T Nation

So I Have Been Reading About Low-Carb Diets...


I have come across some information on this intrawebs that discusses how low carb diets cause our bodies to produce toxic acetones, specifically "ketones", that are causing major health problems both long term and short term. These ketones are what are produced when we break down fat for energy when we lack sufficient carbs.

Short term included things like being tired and whatnot and the long term were things like heart attack, stroke, ect.

Everyone on this site seems to be afraid of carbs on days off and whatnot, personally I try to keep my carbs higher than anything else and it has always worked for me, but I do a lot of cardio as well.

Look forward to hearing some responses!


What is your question?

I avoid carbs all day except for morning and around my workout. If I eat to little carbs before my workout, I cant do anything, and if i eat to few after, I will pass out on my way home.


I am saying everyone here seems to be afraid of carbs on off days, why is that, when evidence has been shown to link so many problems to a low percentage of calories coming from carbs, it should be the other way around no? Obviously I am not talking about refined carbohydrates.


I don't think it's a "fear," necessarily, as you claim; it's just one strategy. Some believe that since less energy is expended on off days, then fewer carbs are required. Others feel that high carbs on off days help to promote recovery (often accompanying a low carbohydrate intake on training days).

Carb cycling works, carb loading/refeeds work - it's just a matter of determining which method suits you and your lifestyle.


If these things were toxic, some peoples would've been out of existence long ago.


If you're going to start talking evidence, an understanding of human metabolism beyond "our body produces this when we do this and that's bad, right?" might be worth gaining. It helps you sort through crap articles/studies.

Also, unrelated: nice avatar.


People who really want to get a grasp on this should refer to the work of Dr. Phinney.


From Dr. Phinney:

"Although high-carbohydrate diets might be more effective in short-term tests of high-intensity exercise, there are multiple clues in the published literature that the debilitating effects of ketogenic diets are overstated. Not only is there the demographic evidence that whole populations of people lived for millennia as hunters, but there are many reports of Europeans crossing over to live within the cultures of these hunting societies without apparent impediment.

One of the earliest documented demonstrations of physical stamina during a ketogenic diet was the Schwatka 1878â??80 expedition in search of the lost Royal Navy Franklin expedition. The Schwatka expedition, sponsored by the New York Herald and the American Geographical Society, departed from the west coast of Hudson's Bay in April of 1879 with 4 Caucasians, 3 families of Inuits, and 3 heavily laden dog sleds. Totaling 18 people, they started out with a month's supply of food (mostly walrus blubber) and a prodigious supply of ammunition for their hunting rifles. After covering over 3000 miles on foot over ice, snow and tundra, all 18 members of the original party plus their 44 dogs returned to Hudson's Bay in March of 1880. Once their initial provisions were depleted, the expedition's only source of additional food was hunting and fishing, as there were no other sources of supply along their route.

The leader of this expedition, Lt. Frederick Schwatka, was a graduate of both West Point and Bellevue Hospital Medical College. His summary of the expedition was published as a news article in the New York Herald in the Fall of 1880, but his written diary was lost for 85 years until its discovery and publication by the Marine Historical Association of Mystic CT in 1965 [6]. This fascinating 117-page saga describes how Schwatka, a frontiersman and U.S. Army surgeon, collaborated with his Inuit guides to accomplish a remarkable feat of physical endurance.

In one notation, Schwatka provides an interesting insight into his weaning from their initial supply of carbohydrate-containing food.

"When first thrown wholly upon a diet of reindeer meat, it seems inadequate to properly nourish the system, and there is an apparent weakness and inability to perform severe exertive fatiguing journeys. But this soon passes away in the course of two or three weeks."

This observation, written a century before the current author first came to grips with the issue of "keto-adaptation", offers an early clue to resolve the dichotomy between impaired performance with low carbohydrate diets in the laboratory and their lack of debilitating effects when taken among people practiced in their use. That Schwatka was not impaired by his prolonged experience eating meat and fat is evidenced by his diary entry for the period 12â??14 March 1880, during which he and an Inuit companion walked the last 65 miles in less than 48 hours to make a scheduled rendezvous with a whaling ship and complete his journey home.

Twenty-six years later, a Harvard-trained anthropologist named Vilhjalmur Stefansson entered the Arctic with the purpose of studying the Inuit language and culture. Having been born in 1879 in Manitoba and grown up in North Dakota, it is unlikely that Stefansson was aware of the Schwatka expedition or its reported technique of extended dogsled travel while living by hunting. However when separated from his expedition and thus his source of supply over the winter of 1906â??7, Stefansson was taken in by a group of Inuit on the Canadian Arctic coast. With the arrival of spring in June of 1907, he both spoke their language and had acquired their skill of living and traveling by dogsled on a hunter's diet.

