1824 'calorie' is invented to quantify energy through combustion
1840 food is classified into calories from carbohydrates, proteins, fats
1920 vitamins are discovered
1992 amid high food prices USDA creates food pyramid with cheap agricultural carbs at the base, veggies fats and proteins as supplemental nutrients

The brain and the body need a constant supply of energy to function. Glucose (metabolized from carbohydrates) and Ketones (metabolized from fats) are the only fuels that the brain and muscles can use. The body stores a limited amount of glucose as glycogen (hours worth) within muscle cells. When this runs out you BONK. Because it is the quickest form of energy to digest, the brain is consistently signaling your body to find carbs and replace glycogen stores. When you eat refined carbohydrates the body releases insulin which removes the resulting sugar from the blood where it is toxic, then converts and stores the sugar as fat, expending vital minerals in the process*. The release of insulin halts fat metabolism creating a cycle of dependance on carbohydrates. Reducing carbohydrate intake immediately effects your ability to metabolize fat and is recommended for maintaining optimum health. However, to fully unlock the bodies ability to efficiently utilize fat for energy requires further adaptation. On a ketogenic diet the aim is to convince the body to burn fat as a primary source for fuel by reducing the intake of carbohydrates and the resulting presence of insulin.

* when refined carbohydrates and/or simple sugars are consumed, minerals such as calcium, magnesium, zinc, and iron are mobilized to bind with and remove toxic levels of glucose being released into the blood. This chemical transmutation produces neutralizing acids which attempt to return the acid/alkaline balance within the blood to normal. This not only uses up valuable mineral stores but prevents absorption of minerals in the digestive tract. High levels of refined fructose are particularly damaging to the liver which is responsible for filtering toxins from the blood.

THE BENEFITS (after 2-3 weeks adaptation)
Low carb diet is anti-inflammatory
Provides access to limitless energy
No more carb cravings, mood/energy swings
Muscle protein is no longer a backup fuel source

Carb restriction (30g-100g/day)
Eat more fat (65-80% of diet)*
Fast for 12-16 HRS (between dinner and breakfast)

Any stressor that elevates blood sugar will have a detrimental effect on fat adaptation.
- WORK: Cortisol(released during physical and psychological exertion) raises blood sugar
- STIMULANTS: Caffein raises blood sugar
- EXCERCISE: Aerobic training and endurance sports improve insulin sensitivity and lower blood sugar
- REST: Reduced sleep leads to impaired glucose tolerance and insulin resistance, increased appetite through changes in leptin and ghrelin levels, and reduced energy expenditure. Perturbations of the internal clock system and chronic poor sleep are associated with metabolic dysfunction.

Most foods contain several types of fatty acids which the body uses as energy and building blocks for DNA. They also help absorb nutrients and as messengers that help proteins do their job. More and more the scientists and chefs and wellness nuts are agreeing: the fats we’ve been told to eat for the past 50 years – the poly-unsaturated, so-called “vegetable” ones – are, in fact, the worst stuff we can put in our bodies. And the fats we’ve been told to never touch – the saturated ones – are actually the healthiest, safest and, in fact, are the least “fattening” (if you’re not eating a sugar and carb-heavy diet while also eating fat). Consuming fat with carbohydrate, such as olive oil on potatoes, has some controlling effect on the blood sugar and insulin spike that comes with high glycemic foods.

Human adipose tissue cell

*Using the healthiest fats is important. Just as a tomato grown in sterile soil, picked before repining, and sprayed with toxic pesticides & preservatives does not provide nutritional benefit to the body, so to a fat from a poorly produced source, that has been overly processed, and sat on the shelf for years is not ideal. Margarine and other PUFA forms of hydrogenated, homogenized, highly refined vegetable oils are particularly unstable, toxic, inflammatory, and immune suppressing. Yet you will find them in most packaged products.

Energy - Monounsaturated Fats + Short and Medium chain SFAs (coconut oil, olive oil) are a good source of energy as they do not need to be emulsified by bile salts but are absorbed directly from the small intestine to the liver where they are converted to ketones rather than being stored.
Balance - Omega 3s (fish and flax oils) are anti-inflammatory. Omega 6s consumed in great quantity can be inflammatory. Getting fat from multiple sources ensures that all necessary variations will be available to the body.
Oils - Use only expeller pressed, unrefined, unbleached, non-hydrogenated, non-trans, no solvent(hexane free) fats and oils.
Dairy - The truth is beginning to spread about the benefits of healthy saturated fats like whole milk and butter. The fat soluble minerals obtained from these sources are essential for the absorption of nutrients, vitamin A and calcium in particular. Try to use only free-range organic & raw - butter, milk, cheese, and eggs. Fat from livestock with a factory diet (grain, soy, etc.) lacks vital nutrients and a balanced fat composition.

