Saturday, August 27, 2016

Berkeley "soda tax" reduced sugar-sweetened beverage consumption and increased water consumption

In the American Journal of Public Health this month, Jennifer Falbe and colleagues found that the penny-per-ounce Berkeley soda tax succeeded in reducing sugar-sweetened beverage (SSB) consumption.

The study asked respondents about soda intake, in Berkeley and in comparison cities of northern California (Oakland and San Francisco, which did not have a new tax), before and after the new Berkeley tax was implemented in March 2015. The findings were remarkable. SSB consumption fell 21% in Berkeley and rose 4% in the comparison cities during the same period.

The SSBs include caloric soda, of course, but also some kinds of other sweetened drinks. However, for various reasons (including sound nutrition reasons plus perhaps political reasons), the tax did not affect milk drinks or 100% fruit juice. Therefore, it is important to understand what other beverages people substituted for soda. The study does not answer all my questions on this point, but it did find that water consumption increased in Berkeley at the same time that SSB consumption fell. Water consumption increased 63% in Berkeley, significantly more than the increase in the comparison cities during the same period. This was reassuring.

A good way to standardize estimates of tax effects is to report an "elasticity" -- the percentage change in consumption for each 1% change in price. A typical elasticity estimate for soda is about -1.2, meaning that the price increase in Berkeley (about 8%) would have been expected to generate a consumption decline of about 10%. The authors took care to confirm that the estimated consumption decline of 21% was significantly different from zero, which is the standard statistical way of making sure the estimates were not a random statistical fluke, but they cannot really be sure the true impact is exactly 21% rather than 10%. They sensibly discussed the possibility that "early reaction to the tax ... could rebound and settle closer to a 10% reduction in consumption."

Even if the impact were a 10% reduction, this study has important public health implications, providing I think the strongest evidence so far that a tax would reduce SSB consumption.

I encourage my colleagues in agricultural and applied economics to read this study. There is a long tradition in my profession of doubting the potential impact of such taxes. In the Washington Post in 2015, Tamar Haspel quoted University of Minnesota applied economist Marc Bellemare saying the results at that time were "not robust." Haspel also quoted my Friedman School colleague and friend Sean Cash saying that product formulation, rather than taxes, are the way to go: "If we could achieve a 5 percent reduction by reformulation, that would swamp what we can achieve with consumer-level intervention.” The TuftsNOW site quoted Sean casting further doubt on taxes: "All studies suggest that for food in general, we’re not particularly responsive to price." Oklahoma State University economist Jayson Lusk, who also is president of the Agricultural and Applied Economics Association (AAEA), has blogged several times about soda taxes, agreeing with most of the Tamar Haspel column  in the Washington Post, and concluding stridently: "I'm sorry, but if my choice is between nothing and a policy that is paternalistic, regressive, will create economic distortions and deadweight loss, and is unlikely to have any significant effects on public health, I choose nothing" (emphasis added).

In the Salt this week, NPR reporter Dan Charles quotes Berkeley researcher Kristine Madsen on whether the new estimates of SSB reduction are large enough to matter for public health. "Madsen says a 20 percent reduction in consumption of sugar-sweetened beverages would be enough to reduce rates of obesity and Type 2 diabetes in years to come. 'This would have a huge public health impact if it were sustained,' she says." I think most experts in public health nutrition would agree with Madsen's assessment.

This week, Jayson's blog post on the Berkeley study raises some measurement issues, but recognizes that these issues are unlikely to overturn the main result. He writes, "All that said, I'm more than willing to accept the finding that the Berkeley city soda tax caused soda consumption to fall. The much more difficult question is: are Berkeley residents better off?" This is a question that surely will be discussed heavily in the next couple years as more municipalities experiment with such policies.

Tuesday, August 02, 2016

Are checkoff programs good for nutrition? (#AAEA2016)

Harry Kaiser (Cornell University) and I have enjoyed putting together a lively session later today, discussing the question: Are checkoff programs good for nutrition?