For the next decade, Stefansson traveled extensively over the arctic mainland and among the islands to the north. During this period, he was away from the outposts of European settlement for periods of up to 18 months at a time, and in the remote regions of the Canadian Arctic he lived with groups of Inuit for whom he was the first European they had met.

Stefansson wrote extensively about these experiences in both the scientific literature and in books for the lay public [7]. One of the main themes of his writing was the adaptation of the Inuit culture to survive as nomadic groups in the arctic on a diet consisting solely of the products of hunting and fishing. Coming as it did in the same time period that the science of nutrition was blossoming with the discovery and characterization of vitamins (eg, the first vitamin to be chemically defined was thiamin by Funk in 1911), Stefansson's claim that one could live and function well on the products of just one food group caused tremendous controversy [8].

Subjected to great criticism and even scorn, Stefansson agreed to recreate the Inuit diet under scientific observation. Therefore, for the calendar year of 1929 he and a colleague from his arctic explorations ate a diet consisting of meat and fat for 12 months. This experiment, supervised by Dr. Eugene DuBois, was conducted at Bellevue Hospital in New York. For the first 3 months of this study, the two explorers were under constant observation to guarantee dietary compliance, after which they were allowed more freedom of movement but with frequent tests to document that they remained in ketosis. This study was reported in multiple peer-reviewed publications, the primary reports being published in the Journal of Biological Chemistry in 1930 [9,10], As noted by DuBois [8], the study results were essentially "negative", in that both subjects survived the 12 months in apparent good health, having no signs of scurvy (which was predicted to occur within the first 3 months) or other deficiency diseases.

It is interesting to note from the careful observations published from the Bellevue study that Stafansson ate relatively modestly of protein, deriving between 80â??85% of his dietary energy from fat and only 15â??20% from protein [9]. This was, and still remains, at odds with the popular conception that the Inuit ate a high protein diet, whereas in reality it appears to have been a high fat diet with a moderate intake of protein. In his writings, Stefansson notes that the Inuit were careful to limit their intake of lean meat, giving excess lean meat to their dogs and reserving the higher fat portions for human consumption [11].

It is also interesting to conjecture that the vigorous defense of his arctic observations by Stefansson may have led indirectly to the development of the carbohydrate loading hypothesis. Stefansson was a polarizing influence in the field of nutrition, and his advocacy of pemmican as an emergency ration for troops during the Second World War led directly to the Kark study quoted above, which in turn was a predecessor to many comparative dietary trials performed in Europe and the U.S. in later decades."


Interesting stuff guys, and thanks for the article, an interesting read indeed.

I find it interesting how you guys say that "ketones" (an acetone) are not harmful to the body. Is it not true that the kidney has to excrete these ketones from the body by using minerals such as potassium and calcium, and we are basically just getting rid of these minerals from your body? Can you honestly argue that acetones are not toxic chemicals that are produced?

Now, I am not arguing with the effectiveness short term of burning fat, but rather the health of one putting themselves through such exercises.

It is definitely true that the absence of the minerals that are used to get rid of these toxic chemicals cause many health issues.

Oh, and thanks Artemisia, gotta love the cat guy bobbing his head!


Yea you just got worked by MODOK.

Also, you have to realize that some people focus on the source of the carb, choosing to use fruits and vegetables instead of breads and grains. There is a difference between that and eliminating carbs.


There's a difference between diabetic ketoacidosis and starvations vs. diet induced ketosis. The former involves large drops in blood pH. Pretty sure fatty acid oxidation provides %80 of the heart's energy at all times.


your body won't go into ketosis if you're eating low carbs on off days (and eating carbs on workout days) anyway. takes a few days for this to happen.


Looks like the OP took lessons from some retard dietitian.

Back before anti-seizure medication, boys and girls would be put on very low carbohydrate diets for their entire lives as it was the only way to control symptoms. They didn't diet at 20 from ketone poisoning, most of them lived very long lives.

If ketones were poisonous, we, as a species, would not exist. There used to be no way to get a bajillion carbs a day - you only had some fruits and vegetables to eat every day. Agriculture, and thus high consumption of grains, has only existed for 8,000 years. For the previous 2.4 million years, humans were probably in a constant state of ketosis, and burning mostly carbs for energy was a rarity.