By Dr. Mercola
Humans suffer more chronic and debilitating diseases today than ever before; more than half of all Americans struggle with chronic illness, and 1 in 5 deaths in the U.S. are obesity-related. These discouraging statistics are largely the result of an inappropriate diet.
Most of us eat far too much sugar and grains, and far too little healthy fat. Many also eat too much protein, and most of it of poor quality processed food to boot. Unfortunately, the notion that glucose is the preferred fuel for your body is a pervasive one.
Everyone from diabetics to top athletes are advised to make sure they eat "enough" carbs to keep their systems from crashing. This misguided advice is at the heart of many of our current health failures. It's also a driving factor in our diabetes, heart disease and cancer epidemics.
Dietary fats are actually the preferred fuel of human metabolism, and this can be traced back to our evolutionary roots. One of the keys to long-term weight management and good health is healthy mitochondrial function, and for that you need to get your net carb, protein and fat ratios correct.
This is the focus of my latest book, "Fat for Fuel." It's by far the most important book I've ever written, and the one I've poured the most heart and soul into because I believe this information has the power to reverse the cancer epidemic and save countless lives.
How to Improve Mitochondrial Function Through Diet
To improve your mitochondrial function through diet, the key is to eat in such a way that your body is able to burn fat as its primary fuel rather than sugars. Ketogenic diets are very effective for this, as is intermittent fasting and longer water fasts for those who are overweight.
An important yet rarely discussed facet of nutritional ketosis that I explain in "Fat for Fuel" is feast-and-famine cycling. The reason for this has to do with the fact that continuous, long-term nutritional ketosis can actually be counterproductive.
Long-term uninterrupted use of a ketogenic diet can trigger a rise in blood sugar by driving your insulin level too low. This paradoxical situation can arise because the primary function of insulin is not to drive sugar into the cell, but to suppress the production of glucose by your liver (hepatic gluconeogenesis).
If your blood sugar is high due to chronically and excessively low insulin, eating a piece of fruit or other sugar-containing food will actually lower your blood sugar rather than raise it.
All of this can be avoided by cycling in and out of nutritional ketosis, basically going through a one-day-per-week fast and one or two days a week of feasting, where you eat double or quadruple the amount of net carbs.
Your body is designed to have the metabolic flexibility to use both glucose and fat for fuel. The problem is, most people lack the ability to burn fat. This metabolic inflexibility is the direct result of eating a high-carb diet for a long period of time.
As a result, they struggle with weight issues and poor health. Even if they are not overweight they may be "skinny fat" with loads of excess dangerous visceral body fat. Feast-and-famine cycling helps reestablish the metabolic flexibility to burn fat. Another important dietary factor is avoiding late-night eating.
Feeding your body at a time when it needs the least amount of energy will simply result in cellular damage due to the excess production of free radicals. For this reason, I often suggest limiting your eating to breakfast and lunch — a "Peak Fasting" strategy that allows you to fast for 16 or more hours each day.
Having the Metabolic Flexibility to Burn Fat for Fuel Is Key for Optimal Health
When your body is able to burn fat for fuel, your liver creates water-soluble fats called ketones that burn far more efficiently than carbs, thus creating far less reactive oxygen species and secondary free radicals that can damage your cellular and mitochondrial cell membranes, proteins and DNA.
This is why being an efficient fat burner is so crucial for optimal health. Ketones also mimic the life span extending properties of calorie restriction (fasting), which includes improved glucose metabolism and reduced inflammation. As noted in a recent study1 on this topic:
"The extension of life span by caloric restriction has been studied across species from yeast and Caenorhabditis elegans to primates … Here, we propose that the life expansion produced by caloric restriction can be duplicated by the metabolic changes induced by ketosis …
[E]xtension of life span results from decreased signaling through the insulin/insulin-like growth factor receptor signaling (IIS) pathway … An effective method for combating free radical damage occurs through the metabolism of ketone bodies …
A dietary ketone ester also decreases circulating glucose and insulin leading to decreased IIS … [K]etosis results in transcription of the enzymes of the antioxidant pathways.
In addition, the metabolism of ketone bodies results in a more negative redox potential of the NADP antioxidant system, which is a terminal destructor of oxygen free radicals."
Good Fats Improve Glucose Metabolism and Reduce Inflammation
The importance of good fats is also evidenced in another recent study,2 which shows animal-based omega-3 fats reduce the autoimmune responses associated with type 1 diabetes (aka insulin-dependent diabetes), an autoimmune disorder in which your body attacks and destroys the beta cells responsible for creating insulin.
