Physician Phollies ~ I: Dr. Cate Shanahan
As often happens with me, certain potential themes for blog series float through my head. A stream of thought that connects things I see, read and hear about the web. One of those themes lately has to do with the quality of information coming from a number of bloggers and otherwise-advocates of low carbing who are by all accounts actively practicing physicians. Many of these physicians routinely chastise, mock and otherwise scorn their fellow practitioners in the course of promoting their views.
This series will highlight the more ridiculous claims made by these doctors, but not so much on the minutia of their entire pro-low carb message. In other words, a bit less about the overarching erroneous themes, and a bit more about individual "schtick" or just what I would call absurd random statments they make. And I guess with each installment of this series, I would ask:
First up, only because I happened to be reading her site because of a reader inquiry, is Dr. Cate Shanahan. If Jimmy Moore has his way, there will be some sort of safe starch debate at the next Ancestral Health Symposium with Dr. Cate on the panel. A quick read of her site and you see she's pretty far to the "left" (as in the opposite of right = correct) on that. A topic for another day ...
The pholly worthy of mention comes from this post:
Stop snacking. Seriously.
If you want to lose weight, there is no such thing as a healthy snack. Why? Because snacking provides you with sugar and/or protein to burn for fuel, the body never had to dip into its fat reserves to keep you going. A few other reasons to quit snacking:
Isn’t it hard enough to plan 3 healthy meals a day? Do you really want to plan for a healthy snack on top of all that? After all, when you’re really in a rush, foods that might seem like a snack could serve as a meal, and seem more like a real, planned out meal if you don’t ever snack. For instance, sometimes I just have a couple of handfuls of nuts and a slice of cheese, or small pile of sauerkraut. For me, that’s a light lunch.
If you avoid snacks then by the time you finally get to eat you are more likely to actually be hungry. The hungrier you are, the better food tastes. Enjoying the taste of REAL food (carb-y and sweet foods don’t count as real food for reasons described elsewhere) is key to health and lasting weight loss success.
Your GI tract needs to rest. If you are eating every three to four hours, your intestinal system is always working and it’s just not designed for that. For one thing, when you eat, your GI tract is forced to draw fluid from your bloodstream, and can take several liters out of your circulation. This drops your blood pressure and can also make you feel tired, cold, or both. If you snack and then have to be up and rushing around, your body now has to route blood to your legs that your GI tract could really use. This is a set up for all sorts of digestive misfortune from GERD to irritable bowel and inflammatory conditions.Whether or not the GI tract needs to rest, that is not such an outrageous claim. But the bolded part that follows is outright ridiculous. It doesn't require a medical degree or even a scientific background to realize just how ridiculous this is.
Several is, at a minimum, more than two. So let's even cut Dr. Cate (as she likes to be called it seems) some slack and say that by several she means three liters. When you eat, several liters of water is diverted from circulation to your GI tract? Really? I presume that any good low carber familiar with the whole "teaspoon of sugar" in circulation meme is aware of roughly how much blood we have. Surely a physician should know. It's about FIVE liters.
sev·er·al (s v
r-
r
adj.
1. Being of a number more than two or three but not many: several miles away.
Dr. Cate's Physician Pholly
After eating, 3L of the 5L of fluid in your bloodstream, or 60% , is taken out of circulation and diverted to your digestive tract.
In other words, eating will kill you.
Comments
On the other hand, the argument that many meals per day (including the snacking is bad argument) leads to constant exogenous fuel supply that doesn't allow our body to use it's own fat, without any mention of dose is shallow thinking. Even if you eat every hour for eighteen hours a day, if you intake results in less than your expenditure, you will burn fat to make up for the lack of fuel. It's like filling your gas tank a gallon at a time-you run out pretty quickly.
So, snacking is not bad (from a weight loss perspective anyway), over-consuming is.
Hey King! Nice to "see" you!
Cos she's a silly billy and must have failed Digestion 101. She never distinguished the difference between DIVERSION of blood and LOSS of blood.
