Welcome! But – what is a ketogenic diet? It is a high-fat, adequate-protein, low-carbohydrate pattern of eating. It has developed from an understanding of how our metabolism operates at a biological level. It is the only diet I am aware of that is based firmly in science.
The US Department of Agriculture (USDA) has ruled over dietary advice for decades. It was given the last say on setting dietary guidelines during the Nixon era, when US agricultural products were in need of a boost and Nixon was in need of re-election. This means that dietary guidelines are still being set by an authority who’s core business is agriculture, not public health.
Ever since their formulation, the USDA’s Dietary Guidelines for Americans have not wavered in their agri-centric advice – maximise plant (agricultural) products and minimise animal (livestock/dairy) products, particularly animal fats. The latest revision of these guidelines (2015) maintains this stance. They continue to promote, strongly and unreservedly, a high-carbohydrate low-fat diet.
Unfortunately, the scientific veneer and gravitas that the USDA brings to their guidelines has created the impression that they are evidence-based. They never have been. At best, it was an hypothesis that has not been borne out despite multiple large-scale (expensive) clinical trials. The idea persists despite the science.
It is not a trivial matter – the adoption of these guidelines is steadily worsening the health of people of all ages living in western countries and, tellingly, of those in less-developed countries as they shift to a western diet. I say ‘tellingly’, because I think this points to causation.
Children are being fed school lunches according to these guidelines. Infants are weaned onto it. Patients are fed this food in hospitals. Government workers in canteens. Armed force personnel. Elderly in nursing homes. Restaurants. Airlines. Institutions. The guidelines have far-reaching implications, even if one wanted to opt out.
The problem is that plant carbohydrates are made up of glucose, and glucose in these quantities is not good for our metabolism. It is only made worse by a parallel rise in sugary products.
Obesity, type 2 diabetes, many cancers, and neurodegenerative disorders such as Alzheimer’s disease and Parkinson’s disease, are all associated with dysfunctions in glucose/insulin metabolism. And all are on the rise. Increased longevity does not explain this. Our lifespan is increasing but our healthspan is decreasing – we are living longer because we are dying more slowly..
A ketogenic diet might be our only chance to halt this ‘epidemic’. The idea is simple – withdraw glucose as a macronutrient and replace it with another macronutrient – ketone bodies, mined from fat stores or sourced from dietary fats.
The energy stored by an average 70kg male with a normal BMI amounts to: ~100,000 calories from fat in adipose tissue; ~25,000 calories from protein in the musculature; ~1,500 calories from glucose stored as glycogen in muscle and; ~500 calories from glycogen stored in the liver.
Of these, it is not desirable to break down muscle for calories. Furthermore, the glycogen stored in muscle cannot be released into the circulation and is for muscle use only.
That leaves only a paltry 500 calories or so of stored glucose (in the liver) that can be released to fuel all the organs of the body, including the brain. This is insufficient. A carbohydrate-fueled body therefore must eat constantly to meet its energy needs. The massive energy in its fat stores is ignored because it is a gluco-adapted body. The high-carbohydrate diet promoted by the USDA does that. The absurdity of this should be self evident.
Keto-adaptation enables fat stores to be mined and converted to ketones by the liver that are then released into the circulation as an alternative fuel to glucose. Keto-adaptation can be achieved in 2-4 weeks with a high fat (~70% of daily calories), low carbohydrate (~10%), adequate protein (~20%) diet. Note that this is not a therapeutic ketogenic diet (such as for epilepsy), which is much stricter. Rather, it is a nutritional ketogenic diet that can be easily implemented and maintained in daily life.
Why does keto-adaptation take a few weeks? Fuels in the circulation (glucose, fatty acids, ketones, amino acids) do not passively diffuse through cell walls to be used for energy. The cell is selective about what it lets in. Each of these potential fuels is carried across the cell wall by transporter molecules. The transporters for fuels differ, and they compete with each other for supremacy. Once a cell has adapted to a certain fuel source (usually the most abundant), that fuel suppresses the other fuel transporters. The cell is now adapted. The cell resists changing the fuel it has adapted to, but will do so after a few weeks of scarcity in that fuel (e.g. glucose) and an abundance of other fuels (e.g. ketones/fatty acids). We probably become gluco-adapted when we are weaned onto carbohydrates, and remain so for life on a high carbohydrate diet. It is remarkable that we can keto-adapt after only a few weeks.
