Diet and Nutrition

No one knows anything about nutrition, especially nutrition experts. For every nutrition PhD, there is an equal and opposite nutrition PhD. Most of them have no training in statistics. The only thing I have much faith in are metastudies, and there are very few metastudies with any dietary signal for life-changing endpoints (as opposed to biomarkers). Diets are mostly fads, mostly promoted by authors who want to make money. I can’t think of a single diet book in the bookstore that is based on any real evidence. Eat Right for Your Blood Type, the China Study, and all other diet books are based on bad study design, wishful thinking, good storytelling, and talk-show marketing.

A perfect example of the difficulty of understanding this is the Keto diet. In this podcast, Peter gives his reasons for going off a keto diet back in 2020. Then we have Gary Taubes’ book, The Case for Keto. Peter and Gary used to be partners! They used to agree on most things. Now they are saying different things.

General guidelines

If your goal is weight training or sport fitness, realize that many people use many different diets to get the same results.

Transfats are bad. These are the “margarine” products of 30 years ago. They have mostly been eliminated.

If you are insulin resistant, you should avoid carbs. The more insulin resistant you are, the fewer carbs you should eat. If you are diabetic, you should probably have zero carbs.

Sugar is generally bad. Not that you can’t manage it in your calorie budget, but it contributes to inflammation.

Processed foods are probably bad. The Standard American Diet promotes obesity and heart disease. We don’t really know that much about this, but it makes sense to go toward less processed food. Whole foods — we don’t really know. The difference between white and brown rice is negligible.

Organic foods do not extend life and provide no health benefits. They may or may not be better for the environment.

Vegans and vegetarians are fine. I’ve been vegan 45 years. Older vegans need more protein and need to figure out how to get it, which is a challenge. Do they need to take B12? I think it makes sense just as insurance, but all animals make their own B12 in their mouths, so it isn’t critical. I think if you don’t use mouthwash, it’s probably okay not to take B12, but it’s cheap and delicious, so why not just take it?

Different diets work for different people. Vegan, paleo, raw, keto — all these diets can be healthy. Keep in mind the Masai people are very strong, and they mostly consume cow’s milk mixed with cow’s blood.

Keto diets are not for everyone. If you’re interested in Keto, here are some resources.

Dietary cholesterol is nothing. Unless you happen to be a cholesterol hyper-absorber, you can eat as much as you want. Eggs are no big deal.

Maybe the pendulum is swinging back toward saturated fats are not so good for your heart. Guidelines are leaning toward 20 percent or fewer from meat. Leaner meat is probably better. But that could change again.

You probably need more protein daily. Before age 40, most people get too much protein. After age 50, most people don’t get enough. You need more protein as you age. And animal protein is more effective than plant protein, though it’s still possible to get enough protein through plants (I’m trying). If you’re 50 to 70, get about 100 to 150 grams of protein every day. Big people should get closer to 200. Over 70, get a bit more.

Carbohydrades and fats are less important. If you’re getting enough protein, it’s hard to overdo carbs or fats. It doesn’t much matter which you get more of. People who are more athletic and do more exercise can certainly get away with more carbs. People who are less active probably should balance carbs and fats roughly the same. Keep in mind that a small amount of fat packs a lot of calories.

Something like a Mediterranean (whatever that means) diet (basically low-fat) may be best for most people, but I think we are just starting to learn and have much more to go.

Fasting or intermittent fasting is not a good idea if you are trying to build muscle. It extends life in mice, but humans are not mice. You don’t want to be too thin. Any time you lose weight, you’re losing a combination of muscle and fat.

Alcohol is bad. From a longevity point of view, the optimal amount of alcohol is zero. It contributes to inflammation, which makes everything worse. Pick your battles. A glass of wine a week is probably not a problem unless you’re already diabetic. If you have a drink a week or more, ask yourself whether you can get by without it and just have a drink on special occasions.

Build a diet you can stick with. Most diets work inside of 3 months, and almost all diets fail inside of 18 months. If it’s impossible to keep up, it won’t succeed.

Keeping the weight off is harder than losing it. If you lose 30 pounds or more in under a year, your body wants the weight back. You have to stay even more strict with your diet and exercise more to keep the weight off.

Almost no one keeps weight off without exercise. Study after study shows that people who exercise a lot — more than 2 hours a day — have a better chance to keep weight off in the years after losing weight. Virtually no one does it without a lot of exercise.

Find what works for you. There are no absolutes and no universal standards. What works for your Facebook friends may not work for you. Experiment and see what works best.

Here’s Chris Gardner of Stanford showing that no particular diet is better, because different diets work differently for different people. But keep in mind Chris has a vegan bias …

If you want to read a book, The Diet Myth would be a good place to start.

One thing I practice is never to be full. Don’t take the last bites that would extend your stomach and give you that “I ate too much” feeling. Stop short. Don’t let it happen more than once a year. If there’s still food on your plate, ask for a bag and take it home. Save it for later. Don’t give yourself permission to overeat.

When should you eat? How much water should you drink? What should the ratio of macronutrients do we need? What about fiber? There are no good studies on any of this. Your guess is as good as any experts’.