Googling "digestion "blood flow"" elicits
Superior mesenteric blood flow during digestion in man - and the abstract includes:
"Within 5 minutes of the end of the meal the superior mesenteric blood flow, on the average, was increased by 60%. The largest increase was 113% and was noted one hour after the meal. The vascular resistance of the superior mesenteric vessles had by then fallen to a mean value of 55% below the prefeed value. The portal venous pressure was only slightly increased. The cardiac output was increased in 2 but slightly decreased in the remaining 3 patients. The pulse rate, blood pressure and haemoglobin concentration were largely unchanged. The ratio of the superior mesenteric blood flow to the cardiac output increased from 12 to 22% during the digestive period. The findings suggest the occurrence of a redistribution of blood after a meal with an increase in the superior mesenteric blood flow."
@ Thomas, if you eat every hour, it is so easy to overeat the whole amount at the end of the day. Why to stock cards against you? Just look around in every shopping mall, you will see a crowd of mostly fat people , most of them carry caps of coffee of food with them. Just in order to be on a safe side, it is reasonable try to follow a different pattern without a justification that there is a safe way to do what they are doing.
I don't agree that snacking inherently stacks the cards against someone, but I do agree how it can be a problem for many.
I am not necessarily pro or anti snacking. My argument is toward the idea that a constant fuel supply (such as eating every hour) leads to reduced weight loss without regards to amount consumed. In the end, it always comes back to how much is being consumed over a period of time, not how often an arbitrary amount of food is being consumed. I think the contrary argument is, as Evelyn said, linked to the insulin trapping idea. But I agree, if snacking leads you to consume more food overall, don't do it. But if snacking allows you to eat less at a major meal, it may not be a bad idea. I personally like to snack at times (like when I'm home all day and generally more hungry) and take advantage of times when I am busy working (and thinking about things other than food) to not snack and eat less.
@Thomas, What somebody does sometimes, doesn't matter much. I often base my opinions on personal observations. According to that, many chubby people want to eat more often than slim ones do. Slim people are less interested in food in general. Whatever comes first, fatties are getting fat and their body requires more food, and thin people are in an energy balance; or a habit to snack promotes weight gain, doesn't matter for me - it is better not to eat every hour. If somebody eats less by constantly chewing - it would be a rare individual.
Don't want to declare that snacking can't be done without harm at all, but want to put emphasis of the potential downside (as I can see from comments, people are basically agree with that). Too many people were led to believe that snacking is important, essential, healthy. I was raised in a culture where children were actually kept away from a food between meals (ironically, in order to preserve their appetite), while here I see a lot of hungry chubby children who are chewing on their snacks all the time. Just imagine myself in my place. What would you think?
So I don't mind when some doctor advices against snacks - it may do some good.
Also, the notion that a snack prevents you from dipping into your fat reserves is total bunk. It's a rate problem. If you're using energy faster than your digestive system is providing it, you'll be running on reserves. Moral of the story: only snack when you're in the middle of a marathon :-)
Here is another abstract. It may have some relevance for you.
Tidsskr Nor Laegeforen. 1999 Feb 20;119(5):664-6.
[Digestive system's large and changing needs of blood supply].
[Article in Norwegian]
Waaler BA, Toska K.
Source
Fysiologisk institutt, Universitetet i Oslo.
Abstract
Doppler utrasonography has made it possible to record blood flow to the digestive tract (the superior mesenteric artery) directly and continuously in unanaesthetized, healthy humans. Several research groups have demonstrated how blood flow to the tract increases gradually and markedly after a meal, and more so after a big meal than after a small one. The increase in blood flow reaches its maximum after 20-40 minutes and lasts for 1.5-2 hours. In the postprandial period there is a parallel and similar increase in cardiac output; the meal thus imposes an increased work load on the heart. Carbohydrate meals, as well as meals of protein or fat all release increases in local blood flow as well as in cardiac output. Surprisingly, during physical exercise of relatively high intensity, there is no reduction in blood flow to the digestive tract in humans. This is in contrast to the exercise-caused flow reduction observed in several animal species. In the postprandial state the large increase in cardiac output caused by muscular exercise is actually added to the increase already established by the meal. This course of events helps to explain why patients with angina pectoris are more prone to chest pains after a meal.
Enjoy.
On the snack/not snack thing--I've been wondering about that forever and would love to 'know' the answer. When I was at my deepest anorexic ~300cals/day state, I was eating tiny amounts, _constantly_. When I did the fruitarian 80-10-10 for years, I avoided snacking like the plague, and was hungry all the time but didn't mind.
