From Dr. Will Cole's blog about his ketotarian diet:
First, let’s look at sugar consumption: The typical American eats an average of 765 grams of sugar every five days – some of it from obvious sources (sugary coffee drinks, soda, doughnuts, cookies, etc.), but much of it from hidden sources in foods that don’t seem like they could be dessert (soup, salad dressing, condiments, bread). Compare that number to the 45 grams of sugar Americans ate in 1822 over the same 5-day period – that’s a massive increase.
To look at it in another startling way, every person in the U.S. eats and drinks an average of 130 pounds of added sugar every year, which is an average of 3,550 pounds of sugar over a lifetime. To put that in perspective, that is the equivalent of eating 1.7 million Skittles or an industrial-sized Dumpster full of sugar! Yuck. On top of that, most of us base our diets on foods made from grains: bread, pasta, rice, granola bars, cereals, and crackers, which the body also breaks down into – you guessed it – sugar.
Putting aside the startling image of an industrial-sized dumpster of sugar, let’s look at what all this sugar does to your body. Carbohydrates broken down into glucose results in the most easily accessible energy source. When glucose hits your bloodstream, you release insulin to help carry the glucose around your body and deliver it where it is needed. That doesn’t sound so bad, does it? The problem is that most people today eat so much sugar and so many carbohydrates that we end up with blood glucose levels that are dangerously high, since our body doesn’t need nearly that much fuel.
High blood sugar is toxic and it can lead to serious health issues, but in addition, any sugar the body can’t burn gets stored as fat around your liver, stomach, and in circulating fat (known as triglycerides). On top of all that, the by-products of glucose metabolism are inflammatory to the body, especially when there is an excess of glucose. Look at it this way: Burning sugar as your primary source of energy is like using dirty fuel: You have to refuel often (or you will get “hangry” on that blood sugar roller coaster), and the burning of the fuel leaves behind pollution in the form of inflammation.
Fortunately, there is another way. You don’t have to get stuck on the blood-sugar roller coaster, with its erratic peaks and crashes and significant health risks. You don’t have to burn sugar for fuel. Instead, you could be burning fat.
Fat-burning is a more efficient fuel source for your metabolism. A by-product of fat metabolism is ketones, which your body and brain can use as a slow-burning, efficient source of fuel. This allows you to consume far fewer carbohydrates while simultaneously increasing your energy. Less blood sugar means less insulin, and as insulin levels fall and your body requires energy, your liver produces ketones to fuel your body. Your brain can also use ketones as an alternative fuel source when blood levels of ketones are high enough to cross the blood-brain barrier. This is great news because ketones have been shown to be very neuroprotective. (11)
One reaction many people have to this concept is to wonder whether it could possibly be healthy to eat that much fat. Let’s consider some basic facts: Your brain is comprised of 60 percent fat. At birth, many of us relied on fat in the form of breast milk for brain development and energy. And for those who drank formula, MCT oil (derived from coconut and palm oil) is added to most formulas as a source of healthy fats. In order for the brain to work optimally, it needs a lot of energy, and from an evolutionary and biological standpoint, the most sustainable form of energy comes from healthy fats.