The New Science Behind Ketones, Weight Loss, and Metabolic Flexibility

What we wish we knew before we ate all the bacon

Everyone has a friend or family member who has lost weight through the ketogenic diet. They banned bread, counted carbs, and shred extra pounds with relative ease.

Going low-carb or keto worked for them. They lost 20, 40, some over 100 pounds. The hype was real. Ketones — the stored energy in fat cells released when the body no longer has glucose to burn — became a gamechanger.

Except for the people who didn’t experience a dramatic weight loss. Try as they might to go into deep ketosis, the miracle fat-burning switch never turned on. They stayed tired, stressed, and restricted, wondering why the magic wasn’t working for them.

Were they cheating? Slipping higher-carb veggies (heaven forbid, grapes!) into their meat and cheese snack packs? Were they genetically immune to ketone production and destined to stay trapped in an insulin-resistant body?

Or was it, once again, a lapse in the science of fat loss?

The Keto Code

The ketogenic diet was created in the 1920s to help patients decrease epileptic seizures. Rapid weight loss was a side effect, one Dr. Robert Atkins utilized in 1972 with his book Dr. Atkins’ Diet Revolution: The High Calorie Way to Stay Thin Forever.

Even with a mouthy subtitle, the high-fat trend stuck. But what about the science? Researchers weren’t sure why eating a diet with a caloric intake of 80% fat, 25% protein, and 5% carbs not only melted extra pounds, it spiked energy levels, decreased inflammation (treating and preventing cancer), and helped protect the brain from Parkinson’s, dementia, and chronic autoimmune diseases.

The bandwagon, doing what the bandwagon does so well, blamed the copious amounts of sugar found in packaged products and highly processed flours and grains stripped of their fiber, but this didn’t explain why some people could eat buckets of fruit and pasta and not gain weight.

Nor did it come close to explaining how the cells in a body produce energy or regain a metabolic set point once the body has found homeostasis.

The Old Science

To make a complex organism as simple as possible, the human body runs off two fuel sources: glucose and ketones. Doctors will forever be armwrestling over which source is ideal, but let’s say they both have roles to play in maintaining a happy equilibrium. Happy means a body can absorb the fuel it needs, burn through reserves without fear of starvation, and utilizes a rest period where it can clean house (make new cells while autophagizing old ones).

This is where the magic words “insulin resistance” and “metabolic syndrome” come into play.

When we consume glucose (pretty much anything that isn’t fat, as protein can be broken down into glucose), our body releases insulin. Insulin is a hormone that signals the metabolism to burn or store excess energy. When we eat too much glucose, too often, our cells become resistant to insulin and can no longer “hear” the signal: use energy now.

A keto diet keeps insulin low so our bodies might relearn how to burn stored energy. Following the bouncing bubble, ketones are fatty acids — literally stored fat being used as energy. Hurray! This should solve everything. Eat bacon, ditch the Spanx, be thin forever —

Not so fast. Some patients eating a ketogenic diet gained weight while feeling depressed, sluggish, and foggy; the opposite of what the diet was supposed to do. Some patients who lost weight plateaued and went back to their old ways of eating.

Keto worked in theory but not for everyone. Even those who found success couldn’t find it sustainable once their bodies were no longer insulin resistant. New research showed the brain prefers 30% of its energy from glucose, and different muscle fibers (like fast-twitch, those responsible for explosive movements) use glucose and ketones in different ways.

Fifty years of keto later, it’s obvious we might be asking the wrong questions. Maybe the answer isn’t Team Ketones or Team Glucose. Maybe the answer is Team Mitochondria, the reason we can actually get out of bed in the morning.

The New Science

“Mitochondria is the powerhouse of the cell.” Remember this from biology? So did Dr. Steven Gundry, author of Unlocking the Keto Code: The Revolutionary New Science of Keto that Offers More Benefits Without Deprivation.

Once again, quite the subtitle, but at least there’s no “thin forever” promise. This might be the applicable time to mention Gundry is author of The Energy Paradox, The Plant Paradox, and The Longevity Paradox, sans subtitles for brevity’s sake. He’s not a newb to the keto debate.

Dr. Gundry writes, “Ketones are not a great fuel. In fact, everything most experts thought they knew about ketosis and weight loss is utterly wrong.”

Them’s fightin’ words.

Gundry goes on to explain the function of mitochondria — ancient bacteria that has been incorporated into complex organisms by evolutionary altruism — is to control energy production. More mitochondria means more power. How do we make mitochondria? We eat foods that tell the body it’s safe to waste fuel.

(See also ATP production and Krebs cycle, but I warn you, it’s a slippery slope. Once you learn a bit of organic chemistry, you may never be able to eat another Twinkie. Those things are Death Stars to mitochondrial function.)

Ketones act as signalling molecules for the body to make more mitochondria, hence the “unlocking” mechanism in The Keto Code.

This shifts the awareness from “eat lots of fat” to “eat foods rich in polyphenols.” A polyphenol is what Gundry calls a mitochondrial uncoupler, or an organic, plant-deprived messenger telling the ancient bacteria to divide and multiply like little bunnies. Popular types of polyphenols are curcumin (turmeric), red wine, green tea, black coffee, and extra-virgin olive oil.

This isn’t a slam against ketogenic diets. It’s okay if you eat the bacon as long as you eat other foods that will allow you to digest the bacon while amping your powerhouses with antioxidants.

To Keto or Not to Keto and What is Metabolic Flexibility, Anyway?

For the purposes of this article, metabolic flexibility is the ability to shift from burning glucose to burning ketones and vice versa without causing metabolic damage or slipping back into insulin resistance.

Have fuel, will burn. Which is great considering eating a restrictive diet past one’s ability to see results can leads to boredom, cravings, binging, and even food dysphoria. The best news, an active body who eats to keep resting insulin levels low has more food choices than ever before.

For many, this means starting off on keto or low-carb, becoming keto-adapted, a process than can take three days or several weeks, and slowly introducing selective carbs when performance falls by the wayside. Your body learns to use the fuel it has without stagnating.

The science of eating is a revolving hotbed of trends, advances, and controversy, but don’t let that keep you from learning the workings of your own body. If keto doesn’t work, try something else. Diets are intriguing, weight loss is alluring, but you are not a diet. Your body is a sensitive instrument, and when it’s finely tuned, it can produce amazing results.

If and when you hit a roadblock, knowledge will keep you from automatically play the blame game, binging a sleeve of Oreos, or unintentionally giving someone bad advice.

In ten years time, this information will be outdated, corrected, and expanded. GOOD. By then, you’ll be more than metabolically flexible. You’ll be ready for the next challenge.

I’ve lost count of how many articles and books I’ve read that try to explain insulin resistance and mitochondrial function in a relatable (edible) way. It’s not easy. If you’ve discovered something that works or disputes this research, sharing it could help someone who is stuck, overwhelmed, or just getting started. Please tell us in the comments.

As always, thank you for reading to the end. You deserve a low-carb cookie packed with polyphenols — Better yet, a hug, but you know…