Archive for 'carbgrrl'

What’s it say?? I can’t read!!

Bacon is all the rage these days. It’s almost…overexposed. Luckily there are still ways to have fun with the subject (other than eating it, of course).

Now, being a big bacon fan myself (we actually wrapped our Thanksgiving turkey in bacon last year), I wondered: what could I possibly add to people’s enjoyment of this savory treat? I know, I could try and convince you it’s healthy!

Searching my new Kindle version of GCBC confirms the contention of the hardcover index that, not counting a whole bunch of references to Francis Bacon, there’s only one real discussion of bacon in the book. It goes a little something like this:

The observation that monounsaturated fats both lower LDL cholesterol and raise HDL also came with an ironic twist: the principal fat in red meat, eggs, and bacon is not saturated fat, but the very same monounsaturated fat as in olive oil. The implications are almost impossible to believe after three decades of public-health recommendations suggesting that any red meat consumed should at least be lean, with any excess fat removed. …. All of this suggests that eating a porterhouse steak in lieu of bread or potatoes would actually reduce heart-disease risk, although virtually no nutritional authority will say so publicly. The same is true for lard and bacon. [GCBC, Ch. 9, pp. 168-9]

So given a chance between “turkey bacon”:

turkey_bacon

…and actual turkey wrapped in actual bacon:

turbacon-small

…why not go for the real yummy thing?

The science of feeling peckish (part 1)

In the diet culture, it’s common to find people talking about “body weight set points”: Your body wants to stay at a particular weight, and fights your attempts to slim down by making you hungry until you top up your weight. I don’t have the heart to link to the huge number of sites claiming you can change your set point by doing things like controlling calories (sigh), but knock yourself out if you want to search for them.

The thing is, set points for body weight, blood sugar levels (a body “glucostat”), blood fats (a “lipostat”), and even body temperature have been tested in the scientific literature to try and explain how hunger works, and found lacking. What turns out to matter most for making you feel hungry vs. sated is the availability to the body of utilizable fuels, seen in toto.

On this subject, Gary Taubes makes this recommendation in GCBC:

Several variations on this hypothesis [about hunger and availability of utilizable fuels] were published from the mid-1970s onward by LeMagnen and others. The most comprehensive account was published in 1976 by Edward Stricker at the University of Pittsburgh, and Mark Friedman, then at the University of Massachusetts and now at the Monell Chemical Senses Center in Philadelphia. Their article, “The Physiological Psychology of Hunger: A Physiological Perspective,” should be required reading for anyone seriously interested in eating behavior and weight regulation. [GCBC, Ch. 24, p. 433]

Go ahead — click that link above. You can buy the article, if you like, for the low low price of US$11.95.

Or, don’t! This is where I demonstrate that carbgrrl has gone around the bend. I went and got the paper, studied it closely, and present here a layman’s summary of its arguments and conclusions. You’re welcome. :-)

(I’ll do this in two parts. Part 1 — call it Energy Metabolism 101 — is below the fold. I’ll provide Part 2, The Hunger, in a later post. As always, I will gladly accept all error corrections and pointers to research that disputes or usefully refines the information below.)

[…]

Vitameatavegamin

Here’s a puzzle. Let’s say you’re trying to get your nutrition “in balance”. You’re told that there are daily reference values of macronutrients (like protein, carbs, and fats) that you should try to consume. Along with that, you’re told you should try to hit certain targets for micronutrients (like vitamins and minerals) as well.

But you’re not told that the one affects the other.

In the last century, anthropologists have had the opportunity to study cultures, such as the Inuit, whose diets consist of nearly 100% meat (along with trying out this lifestyle themselves), and nutrition scientists have tested such a diet several times. Aside from the weight-control and blood-pressure benefits observed, the subjects had no vitamin deficiencies.

