Simple diet rules for good health
I often find myself giving diet advice to friends who want just a few basic rules without a lot of details. Diet interest has increased lately with the awareness that COVID-19 risk factors include obesity and low vitamin D. Fortunately, as in many areas of life, diet rules follow а Pareto distribution: a few rules give most of the benefit. Here’s my model, whose rules you can count on one hand (“Everything should be made as simple as possible, but no simpler”):
- When: time-restricted, within an 8-hour period, which for me is noon to 8 p.m.
- How much: as much as you want. If you follow the other rules, this turns out not to be a problem.
- How: preferably not fried, certainly not fried in seed oils. The common seed oils are soy, corn, rapeseed/Canola, and sunflower.
- What not to eat: sugar (including juice, and especially high-fructose corn syrup), seed oils, and refined carbohydrates.
What to eat: a variety, at least 1/3 meat, 1/3 plant, and 1/3 up to you.
You needn’t read any further (the Pareto principle applies also to this article), but, if you are interested… I take inspiration from millions of years of hominid history:
Our great-ape cousins (chimpanzees, bonobos, gorillas, orangutans, and gibbons) are omnivores who eat mostly fruit (in particular figs) but also a fair bit of meat (or at least insects). Humans have been omnivores throughout the Paleolithic period (3M to 10K years BCE), cooking with fire for hundreds of thousands of years, and processing food in only the simplest of ways. In hunter-gatherer tribes around the world today, the men hunt and the women gather, providing calories in a roughly 1:2 ratio respectively. Without electric light, hominids can’t do a lot at night, especially hunting and gathering far from home. Campfires gave our ancestors something to sit around in the evening, but only in the past century did we start eating potato chips and ice cream in front of the TV until midnight.
The East African Hadza are my favorite hunter-gatherer tribe; just search the web for Hadza plus words like baobab, microbiome, or honeyguide. The Hadza get something like 10% of their calories from honey, but they eat it right from the comb, together with the bee larvae, yum. Without modern tools, honey is difficult to find and dangerous to get. The Hadza find it with the help of the honeyguide bird, a partnership that must have evolved over hundreds of thousands of years. Among successful moderns, the oft-touted Mediterranean diet suggests variety — imagine the rich cuisines of the surrounding countries, as well as the Japanese and Nordic diets. We have an instinct for variety for a reason. Some popular books on these topics: The Omnivore’s Dilemma and Catching Fire: How Cooking Made Us Human.
The really bad stuff (sweeteners and seed oils) is hidden everywhere. Breakfast (“the most important meal of the day”, not) is a catastrophe, with many people drinking a glass of juice with a bowl of corn flakes. What better way to start your day than with a sugar-and-insulin spike? BTW, the typical toothpaste contains artificial sweeteners; I often wonder about the effect of that insulin jolt first thing in the morning and last thing before bed. Not by coincidence, these bad “foods” all increase systemic inflammation. The seed oils (e.g. soy, corn, rapeseed/Canola, and sunflower) are in everything, to replace the lost taste in engineered food. The best example is mayonnaise. Ask anyone this trick question: What’s the main ingredient in mayonnaise? I guarantee 80% will get it wrong. Do not try to reduce or resist the temptation of these bad items — don’t even let them into your house.
Search the web for vegetarian+deficiencies or carnivore+deficiencies, and be shocked at the results. Everyone knows that there are no plant sources of vitamin B12, but neither are there plant sources of vitamin D or K2, both essential for calcium utilization. Even carnivores’ beloved grass-fed beef is low in some nutrients, though you can get nearly enough by including liver (beef, chicken, and cod).
In any event, it matters what your food eats. That goes for your fruits and vegetables as well as your animal products. Modern agricultural products are optimized for many things (e.g. growth speed, transportability, size, color) but nutrition is generally not one of them. They tend to be low in nutrients.
The big question for me was dairy products. On the one hand, dairy milk entered the human diet less than 10K years ago, as unnatural as the other big changes humans made in the Agricultural Revolution. On the other hand, the genetic mutation allowing us to digest milk in adulthood has arisen at least three times, sweeping the local populations (including all of Europe). Milk must be beneficial, at least in some circumstances, e.g. to replace the nutrition lost with the Neolithic decline in meat consumption. Indeed, milk-consuming populations (e.g. the Dutch, Maasai, and Nuer) seem pretty strong and healthy. Happy grass-fed cows produce the most nutritious milk and meat, same as free-range chickens produce the most nutritious (e.g. high in vitamins D and K2) eggs and meat. Milk’s most compelling form is as cheese, several varieties of which (e.g. Emmentaler, Jarlsberg, Gouda, Edam, Muenster, and Stilton) are among the richest sources of vitamin K2 (richer even than liver), not to mention calcium and vitamin D. Humans evolve slowly, but microbes quickly — maybe the microbes that process food (both in fermented foods and in our gut microbiomes) have evolved to make dairy and some other unnatural neo foods more nutritious for us.
The more-paleo-than-thou types will squawk at my heresies. They might be insensitive to other practical requirements, e.g. cost, availability, the compromises of family life, personal preference, and the needs of our microbiome. Sure, you could be a better paleo, and probably squeeze out an extra couple years of expected lifespan. You could also eliminate all risky activities, like cycling, skiing, and crossing the street. But make an informed, conscious, deliberate decision. For most people, it will be a big enough accomplishment just to follow my basic rules. Even that means that you will have to read food ingredients, which shockingly often include sweeteners and seed oils.
Note that the motivation for this diet is overall health, not just losing weight. Obesity is a symptom, not the disease. As one friend put it, “All those who are overweight or obese have metabolic syndrome, but not all who have metabolic syndrome are overweight or obese.” Other symptoms of a poor diet might be allergy, asthma, arthritis, anxiety, Alzheimers, and tooth decay. On this diet I have trouble keeping my weight up, but I feel better.
The paleo diet is a key part of the paleo lifestyle. For optimum health, you need to do more things, e.g. socialize, exercise, and sleep. Be born naturally (not by caesarean, like 1/3 of American kids), be breast-fed by a paleo mother, and avoid antibiotics. Maybe even get infected with a benign helminth. Socializing is probably the most important factor of all. Psychologist Susan Pinker has a great TED talk showing that social integration is a better predictor of longevity than diet or exercise.
Eat smart and well!