One of the main objections with ketogenic diets is that they do not supply enough glucose for the body. Objectors claim that glucose is our main fuel, and if we do not get enough of it, our brain, heart, organs, and even muscle will shrivel up and die. They do not exactly say shrivel up and die. They just say it is bad. The truth seems to be they do not know the exact impacts. Why? Because the events have never happened.
People on hunger strikes do not generally succumb to brain and organ atrophy. There are many cases of people lasting many weeks with no food; yet their brains continue to function. Where do they get their glucose? We do store glucose in the form of glycogen. Ask a marathoner how long their glycogen store lasts. Not long enough to finish a marathon, usually. So how can it carry a person weeks through a hunger strike? How did so many Jews survive concentration camps?
Protein. 58% of protein will be converted to glucose. Yes, the number is in doubt, but that is not really relevant. Our daily carbohydrate need is estimated at between 80g and 120g a day. If you are on a 2,000 calorie diet and eat 20% of it as protein, that’s 400 calories / 4 * 58% or 58g of carbs.
Fat also contains glucose. True. Fat lives in the form of triglycerides, three fatty acids and a glycerol or sugar. About 10% of fat becomes carbohydrate. 1600 calories / 4 * .1 = 40g.
So before we eat any plant food at all, we have 98g of carbohydrates in our diet. Most of us on ketogenic diets eat about 50g of carbohydrates a day. Dr. Bernstein recommends 30g, so will go with that conservative number. It is pretty hard not to eat 30g of carbs a day. 58 + 40 + 30 = 128g. Bingo!
Yeah, when we starve, our bodies will convert fat and protein to enough glucose for our vital parts.
“How often does your sugar go too low on a ketogenic diet?” John asks.
“How is that relevant?”
“If you have sufficient glucose in your bloodstream, your brain, heart, and organs are getting enough. It is like a gas gauge in a car. You cannot see your gas tank or your engine using the fuel, so how do you know there is enough? You look at a gas gauge. If there is sugar in our bloodstreams, our body is being fueled.”
“Yah, but if I don’t eat any carbs, and my glycogen runs out, my body will have to use its own protein.”
“People who starve get very thin, but the muscles atrophy before the organs fail.”
“Yah, but my dietitian says … ”
“Your dietitian might suffer from reactive hypoglycemia. It could explain her inability to use her brain.”
Reactive hypoglycemia is an ironic condition. It occurs when someone eats too much sugar, gets too steep a rise in blood sugars and their body responds with a large insulin response. Unlike a fibrous food, this sugar spike is short-lived. It shoots blood glucose sky-high but does not follow-up with more. A sweet potato on the other hand will also spike blood sugar, but it will keep adding sugar as much of it is entrapped in the fibre. Hopefully the large amount of butter you added also slows down the absorption. The result is a less intense insulin response and a closer time matching. In the case of the pure sugar consumer, the insulin will quickly drive down the blood sugar, but the insulin will linger, expecting follow-up sugar like “real food” will supply. Blood sugar drops below normal and the vital body parts go hungry. Trust me when I say that hypoglycemia affects your brain. I have experienced hundreds of diabetes related hypos, and you do not want to be doing anything dangerous when it happens. I truly am lucky to be alive today.
Yeah, I recommend at least 20% of your calories come from protein. Muscle repair is a constant need, and lets not kid ourselves. With less glucose in the pipeline, the pressure on gluconeogenesis to eat our muscle mass may actually be greater. That too doesn’t make complete sense to me, but nevertheless, eat your protein.
I just don’t see ketogenic eaters suffering from hypoglycemia. Sorry, but I don’t. And I don’t myself. I’ve never come close to it, even when fasting. And here’s the kicker for me. I perform much, much better aerobically and anaerobically when I eat ketogenically. I am too old and too lazy to test intense workouts, but when I walk, jog, lift weights, play hockey, or hike through the woods, I have done a million percent better [apologies for the Minaj mimic].
The worry that we do not get enough glucose in ketogenic diets is bogus in my mind.