Why? As Gary Taubes notes in GCBC:

…[A]nimal foods contain all of the essential amino acids (the basic structural building blocks of proteins), and they do so in the ratios that maximize their utility to humans. They also contain twelve of the thirteen essential vitamins in large quantities. Meat is a particularly concentrated source of vitamins A, E, and the entire complex of B vitamins. Vitamins D and B12 are found only in animal products (although we can usually get sufficient vitamin D from the effect of sunlight on our skin). [GCBC, Ch. 19, pp. 321-2; emphasis in original; footnote elided]

Well, what’s wrong with that? We can eat some meat to get vitamins, and also mix in some grains, veggies, and fruits for “balance”, right? Not so fast. It turns out that carbs compete with your body for vitamins.

Nutritionists would establish by the late 1930s that B vitamins are depleted from the body by the consumption of carbohydrates. “There is an increased need for these vitamins when more carbohydrate in the diet is consumed,” as Theodore Van Itallie of Columbia University testified to McGovern’s Select Committee in 1973. A similar argument can now be made for vitamin C….

[T]here is significant reason to believe that the key factor determining the level of vitamin C in our cells and tissues is not how much or little we happen to be consuming in our diet, but whether the starches and refined carbohydrates in our diet serve to flush vitamin C out of our system, while simultaneously inhibiting the use of what vitamin C we do have. [Ibid., pp. 325-6]

So what is the U.S. Food and Drug Administration trying to achieve when they give nutrition advice like this?

Beats me. But it sure seems like a funny way to execute on their mission.

343,000 reasons to be annoyed

The positive reaction to this new series has really encouraged me, and given that my dear readers tend to be smarties who like to know the logic behind how a thing works, it seems like a good time to lay down some basic information. (Sean, this one’s for you!) So that means this post is going to be somewhat dense.

In GCBC, Gary Taubes reviews the fat-cholesterol hypothesis of overweight, heart disease, etc. that’s been the default position among diet scientists for some decades now, and contrasts its explanatory power with that of the carbohydrate hypothesis. The basic story in making the case for the latter is that insulin and its close hormonal cousins are housekeepers, cleaning up and putting away for later any sugars that flood your bloodstream when you eat.

But there’s more. GCBC goes into exhaustive detail about related impacts of this activity on cholesterol itself, the lipoproteins that convey it, and their various types and subtypes. You may think you know about “good” and “bad” cholesterol and heart attack risk factors and such; I learned just how much was wrong about what I thought I knew. Here’s a tiny sample.

On a diet that [Ronald] Krauss calls the “average American diet,” with 35 percent of the calories from fat, one in three men will have the atherogenic pattern B profile. On a diet of 46 percent fat, this proportion drops: only one man in every five manifests the atherogenic profile. On a diet of only 10 percent fat, of the kind advocated by diet doctors Nathan Pritikin and Dean Ornish, two out of every three men will have small, dense LDL and, as a result, a predicted threefold higher risk of heart disease. …. Krauss and his colleagues even tested the effect of types of fat on these lipoproteins, and reported that, the more saturated fat in the diet, the larger and fluffier the LDL — a beneficial effect. [GCBC, Ch. 9, p. 173; emphasis in original; footnote elided]

Bizarrely, when it comes to scientific study results rather than public-health pronouncements and diet books, there isn’t much that’s particularly controversial about how all this works. (By the way, the cholesterol/lipoprotein discussions were the biggest of the reading “slogs” I mentioned in my first post, but if you really want to know, you’ll really want to read it.)

But fructose is one of those “good” sugars that’s okay to have in your diet, right? You know, ’cause it’s from fruit? Not so much.

As Peter Mayes has explained, our bodies will gradually adapt to long-term consumption of high-fructose diets, and so the “pattern of fructose metabolism” with change over time. This is why, the more fructose in the diet and the longer the period of consumption, the greater the secretion of triglycerides by the liver. [Ibid., Ch. 12, p. 200; footnote elided]

Seen one of those ads on American TV touting the wonderfulness and safety of high-fructose corn syrup? Yeesh.

