Food Fads and Fears

I've been reading the book Fear of Food by Harvey Levenstein.  It is a fascinating read, chronicling the history of food fears and fads that hit Americans in the 19th and 20th centuries.  I have a few quibbles with some of the material in the chapter on "Bacteria and Beef", but overall, good stuff.

One passage showed how at least one version of the Paleo diet had been advanced since the early 1900s for many of the same reasons it is advocated today, almost 100 years later:

“In 1920 Fleischmann’s urged eating its yeast cakes because ‘the process of manufacture or preparation’ removed from many foods the ‘life giving vitamine’ that provided the energy people needed. ‘Primitive man,’ it claimed, ‘secured an abundance of vitamines from his raw, uncooked foods and green, leafy vegetables. But the modern diet - constantly refined and modified - is too often badly deficient in vital elements.’”

Levenstein also chronicles the emergence of food scientists and nutritionists who often had significant effects on dietary fads and public policies.  It is remarkable the hubris with which many of these men made dietary advice and public policy, particularly because we now know they were often quite wrong in their scientific knowledge.  Whether it was Metchnikoff and Kellogg and their views on autointoxication and the merits of yogurt, or Horace Fletcher's method of chewing to "Fletcherize" food,  or Harvey Wiley and his war on benzoate of soda, or Elmer McCollum and his promotion of acidosis, or Russell  Wilder's belief that thiamine deficiencies would cause the nation to loose their will to fight the Nazis - there seems to be a continual stream of people willing to use scant evidence to promote their favored cause to promote public health.  Not just idly promote - but with often with righteous indignation and certitude of belief.  I have no doubt many of these men passionately believed the diets they promoted but that didn't ultimately make them right.  

Levenstein writes, in the midst of concern of lack of vitamin consumption in 1941, that

“The New York Times said, ‘The discovery that tables may groan with food and that we nevertheless face a kind of starvation has driven home the fact that we have applied science and technology none too wisely in the preparation of food.””

Unfortunately, something similar could be said about how applied science and technology have often been used none too wisely to promote various public policies and best selling books.   

It is true that science has progressed and we know more than we used to.  One of the things we've hopefully learned is that we often need to exercise a bit of humility.

A food producing machine

Imagine a biologist on an excursion in the Amazon looking for new plant species.  He comes across a new grass he's never seen, and brings it back home to his lab in the U.S.  He finds that the grass grows exceedingly well in greenhouses with the right fertilizer and soil, and he immediately moves to field trials.  He also notices that the grass produces a seed that durable, storable, and extraordinarily calorie dense.  The scientist immediately recognizes the potential for the newly discovered plant to solve global hunger problems and to meet the dietary demands of a growing world population.

But, there is a problem.  Lab analysis reveals that the seeds are toxic to humans.  Despite the set-back, the scientist doesn't give up.  He toils away year after year until he creates a machine that can convert the seeds into a food that is not only safe for humans to eat but that is incredibly delicious to eat.  There are a few downsides.  For every five calories that go into the machine, only one comes out.  Plus, the machine uses water, runs on electricity, burns fossil fuels, and creates CO2 emissions.  

Should the scientist be condemned for his work?  Or, hailed as an ingenious hero for finding a plant that can inexpensively produce calories, and then creating a machine that can turn those calories into something people really want to eat?  

Maybe another way to think about it is to ask whether the scientist's new product can pass the market test; can his new food - despite it's inefficiencies (which will make the price higher than it otherwise would be) - compete against other foods in the marketplace?  Recall, that the new food must be priced in a way that covers the cost of all the resources it uses - from the fertilizer to grow the new seeds to the gasoline required to run the new machine.

Now, let's call the new grass "corn" and the new machine "cow".  The analogy isn't perfect (e.g., the cow is a living-feeling being and not a lifeless machine), but the thought experiment is useful nonetheless.

It's particularly useful in thinking about the argument that corn is "wasted" in the process of feeding animals.  It is one that appears - in one form - in a recent paper in Science.  West et al. write:

“Although crops used for animal feed ultimately produce human food in the form of meat and dairy products, they do so with a substantial loss of caloric efficiency. If current crop production used for animal feed and other nonfood uses (including biofuels) were targeted for direct consumption, ~70% more calories would become available, potentially providing enough calories to meet the basic needs of an additional 4 billion people (28). The human-edible crop calories that do not end up in the food system are referred to as the “diet gap.””