Here, omega-3s were actually found to help regenerate these beta cells in non-obese mice with type 1 diabetes, significantly improving glucose metabolism and lowering inflammatory markers, decreasing the overall incidence of the disease. As reported by Medical News Today:3
"Both nutritional supplementation and genetic therapy normalized blood sugar and insulin levels for a minimum of 182 days, stopped the development of autoimmunity, blocked the lymphocytes from entering the regenerated islets in the pancreas, and drastically increased the levels of beta cell markers.
These results suggest that omega-3 PUFAs may serve as a new therapy for type 1 diabetes."
Fasting Also Helps Regenerate the Diabetic Pancreas
"In the experiments, mice were put on a modified form of the "fasting-mimicking diet." It is like the human form of the diet when people spend five days on a low-calorie, low-protein, low-carbohydrate but high unsaturated-fat diet … with around 800 to 1,100 calories a day.
Then they have 25 days eating what they want — so overall it mimics periods of feast and famine. [A]nimal experiments showed the diet regenerated a special type of cell in the pancreas called a beta cell. These are the cells that detect sugar in the blood and release the hormone insulin if it gets too high.
Dr. Valter Longo, from the University of Southern California, said: 'Our conclusion is that by pushing the mice into an extreme state and then bringing them back — by starving them and then feeding them again — the cells in the pancreas are triggered to use some kind of developmental reprogramming that rebuilds the part of the organ that's no longer functioning.'"
Fasting May Reverse Type 2 Diabetes
Another researcher specializing in fasting is diabetes expert Dr. Roy Taylor. In a recent calorie restriction trial, type 2 diabetics ate just 600 calories a day for eight weeks. All were disease-free by the end of their fast. Three months later, after returning to their regular diet, seven of the 11 participants were still disease-free. Taylor's team is now testing this type of fasting regimen on a much larger group of 300 people with type 2 diabetes. As reported by The Guardian:6
"… Taylor, who leads the group, thinks that fasting is beneficial because it gets rid of dangerous fat in and around your organs, including two that are important in sugar control — the pancreas and the liver … 'If you have fat around these organs it clogs up the way they work and your body can't control its blood sugars,' says Taylor.
After about 12 hours of fasting, he says, the body uses up all the glycogen in the liver, its go-to source of energy, and starts to dip into its fat deposits. 'The first type of fat to go is that dangerous fat around the organs, freeing them up to do their job properly.' He stresses that people with diabetes should not fast without consulting their doctor — a combination of insulin drugs and fasting can be lethal."
Intermittent Fasting Promotes Health and Longevity
Longo's team has also looked at the health effects of a fasting mimicking diet (FMD) in humans. One hundred participants did three cycles of FMD, which involves semi-fasting for five days each month. The FMD diet is low in calories, sugars and protein, but high in healthy unsaturated fats. After three months, the participants had:7
- Lost an average of 7.5 pounds and had reduced visceral fat and waist circumference
- Lower levels of insulin-like growth factor 1 (IGF-1), a hormone linked to cancer and aging
- Lower levels of C-reactive protein (CRP), an inflammatory marker
- Lower blood pressure
Sports medicine doctor and fitness guru Dr. Gabe Mirkin also recently wrote an article in The Epoch Times8 describing different intermittent fasting regimens, and how intermittent fasting has benefited his and his wife's health. For starters, his wife, Diana, lost 15 pounds in six weeks, and Gabe lost 30 pounds over the course of a few months.
Historically speaking, net carbohydrate intake (total carbs minus fiber) has always been quite low. Likewise, the diseases we now know are associated with insulin resistance — which is primarily caused by excess consumption of refined carbs — have been quite rare.
Switching from a high-carb diet to one high in healthy fat with moderate protein and low in net carbs helps rebalance your body's chemistry. A natural side effect of this is weight loss, and improved weight management, once you're at an ideal weight. One explanation for this is that you don't actually get fat from eating too much and exercising too little. Nor do you get fat from eating healthy fat. Obesity is typically the result of a high-carb diet, which over time leads to an inability to burn fat for fuel.
