Japan's Dietary Transition and Its Impacts uses rich and wide-ranging statistical data to delineate the significant changes in the Japanese diet from 1900 to the present, attentive to the ways Japan's foods have been sourced locally and internationally. Recent studies have profiled the ways in which food enters national discourse as cuisine, notably by Katarzyna Cwiertka21 and by Barak Kushner in his examination of ramen as a symbol of culinary nationalism.22 Smil and Kobayashi's book allows readers to learn the benefits in wellness wrought from improvements in the modern diet as well as the environmental costs.
Chapter 1 provides an overview of the scope of the transformation of the Japanese diet within the last century. In 1900, Japanese per capita consumed virtually no pork or poultry, less than one egg a month, and half a teaspoon of milk a year in a diet that resulted in stunted growth. By the year 2000, Japanese ten-year-olds were 12 percent taller than their counterparts in 1900 and adult Japanese men and women had the highest life expectancies in the world (pp. 2–3). Though evocative, since the chapter is only four pages in length, one of which provides a summary of the book, the material could have been incorporated into the introduction, which has a separate chapter overview.
Major foodstuffs are described in chapter 2, which examines grains (chiefly rice), tubers, soybeans, mushrooms, vegetables, seafood, meat, dairy products, beverages, sources of fat, and sugar. The chapter organization resembles a series of encyclopedia entries providing historical data alongside descriptions for each food and typical methods of preparation, serving as a useful complement to Richard Hosking's classic A Dictionary of Japanese Food: Ingredients and Culture (Rutland, Vt.: Charles E. Tuttle, 1996). The latter provides descriptions of a wider variety of foodstuffs, but Smil and Kobayashi's book includes a wealth of statistical data concerning them.
Chapter 3 measures developments in the production and consumption of foodstuffs, drawing upon statistical sources from before World War II as well as consumption surveys instituted after to describe Japan's dietary transformation. Analyses of per capita consumption before World War II rely upon measuring population against food supply to determine the average amount of calories per person. The authors present a number of previous attempts to compute per capita food energy supply for the year 1900, ranging from 1,948 to 2,445 kcal per day, before presenting their own measurement of 2,100 kcal (p. 81). National statistics have their limitations, especially for the early twentieth century, since they fail to account for pronounced regional differences and do not actually reveal what was eaten on a daily basis. Nevertheless, as someone who has seen varying estimates of the amount of calories available and presumably consumed per capita for the first half of the twentieth century and earlier, I am grateful for the authors’ discussion of how these numbers are computed and their limitations. Japan's National Health and Nutrition Survey, undertaken nationally since 1948, provides a clearer indication of what Japanese actually eat as measured annually on a single day of data collection from more than 12,000 people in 5,000 randomly selected households (p. 85). Remarkably, this data shows a mean per capita food intake of 1,900 kcal daily today, an average that is less than in the year 1900. The authors explain that “in 1900 Japan was a demographically young society [demanding more energy to feed it] with children and young adults greatly outnumbering people over sixty years of age” (p. 86). Yet the modern Japanese diet, especially since 1950, is characterized more by change than continuity, according to the authors, with Japanese in the year 2000 eating three times as much fruit, approximately seven times more eggs, almost 9.5 times as much meat, and nineteen times as much milk and dairy products than fifty years earlier (pp. 94–95).
The contributions of the diet to health and longevity are examined in detail in chapter 4. Green tea, soy foods, and seafood are often highlighted for their health benefits; the authors present contradictory scientific data to indicate that the reasons for longevity and health cannot be boiled down to a single food and that even potential hazards of the traditional Japanese diet, such as high salt intake, related to hypertension, do not translate into higher incidents of stroke in Japan (pp. 121–23). Alas, drinking tea or eating more tofu is no substitute for minimizing the amount of calories consumed over the course of one's life, which appears to be the most significant factor in health and longevity but one that presents the greatest challenge for many of us to emulate (pp. 126–28).
The good news about the diet is tempered by the discussion of its environmental costs, described in chapter 5, which indicates that no other countries could duplicate Japan's diet, which is heavy in seafood, without placing unsustainable demands on the world's already depleted fisheries. The authors measure the impact of Japan's food sourcing domestically and abroad in the amount of land, fertilizer, and water used and above all in Japan's fishing operations and seafood purchases. In Tsukiji: The Fish Market at the Center of the World (Berkeley: University of California Press, 2004), Theodore Bestor examines the cultural, economic, and social outcomes of the fact that Japan remains the world's largest consumer of seafood, but the environmental costs are fully recounted by Smil and Kobayashi, who demonstrate Japan's major role in depleting the world's fishing stock, especially for large, carnivorous species like bluefin tuna, for which Japan took 40 percent of the global share since 1950, roughly fifteen times the country's share of world population, including estimates of the illegal and underreported fishing that have been documented for Japan (p. 182).
In chapter 6, “Japanese Diet: Retrospect and Prospect,” the authors summarize trends in the Japanese diet in light of claims for greater food self-sufficiency in Japan. Apart from the fact that Japan represents 2 percent of the world's population but consumes some 8 percent of its seafood annually, that Japan sources its foodstuffs from other countries should be less worrying than the extent to which its own groundwater is contaminated with nitrogen runoff from fertilizers.
Japan's Dietary Transition and Its Impacts benefits from an extensive bibliography, and the authors, particularly Smil, reveal themselves to be talented photographers providing well-composed and clear images of foodstuffs, essential for a book of this sort. Drawing on quantitative data, Smil and Kobayashi offer many useful insights into the last century of the history of the Japanese diet. Their book might cause everyone who eats Japanese food, especially sushi, to think further about the multiple costs of procuring it, notwithstanding any potential health benefits.