I'm not sure the logic of this sort of argument adds up.  

Unlike my hypothetical example, corn is not toxic to humans (although some of the grasses cows eat really are inedible to humans).  Nevertheless, few people really want to eat the calories that directly come from corn or other common animal feeds like soybeans.  

So, why do we grow so much corn and soy?  They are incredibly efficient producers of calories and protein.  Stated differently, these crops (or "grasses" if you will) allow us to produce an inexpensive, bountiful supply of calories in a form that is storeable and easily transported.  

The assumption in the quote of the Science article seems to either be that the "diet gap" will be solved by: 1) convincing people to eat the calories in corn and soy directly, or 2) that there are other tasty-edible crops that can be widely grown instead of corn and soy which can produce calories as efficiently as corn and soy.  Aside from maybe rice or wheat (which also require some processing to become edible), the second assumption is almost certainly false.  I'm also skeptical about the first assumption - that large swaths of people will voluntarily consume substantial calories directly from corn or soy.

What we typically do is take our relatively un-tasty corn and soy, and plug them into our machine (the cow or pig or chicken) to get a form of food we want to eat.  Yes, it seems inefficient on the surface of it, but the key is to realize the that the original calories from corn and soy were not in a form most humans find desirable.  As far as the human pallet is concerned, not all calories are created equal; we care a great deal about the form in which the calories are delivered to us.

The grass-machine analogy also helps make clear that it is probably a mistake to compare the calorie and CO2 footprint of the corn directly with the cow.  I suspect only a very tiny fraction of the world's caloric consumption comes from directly consuming the raw corn or soy seeds.  It takes energy to convert these seeds into an edible form – either through food processing or through animal feeding. So, what we want to compare is beef with other processed foods.  Otherwise we're comparing apples and oranges (or in this case, corn and beef).

Why are cows more productive?

I've written frequently about the incredible productivity gains witnessed in agriculture, and I often mention such statistics in talks I give.  

But, what does the average person think when they hear this sort of evidence?

I decided to find out.  In the latest edition of the Food Demand Survey (FooDS), I provided respondents with some statistics on increased productivity in dairy production based on some data compiled by Bailey Norwood (I should note that Bailey mentioned that he is revisiting these figures, and thinks current water usage is likely higher than 2 gallons) .  

Here's what was asked:

“In 1945, it took about 10 gallons of water and 50 lbs of feed to produce a gallon of milk. Today, it only takes about 2 gallons of water and 10 lbs of feed to produce a gallon of milk. Each dairy cow today produces about 200% more milk compared to one in 1960. How do you think this change happened?”

People were then prompted to provide an open-ended response.   They could type anything they wanted.

As you might suspect, answers were all over the board (a complete, unedited list of the more than 1,000 responses is here) from "Witchcraft" to "corruption" to "I have no idea".

A keyword search was conducted among the open-ended responses.  Some of the main keywords mentioned were: hormones (69), growth hormones (41), feed (28), technology (25), and selective breeding (20). 

Looking through the responses it seems some variation on "hormones" ("hormones" or "growth hormones" or "steroids" or "drugs") were particularly common.  This is interesting because hormones aren't much used in milk production.  Some dairy cows are given the hormone rBST to boost production, and adoption of the increased in the 1990s and peaked sometime in the early 2000s and then has fallen off since then.  According to one USDA source, only about 22% of cows in the US received rBST in 2002. This paper reports that only 9.5% of dairy producers used rBST in 2010.  Thus, there appears to be something of a disconnect between how people think productivity gains occur vs. the reality on the ground.

Individual responses were placed into seven different categories related to:

• hormones (134 responses)
  
• feed chooses (78 responses)
  
• science (61 responses)
  
• breeding and genetics (61 responses)
  
• drugs and steroids (30 responses) 
  
• farming techniques (27 responses)
• economics (6 responses)
• others

You can read more about the responses in latest edition of FooDS.

What drives ingredient-based food fears?

