In my last update, I had talked about the trouble I was having staying at the β-hydroxybutyrate level I wanted while eating to satiety. Not only was eating to hunger driving my ketone levels down, but higher ketone levels were correlating with irritability. Hunger and irritability are not my style. Besides, I have the intuition that something as healthy as ketosis should not entail health compromises. That's one reason I think the calorie restricted approach to ketogenic dieting, even in cancer, is likely to be wrong. More on that another day.
I am delighted to report that for a couple of weeks now I have consistently been in the 1.5 — 3.5 mmol/L range without restricting the quantity of my food, or even trying to be careful about not passing the satiety mark. Though I do, as always, emphasize fat in my foods, I am not limiting or even measuring my protein intake. My body's signals are clear and accurate and I don't agonize over whether this bite would be the line between enough and too much. There is no longer any correlation, as far as I've noticed, between irritability and higher ketone readings.
The trick seems to be exercise.
A few weeks ago, I made a few lifestyle changes at once. (I don't always have time for controls!)
- I started getting up at 5:30 (amended to 5:00 several days later).
- I gave up all but two small cups of coffee a day.
- I started going to a weightlifting class at the local gym twice a week for an hour. I enjoy the 15 minute walk home.
- I started running around the block once or twice a day in order to keep up with the 3-year-old riding his strider bike. That usually involves a little sprinting as we go the downhill direction, and walking or lightly jogging for the rest of the way. Some days I've also done a longer distance walk or bike ride.
Lyle McDonald: Effects of exercise on ketosis
Way back in 2002, I got my hands on a copy of Lyle McDonald's The Ketogenic Diet. It was out of print at the time, and was acquired for me magically by Zooko, in honour of our second anniversary. (Thank you, Sweetheart!) Back then, it was one of the few resources available for studying ketogenic physiology. Lyle McDonald's purpose in writing his book was to promote Cyclic Ketogenic Dieting for bodybuilding, and dispel myths associated with it. It is fairly technical, and well-referenced, but it does not presuppose detailed knowledge about specific biochemical pathways, so it's also accessible.
In it he shows that high intensity exercise (weight training or interval training) is a quick route to establishing ketosis, because it uses up glycogen stores. In the short term, however, high intensity exercise can decrease ketosis by inhibiting free fatty acid (FFA) release into the bloodstream. He also emphasizes the utility of low-intensity aerobic exercise, both for lowering glycogen and for increasing FFA for the liver to make ketones with. Low intensity aerobic exercise is very effective in establishing ketosis, but it takes a long time to deplete glycogen that way.
His bottom line recommendation, then, for establishing ketosis quickly, is to do a high intensity workout to deplete glycogen, followed by 10-15 minutes of low intensity aerobics.
This is precisely what I've been doing every day! Lifting and then walking home, sprinting and then a fast walk around the block, or a long distance, low intensity walk or ride, all qualify as efficient ketosis enhancement.
This is working for me without recourse to hunger-inducing protein restriction.
Fat loss without muscle gain necessarily implies a caloric deficit even though caloric deficit does not necessarily result in fat loss. Analogously, inducing ketosis through exercise and carbohydrate restriction may well be resulting in a naturally lower protein intake for me. I don't really care that much. I'm eating as much as feels good to me of foods that make me well, and it is no longer interfering with my health goal of being in ketosis.
Whether and to what degree this affects my body composition is not yet clear. My clothes are fitting better. I guess I ought to buy a scale.