Suppose you want to live long, and are willing to adjust your diet to accomplish that. What should you eat / not eat?
Of course everyone has their pet theories, but what I’m interested here is only the stuff that is 100% undisputed fact that applies to the general population, not just to people with certain predispositions.
It looks like the two main causes of death in the developed world are cardiovascular diseases and cancer. These share the properties that they sneak up on you and may not be reversible by the time you find out you have them, and they both have significant links to nutrition. So maybe we should focus on these diseases.
The Wikipedia diet and cancer page mentions alcohol as a carcinogen and “implicates” red meat, but everything else, including eating fruit and vegetables and fiber intake, is surrounded by works such as “inconclusive”, “no evidence”, “not confirmed” and so on. I am pretty sure that cooking carbohydrates at very high temperatures and blackening proteins generates carcinogens.
As for cardiovascular disease, here fruits and vegetables seem to help. Trans fats are bad but otherwise all the previous advise about reducing fat, reducing saturated fat and increasing omega 3 fats are now all at least in some doubt. There’s still warnings about high salt intake, although I seem to remember that only a relatively small percentage of the population actually sees blood pressure increases from eating too much salt.
Could it be that apart from a few obvious (alcohol) and obscure (trans fat) bad things and as long as you apply a modicum of common sense/variety, it really doesn’t matter what you eat but only how much you eat of what you eat matters? (For people not already suffering from a disease.)
Then choosing a diet comes down to philosophical, palatability, financial, convenience and ease of adherence factors.
Something I was thinking about while shopping yesterday was how much fat domestic meats carry compared to wild game. I also think the output of calories we put out to earn food is way out of ballance with how we have evolved. I wonder how much research has been done on seasonal dietary changes like we would have encountered in nature as well as fasting. When all is said and done we are living longer but I agree with you that we just don’t know enough about diet.
There are no undisputed facts about nutrition for the general public. There are many diets that most people can live healthily on, but they can include seeming opposites.
So yes, eating a common sense diet of any given kind will work for most people. It’s possible that you may have to try several before you find the one that’s right. You may also have any of a large number of problems, whether diseases, allergies, intolerances, imbalances, deficiencies, or hereditary conditions that you currently are unaware of but might need to compensate for in the future. Environmental conditions, surgeries, job or activity-related needs, pregnancy, or a million other factors may interfere at various times.
So “choosing a diet comes down to philosophical, palatability, financial, convenience and ease of adherence factors” is mostly right but not as comprehensive as real life sometimes demands.
There are seven billion stories on the naked earth. You are one of them. [Obscure reference to this old film. Don’t worry if you don’t get it.
The indisbutible one seems to be “don’t be obese”. Having a BMI of over 30 or so is very strongly correlated with diabetes, heart disease and early mortality. Obesity is caused by over-eathing, so that’s pretty clearly a nutritional issue.
Chronic smoking or over-use of alcohol are also pretty indispudibly bad, but I’m not sure I’d classify drug-use as “nutrition”.
Beyond those the evidence for nutrition affecting longetivitiy gets pretty hazy pretty fast. This is partially because its really hard to study: you can’t do experiments on humans, the timescales involved in studying marginal effects on longetivity, its hard to track exactly what people eat, especially over long periods of time, there are a lot of confounding factors like genetic differences, etc.
But I’ve gotten kind of skeptical over the years of the basic hypothesis that beyond avoiding severe obesity and malnuioshment (and not eating obviously toxic things) that nutrition has a strong effect on health and longetiivity. It seems a lot of people take this as a given and then treat the problem of figuring out what exactly the links are, but I think the basic premise isn’t questioned enough.
Hm, there are tons of non-obese people who get sick and also a fair number of obese people who don’t. I saw a lecture on Youtube a while ago where they compared people with four risk factors, I think smoking, not eating fruits/vegetables, not getting exercise and one I forget, where obese people with none of the risk factors only had a slightly higher risk of dying than normal weight people with no risk factors. The normal weight people with all risk factors were about twice as likely to die within a given period, but for the obese people the risk went up much quicker with every risk factor added. Conclusion: you can either have bad habits or be overweight, but both of them will land you an early grave.
My suspicion is that many of the obesity-related problems are not so much caused by the weight/fat itself, but by ongoing weight gain. For instance, if an obese person who is still gaining weight eats a bunch of carbs, the glucose has nowhere to go except fat cells that are already the biggest they’ve ever been. Someone who weighs the same but is losing weight on the other hand, will have room in muscle glycogen stores to absorb the glucose, so it’s cleared from the blood quickly. This could explain why even a 5% weight loss leads to considerable health benefits.
