Soylent is an almost pure chemical diet, whose most natural looking ingredients are olive oil and whey protein. It provides the FDA recommended nutrients from mostly purified sources of the individual nutrients. The creator claims to have experienced improved health after adopting it (after previously eating something slightly better than a typical US diet).

This seems like a very effective way to minimize the poisons in our diet.

It’s also cheaper than most diets (he claims less than $2/day, but that seems questionable). He claims it tastes good, although eating the same thing day after day would seem a bit monotonous.

FDA recommendations are known to be suboptimal – too little vitamin D, too much calcium.

He seems confused about the fiber requirements, and is a bit reckless about his omega-6/omega-3 ratio. But these are easily improved.

He almost certainly misses some important nutrients that haven’t yet been identified, but that can be partly compensated for by adding a few low-risk foods such as salmon, seaweed, spinach, and sweet potatoes (the four S’s?).

I’m giving some thought to replacing 25-50% of my calories with something along these lines.

In my quest for a diet that more closely resembles what we evolved to eat, I tried eating some insects.

Fluker’s Gourmet Canned Mealworms are ok, but the taste isn’t memorable. The texture is interesting, but hardly a reason to eat them again. They’re sold as pet food, and labeled not for human consumption. That might mean too much bacteria, but cooking should kill those. Could they have pesticides? Maybe, but insects are usually what pesticides kill, so it would be odd to use pesticides to grow them.

I tried some insects from Hotflix, which markets them as candy. All seem to be coated with varying amounts of sugar. The “chocolate covered insects” are mostly packaging, and have an ingredient list that includes hydrogenated oil but no chocolate. The various flavors of Larvets are better – mostly insect with only a small amount of sugar, spices, and artificial flavor or color. The spices make them taste fairly good, but the price per gram makes them too expensive to be a reasonable source of significant nutrition, and the artificial additives make me consider them less safe to eat than the bugs sold as pet food.

It seems like there ought to be a way to get affordable healthy nutrition from insects, and I’ll keep looking occasionally, but we probably need more demand for economies of scale to make that practical.

I’ve researched omega-6 some more and the evidence that it is harmful is much less clear than I previously thought.

There’s some evidence that omega-6/omega-3 ratios above some threshold (between 2.5 and 4?) are harmful, but also arguments against focusing on the ratio:

This paper reviews a variety of studies that, in the aggregate, suggest that the ratio is, both on theoretical and evidential grounds, of little value. Metrics that include the n-3 FAs alone, especially eicosapentaenoic and docosahexaenoic acids, appear to hold the greatest promise.

While omega-6 can be converted into proinflammatory molecules, it also has antiinflammatory properties.

in observational studies, higher omega-6 PUFA consumption was associated with unaltered or lower levels of inflammatory markers

in 1 study in Israel,39 where 25% of the population consumes >12% of energy as omega-6 PUFA, an inverse association was found between adipose LA [Linoleic acid] and acute myocardial infarction after controlling for other omega-6 PUFAs.

This meta-analysis seems to be the most rigorous analysis:

They looked for

all RCT that increased PUFA and reported relevant CHD outcomes

For non-fatal myocardial infarction (MI)+CHD death, the pooled risk reduction for mixed n-3/n-6 PUFA diets was 22 % (risk ratio (RR) 0·78; 95 % CI 0·65, 0·93) compared to an increased risk of 13 % for n-6 specific PUFA diets (RR 1·13; 95 % CI 0·84, 1·53).

They found 7 randomized trials that raised omega-6 levels and provided a tolerable amount of info about other fats. Three that had apparently low dietary omega-3 showed that higher omega-6 combined with lower trans-fats produced more heart disease/death (i.e. above some high omega-6/omega-3 ratio, omega-6 can cause more harm than trans-fats), while four where the higher omega-6 was combined with arguably adequate omega-3 and lower trans-fats had less heart disease/death with that combination (i.e. omega-6 might have helped or might have caused harm that was small compared to trans-fats).

From another paper:

High intakes of linoleic acid were not associated with excess risk of AMI [acute myocardial infarction]
…
arachidonic acid, the long chain n?6 derivative of linoleic acid, was positively associated with AMI

(Arachidonic acid is found mainly in eggs, meat, and seafood).

Other sources suggest arachidonic acid is safe, mentioning studies of biomarkers that show no harm from arachidonic acid, but biomarkers are less convincing than actual disease. There are some reports that ratio of arachidonic acid to eicosapentaenoic acid (AA:EPA) in blood plasma is a useful measure of cardiovascular problems.

