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fubarobfusco comments on Lifestyle interventions to increase longevity - Less Wrong

121 Post author: RomeoStevens 28 February 2014 06:28AM

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Comment author: fubarobfusco 28 February 2014 05:12:27PM 2 points [-]

Clearly, in assessing the nutrient density of a food, one should exclude whatever nutrients are added in supplement form by manufacturers.

Most of the milk I see for sale is fortified with vitamins A and D. I would want studies regarding milk's health effects to report on the same sort of milk that I can buy in a store.

Comment author: Pablo_Stafforini 28 February 2014 05:17:41PM *  0 points [-]

I think that for the purposes of assessing the claim in question ("Eggs and whole milk are very nutrient dense"), unfortified versions of those foods should be considered. Otherwise, we should also regard cereals and many other foods as "very nutrient dense", simply because manufacturers decide to fortify them in all sorts of ways. (And I note that it's generally not a good idea to obtain your nutrients from supplements when you can obtain them from real food instead.)

In any case, even if we used data for fortified milk, it would still be false, in my opinion, that "whole milk is very nutrient dense." Vitamin D levels make a minor contribution to overall nutritional density.

Comment author: shokwave 02 March 2014 12:26:31AM *  0 points [-]

I suspect the real issue is using the "nutrients per calorie" meaning of nutrient dense, rather than interpreting it as "nutrients per some measure of food amount that makes intuitive sense to humans, like what serving size is supposed to be but isn't".

Ideally we would have some way of, for each person, saying "drink some milk" and seeing how much they drank, and "eat some spinach" and seeing how much they ate, then compare the total amount of nutrients in each amount on a person by person basis.

I know this is not the correct meaning of nutrient dense, but I think it's more useful.

Comment author: Pablo_Stafforini 02 March 2014 02:14:14AM *  0 points [-]

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.

Comment author: Jiro 02 March 2014 07:38:45AM -1 points [-]

Googling quickly brings up http://www.cnpp.usda.gov/Publications/NutritionInsights/insight11.pdf

Serving size is defined as follows:

  1. Amount of foods from a food group typically reported in surveys as consumed on one eating occasion;
  2. 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;
  3. 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);
  4. 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.