In a friendly debate, Harry will argue "yea" and I will argue "nay" (though in fact we agree on many aspects of these programs). John Crespi from Iowa State will be independent discussant, and Kristin Kiesel of UC Davis will moderate.

The session takes place in the Berkeley room 2:45pm today, Aug 2, at the conference site for the Agricultural and Applied Economics Association (AAEA) here in Boston.

Harry was one of my professors in graduate school at Cornell in the 1990s, and he is a leading economist in the evaluation of generic advertising effects on food consumption. This recent infographic from the beef checkoff program highlights his work (click for full size).


Thursday, July 28, 2016

Food policy in Brazil emphasizes enjoyment of meals and criticizes overprocessed foods

The Food and Environment Reporting Network (FERN) and the Nation have an in-depth article by Bridget Huber this week on national food policy in Brazil, led by Carlos Monteiro and colleagues. Dietary guidelines in Brazil bluntly criticize highly processed foods while simultaneously communicating a healthy enjoyment of food more generally.
Monteiro came to believe that nutritionists’ traditional focus on food groups and nutrients like fat, sugar, and protein had become obsolete. The more meaningful distinction, he started to argue, is in how the food is made. Monteiro is most concerned with the “ultraprocessed products”—those that are manufactured largely from industrial ingredients like palm oil, corn syrup, and artificial flavorings and typically replace foods that are eaten fresh or cooked. Even by traditional nutritionists’ criteria, these sorts of products are considered unhealthy—they tend to be high in fat, sugar, and salt. But Monteiro argues that ultraprocessed foods have other things in common: They encourage overeating, both because they are engineered by food scientists to induce cravings and because manufacturers spend lavishly on marketing.
This blog has previously discussed the way Brazilian dietary guidelines combine nutrition and sustainability issues, in a manner that is not done in the United States. I helped colleagues at George Washington University organize a conference on sustainability issues in dietary guidance in 2014, at which Monteiro was a speaker, and the Brazilian experience has influenced my sense of what might be possible in the United States.

Regarding enjoyment of healthy meals, Huber writes:
Pleasure is an essential part of the new guide, which frames cooking as a time to enjoy with family and friends, not a burden. And instead of sterile prescriptions for the number of grams of fat and fiber to eat each day, the guide focuses on meals. Sample meals were created by looking at the food habits of Brazilians who eat the lowest amount of ultraprocessed foods. One dinner option is a vegetable soup followed by a bowl of acai pulp with cassava flour, as one might eat in the Amazon region. Another plate, more typical of São Paulo, is spaghetti, chicken, and salad. If these seem like ordinary meals, that would be the point, one of the researchers said: They wanted to counteract the idea that a “healthy” diet is one full of unfamiliar and even unpleasant foods.

Tuesday, July 12, 2016

July 2016 update on the #flyingless initiative

The ‪#‎flyingless‬ campaign has been enjoying a flurry of activity since the last update.

1. See Joe Nevins' new interview, posted today on the flyingless.org website, with legal innovator Professor Mary Christina Wood. She contributed to the idea that nature is a "public trust," with dramatic potential implications for addressing climate change. She also is a #flyingless supporter: "Universities will have to re-think their flying practices in a very serious way."

2. Several people connected with our campaign were involved with the remarkable nearly carbon-free conference on Climate Change and the Humanities. Ken Hiltner was the lead organizer and inspiration. Presenters included Peter Singer, Joe Nevins, Peter Kalmus, and myself. On the final day, in addition to the main event in California, we had a fine group of about 12 participants on the Tufts University campus linked by videoconference. Ken Hiltner has created a White Paper / Practical Guide with lessons about how to organize such a conference, and there already is a future conference planned "The World in 2050: Creating/Imagining Just Climate Futures."

3. Please continue to share the flyingless.org website. Important links are available from the "Menu" button at top right of the page. There now are 375 academic signatories for the petition! Twitter: @flyingless.