Recently, I had bad enough reactive hypoglycemia that I had to eat several times a day. More recently, I've psyched myself out of snacking and don't so much but my ND says I should.
Matt Stone recently mentioned that bigger meals in one sitting are harder work to process than several smaller meals, and so less might be absorbed (inadvertent CR). If I can make myself eat a big meal, I usually feel sick and then eat much less later on, so I guess there's some truth in that...
I'm beginning to think that the reason some have a problem with what I write is that they have a problem with what I didn't write. I didn't say anything about the value of Cate's advice on snacking. I was specifically calling her out on that ridiculous notion that the GI tract needs rest and eating draws blood out of circulation. This is made up crapola, unnecessary, and undermines her credibility. If snacking increases the likelihood of overeating, say that. No need for whacky theories.
It sounds like Cate doesn't eat a whole lot many days. A glass of milk (even raw whole milk) and some cream in coffee for the whole day until an evening meal isn't much. Ditto for her light lunch "snack". So to lose weight you need to not eat a lot. Sounds familiar ...
It is the made up science that I blog about because I think it matters. If someone is giving out medical advice or science-based arguments, they should be backed by substance. One shouldn't have to say "well, maybe (s)he is wrong on that, but they're right about this other thing so it's no problem". At some point, you have to wonder if they are even right about that other thing.
I would note that Cate's advice is the opposite of that of many others, who advise to never let yourself get too hungry. In my experience, when I'm really hungry food doesn't taste better because I tend to eat it faster. But again, that's just me.
I think I would really like to see more advice in terms of strategies you should consider trying rather than imperatives.
It seems a frequent tactic to say something that is proverbially true [even better if it's also emotionally provocative] then slide the nonsense in under the radar. I think it is expected, maybe even relied upon, that people will focus on the part they agree with and let the rest slide. That's how you get people who sit and fret over whether their GI tact is "rested" or not without any possible way of measuring that or even a functional definition for the meaning of the term.
There is a tendency of making strange claims in order to make more people convinced among medical professionals, especially thous who work with people . A good example of it - Dr. Davis with his battery acid post. Now he is(or was) on a best-seller list. Also, there is a very dramatic Dr. Mercola. Looks like it works - the claim gets attention sooner, more people get convinced rather than disappointed. There is Dr. Oz giving a clown-like performances to the audience of silly-screaming mostly overweight females. I remember, how some lady posted a comment how she was convinced in the carbohydrate theory of weight-loss when she saw stearfoam melting under fire during Dr.Oz show, when he told about different diets for different body types. He is not a stupid man, but act silly in order to hold attention. If people are teaching doctors that simplified dramatic claim is the key to people's ears, than you will get a bottomless supply of the blogging material.
As for snacking, I think the issue is with the sheer amounts of snack foods available to us these days. I grew up in the 70s and we were pretty poor, so it was three meals a day and whatever we might be able to sneak or scrounge in between, which usually wasn't much.
But these days... most local supermarkets have SEVERAL aisles dedicated to snack foods. Chips and dips in one aisle, cookies and snack cakes in another, "healthy" snacks in yet another. And then there are a number of shelves dedicated to the snack foods of specific companies (Hostess, Entenmann's, etc). And we haven't even arrived at the frozen foods section, with it's freezers stocked with ice cream and other goodies.
Snack foods might make up more than a third of the shelf space in your typical grocery store or supermarket these days. And as you would expect, it is hyper-palatable stuff. "Betcha can't eat just one" is not a challenge-- it's an inevitability!
I still snack, but not every day. Now and then I'll get a package of almonds or mixed nuts. Something that I can grab a handful of and know that I won't come right back and finish the box. That or fruit, for the same reason. Fruit may be sugar, but I can stop at one banana or apple, which I cannot say for one Twinkie or cup cake.
Hey, I'd be a hypocrit if I didn't acknowledge that sometimes you have to be a little edgy to get heard. But it's a fine line between that and misleading and misrepresenting facts to promote some message. I realize the likes of L.Ron are probably convinced that they are right and hold the key to as close-to-eternal life as possible. I don't think he thinks he's misleading people. On the other hand, I'm not sure why Dr. Cate wrote what she did here ... it's just preposterous and doesn't seem to have any promotional value. I'm not so generous about Taubes motives at this point. I believe he knows in his heart of hearts the truth. Either that or he's delusional, because he should.
