Friday, February 8, 2013

Food measurement problem

One of the basic ideas of science is that measurements must be precise and repeatable. If the original measurements aren't precise, then no one can set up repeatable conditions and no one can expect repeatable results. Even if they could get repeatable results without repeatable conditions, the results would have no clear meaning. And if no one can expect repeatable results because no one can repeat the conditions of the experiment, then no one even tries.

Only a week into the Wahls diet, there's one thing that really bothers me about how Dr. Wahls describes the specifics of following her diet (at least on the internet): She expresses food measurements volumetrically (in cups), rather than as weight measurements (ounces or grams). This bothers me because there's no way to accurately measure most types of food volumetrically; particularly the kinds of food that make up this diet.

For example, exactly what constitutes "one cup" of onion? I ask [rhetorically] because a diced onion takes up a lot more volume than the same onion before it's diced. If I'm measuring one cup of diced onion, am I supposed to pack the pieces of onion tightly into the measuring cup? Or am I supposed to eyeball the whole onion and go, "Uhh, that's about a cup"?

Even if I know exactly how Dr. Wahls intends for me to measure, the diced onion will still occupy considerably more volume than the same onion before it was diced. Or if I slice the onion instead of dicing it, it will occupy an even different volume than either the same onion whole or the same onion diced. Also, when measuring volumetrically, every "one cup" of onion will be at least a slightly different amount than every other "one cup" of onion, even if identical prep methods are used for every cup measured.

I'm very experienced in food preparation and food measurement, yet I have no idea what constitutes 3 cups of any of the foods I'm supposed to be eating, because volumetric measurement of food cannot be done with any kind of precision. And this matters to me. The precise amount of any certain food I'm supposed to be eating is something I need to know because I want to do this right. And I probably haven't been doing it quite right yet, specifically because I have no idea if my volumetric measurements are in any way similar to Dr. Wahls's volumetric measurements.

This is important stuff here, and hopefully Dr. Wahls will see this post and use it as a tool to better communicate the specifics of her diet. Or maybe she'll even recruit me to do it for her. Regardless, once I start writing posts about how I apply the diet, I will express my food measurements in weight (ounces and grams), not volume.

Measuring food by volume is one of the least insightful things humans do, especially in an age where accurate digital scales are widely available for as low as $20 and not more than $30. The way one person measures 3 cups of greens might yield the same amount of greens that someone else considers only 2 cups. That's a huge disparity, yet it's a very realistic scenario. So whose measurement is correct? Neither of them, because there is no such thing as 3 cups of greens. And Dr. Wahls needs to address that problem.

Here's some good news.

All of this confusion can be eliminated by simply using weight measurements instead of volumetric measurements. It's impossible to mismeasure or miscommunicate with weight measurements, as long as you use the scale properly. If you measure food by weight, an ounce of spinach is always an ounce of spinach, regardless of who measures it or how much volume it occupies. And 100 grams of onion is always 100 grams of onion. It just works.

Almost every kind of food you buy at the grocery store is priced and sold by weight, not volume. There's a reason for that: accuracy. With almost every type of food, it's simply not possible to measure accurately using volumetric measurements.

If you're serious about using food to heal yourself (or even if you just want to become a more consistent cook), I urge you to buy an electronic kitchen scale. It'll be one of the best purchases of your life.

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