Because sucrose and high-fructose corn syrup (HFCS-55) are both effectively half glucose and half fructose, they offer the worst of both sugars. The fructose will stimulate the liver to produce triglycerides, while the glucose will stimulate insulin secretion. [Ibid., Ch. 12, p. 201]

The really frustrating part is that these feedback mechanisms in our bodies can lead to a vicious circle of starvation in the land of plenty, so to speak.

[I]nsulin renders the fat deposits temporarily invisible to the rest of the body by shutting down the flow of fatty acids out of the fat cells, while signaling the cells to continue burning glucose instead. As long as insulin levels remain elevated and the fat cells remain sensitive to the insulin, the use of fat for fuel is suppressed. We store more calories in this fat reserve than we should, and we hold on to these calories even when they’re required to supply energy to the cells. We can’t use this fat to forestall the return of hunger. [Ibid., Ch. 24, p. 436]

Well. That’s encouraging, isn’t it?

Not to pick on anyone specifically, but in the first dozen (out of 343,054) diet books that happened to be listed on Amazon at the moment, I found a lot of reasons for frustration:

  • Advice on how to “think like a thin person”, from someone who believes that any calorie-controlled diet will work
  • Instructions on how to lose belly fat by eating things like English muffins (at least they’re whole-wheat ones)
  • How to swap items at your local fast-food place to choose lower-calorie ones
  • A book about getting a flat belly that insists low-carb foods make you fat
  • A popular and not entirely clueless diet that nonetheless lists low-fat (vs. high-fat) dairy as an inherently good thing
  • One book on “eating clean” that seems to have a clue about the actual science of metabolism

All of the above — the science and the largely contradictory diet advice — explains a lot, if you’re a long-time low-fat dieter: you’ve probably been doing it the hard way (and the unhealthy way), assuming it’s even been working for you at all.

While I acknowledge that different diet approaches really do seem to work for different people (another future post or three), increasing the knowledge and awareness of metabolism-science facts is a great Step 1.

Can we agree that a good Step 2 is starting to ignore stuff like this?

If they’d called it fecula, I wouldn’t have eaten it

Nutrition-wise, I reached my impressionable teenage years at an unfortunate time in history.

As a kid, I remember going to coffee shops with my parents in the early 1970’s and sometimes ordering a standard “diet plate”: a naked hamburger, some tomato slices, and a scoop of cottage cheese — because, as everyone knew, bread made you fat.

Then, somewhere around 7th or 8th grade (that would be the mid-70’s), my schoolmates and I were taught all about calories and the dreaded grams of dietary fat, which had nine calories versus the paltry four of protein and carbohydrates. The lesson came with a homework exercise to keep a food diary. I became a habitual calorie counter and at least an aspiring dietary-fat-avoider that day, destructive habits that persisted for more than thirty years.

The war against dietary fat has raged in much of Western society since around that time. For my part, I tried Susan Powter‘s very-low-fat eating; the “baked, not fried” mantra; the new food pyramid (versus the old “four food groups”); Snackwell’s fat-free cookies; and on and on. I tried it all and felt extremely virtuous, if not downright superior, and I lost not a pound. Most perniciously, in 1994-5 I tried an approach called Overcoming Overeating out of sheer desperation — and added 40 pounds to my already overweight frame.

Eventually I’ll discuss here some of the backstory behind this “war on dietary fat”. For now, I just want to convince you that controlled-carb approaches like Atkins (which itself debuted in 1972) aren’t crackpot; not only are they entirely consistent with that old diet plate, they’re pretty much how dieting used to be done since at least the 19th century.

In GCBC, Gary Taubes catalogues the medically prescribed reducing diets of the 1940’s and 50’s, in which — contrary to today’s thoughtless mantra about undistinguished “fruits and vegetables” being good for you — the percentage of carbohydrates by weight indicated whether even some veggies were okay or verboten:

When physicians from the Stanford University School of Medicine described the diet they prescribed for obesity in 1943, it was effectively identical to … Harvard Medical School … in 1948, at Children’s Memorial Hospital in Chicago in 1950, and at Cornell Medical School and New York Hospital in 1952. …. [On these diets,] potatoes … were known as 20-pcercent vegetables. Green peas and artichokes are 15-percent vegetables. …[and so on]… These weight-loss diets allowed only 5-percent vegetables…” [GCBC, Ch. 19, p. 313-4]