It's a fact that I am surrounded by food all day most days. I will very seldom be in a position that will make it difficult or inconvenient for me to get fed. I don't need a snack. If I were, a snack might be advisable to have as an option. KWIM? Every person is different, every day is different. I'm not giving up the freedom to work my agenda to some contrived boogeyman.
I find if I eat 600-800 or so meals, I'm full and stay full. So, for me, 2 meals of 600-800 is doable. I do better if I stay under 1700 (or I regain). Those are hardly luxurious meals..it still takes planning. But that's what satisfies ME, hence, I do better to eliminate snacking.
When I snacked from a particular dietitian's plan, I was just thinking abbout food all fricken day. Now I think about it 2x. :D I do carry snacks for emergencies (when I may have to delay meals)--nuts, fruit, protein bars. But I prefer to sit down and eat my breakfast/dinners. :D
And man, I'm so glad I didn't exsanguinate when I did the 3 meals + 2 snacks plan.
@Princess Dieter, I also like a dish of yogurt/fruit/nuts. I agree it's a bit much to consider it a snack but also a bit too much to build into a meal. I call it my "small" meal. :-))
Now, I get dizzy if I exercise totally fasted, so I do a light (no more than 150 to 200) calories of whey protein with water or almond milk, and I do fine.
So, intersesting...
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wow ... really
from this page:
http://www.americasblood.org/go.cfm?do=page.view&pid=13
> How much blood is taken?
> Whole blood and apheresis (platelet)
> donations are about 1 pint. One pint
> is roughly equal to 1 pound.
one US pint is ~473 ml
The Canadian Blood Services takes 450 ml but I've seen people faint ... 4 people over the 10 years I regularly donated
They tell you to do NOTHING strenuous for at least that day and take it easy the next day.
oops ... a little misleading, I also did some volunteer work at the clinics, there was one right beside my work place. So I saw many more than a straight donor who's in and out would see.
It took me a whole year to get adjusted to work out in a fasted state. At the very beginning I had concrete legs, later , if I exercised more than 45 min, I had a migraine. It lasted for a while, I just avoided overextending myself too much, than probably 2 months ago I noticed an unusual increase in endurance - 2 hours of hard cardio without being particularly tired. At the same time I noticed that my Fasting BS became higher. So , it is better to keep in mind than exercising in a fasted state affects blood sugar. Is clear than body keeps adjusting if pushed to some limit. I remember having migraines when I just started LC eating, when I tried to increased fasting intervals at first to 4 hours, than 5, increase to 6 hours went without anything. So it may be inaccurate to say "when I do something I get lightheaded or get a migraine", it should pass if you go through discomfort several times. I am not advising you to do it, just sharing my experience.
On the other hand, on longer runs, there have been times when I get a second wind by taking in some carbs while on the move. I've certainly never slowed down as a result of downing a cup of Gatorade.
Good thing we got this asylum to keep things sane ;)
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Has the bro/Wieder/$upplement (p$eudo)$cience changed? AGAIN? What happened to getting insulin spikes right after a workout?
All the current best recommendations are to consume protein plus fast acting carbohydrate (dextrose or maltodextrin or that Vitargo stuff) during and post workout ...
There's so much more in this article -- if you go above a 10-30g/meal carb allotment you could shut down fat burning all day! Yikes!!! That would kill me too, because my body NEEDS to burn some fat all day long. I hope if she reads this she can see how my sarcasm is directed at the utter absurdity of her "educated" claims.
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GOOD LORD ... my mom (all moms of little boys IMHO) told me that because she didn't want broken dishes (even though in rural India all the dishes used to be stainless steel) and broken furniture (or what laughably passed for furniture) and food all over the walls ... It may be different for little girls but geeez ... motherhood does NOT come with an automatic knowledge of gut fluid dynamics.
apparently the "Jenny McCarthy MOMMY INSTINCT school of medicine", is now granting degrees
When I have kids I hope they're all daughters ...
It will get you pretty familiar with guts and fluids though :) Every mommy knows you eat sitting at the table and don't snack because clean up is a pita and we like to put some limits with regard to square footage on that.
If it ends up being good for you...fine...but let's not lose focus on what's important. No one wants their evening to be an advertisement for discount vasectomies.
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