That was the question asked in this article just published in the journal Food Quality and Preference.  The authors, Brian Wansink, Aner Tal, and Adam Brumberg surveyed over 1,000 mothers to study which food ingredients they found fearful, and they consider how such fears can be alleviated.  

The abstract:

“This study investigates food fears that are ingredient-based, focusing on the case of high-fructose corn syrup. The results of a national phone survey of 1008 U.S. mothers offer five preliminary sets of observations: first, consumers with a fear of a specific ingredient – such as high-fructose corn syrup – may exaggerate and overweigh perceived risks. Second, such consumers may often receive more information from the internet than from television. Third, they may be partly influenced by their reference group. Fourth, ingredients associated with less healthy foods mainly hurt evaluation of foods perceived as relatively healthy. Fifth, food fears may be offset when an ingredient’s history, background, and general usage are effectively communicated. These findings suggest new insights for understanding how public health, industry, and consumer groups can more effectively target and address ingredient fears.”

From the conclusions:

“When health risks exist, food fears are merited. In other cases, ingredient fears and avoidance may be wrongly based on the stigmatization of an ingredient or on misinformation. These results offer new preliminary insights about who is most prone to ingredient avoidance, where they receive their information, what types of ingredients are most susceptible to being feared, and how fears might be mitigated.

There appear to be at least two non-mutually exclusive motivating factors behind ingredient avoidance. First, some individuals may overweigh the perceived risks of the avoided ingredient. Second, some individuals who avoid ingredients may have a greater need for social approval among their reference group than those with a more moderate view (though such effects were small in our sample). This is a key contribution to the literature on risk because it underscores a novel potential motivation – akin to the Prius Effect – behind ingredient avoidance. ”

Future of Food

National Geographic has launched a series of stories and videos on the future of food.  One of the big questions they intend to answer is: how will we feed 9 billion people by 2050 without harming the planet? 

A video on the site hints at their five answers:

• use resources more efficiently
• grow more on existing farmland
• stop expanding farms
• change our diets
• reduce waste

It's not a bad list.  The first three will require science and new agricultural research and development if they are to be achieved.  The need for technological progress often gets short shrift in discussions about food sustainability, but here it is (implicitly) a prominent solution.  Even the last "food waste" issue has an important technological dimension.  In many developing countries, food waste is a result of poor storage facilities and transportation infrastructure; it isn't all just a result of rich people throwing away too much food (although that is part of it too).  It seems to me that Land Grant Universities are well poised to address precisely these issues, although I suspect we won't get much mention in National Geographic's stories.   

It is also important to discuss the role of economics - particularly the role of prices - in achieving these outcomes.  We may well need to "change our diets."  But, the question is whether this outcome will result from paternalistic policies and dictates or whether changes in relative prices will cause us to change our diets.  If eating a particular food is, truly, "unsustainable", then the price for it must rise as the resources needed to produce the food become more scarce.  

Here is what I had to say on this issue in the Food Police when discussing organics.

Economics teaches that price differences are important, though sometimes imperfect, signals about resource use.  The price we pay for food in the grocery store must reflect all the costs that went into producing it: from land rent to the value of the farmer’s labor to the prices of seed and fertilizer.  Higher prices for organic means that somewhere along the line, organics used more land, more labor, more seed, more fertilizer, or more of any of the other inputs required to produce food.  The prices of all these inputs were each determined by their scarcity relative to people’s desires to use them for other purposes unrelated to food production.  So, when we see that organic is higher priced, it signals us that organics are using many more of the resources that society finds valuable than non-organics.  Using up more resources is exactly the opposite of sustainable.      

Normally the price mechanism is used to ration scarce resources and signal us as to how to allocate resources over time.  Rising prices for increasingly scarce resources like oil and fertilizer cause us to naturally back away from consuming them – thereby resulting in a “sustainable” future.  The fact that we are now using a lot of oil and fertilizer in agriculture means they are currently in ample supply relative to demand.  The sustainability movement represents an elitist attempt to ration scarce resources using social pressure, guilt, and regulation.

As I've previously discussed, desiring sustainable outcomes is uncontroversial - it's how we go about it that matters.  We need to let price mechanism work in telling us when to cut back on particular foods.  That last sentence in the above quote might seem a tad harsh, but shielding consumers from price changes, and distorting market forces, is truly unsustainable.