Everybody is gonna die. THere is a story about a guy who went to his doctor at 60 years old for a physical. He asked the doctor if he’d live to be 80. The doctor asked him if he ate red meat, NO Drove motorcycles NO flew in airplanes NO Had a lot of sex NO Drank alcohol NO smoked NO
“SO why would you want to live to 80?” That is my philosophy. I’m 68 and had a triple bypass surgery 9 years ago and was told at the time I had a 50 50 chance of living another 5 years. SO I do what I wish to do and eat what i desire. As well as taking my 11 pills every day.
So the correlation isn’t 100%. Why is that a problem? Focusing on the few exceptions rather than the massive numbers that follow the pattern is a mistake.
“Don’t be obese” has better research backing than most things.
One undisputed fact: if you don’t eat, you will starve to death.
Beyond that, it is mostly speculation combined with some population level statistical evidence. Some populations don’t have as much heart disease. But their life style differs from ours in too many ways to control for.
I will go along with Mark Bittman’s advice: eat a balanced diet (roughly 1/3 each of protein, fat, carbs), mostly but not entirely vegetarian and mostly unsaturated fat. I would add: Don’t be fat. In other words, common sense. Don’t smoke, drink a little, but not too much and don’t be sedentary.
Humans have evolved/changed further since, to adapt to different climates & other changes. For example, in some areas we’ve adapted to be able to digest lactose even as adults. So a diet used by (or perfect for) our pre-historic African ancestors is not necessarily the best for present day humans.
You want 100% rock-hard facts? OK, are you a mouse? Longevity has been studied extensively in mice, and we have some pretty solid facts about them. Do those facts generalize to humans? Well, maybe… but there are some pretty significant differences between mouse aging and human aging, and it’s really hard to study human longevity, since a full experiment would take the better part of a century.
Well, if it takes 100 years to determine that some foodstuff is going to kill you, then it probably won’t. I’m thinking more along the lines of: eggs are good / eggs are bad, saturated fat is bad / seed oils are bad / all fat is bad / fat is good. At different points in time more people are saying one thing, but either there is significant opposition or the advice is reversed some time later.
About “don’t be fat”: see another recent thread about the 90% long term failure rate for weight loss. Do we really want to tell people who can’t lose weight that there is nothing they can do to improve their health? In that case they’re just going to give up, eat crap and die a good deal younger than necessary. Of course that is not to say “don’t be fat” is bad advice. But it’s a bit like telling teenagers “don’t have sex” and being surprised they get pregnant anyway.
Just because we don’t have 100% certainty about things doesn’t mean we give up. It’s not all or nothing.
We muddle along with the best currently available information, just like we always have.
Well, no. It’s like telling a teen “Don’t get pregnant or get a disease”. There are a number of ways to do that. Abstinence is one favored by many.
Educating them about safe sex practices actually does work. But not 100%. Abstinence actually will but it isn’t followed by most.
Just because the best practices won’t work 100% of the time doesn’t make them bad. Or even questionable. Sure, we can always point to a teenager whose condom broke. Or for whom the pill didn’t work. There are always going to be those examples. But pointing at the exceptions over the vast majority doesn’t make sense.
Seriously. Evolution did not just stop. Modern humans migrated out of Africa over 60K years ago and possibly in waves beginning 120K years ago. Modern humans main defining feature has been the variety of environments they have adapted to, both by behavioral and by genetic changes, including since the Agricultural Revolution. We are a varied bunch and apparently can thrive on a variety of sorts of diets.
Avoiding obesity in the first place - solid.
Losing at least 5 to 10% of your body weight and maintaining it off if you have become obese - solid as well.
A diet high in fiber of a variety of sorts - solid evidence. Also for some of that diet, probably a largish part of it, coming from vegetables - solid. (More to the vegetables than the cancer link.)
Avoiding much highly processed meats and much added sugars (including those hidden in processed foods) - solid.
Otherwise what we can say is that certain dietary patterns are associated with better outcomes than others but mostly that what gets called the Standard American Diet loses out to many many others, as different as those others may be from each other.
Yes, exactly. We do know with 100% certainty that eating a big bowl of bitter almonds is bad for you, because that kills you very quickly. But eggs (or their lack) don’t. So how can you tell? Well, you have a bunch of people, and you get some of them to eat eggs, and some not… and then you wait. In 70 or 80 years, they’re all dead, and you can see which group died first. There, now you know whether eggs are good for longevity or not.
Except, of course, it isn’t even that simple. Maybe eggs are good for you if you eat them three times a week, but bad if you eat more. Maybe they’re good for you but only if you’re getting enough fiber, and bad if you’re not. Maybe they’re good for some people and bad for others, depending on their genetics. Maybe they’re neutral, but most people who eat eggs eat them with bacon, and it’s actually the bacon that’s having the health effects. Maybe the people you told not to eat eggs cheated and ate them anyway. It’s really hard to do good experiments on this.