Fructose Is a Major Culprit in Obesity and Ill Health
Diets high in refined fructose are particularly troublesome, as fructose activates the enzyme fructokinase, which in turn activates another enzyme that causes cells to accumulate fat. When this enzyme is blocked, fat cannot be stored in the cell. In essence, fructose is the dietary ingredient that causes cells to accumulate fat. Dietary carbohydrates, especially fructose, are also the primary source of a substance called glycerol-3-phosphate, which causes fat to become fixed in fat tissue.
At the same time, high carb intake raises your insulin levels, which also prevents fat from being released. Furthermore, no amount of exercise can compensate for this. This is why it can seem nearly impossible to lose weight when you're eating a lot of refined carbs and foods containing high fructose corn syrup, and why cutting carbs is so critical when you're trying to lose weight.
Keep in mind that when we're talking about harmful excess carbs (aka excess net carbs), we're only referring to grains and sugars, not vegetable carbs. Vegetables contain valuable fiber, and when you cut grain/sugar carbs you actually need to radically increase the amount of vegetables you eat.
You also need to dramatically increase healthful fats such as avocados, coconut oil, egg yolks, raw grass fed organic butter, olives, and nuts like macadamias and pecans that are both low in protein and carbs and high in healthy fat.
The Importance of Fiber Carbs
Fiber from vegetables are important for several reasons, including building a healthier gut microbiome, stabilizing your blood sugar and improving fat burning.9 Fiber is in fact a carbohydrate, but unlike sugars and starches you don't digest it. However, your gut bacteria do, and benefit from it. This is one of the reasons why vegetables, which are low in net carbs, will typically not take you out of ketosis, and you can eat as many veggies as you want.
Fiber can be broadly divided into soluble and insoluble types, and ideally you want to get plenty of both. Soluble fiber helps your body extract and absorb more nutrients from the foods you eat, subdues blood sugar and insulin spikes after eating and keeps you feeling full longer. Insoluble fiber curbs ghrelin, the hunger hormone, thereby preventing hunger pangs from setting in and lowering the risk of overeating. It also boosts your body's fat burning ability by nourishing gut bacteria involved in metabolism.
A third category of fiber, which includes both soluble and insoluble fiber, is prebiotic fiber and digestive-resistant starches. These provide nourishment for beneficial gut bacteria that ferment the fiber, breaking it down into short-chain fatty acids that have potent anti-inflammatory properties and help maintain the structural integrity of the lining in your gut. Raw garlic, leeks, Jerusalem artichoke, green bananas and unripe papaya or mango are good sources.
How to Implement a Ketogenic Diet
To implement a ketogenic diet (a diet high in healthy fats, adequate in protein and low in net carbs), the first step is to eliminate packaged, processed foods. The emphasis is on real whole foods, plenty of healthy fats and as few net carbs (total carbs minus fiber) as possible. This typically involves dramatically reducing or temporarily eliminating all grains and any food high in sugar, particularly fructose, but also galactose (found in milk) and other sugars — both added and naturally-occurring.
As a general rule, you'll want to reduce your net carbs to 20 to 50 grams a day or less, and restrict protein to 1 gram per kilogram of lean body mass. To make sure you're actually meeting your nutritional requirements and maintaining the ideal nutrient ratios, a nutrient tracker can be an invaluable tool.
I believe www.cronometer.com/mercola is the most accurate and best nutrient tracker available. Like my nutrition plan, this nutrient tracker is completely free. It's set up for nutritional ketosis, so based on the base parameters you enter, such as height, weight, body fat percentage and waist circumference, it will automatically calculate the ideal ratios of net carbs, protein and healthy fats (including your omega-3 to omega-6 ratio) to put you into nutritional ketosis.
This is what will allow your body to start burning fat as its primary fuel rather than sugar, which in turn will help optimize your mitochondrial function and overall health and fitness. Another key to success on a high-fat, low-carb diet is to eat high-quality healthy fats, not the fats most commonly found in the American diet (the processed fats and vegetable oils used in processed foods and fried restaurant meals). Examples of high-quality healthy fats include:
✓ Olives and olive oil (make sure it's third party certified, as 80 percent of olive oils are adulterated with vegetable oils.
Also avoid cooking with olive oil. Use it cold)
✓ Coconuts and coconut oil (excellent for cooking as it can withstand higher temperatures without oxidizing)
✓ Butter made from raw grass fed organic milk
✓ Seeds like black sesame, cumin, pumpkin and hemp seeds
✓ Grass fed meats
✓ MCT oil
✓ Ghee (clarified butter); lard and tallow (excellent for cooking)
✓ Raw cacao butter
✓ Organic, pastured egg yolks