Saturday, July 02, 2016

Exercise, weight loss, and the food environment

A clear and effective video from Vox explains why exercise is not directly a cure for overweight. The video's message -- rightly -- is that we should pay close attention to food intake and the quality of the food environment.

The video does note that physical activity has strong direct effects on health. Nonetheless, I would have emphasized the benefits of physical activity even more strongly than the video does.

My first reason for giving physical activity yet more credit is a bit geeky. Much of the research literature uses regression models where a weight measure is the outcome variable and physical activity or exercise is the main explanatory variable. To make sure the analysis really reflects the "effect" of exercise, the studies include additional control variables such as food intake and general health. Yet, when we step up our physical activity, we may experience improvements in health, mood, and feelings of self-efficacy. Including explanatory variables for food intake and health status may risk "over-controlling" for other factors. We may eat healthier when our mood is good. We may avoid periods of poor health and inactivity that lead to weight gain. Perhaps stepping up our physical activity deserves some of the credit for improvements in weight that are being picked up by the control variables.

My second reason for giving physical activity yet more credit is more superficial. For some people who seek to lose weight, the ultimate goal is to look better. I have mixed feelings about whether this is good psychology, but it does seem to be common. Stepping up physical activity may affect posture, muscle tone, and confidence, making people look better in ways that the scale may not register.

But the video certainly is right that researchers in recent years have become more careful about not over-promising physical activity as a complete weight loss program on its own.

 

Friday, June 10, 2016

Tufts Research Day 2016: Global food security

The Tufts Research Day is an annual event highlighting inter-disciplinary work on a cross-cutting topic. The 2016 event, on April 25, was titled Research Day on Global Food Security: Crisis and Opportunity. The format was a series of short accessible "lightning talks." My session on metrics and data needs included Tufts faculty members: Colin Orians (biology), Jennifer Coates (nutrition science and policy), and Christine Wanke (public health).

My talk focused on the diverse measurement tools for and policy uses of domestic food insecurity statistics. The conclusion is that there is no fundamental economic or physical barrier preventing us from having much lower rates of food insecurity and hunger in the United States.


Tuesday, May 03, 2016

A most innovative conference on Climate Change: Views from the Humanities

Today is the opening of a remarkable and nearly carbon-free conference organized by Ken Hiltner and colleagues at the University of California, Santa Barbara. The title is Climate Change: Views from the Humanities.

From today until May 31, all of the talks will be available at the conference website. Then, there will be closing events by videoconference on May 31. You may sign up for free to participate in the online question and answer threads.

The keynote talks include noted ethicist Peter Singer, literature professor E. Ann Kaplan, bestselling science fiction novelist Kim Stanley Robinson, and English professor Ashley Dawson. Singer's thesis is fierce: "What the rich nations are doing is indefensible."

The breakout session titled "Flying and Focusing on the Everyday" includes climate scientist Peter Kalmus, geographer Joe Nevins, and myself. Peter's talk is a heartfelt, sincere reflection on the personal aspects of being a climate scientist in our surreal times, drawing heavily on a small convenience sample of his colleagues. Joe's offbeat and irreverent talk considers whether non-flying conferences such as this one are "self-referential self-righteous ascetic bullshit," and his rebuttal to this accusation is 100% convincing. I'll embed my own talk below.

Joe and I come from different disciplines, but have become friends in the past year while founding an international campaign to encourage constructive progress by universities and professional associations to change our culture of flying. Our website is flyingless.org, and our Twitter handle is @flyingless. There are links on the website to a general petition, a list of more than 360 academic supporters, and a Frequently Asked Questions page. If you are an academic who wants to support a well-considered and sensible initiative to encourage universities and professional associations to make an essential cultural change -- while maintaining the good that we seek to do through our work -- then please email us at academicflyingpetition@gmail.com.

I have not been so inspired by a conference for many years. There is something liberating and joyous and rebellious in hitting "pause" on the usual dissonant soundtrack of our jet-setting academic lives, and instead actually starting to live the professional practice that we would live in a sane world that takes climate change seriously.