Sleep: Summary of What I’ve Learned

I want to summarize what I’ve learned about how to sleep well. I’ve found about a dozen changes that helped. Taken together they suggest the importance of four dimensions:

1. Healthy brain. My sleep greatly improved when I ate a lot of pork fat. (As far as I can tell, butter produced the same effect.) I wasn’t getting enough animal fat. My sleep also improved when I started eating honey at bedtime. I assume honey raised blood sugar to better levels during sleep, improving brain performance. The great importance of this, I believe, is why we evolved preferences that push us to eat strongly sweet foods, such as fruit, separately and later, i.e., dessert. Bedtime honey also caused my muscles to grow more in response to exercise — a sign of better sleep, since muscles grow during sleep. I have never measured the effect of flaxseed/flaxseed oil on my sleep but the brain benefit was so clear in other ways I’d be surprised if it didn’t improve sleep. Continue reading “Sleep: Summary of What I’ve Learned”

More About Pork Fat and Sleep

One day in 2009, I ate a large amount of pork belly (very high in fat — pork belly is the cut used to make bacon). That night I slept an unusually long time. The next day I had more energy than usual. This led me to do an experiment in which I ate a pork belly meal (with lots of pork belly, about 250 g) on some days but not others. I compared my sleep after the two sorts of days. I kept constant the number of one-legged stands I did each day because that has an effect. During the first half of the experiment I kept this constant at 4; during the second half, at 2. I originally posted the results only from the first half.

Now I’ve analyzed the results from both halves. Here are ratings of how rested I felt when I woke up, on a scale where 0 = 0% = not rested at all and 100 = 100% = completely rested.

The two halves were essentially the same: pork belly produced a big improvement.  Here are the results for sleep duration.

No clear effect of pork belly in either half of the experiment.

The main thing I learned was that pork fat really helps. The effect is remarkably clear. With micronutrients, such as Vitamin C, the body has considerable storage. It may take months without the nutrient to become noticeably deficient. With omega-3, which is between a micronutrient and a macronutrient, my experiments found that it takes about two  days to start to see deficiency. With pork fat there seems to be no storage at all. I needed to eat lots of pork fat every day to get the best sleep. That repletion and depletion are fast made this experiment easy. How curious we are so often told animal fat is bad when an easy experiment shows it is good, at least for me.

Science in Action: Why Energetic?

Last night I slept unusually well, waking up more rested and with more energy than usual.  I slept longer than usual: 7.0 hours versus my usual 5.1 hours (median of the previous 20 days).  My rating of how rested I felt was 99.2% (that is, 99.2% of fully rested); the median of the previous 20 days is 98.8%. Because the maximum is 100%, this is really a comparison of 0.8% (this morning) with 1.2% (previous mornings); and the comparison is not adjusted for the number of times I stood on one leg to exhaustion, which improves this rating. During the previous 20 days I often stood on one leg to exhaustion six times; yesterday I only did it four times. Above all, I felt more energy in the morning. This was obvious. I have just started to measure this.  At 8 am and 9 am, I rate my energy on a 0-100 scale where 50 = neither sluggish nor energetic/energized, 60 = slightly energetic/energized, 70 = somewhat energetic/energized, and 75 = energetic/energized. My ratings this morning were 73 (8 am) and 74 (9 am). The median of my 9 previous ratings is 62. The energy improvement (73/74 vs 62) is why I am curious. I would like to feel this way every morning.

What caused it? I had not exercised the previous day. My room was no darker than usual. My flaxseed oil intake was no different than usual. I had not eaten more pork fat than usual. However, four things had been different than usual:

1. 2 tablespoons of butter at lunch. In addition to my usual 4 tablespoons per day.

2. 0.5-1 tablespoons of butter at bedtime. Again, in addition the usual 4.

3. 1 tablespoon (15 g) coconut butter at bedtime. Part of a longer study of the effect of coconut butter. Gary Taubes suggested this. I had eaten 1 T coconut butter at bedtime 13 previous days. On the first of those 13 days, I had felt a lot more energetic than usual in the morning. On the remaining days, however, the improvement was less clear. I started measuring how energetic I felt in the morning to study this further. Last night was Friday night. On the previous two nights (Wednesday and Thursday) I had not eaten the coconut butter. Maybe absence of coconut butter followed by resumption of coconut butter is the cause.

4. Fresh air and ambient noise. Following a friend’s suggestion, I opened one of my bedroom windows.

My first question is whether the improvement is repeatable. If so, I will start to vary these four factors.







More Animal Fat, Better Sleep

After I wrote about eating a lot of pork fat and sleeping better, David Shackelford commented that he had had a similar experience: After he started eating much more animal fat and meat, he too slept better. (He posted about this before he read my post.) I asked him for details. He answered:

About three weeks ago, I started a carnivorous diet. I did this primarily for its supposed benefit to insulin sensitivity, energy levels, and general health, and also because I wanted to see if it was really possible to thrive on nothing but meat.