And he notes (bracketed explanation his):

Until the 1970s and the beginning of the obesity epidemic, carbohydrates were widely, if not universally, considered fattening. The dietary cause of obesity, as Brillat Savarin suggested in 1825, appeared to be “the floury and feculent [i.e. starchy] substances which man makes the prime ingredients of his daily nourishment” and this “fecula produces its effects sooner and more surely in conjunction with sugar.” [GCBC, Anchor ed. afterword, p. 461]

Honestly, if only they’d used the word fecula in that class — four calories per gram or no — I wouldn’t have touched the stuff.

Don’t eat the monkey chow

I’ve wanted to write this post for a long time, but kept delaying because I worried about coming off as a zealot or a loon. Yeah, I know, some people already think of me as zealous and loony about a lot of things, but somehow the noun versions seem worse.

The thing is, I want my family and friends and colleagues (and myself) to be as healthy and happy as possible. And over the last five years I’ve learned, and confirmed to my own satisfaction, some information about health and nutrition that I very much want to share towards that end. But while the science is pretty much settled (no, not that science), public-health stances and conventional wisdom are another matter.

In a nutshell, the science I’m referring to is:

carbohydrate intake (not dietary fat) drives insulin response, which drives fat accumulation and potentially other serious health issues

or, in a smaller nutshell:

carbs drive fat

By now, lots of ordinary people and big-time news outlets have become aware of this Atkins diet/Gary Taubes/low-carb stuff and taken it seriously, so it’s not exactly news. But I finished reading Taubes’s book Good Calories, Bad Calories a few months ago, and it left such a strong impression on me that I thought I might have something to add to the discussion.

My original intent was to do a humongous book review/analysis here and get it out of my system, but I realized that wouldn’t work — there’s too much to say. Then it occurred to me: Blogs allow for these things called entries, which can be written over time… My next thought was to start a new blog to hold all this stuff, and in fact I got as far as securing carbgrrl.com for that purpose. But then some friends convinced me that integrating my interests in one place is best, and after all, this is already a hybrid blog that has seen lots of evolution. (If you want to see just the stuff in my new carbgrrl category, carbgrrl.com will take you straight there.)

If you’re curious, or skeptical but interested, or have struggled as I have with a lifelong weight problem and associated health issues, I hope I’ll succeed in enticing you to check out Good Calories, Bad Calories (hereinafter GCBC, and now available in paperback). One review on the dust jacket of my hardcover edition describes it as having “engaging narrative”; I’d say it’s more like a 50/50 split between “gripping” and “a hard slog”. For me it was an important slog, but if you want the easy-breezy route, you could do worse than read Dr. Atkins’ New Diet Revolution, which, to the first couple of approximations, turns out to be…correct.

My original book review was shaping up to have several themes, so keep an eye out for ruminations along these lines:

  • The mechanisms at work
  • Diet studies and stats
  • Now they tell us (otherwise known as “Duh”)
  • Correlation is not causation
  • The public-health establishment

If you’ve stuck with me this far, by now you’re probably wondering: What’s with the monkey chow? Here’s some food (ahem) for thought to get things started.

Monkeys in captivity, by the way, will also get obese and diabetic on high-carbohydrate chow diets. One of the first reports of this phenomenon was in 1965, by John Brobeck of Yale, whose rhesus monkeys got fat and mildly diabetic on Purina Monkey Chow — 15 percent protein, 6 percent fat, and 59 percent digestible carbohydrates. According to Barbara Hansen, who studies diabetes and obesity and runs a primate-research laboratory at the University of Maryland, perhaps 60 percent of middle-aged monkeys in captivity are obese by monkey standards. “This is on the kind of diet recommended by the American Heart Association,” she says, “high-fiber, low-fat, no-cholesterol chow.” [GCBC Ch. 14, p. 249]

Stay tuned for more.