Have American Diets Improved?

We are constantly told things like: "Americans have a national eating disorder" (that's Michael Pollen in Omnivore's Dilemma) or that Americans live in a "toxic food environment" (that's Kelly Brownell in the book Food Fight).

How does that hyperbole match up with the facts?  

Maybe Americans were eating poorly in the past.  But are they eating better today?

Recently released research by Tim Beatty, Biing-Hwan Lin and Travis Smith in the American Journal of Agricultural Economics suggests the answer is "yes" - we are eating better.

They write:

Conventional wisdom maintains that the quality of the American diet has been deteriorating for at least the past two decades. In contrast, we document a previously unknown pattern of improvement in U.S. dietary quality. We find statistically significant improvements for all adults over the period 1989–2008, at all levels of dietary quality.

and

Although we find that higher-income individuals consistently have higher dietary quality than low-income individuals, we also find some evidence that the gap is shrinking over the sample period.

and

We also show that most of the improvement in dietary quality can be attributed to changes in food formulation and changes in demographics. Moreover, we find that changes in food formulation help explain considerably more of the improvement in dietary quality for low-income individuals than for higher-income individuals.

Fruits and Veggies and the Food Dollar

Last week, I put up a post show the trend in share of consumers' at-home food dollar allocated to meat, dairy, and poultry items.  I had a couple inquiries asking about fruits and vegetables. Using the same data source, I calculated the share of at-home food dollars going toward fresh fruit, fresh vegetables, processed fruits and vegetables, and the total going toward all three from 1959-2013.

During the 1960s and 70s, consumers allocated a smaller share of their food budget to fresh fruits and vegetables, and more toward processed.  The overall trend in share of expenditures spend on F&V was down from 1950 to about 1992.

However, starting in the early 1990s, there has been a slow up-tick in share of expenditures allocated to total F&V, from about 10% of total at-home food expenditures to about 12%.  Over time, there was a precipitous decline in the share of food dollar allocated to processed F&V, but this was more than compensated for by an increase in the share of the at-home food dollar allocated to fresh vegetables.  

Expenditure shares can sometimes be misleading if there are big price changes, so it is also useful to look at actual consumption.  Here is data from the USDA-ERS (see table 2 in the "general" spreadsheet) on per-capita consumption of fresh vegetables since 1980. 

Americans are today eating about 56lbs more fresh vegetables than they did in 1980, a 50% increase.  These data exclude potato consumption, so the upward trend is not some kind of french-fry effect.  

It is a bit ironic that the upward trend in fresh vegetable consumption, and the recent leveling off, mirrors the change in obesity rates over time.  Tells us that obesity is a complicated problem.

Overall, these data would seem to suggest we're eating a little better (not worse) than we did 20 to 30 years ago.  

Assorted Links

A nifty tool from Google that let's you easily compare the nutritional content of two foods

New FDA rules are set to outlaw beer makers' sales of spent grain to livestock feeders

Are small farms really more animal welfare friendly? 

More evidence of local elections to ban or require labeling of GMOs

More on Soda Taxes

The Huffington Post just ran a piece I wrote in response to prior post in the same outlet by a doctor advocating for soda taxes.  Here are some excerpts: 

Jeff Ritterman, Vice Present of the Board of Directors for his local chapter of the Physicians for Social Responsibility recently wrote on The Huffington Post that we should "Tax a Cola, Save the Planet."

I've read lots of editorials advocating soda taxes, but this one beats them all in promising what a soda tax will deliver. He argues that:

"A simple policy change like the Soda Tax can help us waste less water, lower our GHG production, and lessen the pollution of our air, water and soil. At the same time, it can fund vital programs in our schools, parks and neighborhoods to improve nutrition and physical education opportunities for our children. It's a win-win-win: a win for the environment, a win for our children, and a win for our communities."

Wow, one tax will do all that! H.L. Mencken reportedly said that "for every complex problem there is an answer that is clear, simple, and wrong."

After discussing the literature showing how price changes and soda taxes cause people substitute toward other beverages and foods, I argued:

Ritterman argues that a soda tax will results in less soda being consumed, and he's probably right. But does that mean that there will be less water and less aluminum consumed? Well, it depends what consumers drink and eat instead of soda. If people instead drink more milk or more beer, as previous studies have suggested, will water consumption really be cut? If more cows are needed to produce more milk due to the increased demand caused by soda taxes, will greenhouse gases really fall?

Ritterman is right to suggest that enacting a soda tax can raise revenue for the government. But, that hardly makes it an economically efficient thing do. A tax is akin to reducing in one's income. No one likes having less income. Using taxes to direct people to buy goods they didn't purchase before the tax cannot make people better off. 

Meat expenditure shares

It seems there is a constant barrage of studies, books, and media critical of animal agriculture. The negative publicity is multifaceted and ranges from concerns about animal welfare, health impacts, food safety, climate change, environmental impacts, water usage, food security, and on an on.  

Just to given one representative example, here is James McWilliams writing in the New York Times in a 2012 article entitled The Myth of Sustainable Meat:

 THE industrial production of animal products is nasty business. From mad cow, E. coli and salmonella to soil erosion, manure runoff and pink slime, factory farming is the epitome of a broken food system.

He argues there, and in a more recent 2014 editorial in the same outlet that we the best solution is to give up eating meat.  I used McWilliam as an example, but I could have picked any number of high profile books (e.g., here or here), academics, advocacy groups (e.g., here or here), or news stories that paint conventional animal production industries in a less than favorable light.

Here is my question: how much impact, if any, has this had on consumers' demand for meat, dairy, and eggs?  

To indirectly get at this question, I turned to some data collected by the Bureau of Economic Analysis (BEA) on Personal Consumption Expenditures.  The BEA reports total expenditures on food at home in a variety of categories going back to 1959.  I took this data and calculated the share of total expenditures on food eaten at home (what the BEA calls " Food and beverages purchased for off-premises consumption") attributable to beef, pork, poultry, eggs, and dairy products.  For reference, total expenditures on food eaten at home was about $61.5 billion in 1959 (in 1959 dollars) and was about $884 billion in 2013 (in 2013 dollars).  

There was a remarkable downward trend in the allocation of consumers' food budget away from dairy and beef from 1959 till the early 1990s, and an uptick in poultry.  Consumers went from spending about 12-14% of their food budget on beef and another 12-14% on dairy in the early 1960s down to about 5-8% on each in the early 1990s.  Stated differently, consumers just about halved the proportion of their food budget going toward beef and dairy in a 30 year time period.  

There were a lot of reasons for these changes.  These industries became much more productive and prices fell, so consumers could allocate less of their budget to these items but still consume the same amount or more.  The price of poultry fell much more rapidly than the price of beef, and thus some of the downward trend reflects substitution away from beef toward poultry.  There were other consumer concerns during that period related to cholesterol, saturated fat, E coli, etc. that led to less consumption of beef and dairy.  

Despite, all that, it is remarkable how resilient meat demand has been over the last 20 years in light of the large amount of negative publicity mentioned earlier.  To illustrate, here is the graph  just from 1993 to 2013.

The lines are essentially flat.  People are allocating just about the same amount of their food budget to beef, pork, dairy, poultry, and eggs today as they did 20 years ago.  

It may be the case that all the aforementioned negative publicity in recent years will eventually cause consumers to allocate their food budget away from animal products.  But, at least so far, it doesn't seem to have had much of an impact.