In 2018, at the peak of the keto frenzy, I was a ketogenic diet specialist who started spreading a very unpopular message from inside the keto community: Do keto. Not forever.
At that time, carbs were not welcome at the dining table. Many promoted keto as the "ideal" human diet, a lifestyle, and something you do forever. While I didn't want to discredit the value of doing (a temporary phase of the) ketogenic diet, I also wanted to be very clear: being in a state of nutritional ketosis for the rest of your life isn't optimal.
Why? Our bodies are designed to run primarily on carbohydrates. When we eat both fat and carbs, our bodies don't make ketones out of fat first. We only make ketones when our bodies are extremely deprived of carbs and have no other choice.
But given a choice? Our bodies will run on carbs. So why would the human body be designed to primarily run on carbs if we weren't "meant" to eat them? This should be your first clue: we are designed to eat carbs. In addition, our bodies will only use ketones for fuel when those carbohydrates are severely restricted.
Does that mean energy from ketones isn't as good? No. It just means the human metabolism is intelligently designed to do both. This natural adaptability also hints that it's something we should be able to do without suffering.
So let's get into the misconceptions about nutritional ketosis, carbs, and metabolic flexibility.
Getting what's described as the "keto flu" is a form of suffering. Dieters coined that term for the symptoms they'd experience the first time they went into nutritional ketosis. However, most people say these symptoms decrease (or disappear) each time they return to ketosis after taking a break.
This is a sign their bodies are becoming better at doing something they should easily be able to do – but have lost the ability to do well – because of the modern sedentary lifestyle and the food abundance that prevents it from happening often.
The truth is, nutritional ketosis is a healthy part of human metabolism. And an optimal metabolism should be able to function well in either of these states: glycolysis (running primarily on carbs) or ketosis (running primarily on fat that's been converted into ketones).
Fact 1: If you really struggle when you eat carbs, that's a sign of poor metabolic health.
Fact 2: If you really struggle being in nutritional ketosis, that's also a sign of poor metabolic health.
Being able to easily operate in either system is now commonly referred to as "metabolic flexibility." And that's the ticket. It's the ticket to improved energy, easier weight maintenance, and more food freedom, meaning you can eat according to actual hunger cues and be less likely to have weight issues.
I'm reminded of a line from the children's movie, Megamind:
"Girls, girls, you're both pretty."
Carbs are awesome. Keto is awesome. Everyone wins. And if you can thrive in either state, you'll win too.
Many people get lean without going into ketosis. So why bother? Lots of reasons. Here's a list of benefits from my book, Short-Term Keto:
Free radicals are unstable atoms that can damage cells, causing illness as we age. Obviously, since we produce ATP every second of our lives, our bodies are prepared for this. They minimize the damage by creating endogenous (meaning "made within the body") antioxidants like glutathione. But if the free radical load becomes too great, it causes us to age prematurely and increases our risk of stroke and neurodegeneration. Ketones can inhibit inflammation and oxidative stress by enhancing the breakdown of free radicals and increasing the activity of our innate antioxidant system.(2)
While research is limited, a large amount of anecdotal evidence points to the promise of keto's impact on reducing inflammation and consequently autoimmune symptoms.
In research, implementing a ketogenic diet has been shown to reduce symptoms of PCOS, the most common endocrine disorder for women of childbearing age.
Rodent studies and small human studies have also shown the benefits of the ketogenic diet regarding cancer, particularly glioblastoma (an aggressive type of brain cancer), prostate, breast, liver, and stomach cancers. Scientists believe these benefits are due not only to the starving of the tumors, which feed on sugar, but also to the fact that keto changes gene expression, which in turn changes the way cells behave.
Nutritional ketosis serves as a treatment for metabolic syndrome by improving metabolic and inflammatory markers, including HbA1c, CRP, fasting insulin, and glucose levels, as well as aiding in weight loss, decreasing hunger, and increasing satiety.(9)
This is difficult to answer. Those who are already metabolically healthy, but haven't quite trained their body to thrive on ketones, might only need to do it for 4 weeks. Others who are very metabolically unhealthy might need to do keto for several years to get the full benefit.
I also must add that some people – a tiny percentage of the population – truly will do better on keto indefinitely. This includes people who are using keto as a therapeutic intervention for diseases such as epilepsy or other neurological diseases, type-2 diabetes, or autoimmune diseases.
For everyone else, here are some signs that keto has served its purpose and you're ready to reintroduce carbs to your body:
Note: Please don't judge your keto experience by the first few days. This period can suck for most people. Your body isn't getting what it's used to (lots of carbs) and is adapting to operating in a completely new metabolic state. It gets better as it goes. And to make it better, get plenty of salt and water during your entire keto phase.
Slowly decrease your fat intake one week at a time. Replace those calories you'd be getting from fat with calories from carbs, which will increase each week (more details below).
The reason for the slow shift is multi-faceted:
To allow your body time to produce the correct amount of digestive enzymes so you can assimilate the changing macronutrients. You have different enzymes in your gut responsible for digesting proteins, fats, and carbs. Your body produces more or fewer of each type of enzyme in accordance to how you're eating. Doing this process gradually will help you avoid gut issues that often accompany drastic macronutrient changes.
To allow your gut bacteria to gradually adapt to the increased amount of fiber you'll be eating with increased carbohydrate consumption (because yes, your carbs should come from nature and have fiber content, not from candy).
To allow you to truly see how you feel at different levels of carbs and fat so you can find your unique carb threshold or the general amount of carbs you feel best consuming.
Here's an example of how to configure your macronutrient changes week by week. Calories are up to you, but if you have no idea where to start, a good starting point is:
If you have a slower metabolism, hypothyroidism, are perimenopausal, or are over age sixty, you'll likely need fewer calories, so play with it until you find a spot where you experience some hunger at some point during the day, but it's tolerable, and you're slowly losing body fat.
If you're a fast metabolizer, have more muscle and/or are very active, you'll likely need more calories than what's indicated above. So find your sweet spot.
So now let's talk macros. This is what I recommend when transitioning off keto, which is generally about 60-70% fat, 30-40% protein (I always recommend a higher protein keto), and 5% carbs.
I like to immediately push people to 40% protein (and highly recommend resistance training as part of your plan), with fat and carbs as follows:
Percentage of total calories by macronutrient:
Continue playing with percentages as needed. Don't go below 20% of total calories from fat, however. Your body needs it for hormone production, cellular health, and brain and nervous system health.
Keto has its seat at the nutritional table. It's a natural part of human metabolism. Going through a phase of keto is extremely helpful for achieving optimal metabolic flexibility. Once that's established, your body should be able to absolutely thrive on carbohydrates and easily transition into ketosis on an as-needed basis.
Editor's Note: This is an intriguing topic. If you'd like to learn more, check out Tara's book, Short-Term Keto: A 4-Week Plan to Find Your Unique Carb Threshold.
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