Suppose I gave you a choice:
- consume a food that provides quick but short-lived energy that you must replace frequently with no nutrients to build and repair your body’s structures
- consume a food that provides twice the energy at a slow and steady release for much longer while also providing building material for your body
Which would you choose? More importantly, which would you call the “starvation” diet? This is the question that should be put to every nutritionist who characterizes low-carb/ketogenic/fat-fueled diets as what your body does during “starvation”, as if it’s a sort of “adaptation” away from being primarily a plant-eating species. We are adaptable omnivores, for sure. We can eat carbohydrates for fuel when better food is limited. We can fatten up on, say, summer fruits to prepare for the long winter.
These are the adaptions to our diet of consuming animals.
If you include the decades of research (proteomics) showing that almost all of our paleolithic ancestors’ proteins came from animal sources and that there was a necessary increase in dietary fat that our brains required, then the idea that our normative state is to use glucose for fuel (and that a diet high in fat or protein is damaging) falls apart. (Some good background reading: Meat Consumption: Evolution and Progress, Man the Fat Hunter)
It is high carbohydrate intake that damages. It is carbohydrates that fill in. Relying on glucose for fuel is a last resort. It is the original starvation diet.
Nutrition and metabolism are complex subjects. I ran across some terrific free youtube videos on metabolism and nutrition. How the human body breaks down food (catabolism) and builds up structures (anabolism) while using and releasing energy is complicated. These videos make it fun, funny, and clear(er). I encourage you to invest 10 minutes in order to understand the basics.
But please read this post to understand what is NOT being said and the difference between what DOES happen and what SHOULD happen.
The Blind Spot
As with most education that sticks to the current nutrition paradigm, these videos have a serious flaw. They assume the human body needs glucose as fuel. Now it’s true the human body can use glucose to create energy and conversion is more simple than using either fats or proteins, but that doesn’t mean glucose is the only choice. And it’s certainly not the best choice.
These videos tell us that glucose is necessary fuel, and they support their notion by pointing out that a few specific cell types require glucose for fuel. Of the 37 trillion cells in your body, brain cells, red bloods cells, and a few other types need glucose to function. Nowhere do the videos acknowledge that:
- Keytones can be used rather than glucose for some of this energy once your body has begun to make enough
- Your liver can provide the rest of the necessary glucose every day by breaking down stored glycogen or fats or converting ingested fats and proteins.
The absolutely ridiculous part of this kind of nutrition information is the blind spot. Nutritionists are providing recommendations based on how the average diet affects the human body. That is, they are arguing how things work based on how we currently eat. It’s absolutely true that the average western diet is high in carbohydrates, which means glucose get dumped into your bloodstream for easy fuel and fat storage. Most bodies — very likely yours — run on glucose for fuel.
However, that doesn’t mean this carbohydrate-fuel is what the human body was meant to use. It doesn’t mean carbohydrates are necessary and it doesn’t mean they are healthy. It only means they are usuable.
In fact, other parts of these videos show just why low-carb and ketogenic diets are best but fails to mention anything about keytones or fat for fuel:
- insulin is kept low
- the body has nearly endless energy if it increases enzymes to convert stored fat (about 30,000+ calories) and ingested fats rather than lazily relying on small glycogen stores (about 1500 calories) or ingested glucose
- the human body is merely 1% carbohydrates in the form of stored glycogen
- there are essential amino acids (proteins) and fatty acids (fats) but NO essential mono-, di-, poly-saccahrides (carbohydrates) that we must eat for heath
Identify the Assumptions
Because the common diet is high in carbohydrates (which is a strategy for eating that creates current metabolic and degenerative diseases), nutritionists use this as the normative state, suggesting to us that this is the way it’s supposed to be. That means nutritionists use words like your body is in “starvation” mode when making ketones or using fat for fuel. It “reverts” or “adapts” or when there is “scarcity” and your body “can” use ketones to “get it through”.
Unfortunately, a great deal of money and reputation has been invested in the carb paradigm, and the support for it is based in politics not science. Researchers are already destroying the underlying theories and individuals everywhere are proving the good health and energy that happens when the human body converts to burning fat for fuel. And none of them have had their brain shut down or their health degraded from lack of dietary carbohydrates. In fact, they all do much better.
Glucose is not the preferred fuel of muscle cells under normal human resting metabolic conditions or even under most normal human movement patterns (exercise). Fat is. Sure, given an unlimited supply of glucose and regular refilling of glycogen stores, skeletal muscle will burn through it during exercise the same way a fire burns through kindling when that’s all you have to offer. The body can shift carbohydrate oxidation to keep up with intake. But skeletal muscle can burn fat with great efficiency (and far less oxidative fallout) at relatively high outputs for very long bouts. Cardiac muscle actually prefers ketones, and the brain can run just fine (maybe even optimally) on a blend of ketones and minimal glucose. Our survival as a species has depended on these evolutionary adaptations away from glucose dependency. Entire civilizations have existed for ages on what is practically a zero-carb diet. Think about this: there is actually no requirement for any “essential dietary carbohydrates” in human nutrition. It’s possible to live a very long and healthy life never consuming much – if any – in the way of carbs, provided you get adequate dietary protein and fat. The same can’t be said for going too long without protein or fat. Cut too far back on either of those macronutrients and you will eventually get sick and die. (A Metabolic Paradigm Shift, or Why Fat Is the Preferred Fuel for Human Metabolism)
So learn from these videos and with critical thinking, notice the blind spot and ask questions.