We’ve all had the experience. We go off our low-carb diet for a while, then decide to get serious and get back on the straight and narrow. We start counting every carb and being good as gold, and suddenly we’re fatigued. We find ourselves puffing and panting just walking out to the mailbox. Old time low-carbers know this will pass, but newbies aren’t so sure. No one told them about this, and all they can think of are all the horror stories they’ve been told about low-carb diets.
I’ve had countless people tell me of how they tried a low-carb diet once and got so tired they had to give it up. They then usually tell me that a low-carb diet just doesn’t work for their bodies. I tell them that if they’ll just hang in there a while, it will all get better, and, in fact, they will have more energy and less fatigue than before they started the diet.
There is an adaptation period that takes place when starting a low-carb diet. Someone who has been on a high-carb diet–the standard American diet, for example–has to metabolize a lot of sugar. All metabolic processes require enzymes to carry them out. Our DNA codes for these enzymes, but we don’t make them unless we need them. And when we do need them it takes a while for them to get brought up to the necessary levels. So, when we’re on a high-carb diet, we’ve got a lot of sugar-metabolizing enzymes kicking around, ready to metabolize sugar. All the sugar-metabolizing pathways are working efficiently.
Suddenly we switch to a low-carb diet. Now we don’t have much sugar to be metabolized–we’ve got fat instead. But our fat metabolizing pathways are kind of rusty. We’ve got plenty of sugar enzymes, but not enough fat enzymes. The body stays put for a bit to see what’s going to happen. Is this just a few hours without carbs or is it a real low-carb diet for sure? Once the body gets serious, signals go to the DNA, which starts coding for the fat-burning enzymes. They are soon made and start to work, and the fatigue goes away because the body can now efficiently metabolize fat, the main fuel on a low-carb diet.
For years it was thought that athletes did better on high-carb diets because whenever they were tested the high-carb diet always performed better than the low-carb, higher-fat diet. That was before trainers understood the low-carb adaptation requirement.
These studies were usually done on young, conditioned people who were normally consuming diets pretty high in carbohydrate. These subjects would then consume high-carb meals for a day, then get on a stationary bicycle and cycle to exhaustion. They would then be fed a diet low in carbohydrates and high in fat for a day or two, then put on the stationary bicycle again. They would fatigue rapidly. Consequently, for years it was thought that low-carb diets reduced endurance, and the idea of carb loading was developed.
Several years back some researchers decided to have their subjects go on low-carb diets for a couple of weeks before the testing and found that when the subjects had the chance to adapt to their low-carb diet, they had better endurance than when they had been adapted to the high-carb diet.
Lt Frederick Schwatka discovered this period of adaptation 130 years ago and wrote about it.
In 1849 Sir John Franklin and a crew of 129 men aboard two ships, the Erebus and the Terror, set out to discover the Northwest Passage. Sir John, his ships, and crew made it to Lancaster Sound in northern Canada, but vanished. It was one of the great mysteries of the time. A number of groups searched without success to locate and perhaps save some of the members of the Franklin expedition, but, alas, no living members were ever found.
One of these search parties was led by Lt. Frederick Schwatka, a West Point graduate and an army physician. Schwatka’s team headed north in 1878 not with hopes of finding any members of Franklin’s party alive, but with the intent of discovering what happened to them. Schwatka and his team stayed in the far north for two years living with the Inuit. During this time Schwatka lived on “white man’s” food while his supplies lasted and when he could get it replenished, but when that ran out, he and his crew lived as the Inuits, on reindeer, seal, and bear.
During Schwatka’s expedition he kept a dairy, which was packed away in a chest and not discovered until long, long after his death. Once discovered, his diary was published by the Mystic Seaport True Maritime Adventure Series in a book titled The Long Arctic Search.
Schwatka’s diary records the grim daily toil just to stay alive in the hostile climate, not to mention to travel the many miles he did on foot, in small boats, and by dogsled. He also comments throughout on the abundance of game and how easily the Inuit supply themselves and his crew with fresh meat. He noticed the period of adaptation required when he and his team switched from their regular trading-post diet to one solely of meat.
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. At first the white man takes to the new diet in too homeopathic a manner, especially if it be raw. However, seal meat which is far more disagreeable with its fishy odor, and bear meat with its strong flavor, seems to have no such temporary debilitating effect upon the economy.
Quaint, but it pretty much describes low-carb adaptation. And it tells us that markedly increasing the fat content of the low-carb diet (seal and bear are much fattier meats than reindeer) decreases the time for the adaptation to take place. Why? Because the increased fat forces the production of ketones, which replace the carbs as a source of energy, especially for the brain. The more fat, the quicker this conversion takes place, and the less time is spent in the miserable period of low-carb adaptation.
A tip of the hat to Stephen Phinney for putting me onto this book.