Immediately after starting, I noticed that I was sleeping easier, longer, and deeper, and having more vivid dreams than usual. I’ve had a hard time falling asleep for my entire life, usually taking 45 minutes to two hours after going to bed, and occasionally not being able to sleep at all, so this was a very pleasant surprise.

At first I thought that this was due to standing on one foot, which I had started a few days prior, but I stopped one-foot-standing and the effect persisted. The all-meat diet has been pretty great all around-food is delicious, I’ve got a ton of energy, and I’m rarely hungry-but the sleep has been the best part.

21 years old (senior in college)
130-ish lbs
12-15% body fat
Moderately active, fairly good shape.

My diet
-Breakfast of 3-4 egg omelette, with 1-2 oz cheese and occasionally bacon.
-Lunch: chicken breast, sausage, or eggs.
-Dinner: 1lb+ steak.
-Snacks: nuts and/or cheese.

Approximate macronutrient composition
Before: 50% carbohydrate / 30% protein / 20% fat (at least half unsaturated olive oil)
After: 60-70% fat (all animal fat), 30-40% protein;10% carbohydrates (nuts and the occasional glass of wine, plus trace amounts in sauces and cheeses). Unsure of my caloric intake; I think it varies between 1500 and 2000 a day.

-I cook chicken, beef, and eggs in butter.
-I drink coffee 1-2 times a day, and tea about once a day.
-I take a multivitamin (I don’t know why), 5,000 IU Vitamin D (I live in Oregon, which gets very little sunlight), and 2.5g fish oil (the grain-fed beef I eat has low 3:6 ratios; if I could afford grass-fed, I probably wouldn’t need the fish oil).
-I let the diet go on weekends, for the sake of social life. I probably have 3-5 drinks on Friday and Saturday night, as well as some junk food (pizza/chips/fries). I feel like I don’t sleep quite as well on these days, but there are so many confounding variables (alcohol, staying up later than usual, seeing faces later into the night, sex) that isolating a cause of the difference is tough.

-I lift weights for about 30 minutes, twice a week.
-I go out social dancing for about four hours, once to twice a week.
-Sleep does not seem to vary with whether I exercise or not.

He blogs about this at His story is more evidence that the animal fat/sleep connection is cause and effect (animal fat –> better sleep), and suggests that the effect is not limited to me.

My self-experiment about this.

Effect of Animal Fat on Sleep (more)

After the striking correlation I described earlier — I ate lot more animal fat than usual and slept longer and had more energy the next day — I started eating much more of what had produced the correlation: pork belly (which is used to make bacon). I couldn’t get uncured pork belly, so I ate bacon. I usually ate it raw. I tried several brands; the only one I liked was from Fatted Calf ($10/pound).

In Beijing I discovered pork belly for sale in every meat department. It is used to make a dish said to be Chairman Mao’s favorite. I bought a soup cooker, an appliance I haven’t seen in America, which made it easy to cook the pork belly. I seemed to sleep better when I had it for lunch.

Finally I did an experiment. I ate pork belly for lunch some days but not others. I ate the pork belly in miso soup, with vegetables. I always ate a whole package of pork belly, which was about 0.7 lb and perhaps 80% fat, 20% meat. On baseline days I ate my usual diet, which was already high-fat by people’s standards. (For example, I ate a lot of whole milk yogurt, a fair amount of nuts, and ordinary amounts of meat.) I tried to alternate baseline and pork-belly days but this wasn’t always possible.
Here are the results on ratings of how rested I felt when I awoke (100% = completely rested = the most rested I have ever felt, 0% = not rested at all).

The lines were fit separately to each set of points (red line to the red points, etc.). The difference is is very consistent (t = 5). Differences in how long I slept were much less clear. I will discuss them in a separate post.

The fascinating thing about this effect isn’t just how clear it is; it’s also how fast it goes on and off (within a day). With most nutrients you’d never see an effect like this. For example, scurvy takes months to develop and a few weeks to recover from. The omega-3 effects I’ve studied have a fast onset but take days to go away.

Sleep is controlled by the brain, of course. The brain is more than half fat, but determinations of how much fat the brain has have measured structural fat. This effect is so fast, both on and especially off, that it must involve circulating fat. Apparently my brain works better when there is a certain amount of animal fat in my blood. This supports Chairman Mao’s idea that pork belly is “brain food” but is a new idea for American intelligentsia. I think the chance that a nutrient that is good for one part of the body is bad for another part is zero — the same as the chance that the electrical appliances you own work best with widely-different currents. The obvious conclusion suggested by this data is that we need plenty of animal fat to be healthy. The only novel element of these lunches was the animal fat. Miso soup with ordinary meat has no effect on my sleep, as far as I know.

