For some reason, I have always had a keen interest in my personal health – I took nutritional sciences courses in college before I went to medical school, something only a few of us pre-med students did.
The curiosity of my medical school pathology textbook warning about high carbohydrate diets and atherosclerosis
To this day, I still remember a curious statement in my Pathology textbook from medical school (and while writing this post, I confirmed that it was there, as of the 2005 Edition). It said:
Risk Factors for Atherosclerosis: Lesser, Uncertain, or Nonquantitated: High carbohydrate intake
I thought that was strange to see in my pathology textbook at the same time my professors were advocating, and all of America were/are being told to indulge in a high carbohydrate diet.
This book, by Nina Techolz (@BigFatSurprise), develops that theme in exquisite detail. On the topic of high carbohydrate diets of the 1990’s she includes this historical context:
Choose “snacks from other food groups such as . . . low-fat cookies, low-fat crackers, . . . unsalted pretzels, hard candy, gum drops, sugar, syrup, honey, jam, jelly, marmalade,” stated a 1995 AHA publication. In short, to avoid fat, people should eat sugar, the AHA advised.
Teicholz, Nina (2014-05-13). The Big Fat Surprise: Why Butter, Meat and Cheese Belong in a Healthy Diet (pp. 136-137). Simon & Schuster. Kindle Edition.
I followed up in my own grocery store where in 2016, there are still traces of this diet approach:
The AHA even rode the profit wave of refined carbohydrates from the 1990s onward by charging a hefty fee for the privilege of putting the AHA’s “Heart Healthy” check mark on products …. in 2012, the check mark still appeared on boxes of Honey Nut Cheerios and Quaker Life Cereal Maple and Brown Sugar, which might have healthier-sounding names but are both higher in sugar and carbohydrates than Kellogg’s Frosted Flakes.
Teicholz, Nina (2014-05-13). The Big Fat Surprise: Why Butter, Meat and Cheese Belong in a Healthy Diet (p. 137). Simon & Schuster. Kindle Edition.
Does eating fat make you fat?
The answer, according to the book, is probably no.
It’s a very in depth read of the history, personalities, and science behind the diet-heart hypothesis, about what has been thought to make people fat and cause heart disease, and whether the evidence supports it.
The book has been well reviewed and critiqued with lots of surrounding controversy, so I won’t re-cover what Teicholz covers about this, which in a nutshell is
- many of the studies that we have counted on to tell us what’s right about our diets are flawed
- there are numerous people involved with long careers dependent on a particular version of diet and health
- things we take for granted, like the Mediterranean diet, didn’t really exist in the way we think they did
- the impact of saturated fat, especially when substituted for carbohydrates in the diet, is probably not as dire as we were taught
The part about the people is really important. Teicholz goes in depth into the careers of the most famous food scientists across human history, alive and no longer alive. I now see their names in name-your-article and I have to go back to the book to understand from which perspective/history they are speaking. Otherwise, their conclusions to me are uninterpretable.
A 40 year experiment in low-fat diets, is it over?
I was especially taken by this quote:
No doubt a Cretan or Calabrian peasant might find it ironic that New York socialites and Hollywood movie stars— indeed, nearly all the wealthy peoples on the planet— are now trying to replicate the diet of an impoverished post-war population desperate to improve its lot.
Teicholz, Nina (2014-05-13). The Big Fat Surprise: Why Butter, Meat and Cheese Belong in a Healthy Diet (p. 223). Simon & Schuster. Kindle Edition.
..because following this era in Italian history, meat intake tripled, heart disease rates declined, average height increased by 3 inches.
There’s a lot more going on in this dialogue (and I know I’m several years into it) including the recent decision by the British Medical Journal not to retract Teicholz’ 2015 article, which you can read about here.
Suffice it to say, I believe that my Pathology textbook was telling me to be as curious as possible in my medical career…
If ever there was tipping point in this argument, this is it. Diet-heart hypothesis officially died Friday Dec 2 2016.Thanks @bigfatsurprise https://t.co/D89gCH2MXK
— Tim Noakes (@ProfTimNoakes) December 3, 2016
Addendum, forgot to add this (thanks for the heads up @SDThinkBig & focus on the deep fat and steak part only 🙂 )
Extreme controversy on fat vs sugar, 2/2: @tedeytanblog on Teicholz book “Big Fat Surprise” https://t.co/vMgLp6dODd Feed your head, people
Elite endurance athletes who eat very few carbohydrates burned more than twice as much fat as high-carb athletes during maximum exertion and prolonged exercise in a new study — the highest fat-burning rates under these conditions ever seen by researchers.
The study, the first to profile elite athletes habitually eating very low-carbohydrate diets, involved 20 ultra-endurance runners age 21-45 who were top competitors in running events of 50 kilometers (31 miles) or more.
“These low-carb athletes were spectacular fat burners,” said lead researcher Jeff Volek, professor of human sciences at The Ohio State University. “Their peak fat burning and the amount of fat burned while running for three hours on a treadmill was dramatically higher than what the high-carb athletes were able to burn.
“This represents a real paradigm shift in sports nutrition, and I don’t use that term lightly,” he said. “Maybe we’ve got it all backwards and we need to re-examine everything we’ve been telling athletes for the last 40 years about loading up on carbs. Clearly it’s not as straightforward as we used to think.”
The 10 low-carb athletes ate a diet consisting of 10 percent carbs, 19 percent protein and 70 percent fat. Ten high-carb athletes got more than half their calories from carbs, with a ratio of 59 percent carbs, 14 percent protein and 25 percent fat.
In all other respects, the athletes were similar: elite status, age, performance, training history and maximum oxygen capacity. “They all had the same engine, so to speak,” Volek said.
Scientists measured gas exchange repeatedly during a test determining the athletes’ maximum oxygen intake to gauge carb- and fat-burning rates. On average, the low-carb runners’ peak fat-burning rate was 2.3-fold higher than the rate for high-carb athletes: 1.5 versus .67 grams per minute.
The research is published online in the journal Metabolism: Clinical and Experimental.
Volek has been studying the effects of low-carb eating — and ketogenic diets specifically — for years, particularly in the context of obesity and diabetes. But he has always been interested in how such a diet might augment physical performance and recovery. Ketogenic diets are those that reduce carbohydrates enough to allow the body to access its fat stores as the primary source of fuel. Lowering carbs and increasing fat intake leads to the conversion of fat into ketones, molecules that can be used by cells throughout the body, especially the brain, as an alternative to glucose.
It can take weeks or longer for the human body to fully adjust to a ketogenic diet, so the low-carb athletes in the study were eligible only if they had been restricting carbs for at least six months. Their average time on a ketogenic diet was 20 months.
“The goal was to characterize their metabolic response to a standardized exercise test,” Volek said. “This is the first time we’ve had the opportunity to peek under the hood at what a long-term low-carb, fat-adapted athlete looks like.”
Thank you for the link to the info about athletic performance and LCHF diet!