Metabolic Flexibility

What is metabolic flexibility?

Metabolic flexibility is the ability to easily shift from burning carbohydrates as your main fuel to fat burning, either from your diet or from stored body fat. Our bodies are designed to be metabolically flexible. However, our modern diet is based on easy-to-access carbohydrates which force our metabolism to be carbohydrate dependent. Because of this, over time, we lose the ability to easily use fat as fuel. 

Why can’t we easily burn fat?

The answer is in two parts:

  1. Carbohydrates are easy to access fuel. If you eat carbohydrates several times a day, every day, you will use those calories as fuel because carbohydrates are easy to access, and they do not store well in the body. It does not matter if you eat complex carbs such as vegetables, fruits, whole grains or beans, or you eat simple carbohydrates such as pasta, bread, and desserts.

  2. Another aspect of carb consumption is the effect carbs have on insulin production. When carbohydrates are consumed they break down to glucose, an energy molecule used by most cells. A carbohydrate meal raises blood sugar and stimulates insulin production and release. Insulin also blocks fat metabolism. If you have eaten a carbohydrate-dominant meal within the past 4-5 hours, your insulin will be high and you will not be able to easily burn fat.

What happens if you eat more carbohydrates than you can burn?

Cells are stimulated by insulin to intake sugar from the bloodstream. When cell capacity for glucose is maximized that cell becomes resistant to the effects of insulin. If blood sugar is still high, insulin signals the liver to store excess glucose as glycogen (storage form of glucose) and triglycerides (a type of fat). Glycogen is our main carb storage unit. However, because of its large size and the limitations on where it is stored, we cannot store much glucose as glycogen.  In contrast, triglycerides are very compact and have vast storage potential in fat cells. This is why eating too many carbs will increase triglyceride levels (which show up in your cholesterol panel at the doctor) AND your body’s fat stores even if you eat a low-fat diet. 

How can you increase fat metabolism?

We can train our bodies to burn fat instead of carbs as fuel,  in a healthy and safe manner! Even though our bodies “know” how to do this, it is not the way we have been taught to eat in our carb-dominant culture.  We will learn a healthy and safe process for this in the Keto Boot Camp series.  

In the most basic terms:  to easily burn fat (especially from stored body fat), you will need to lower insulin. Since carbs stimulate insulin secretion, the best way to lower insulin is to eat a very low-carb diet. When there are no carbs to burn and no insulin to suppress fat burning, you will start to burn fat. It can take several days to several weeks of eating a low-carb ketogenic diet to successfully shift from a reliance on carbs for fuel to begin to easily burn fat for fuel.

Is a ketogenic diet just a popular health fad?

In short, no.

The science behind ketogenic metabolism has blossomed in the past few years. Doctors use very low-carb diets to help treat diabetes, seizures, fatty liver, cancer, and even heart disease. It has shown to be effective because it can decrease inflammation and correct metabolic disorders. 


We will learn the science and health benefits of a ketogenic diet in detail in the Keto Boot Camp series. For example, the ketogenic diet allows for the mobilization of body fat to fuel with the net effects of increased energy and decreased body fat. There are many benefits, as stated above, to having this kind of metabolic flexibility. Of course, burning fat for energy will allow you to more easily lose weight (fat, and not just water loss, or more harmful… muscle loss). It also helps optimize body composition, e.g. muscle mass to body fat ratio. People who have optimal muscle mass in relationship to body fat are more resilient to conditions including Alzheimer’s, diabetes, heart disease, and infertility.

Why would you choose to take a keto class?

We are all unique. While there are many examples of ketogenic diets available in books and online, what works for one person may not work well for another. For the past six years, I have led hundreds of people through keto-adaptation. Medical guidance provides both safety and a greater likelihood of success. Some of the negative side effects of a ketogenic diet are keto-flu, kidney stones, gout, muscle loss, and elevated cholesterol. Screening for risk factors and providing additional support can mitigate these effects.

What is optimal health and how is it measured?

Most people have a sense of what it feels like to be healthy. It is a good idea to stop and ask yourself how healthy you feel. Sometimes life gets so busy the opportunity to notice health (or a lack of it) slips by for too long. Another excellent way to measure health is with biomarkers. There are many common blood tests that monitor health and health risks including liver enzymes, various tests for blood sugar and C-reactive protein. Blood pressure reading, hip-to-waist ratio, and muscle mass-to-fat mass ratios are other objective measures of health.

Is it important to detox when you lose weight?

It is essential to detox when you lose weight because many chemicals are stored in fat. When you lose weight, those chemicals move into your bloodstream where they can travel to your brain, your liver, and other organ systems. It is important to incorporate detoxification practices to assure that chemicals leave your body when they leave your fat. These include sweating, regular bowel movements, deep breathing, and nutrients to support liver biotransformation of chemicals.

Should you stay on a ketogenic diet forever?

A long-term high-fat ketogenic diet can be just as harmful to your health as a carbohydrate driven diet. Mother nature has provided a huge array of healthful foods that humans are designed to partake in. A ketogenic diet limits or eliminates roots, fruits, grains, and beans. These food groups have significant nutritional value unrelated to their macronutrient balance. Once you develop metabolic flexibility, you can bring healthy carbohydrates back into your diet while maintaining the ability to easily burn fat. Consider Ketosis another tool in your toolbelt for gaining optimal health and weight.

Is a ketogenic diet good for everyone?

No one diet is good for everyone.  However, metabolic flexibility is good for most people! I like to think of a ketogenic diet as an excellent tool in your health tool bag. A very low-carb diet trains your body to burn fat. You may want to burn fat because you need more energy or because you have stored too much fat. Either way, turning body fat into ketones can be a huge asset.

To find out more...
Pick up a copy of Dr. Nedrow’s brand new book, Metabolic Flexibility, How to Heal Your Metabolism With a Ketogenic Diet. Better yet, come to hear her talk about her program at Farmacopia on Saturday, January 11th at 9:00-10:30 am. The class will be followed by a book signing. Or, sign up for the 6-week Keto Boot Camp series!

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