I think the science of nutrition proceeds in four steps, repeated over and over for each necessary nutrient: 1. Figure out that we need it. 2. Determine a way to measure how much of it we need. 3. Figure out the optimal amount. 4. Check your answer. With animal fat, conventional nutrition science hasn’t quite reached Step 1. Before this data, I’d say the clearest evidence that we need animal fat is that fat tastes good and long ago we had very little plant fat so it must have been the benefits of animal fat that produced the fat-tastes-good linkage. But conventional nutrition scientists never think this way — never take what we want to eat as meaning anything. And the mere fact that fat tastes good is no help figuring out how much is best.

This data pushes our knowledge toward Step 2. It doesn’t just suggest we need plenty of animal fat for best health, it also makes two methodological points: 1. Animal fat improves brain function. There may be better measures of the improvement than sleep quality. 2. The timing of the improvement — which as far as I know is unprecedented in the study of nutrition — makes it easy to measure.

Yesterday at a Carrefour I watched a pig being cut up. The butcher cut off the skin (with a thick layer of fat) and tossed it into a section of the display of pork for sale. I could buy the part of the pig I valued most for an incredibly low price (about 25 cents/pound). All other pork cost more. That’s how much Chinese shoppers wanted it. No one rushed to buy the newly-cut piece of skin. It reminded me of New York where I tried to buy food past its expiration date, ordinarily considered worthless.

Effect of Animal Fat on Sleep?

Recently I listened to Robert Spector discuss his book The Mom & Pop Store: How the Unsung Heros of the American Economy are Surviving and Thriving. He had a personal connection to the subject: His father was a butcher. “As I watched him trim the meat . . . ” he said at one point. I thought: Oh-oh. To “trim” meat is to cut fat off of it.

Last spring, I bought $80 of organic grass-raised pork from a farmer near Berkeley. My order included a variety of cuts.  I cooked the ones I was familiar with, leaving one I’d never seen before: pork belly. Pork belly is used to make bacon. I’ve never seen it for sale in America. Ugh, I thought. Fat. It’s 80-90% fat. I too trim the fat off meat. It sat in my freezer for a long time. Finally I decided I shouldn’t waste it. I cut it into chunks which I put in miso soup and had for lunch.

That night I slept much longer than usual (8.3 hr) and woke up feeling unusually well-rested. Here is a graph that shows my sleep duration for that night and several preceding nights:

2009-10-25 sleep duration and animal fat

Sleeping 8.3 hours was less common than this graph may suggest. I’d moved back to Berkeley in January and from then until the miso soup had measured how long I slept on 130 nights. I’d slept more than 8.3 hours on 2 of them (2%). Even rarer was how energetic I felt the day after the miso soup. I couldn’t quantify it, but it was very rare — once in 10 years?

Was it a coincidence — that on the very day I ate far more animal fat than usual I also slept much longer than usual and had much more energy than usual the next day? Or was it cause and effect? Here’s why the second explanation — which implies that for best health I need much more animal fat than I usually get — is plausible:

1. As Spector said, butchers cut the fat off meat. The odds that our Stone-Age ancestors, living when food was sometimes scarce, did the same thing: Zero. Perhaps our meat is unnaturally low in fat. If for a long time in our evolutionary past we ate a lot of animal fat it makes sense that our bodies would be shaped to work best with that much fat.

2. Many video games, which boys enjoy, resemble hunting. I think this reflects an evolutionary past in which men hunted. If so, for a long time humans ate meat. That they ate a lot of meat is suggested by the fact that when big game went extinct (probably due to hunting) human health got worse.

3. American culture demonizes animal fat. The conclusion that animal fat is bad rests on epidemiology. Once something becomes heavily recommended or discouraged, a big problem for epidemiologists arises: the people who follow the advice are likely to be different (e.g., more disciplined, better off) than those that don’t (the healthy-user bias). As I blogged yesterday, an example is vaccine effectiveness: Those who get vaccinated are different than those who don’t.

4. Fat tastes good. Which implies we need it. We like whipped cream, butter on toast, milk in tea, and so on. Butter vastly improves toast even with my nose clipped. Long ago, when this fat-pleasure connection evolved, dietary fat was mostly animal fat and fish oil.

All this makes it plausible that animal fat is good for us. That’s not surprising. Based on Weston Price’s observations plus these four arguments, I already believed this. Many people believe this. The interesting idea suggested by my data is the possibility of measuring its benefits quickly, by measuring brain function. My experience suggested that animal fat improves brain function quickly. Brain function is easier to measure than the functioning of other parts of the body. By measuring my sleep, my energy, or something else controlled by the brain, maybe I can figure out the optimal amount of animal fat. This is what happened with omega-3. The idea that omega-3 is good wasn’t new; the novelty was the ability to measure its benefits quickly. (At first I measured my balance, later other things controlled by the brain.) With a fast measure I could determine the optimal amount. It’s likely that what’s optimal for the brain is optimal for the rest of the body, just as all the electric appliances in your house work best with the same house current. If you figure out the best current for one appliance, you are probably simultaneously optimizing all of them.