Best Diet Response

The study found that a 10% increase in the price of soda (roughly 20 cents/1-L bottle) resulted in a 3% decline in the probability of consuming soda and a decrease in the amount of soda consumed. Pizza followed a similar trend. A $1 increase in the price of both soda and pizza was associated with even greater changes in total energy intake, body weight, and individuals' homeostasis model assessment of insulin resistance scores, the study found.

As a result, the authors estimated, an 18% tax on soda and fast food could cut energy intake among young to middle-aged adults by about 56 kcal per day. At the population level, this reduction could lead to about 5 fewer pounds in weight gain per person per year “and significant reductions” in the chronic disease risks.

In an editorial, Dr. Mitchell Katz, director of San Francisco department of public health, and Dr. Rajiv Bhatia, medical director of San Francisco's division of occupational and environmental health, advocated that “agricultural subsidies be used to make healthful foods such as locally grown vegetables, fruits, and whole grains less expensive.”

The study was conducted by researchers at the University of North Carolina at Chapel Hill, the University of Alabama at Birmingham, the University of Minnesota, Minneapolis, and the University of Oslo, none of whom reported any conflicts. Dr. Bhatia reported no conflicts, and Dr. Katz received consulting payments from the hospital management company Health Management Associates Inc.

—Jane Anderson