Among the specious claims about the role
of meat in the history of humanity: A meat-rich diet brings with it a masculine
vigor that distinguishes carnivorous races.
By Josh Berson
The MIT Press Reader -- Prior to the
identification of the micronutrients we call vitamins in the 1930s, nutrition
science was mainly a science of animal energetics, or the study of how animals
metabolize food into energy. Animal energetics, in turn, was a science of
animal starvation. It was also a science of race.
The questions physiologists asked about
animal energetics were straightforward: How much energy was required to keep an
animal from starving under various conditions (for example, physical regimen,
ambient temperature)? How much protein — specifically, in the early days, how
much meat — was required to maintain the animal in nitrogen equilibrium, that
is, to ensure that the quantity of nitrogen lost as urea in the urine was equal
to that ingested? Efforts to measure metabolic rate by gauging the volume of
carbon dioxide expelled in respiration went back at least to the French chemist
Antoine Lavoisier’s experiments with guinea pigs in the 1780s, but for a long
time, respirometry remained cumbersome and subject to the concern that what an
animal did under a respirometer hood did not represent a good approximation to
what it did out in the world. So in most labs, the key methods of research into
the 1910s were collecting animal waste and fasting animals, often to the death.
A variety of animals were sacrificed by
starvation: rats, rabbits, guinea pigs, chickens, cats, and dogs.
Physiologists
were partial to dogs, and canine hunger artists were cited with approval in the
energetics literature into the 1950s. A dog in one lab in Tokyo was reported in
1898 to have survived 98 days without food before succumbing, having lost 65
percent of its body mass. Fourteen years later, physiologists at the University
of Illinois reported they had fasted their dog Oscar 117 days before ending the
experiment: Oscar refused to manifest the increase in excreted nitrogen typical
of late-stage morbidity and in fact remained in such good spirits, as his
handlers reported, that he had to be restrained as the fast went on from
leaping out of and into his cage before and after his daily weighing lest he injure
himself.
Humans, of course, could not be
involuntarily fasted to the death, but self-experimentation was rampant in the
energetics world. After 1890, fasting gained popularity as a health cure and
the key to vigor, productivity, Christian virtue, masculinity, and racial
superiority. Interest in fasting cures continued into the 1920s even as fasting
gave way, in energetics research, to respirometric studies of resting metabolic
rate and controlled trials of calorie restriction.
The practical aims of animal energetics
were twofold. One was to improve feed conversion in livestock and, more
broadly, to formulate generalizations about the relationship between body size
and basal metabolic rate. The other was to understand the energy and protein
needs of humans under different occupations. To most of the people involved in
the debate around these questions, the underlying policy concern was clear: How
much meat did you need to maintain an industrial labor force? — not to say a
modern army and navy.
Around 1900, conventional wisdom held
that active men required between 100 and 120 grams of protein a day at a
minimum — a grossly high estimate — predominantly from animal sources, and an
energy intake in the vicinity of 3,000 kcal. Periodically, reports would emerge
of people getting by on considerably less — a community of fructarians in
California, say — but these reports were mostly ignored..
The dominant voice in this conversation
was that of German physiologist Carl von Voit. Voit’s laboratory at Munich had
pioneered a number of the techniques then becoming standard in the physiology
labs of the United States and Japan, notably the use of nitrogen equilibrium as
a proxy for protein needs. Voit clove to a figure of 118 grams (4 ounces) of
protein per day for a man of 70 kilograms (154 pounds) doing light work. This
struck Yale physiologist Russell Chittenden as nonsense. In 1902 Chittenden
undertook a series of clinical studies to demonstrate that 50 to 55 grams (2
ounces) of protein a day, and a considerably reduced energy intake, would keep
young men in vigor and nitrogen balance indefinitely.
Chittenden put groups of Yale athletes
and newly inducted U.S. Army soldiers (N of eight and 13, respectively) on
carefully controlled diets and exercise regimens and observed them over a
period of months — their food intake, their excreta, and their performance on
various measures of fitness. He also kept notes on his own food intake and
physical activity. The diets in question were experimental only in the sense
that portions and protein content were controlled. In other respects, the food
was ordinary and not especially healthy (lunch for the soldiers for one week
included hamburgers, macaroni and cheese, clam chowder, bean porridge, and beef
stew).
Opinion was divided as to the
significance of his findings. One contemporary praised Chittenden’s rigor but
thought it was too soon to attribute participants’ physical achievements to
diet, since there was no control for the independent effects of the regimented
way of life implicated in the experiments. Fifty years later, the nutritional
biochemist Henry Sherman would hail Chittenden’s work as a breakthrough in
understanding just how elastic the human response to protein is. Others
regarded Chittenden’s results as a curiosity. But there were those who saw
Chittenden’s work as anathema.
Chief among these was Major D. McCay, a
professor of physiology in Calcutta. McCay, on the basis of long observation in
India and a series of experiments with the diets of prisoners in Bengal, argued
that Chittenden’s conclusions were not just wrong but dangerously so, for they
undermined the clear connection between a diet rich in animal protein and the
masculine vigor of the more advanced races. “There is little doubt,” he writes,
“that the evidence of mankind points indisputably to a desire for protein up to
European standards.
“As soon as a race can provide itself
with such amounts,” he adds, “it promptly does so; as soon as financial
considerations are surmounted, so soon the so-called ‘vegetarian Japanese’ or
Hindu raises his protein intake to reach the ordinary standard of mankind in
general.”
That is, McCay argues, it is meat’s
income elasticity that determines its rate of consumption. As soon as a race
achieves the income necessary to support a meat-rich diet — presumably by
adopting the industrial labor discipline of Europeans — its meat consumption
shoots up and, with it, the masculine vigor that distinguishes meat-eating
races everywhere. Writing a hundred years later, the geographer Vaclav Smil
puts it another way: As soon as incomes rise, the “cultural constructs of
pre-industrial societies” fall away.
With time, the tone of arguments like
McCay’s changes. Talk of race becomes more muted, but concern about the
implications of a vegetarian diet for national development persists. For
Cornell biochemist William Adolph, writing toward the end of World War II, the
“protein problem of China” was that for the 85 to 90 percent of the population
living in the countryside, the diet was basically vegetarian. More precisely,
95 percent of the protein in the rural diet came from plant sources.
Plant-source proteins, Adolph frets, are inferior both in that they are less
easily digested and in that the protein they provide is lower in “biological
value”; today we would say its Digestible Indispensable Amino Acid Score is
lower. He expresses surprise at the success of the Chinese peasants he has
observed in devising combinations of plant proteins that exceed those of any of
the constituents — “another case of blind experimentation, examples of which
are wide-spread throughout Asia.” But his experiences in China do not leave him
sanguine about the possibilities of diet modification in the United States in
service of the war effort: “Do we know, for example, how far the change from the
omnivorous diet to the vegetarian can be carried with impunity? Many of our
blessings in health and vigor are, nutritionally speaking, related to animal
protein.”
Today we are faced with the opposite
question: How far can the change to a carnivorous diet be carried with
impunity? In the nutritional niche characteristic of emerging urban markets,
growing meat consumption masks, and perhaps makes possible, growing
precariousness.
[Josh Berson is an independent social
scientist. He has held research appointments at the Berggruen Institute and the
Max Planck Institute for Human Cognitive and Brain Sciences, among other
places. He is the author of “The Meat Question,” from which this article is
adapted.]
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