I think the best we can hope in this context is to have a number of distinct and precise metrics—like nutrients per calorie, nutrients per dollar and nutrients per bulk--, feed these to intuition, and decide accordingly. In other words, when it comes to food, I think we should make decisions according to a “rational” rather than a “quantified” model, given the difficulties of coming up with adequate definitions of a “serving size”. Your approach wouldn’t work, I believe, because how much people eat of a given food often depends on the presence or absence of other complement and substitute foods.
Amount of foods from a food group typically reported in surveys as consumed on one eating occasion;
Amount of foods that provide a comparable amount of key nutrients from that food group, for example, the amount of
cheese that provides the same amount of calcium as 1 cup fluid milk;
Amount of foods recognized by most consumers (e.g., household measures) or that can be easily multiplied or divided to describe a quantity of food actually consumed (portion);
Amount traditionally used in previous food guides to describe servings.
While the amount of food people would eat is not the only factor used, it’s a major one.
I think the best we can hope in this context is to have a number of distinct and precise metrics—like nutrients per calorie, nutrients per dollar and nutrients per bulk--, feed these to intuition, and decide accordingly. In other words, when it comes to food, I think we should make decisions according to a “rational” rather than a “quantified” model, given the difficulties of coming up with adequate definitions of a “serving size”. Your approach wouldn’t work, I believe, because how much people eat of a given food often depends on the presence or absence of other complement and substitute foods.
Googling quickly brings up http://www.cnpp.usda.gov/Publications/NutritionInsights/insight11.pdf
Serving size is defined as follows:
Amount of foods from a food group typically reported in surveys as consumed on one eating occasion;
Amount of foods that provide a comparable amount of key nutrients from that food group, for example, the amount of cheese that provides the same amount of calcium as 1 cup fluid milk;
Amount of foods recognized by most consumers (e.g., household measures) or that can be easily multiplied or divided to describe a quantity of food actually consumed (portion);
Amount traditionally used in previous food guides to describe servings.
While the amount of food people would eat is not the only factor used, it’s a major one.