Photo credit: Life’s Ambrosia
“Low energy density [high Nutrition] is not an inevitable characteristic of low-fat diets; as many of the low-fat foods presently being promoted in our commercial food supply are based on sugar or highly refined carbohydrates.” – W.C. Willett, Harvard University
Two hundred and fifty calories of Twinkies are not the same as 250 calories of broccoli. Clearly a calorie is not a calorie when we are discussing the Nutrition we need to burn body fat and be healthy. So what is nutritious? Like everything else, the key to Nutrition is quality, but all we are ever told about is quantity—aka the Nutrition facts labels on food.
The information found on food labels tells us half of what determines Nutrition: the quantity of nutrients in the food. The other half is the quality of the calories we are getting along with those nutrients.
Talking merely about the quantity of nutrients in food leads to a very fattening view of Nutrition. Consider the American Heart Association’s endorsement logos on boxes of sugar-stuffed cereal because the cereal was “enriched.” A high quantity of nutrients combined with low-quality calories is not nutritious.
Most people already know that thinking about the quantity of nutrients in food is not sufficient. We know that ten doughnuts are not ten times as nutritious as one doughnut. We have to consider nutrients relative to calories, or Nutrition quality.
Determining Nutrition quality is simple. We take the nutrient quantity information provided on Nutrition labels and divide it by the number of calories in a serving of the food. This provides the food’s Nutrition per calorie. Many nutrients per calorie—provided by non-starchy vegetables, seafood, lean meats, select dairy, and fruits—means high Nutrition. Few nutrients per calorie—see starches and sweets—means low Nutrition.
For example, here’s how one cup of enriched wheat flour compares to one cup of spinach in terms of nutrient quantity. I’ve shaded the cell of the food with more of the given nutrient when we measure by the cup.
Looking at quantity, enriched wheat flour seems more nutritious than spinach. Here’s why that’s misleading:
One cup of enriched wheat flour contains 495 calories. One cup of spinach contains 7 calories.
Looking at quality—nutrients per calorie—we see something much different—and more useful.
When we make a fair comparison—comparing 250 calories of enriched wheat flour against 250 calories of spinach, instead of comparing 495 calories of enriched wheat flour against 7 calories of spinach—we see that spinach is dramatically more nutritious than enriched wheat flour.
Looking at Nutrition this way is useful for two reasons we’ll cover in the next post.
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- Willett WC. Is dietary fat a major determinant of body fat? Am J Clin Nutr. 1998 Mar;67(3 Suppl):556S-562S. Review. Erratum in: Am J Clin Nutr 1999 Aug;70(2):304. PubMed PMID: 9497170.
- Nestle, Marion. What to Eat. 1 ed. New York: North Point Press, 2007. Print.
- USDA SR-21