In my previous post I expressed doubts about high omega-3 diets, but this paper on hunter-gatherer diets gives the following estimates for fat intake:

• Omega-3 9.6g/day
• Omega-6 14.2g/day
• Saturated 18g/day
• Monunsaturated 44.3g/day

I don’t know how typical this is of our ancestors, but at least it’s likely within the range of diets that we’re adapted to. This suggests it’s hard to get too much omega-3 or too much fat from seafood (I’d get too much protein if I ate much more than 2 pounds of salmon, but not too much of any type of fat). It also suggests that it’s reasonable to aim for high enough omega-3 that I can’t easily get an omega-6/omega-3 ratio that is high enough to be of much concern.

More from that paper:

Compiled ethnographic studies of 229 hunter-gatherer societies, as well as quantitative studies of hunter-gatherers have demonstrated that animal foods contributed slightly more than half (55-65%) of the daily energy, whereas plant foods would have made up the remainder (35-45%) of the average daily caloric intake. Of the energy obtained from animal foods, historically-studied hunter-gatherers typically derived half of their energy from aquatic animals and the other half from terrestrial animals. Animal food intake would have also been constrained by the physiologic protein ceiling, which has been shown to occur between 30 to 41% of total energy.

There is an increasing body of evidence that suggests high protein diets may improve blood lipid profiles and thereby lessen the risk for cardiovascular disease (CVD).

[I plan to check this evidence later.]

In early April I started measuring my diet fairly carefully (using CRON-O-Meter). It is a somewhat tedious project, but it has has shown me that I’m getting too much Omega-6.

Most of the discussion I’d previously noticed implied that I should improve my Omega-6/Omega-3 ratio by consuming more Omega-3.

But after finding Dave Asprey’s website and hearing him at the Personalized Life Extension Conference, his framing of the issue as Omega-6 poisoning led me to look more carefully at my Omega-6 consumption, and is one of the reasons I tried CRON-O-Meter.

There are conflicting opinions about what ratio people ought to aim for, but those who advocate a ratio close to 1:1 seem to have a good theory (resemblance to hunter-gatherer diets), while I suspect those who advocate much higher Omega-6 levels either assume it’s hopeless to convince many people to achieve a ratio anywhere near 1:1 or have motives unrelated to Omega-fats for pushing oils with a high Omega-6 to Omega-3 ratio.

So my guess is that I should aim for a ratio less than 2:1, and be concerned if my ratio exceeds 3:1.

Even with fairly drastic changes to my diet (virtually eliminating canola oil and olive oil, and cutting back on my peanut addiction by an order of magnitude), I still find that it takes careful thought to keep my daily Omega-6 consumption below 10 grams.

I could in principle take a dozen or more fish oil pills to offset the Omega-6, but the safety of taking over 6 grams of Omega-3 per day seems unknown.

So I am working on switching to foods that have fat that’s very low in Omega-6, mainly coconut oil and butter from grass-fed cows (Kerrygold is the widely available brand).

That mostly doesn’t require eating food that’s less tasty (Kerrygold butter tastes better than most other fats), but it reduces the variety of foods I can eat. It rules out what I used to consider ordinary amounts of most nuts, and many processed foods (Trader Joes’ eggplant and red pepper spreads looked like a convenient way to get veggies until I quantified the effect of the sunflower oil that is the fourth ingredient in each).

I’ll try to post some of my best recipes in a few months.

For more references, see this pubmed entry and Wikipedia.

A protein rich diet may make us more alert and help us lose weight.

The reaction of Hypothalamic orexin/hypocretin neurons to amino acids (especially nonessential amino acids) appears to be a mechanism for this effect.

Poultry products appear to be one of the better ways to get nonessential amino acids.

I’ve been trying to increase the protein in my diet for the past four months (in response to weaker evidence than I’ve linked to here), and have found that animal sources have been the easiest way to do that (I’ve mainly increased my egg and meat consumption). I think I’ve found it slightly easier to avoid gaining weight. I think I’ve also been more alert, but I don’t think the increase in alertness coincided too closely with the increase in protein consumption.

There seem to be serious risks in some food oils that are commonly considered healthy. This report says:

hexane processing strips the remaining nutrients from the oil, and turns a significant quantity of polyunsaturated fats into inflammatory, artery-clogging trans fats!

Hexane processing is apparently common for Canola oil, soybean oil, and other plant-based oils (but not olive oil). Trans-fat levels have been measured at 0.56 to 4.2 percent in commercial oils.

Since FDA-regulated labels are only accurate to about 0.5 grams, and oils are often labeled for 14g serving sizes, a 1 or 2 percent trans-fat content would apparently show up as zero. I suspect those levels are more harmful than most additives that the FDA has banned from foods.

The bottled Canola oil I buy from Trader Joe’s says it’s expeller pressed – no solvents used, so I’m still guessing it’s healthy, but I’ll try harder to avoid processed foods containing plant oils. (There a lot of misleading arguments against Canola oil that should be ignored).