-- There are essential amino acids(proteins) and essential fatty acids(fats) but there are no essential carbs. --

Low carb fruits: Berries, Tomatoes, Avocados, Lemons, Limes
Low carb veggies: Asparagus, Brocolli, Cucumber, Cauliflower, Dark Leafy Greens, Eggplant, Green Beans, Kale, Mushrooms, Onions, Peppers, Summer Squash

glycemic load comparison (approx)

It is only recommended to eat a moderate amount with the ketogenic diet (1g per lb lean body mass) because it is partially turned into glucose in the body. It is important for vegan athletes to have a dependable complete protein source for all essential amino acids such as microalgae(spirulina), Goji berries, hemp seed, raw cacao, quinoa, amaranth, spirulina and bee pollen. Some argue that the B12 in these foods is not absorbed by the body. Other good but incomplete sources include seeds(chia), beans(kidney), tree nuts(6g/oz), and other nuts(4g/oz).

In the context of a high carbohydrate diet the body retains water and sodium in the kidneys. When carbohydrates are severely reduced the kidneys kick out sodium and water and blood volume is reduced. This can cause symptoms of light headedness, fatigue, and poor heat resistance. It also decreases potassium levels in the body. Replacing this sodium is essential to thriving on a low carbohydrate diet.

Sodium : up to 2grams of salt supplementation may be required. Particularly before training especially in hot conditions.
Potassium : Meat broth is the best source of all essential minerals. Although raw leafy greens (especially spinach) and other vegetables have good mineral content, they can interfere with absorption because of the oxalic acid they contain. raw, unsprouted nuts have phytic acid and other enzyme inhbitors that can also prevent proper digestion.

Adenosine tri-phosphate (ATP) is the chemical energy that fuels your body processes including muscle contraction. ATP is not stored in the body. We must break down either fat or carbohydrate to synthesize it. When we exercise ATP demand rapidly increases causing the body to produce ATP. "How the body chooses the proportion of carb and fat for fuel is complex, but one factor that has a consistent and profound effect is the availability of carbohydrate." (The Art and Science of Low Carbohydrate Performance) The very presence of carbohydrates in the diet suppresses fat metabolism.

Glucose is metabolized directly into ATP thus making it the 'go to' fuel that the body breaks down. Whenever it is available fat metabolism will be essentially shut down. Glucose cannot be stored in large amounts in the body(400-500g). Your glycogen stores max out at 2000kcal (1g = 4kcal).

Fat is converted into ATP in muscle cells by mitochondria. The body has a vast capacity to store fatty acids both in Adipose tissue as lipid droplets and in muscle cells as fatty acids. Even a fit, skinny athlete will hold fat stores upwards of 40,000kcal (1g = 9kcal).

Endurance training has the potential to increase the ability of muscles to both store and metabolize fat. An athlete can in theory eat a higher percentage of well timed carbs while remaining in a state of keto-genesis.

- Most efficient fat oxidation takes place at 65-75% effort (VO2)
- Fueling is not necessary up to 2-3 hours of aerobic running
- Consume by feel and consider sources with fat in them such as avo, coconut milk

When transitioning away from carbohydrate dependance, many will experience symptoms of 'withdrawal' as the body begins searching for a new source of energy. During this period it is important to avoid satisfying the sugar fix which will disrupt the process altogether.

In ketosis your body will produce an increased number of the Beta-Hydroxybutyrate keytone which supplies the heart and brain with energy. Blood ketone levels (measured in milomar units) is the most accurate form of testing. Home glucometers with ketone strips are available. Ketone levels will be lowest in the morning. Not everyone reacts the same way to diet changes. Insulin monitoring may help by informing you what foods you are especially sensitive to. A DXA scan gives a reading of body fat composition.

Extra References
The Metabolic Winter Hypothesis

Fat intake and Athletic Performance

Which Fats should I be Eating?

Proteolytic Enzymes and recovery

Why you don't Have a Six Pack

The Complexity of Reducing Calorie Intake