Some advantages of keto-adaptation are: Access to our natural (and often plentiful) fat stores for energy; a steady source of fuel 24-hours a day without peaks and troughs in supply (as with glucose); a fuel source that produces fewer free radicals than glucose and that up-regulates anti-oxidants and is anti-inflammatory; an effortless way to burn fat and lose weight without calorie-restriction; a potential weapon against diseases of modern living (obesity, heart disease, type II diabetes, Alzheimers disease, cancer).
This is explained in a number of posts on 6XC. Here, on this page, I have brought them together.
It is best to start by understanding the hormonal (insulin) model of obesity. It is explained in 10-points here.
The history of how animal fats (saturated) came to be so demonised gives a good background to the failed workings of dietary advice committees. That sorry history is explained here.
The next step might be to better understand the makeup of animal fats. That’s here. I call them our heritage fats.
Then, it is useful to look more closely at our three main macronutrients: carbohydrates; fats; proteins, and how they relate to obesity. They are explained here. We can actually live without one of these macros – guess which one.
That leads to a more detailed look at the nutritional ketogenic diet. Here.
Some practical tips and recipes here.
While a ketogenic diet is high in fat, it is important that the fats not be polyunsaturated vegetable oils. This is despite the USDA advice to eat mostly polyunsaturated vegetable oils (vegetable oils are another agriculture-based product). The reason is here. You will be unwell on a ketogenic diet high in polyunsaturates.
A concern might be the purported link between high dietary fats and high blood cholesterol. That is covered here.
Likewise, the now discredited link between dietary cholesterol and blood cholesterol. Here.
It is usually recommended that dietary salt be increased on a ketogenic diet, due to adaptations that occur in the kidneys. Salt is another one of our nutrients that doesn’t deserve its reputation. I explain here.
If you are wondering about sugar substitutes.
I have made a start on the links between glucose metabolism and the diseases of western living. The first one, on cancer, is here. More recently, on the brain (epilepsy and Alzheimer’s disease) here, and diabetes here (and here). The most recent post on pre-diabetes and diabetes is here.
Exercise is medicine, and here’s what a KD might do for exercise performance.
Calorie-restricted diets for weigh-loss fail in the long-term. Here’s why, and how a KD can help.
More on calorie restriction, and fasting.
And, if you ever wondered where the weight you lost went to, there’s an explanation here.
I recommend rendering your own lard and tallow. The methods for doing that are outlined here.
Finally, here’s a practical idea for breakfast – deep fried bacon!
By all means explore my main site. It started out as a modernist food blog, but has been temporarily hijacked by posts on diet and nutrition. Check out some examples of what I mean on my portfolio page. Or get my eBook about sous-vide cooking on Amazon, even.
The Noakes Foundation provides information on the scientific basis of the ketogenic diet
The Real Meal Revolution, which is the community interface and commercial arm of the endeavour, provides practical recipes and meal plans. Also available in book form. They call it the Banting Diet, after William Banting who first popularised high fat eating for weight loss – in 1863!
Another comprehensive resource, with diet plans, is here.
Something else I found useful is by Volek and Phinney
A 2015 feature article in the British Medical Journal by Nina Teicholz, highlighting the selectivity of the science used to prop up the USDA Guidelines.
Steve Phinney, a pioneer of ketogenic diets:
Jeff Volek another of the pioneers of the modern revival of the KD. Here he calmly, and without fuss, explains low-carb eating.
Finally, a link to a video by a strapping giant of a Swedish doctor with an almost unnaturally-correct posture who is his own best advertisement for a ketogenic diet. He covers the background to the diet well (he refers to it as low-carb high-fat, LCHF). The animation of obesity rates in the US is a must-see. His website is also an excellent resource.