Viliam's Shortform

Viliam

This is a special post for quick takes by Viliam. Only they can create top-level comments. Comments here also appear on the Quick Takes page and All Posts page.

When you tell people which food contains given vitamins, also tell them how much of the food would they need to eat in order to get their recommended daily intake of given vitamin from that source.

As an example, instead of "vitamin D can be found in cod liver oil, or eggs" tell people "to get your recommended intake of vitamin D, you should eat every day 1 teaspoon of cod liver oil, or 10 eggs".

The reason is that without providing quantitative information, people may think "well, vitamin X is found in Y, and I eat Y regularly, so I got this covered", while in fact they may be eating only 1/10 or 1/100 of the recommended daily intake. When you mention quantities, it is easier for them to realize that they don't eat e.g. half kilogram of spinach each day on average (therefore, even eating spinach quite regularly doesn't mean you got your iron intake covered).

The quantitative information is typically provided in micrograms or international units, which of course is something that System 1 doesn't understand. To get an actionable answer, you need to make a calculation like "an average egg has 60 grams of yolk... a gram of cooked egg yolk contains 0.7 IU of vitamin D... the recommended daily intake of vitamin D for an adult is 400 or 600 IU depending on the country... that means, 9-14 eggs a day, assuming I only get the vitamin D from eggs". I can't make the calculation in my head, because there is no way I would remember all these numbers, plus the numbers for other vitamins and minerals. But with some luck, I could remember "1 teaspoon of cod liver oil, or 10 eggs, for vitamin D".

Obvious problem: the recommended daily intake differs by country, eggs come in different sizes, and probably contain different amounts of vitamin D per gram. Which is why giving the answer in eggs will feel irresponsible, and low status (you are exposing yourself to all kinds of nitpicking). Yes; true. But ultimately, the eggs (or whatever is the vegan equivalent of food) are what people actually eat.

4ChristianKl6y

This assumes that the RDA that those organization publish are trustworthy. You have other organization like the Encodrine society that recommend an order of magnitude more vitamin D. If the RDA of 400 or 600 IU would be sensible you also could solve it by being a lot in the sun once every two weeks.

3dyne6y

Have you tried using Cronometer or a similar nutrition-tracking service to quickly find these relationships? I've found Cronometer in particular to be useful because it displays each nutrient in terms of a percent of the recommended daily value for one's body weight. For example, I can see that a piece of salmon equals over 100% of the recommended amount of omega-3 fatty acids for the day, while a handful of sunflower seeds only equals 20% of one's daily value of vitamin E. Therefore, I know that a single piece of fish is probably enough, but that I should probably eat a larger portion of sunflower seeds than I would otherwise. I suppose a percentage system like this one is just the reciprocal of saying something like "10 eggs contain the recommended daily amount of vitamin D."

Thank you for the link! Glad to see someone uses the intuitive method. My complaint was about why this isn't the standard approach. Like, recently I was reading a textbook on nutrition (the actual school textbook for cooks; I was curious what they learn), where the information was provided in the form of "X is found in A, B, C, D, also in E" without any indication how often are you supposed to eat any of these.

(If I said this outside of Less Wrong, I would expect the response to be: "more is better, of course, unless it is too much, of course; everything i... (read more)