Wednesday, December 31, 2014

No Crazy Diets...But What's Crazy?

A "sensible diet" must be the one of the hardest things to figure out, even for a sensible person. There's always been conflicting advice, but with medical studies in respected journals being retracted and authorities admitting they were wrong about fat, and various laymen flip-flopping on dietary advice, we're living in confusing times. This post is to help readers sort it out for themselves.

First, what is "sensible," or more to the point, what is the truth? I think it's something that meets one or more of these criteria:

  • Something observable, directly or indirectly
  • Something that stands up to scrutiny (i.e., it's not a trick)
  • Something that fits with everything else you know
  • Something that can be used to reliably predict other things

Note that something sensible or truthful isn't necessarily balanced, it doesn't matter who does or doesn't believe in it, or how long it's been around. It's independent of all those things. Think of things that used to be common sense: creation myths, the sun going around the earth, illness due to "humors" being out of whack. Even though they were popular ideas, they didn't stand up to scrutiny, didn't fit with other facts that were discovered, and couldn't reliably predict things like eclipses* or reduced rates of illnesses. The truth wasn't "balanced" (the sun never goes around the earth, humors don't exist, and the myths were just that) and believing in the old ideas, even to the point of repeating them tirelessly and prosecuting skeptics, didn't make them so. As physicist Lawrence Krauss put it, "There are no authorities in science."

Why sort all this out--why not get a short-term diet that works? General observation is that once you go back to your old eating habits, you go back to your old health problems or weight--and then some. There are also diets that don't provide enough nourishment or can cause health problems, long-term. I was on such a diet once, and if I'd read the book with a more critical eye, I could have avoided GERD and a mouthful of cavities. Therefore, you need a diet you can live with and live on for the rest of your life.

So where do you go for facts about diet? Studies on diet abound, but many of them don't stand up to scrutiny (the researchers use tricks of design and statistics to get desired results, or they start out with unreliable data). If you don't know how to parse diet studies, don't bother with them.

Two sources of information come from groups who don't have any dog in the dietary fight: endocrinology textbooks and books on human evolution. For laymen, one the best books I know of on the subject of endocrinology is It Starts with Food by Dallas and Melissa Hartwig. (They do promote a particular diet.) I've fact-checked this book with endocrinology textbooks, and everything I looked at was accurate (see this and this). The Hartwigs also treat many clients with their diet--they observe what works and what fails.

A wonderful book on evolution is by Alan Walker and Pat Shipman, Wisdom of the Bones. Although it isn't specifically about diet, it describes, in places, how scientists know our ancient ancestors, from 2.5 million years ago on, ate meat as a significant part of their diet. Grains and dairy, of course, weren't eaten at that time since it was millions of years before agriculture began. In other words, humans adapted through evolution to eat a significant amount of meat, plus plants that could be eaten raw (and later on, starting perhaps 100,000 years ago, those that could be cooked).

In fairness, eating fatty meat and veg and avoiding dairy and grains probably doesn't fit with everything else you know. But what we "know" about diet has lately been the subject of scrutiny and exposed as bad science: statistical and methodological tricks, bad data, and out and out fraud in some cases. It isn't true or sensible, and it doesn't fit with what is sensible in endocrinology and human evolution.  Two books criticizing the science behind conventional dietary wisdom are Good Calories, Bad Calories by Gary Taubes and The Big Fat Surprise by Nina Teicholz.

A very simple method you can use to figure out what's sensible is to use a blood glucose meter. You squeeze a drop of blood on a test strip and check your blood sugar before and one and two hours after meals. Even blood sugar (around 70-90) is good. High blood sugar is less good, and can be a sign of impending diabetes (blood sugar of over 200). Sustained blood sugar levels over 140 damage all the tissues in your body. Low blood sugar is uncomfortable, can make you cranky and hungry, and tends to be caused by eating too much carbohydrate: it can make your blood sugar go way up, then way down. Blood glucose meters sell for $10 and up at drugstores. No need for a prescription. And no need for authorities or detection of craziness or trickery.

*ETA: I've since read that some ancient astronomers could predict eclipses, but once the earth-round-the-sun model was adopted, the calculations became a lot simpler.


Galina L. said...

When "sensible diet" is hard to define and "balanced diet" is hard to follow, what is left is either something not working or some diet objectionable for others.

Lori Miller said...

The field of diet has been so muddled with junk science and gurus that it's hard to know what a sensible diet is now without learning some science. Even the term "balanced diet" has been turned on its head since it became popular in the early 20th century.

Lowcarb team member said...

Well here in the UK all the 'diet/weight loss' adverts are on TV, and believe it or not Easter Eggs were on sale in the supermarket today !!! ???

Going back to diets, with so many big firms competing for money from those who want to lose weight it sickens and saddens me - because if they would only do a little research / reading, at the click or two of the mouse they could just discover a new lifestyle which would bring health and weight benefits.

Meanwhile these 'diet guru's' and weight loss firms continue to hear their cash registers ringing.


On a happier note Happy and Healthy New Year Wishes

All the best Jan

Lori Miller said...

Probably, all those weight loss programs are just variations on the theme of calorie restriction.

One nice thing about eating in harmony with our hormones and evolutionary background is that, for the vast majority of people, there's no need to deliberately restrict calories. Our hormones act as they're supposed to--giving both hunger and satiety signals.

Another nice thing: there's no group to join, meetings to attend or special meals to buy. You might spend some money on a few books or library fines and a blood glucose meter.

And I think Easter eggs are great--as long as they're from a bird and have had their yolks mixed with some mayonnaise and mustard.

tess said...

"Easter eggs are great--as long as they're from a bird and have had their yolks mixed with some mayonnaise and mustard."

I like them from fish, too! ;-) Happy New Year, everybody!

Lori Miller said...

Happy New Year, Tess!

Val said...

Belated Happy New Year! Bought myself Nina's book as late Xmas present but haven't gotten deeply into it yet...
Still refining my own "ideal diet" but so far carnivorous heavily reduced carb seems to be working for me.
Only issue is mild constipation - chugging water but may need to add psyllium supplement until my colon adjusts :-(

Lori Miller said...

I find a magnesium supplement helps in that department. The good kind that ends in -ate.