Recently my sister informed me that her spouse decided they were going to lose weight. They have a trip planned for the Labor Day weekend to Hawaii and they both like scuba diving so they want to be in good shape. Her spouse chose Atkins, which my sister had never done before, so she had a few questions about low carb diets. She knows I have been Paleo for the last couple of years and I was flattered that she thought of me as a resource (she is usually very hands-on). A couple of days ago, I got a text from her asking if low energy was normal for low carb diets, so I asked her how many carbs she was eating daily and her answer was 20 g. I told her if her carbs were that low, she either needed to eat more carbs or eat more fat, since she was probably transitioning into ketosis. I got back a text: what’s ketosis?
For those of us who’ve been in the ‘low carb nutrition world,’ ketosis (keto) has been a real hot topic for a while, and texts like this are good reminders that not everyone ‘lives and dies’ according to our daily carb count. It made me smile a bit- at least before I started thinking how hard it was for me to get my carbs that low and hey- how did she do it without even really thinking about it?! Grrr!
For those of us who don’t have a real good idea of what keto is and why someone might want to try it, ketosis (sometimes called ‘nutritional ketosis’) is when your body burns ketones instead of glucose. When we eat carbohydrates (sugar, grains/ rice, fruit, veggies), our bodies metabolize them down into glucose and that is what our bodies burn for fuel. When there are no carbs coming in for an extended time, the body starts metabolizing the fat in our food or in our bodies into ketones and burns the ketones instead of glucose. (FYI: ketosis is not the same thing as ketoacidosis, which is a serious and often deadly condition.)
It sounds kind of simple, but it really isn’t as easy as flipping a switch. Before switching over to ketosis, our body will trigger us with hunger, cravings, and low energy. Basically, it’s trying to get you to eat carbs. This is usually called keto flu or carb withdrawal, and it can last anywhere from a few days to a couple weeks or so. Once your body realizes it’s not going to get any carbs, it starts making ketones and running off of them. When people talk about being a “fat adapted” or a “fat burner,” they usually mean that they are in ketosis and are metabolizing fat/ ketones for energy. By contrast, a “sugar burner” is some who is still using glucose for fuel.
Fans of ketosis usually say that they have a lot more energy, aren’t as hungry and can go longer stretches without eating, and they have a lot more mental clarity than when they were burning glucose. Most people lose a lot of weight fairly quickly once they are in ketosis, since they burn more body fat. That is the biggest draw, but another important reason is that ketosis helps with insulin resistance. This is really a good thing if you are pre-diabetic or have type 2 diabetes: your body becomes more sensitive to insulin again. Incidentally, ketosis has been used since the 1920’s to treat epilepsy (when there weren’t a lot of medications available).
But, ketosis does have a few drawbacks. The biggest problem for most people is keeping your carbs under 20 g a day. For example one slice of whole wheat bread has 12 g of carbs and a grande latte with 2% milk has 18 g of carbs. Although some people have said they can get into ketosis with somewhere between 20-50 g a day, that is still not a lot of carbs. My own low carb Paleo diet usually has my carbs somewhere around 65-75 carbs, and frankly most of my carbs come from cruciferous veggies, beets, spinach and a few incidental carbs like those in half & half, cheese, nuts and fruit. This can be problematic because if you are in ketosis, you need to be eating fiber to keep everything moving. Most athletes also report that strenuous exercise is really hampered by ketosis- there’s not a lot of quick energy to burn. It’s great for stamina, but if you are running a marathon or doing laps in the pool, you will probably get tired pretty quickly. You also need to drink more water and make sure you get your electrolytes. The body flushes out the system quickly in ketosis, so you need to keep hydrated and that usually means you need to keep your sodium level a little higher as well. Getting enough water is a problem for some people even who aren’t in ketosis. The biggest complaints about keto however are usually about the rigid diet; it can be very difficult for some people to maintain for extended periods.
Ketosis is not for everyone. There are people who think it’s the way that humans should be eating and I’ve heard the exact opposite. Some people have trouble eating so much fat and others simply like too many veggies to stay in ketosis, even though they’ve given up the breads and grains. This isn’t something that you can just jump into one day: it takes some time to transition and some people take longer than others. While I am not actively trying to eat a ketogenic diet, over several weeks, I have managed to get my carbs consistently under 100 by a good amount while not feeling starved or being low energy. It has not always been easy and there were several days of being tired, but now my energy level is back where it used to be.
If you want to experiment with keto, like my sis is doing right now, a good resource is Jimmy Moore’s book Keto Clarity. He discusses some of the methods used to check your ketone levels, how to transition into ketosis and how to determine how many carbs work for you. (He also explains the difference between ketosis and ketoacidosis very well.)There is also a podcast, 2 Keto Dudes, and I’ve heard there is an iPhone app available. Robb Wolf’s new book Wired to Eat offers some keto meal plans as well.