74 THE CHINA STUDY
rural China only 9-10% of total calories comes from protein and only
10% of the protein comes from animal-based foods. This means that
there are major nutritional differences in the Chinese and American
diets, as shown in Chart 4.3.CHART 4.3. CHINESE AND AMERICAN DIETARY INTAKES
Nutrient China United States
Calories (kcal/ dayV 2641 1989
Total fat (% of calories) 14 .5 34-38
Dietary fiber (g/day) 33 12
Total protein (g/day) 64 91
Animal protein (% of 0.8 10-11
calories)
Total iron (mg/day) 34 18The findings shown in Chart 4.3 are standardized for a body weight
of Sixty-five kilograms (143 pounds). This is the standard way that
Chinese authorities record such information and it allows us to easily
compare different populations. (For an American adult male of seventy-
seven kilograms, calorie intake will be about 2,400 calories per day. For
an average rural Chinese adult male of seventy-seven kilograms, calorie
intake will be about 3,000 calories per day.)
In every category seen above, there are massive dietary differences
between the Chinese and American experiences: much higher overall
calorie intake, less fat, less protein, much less animal foods, more fiber
and much more iron are consumed in China. These dietary differences
are supremely important.
While the eating pattern in China is far different from that of the
United States, there is still a lot of variation within China. Experimental
variation (i.e., a range of values) is essential when we investigate diet
and health associations. Fortunately, in the China Study considerable
variation existed for most of the measured factors. There was exception-
al variation in disease rates (Chart 4.2) and more than adequate varia-
tion for clinical measurements and food intakes. For example, blood
cholesterol ranged-as county averages-from highest to lowest almost
twofold, blood beta-carotene about ninefold, blood lipids about three-
fold, fat intake about sixfold and fiber intake about fivefold. This was