What exactly is a 'healthy diet', is there a scientific consensus

The definition of a healthy diet (my defintion: one that improves a persons physical and mental health irrespective of impact on bodyweight) seems highly varied from author to author. The only common threads I have seen are generally to

eat vegetables
generally avoid refined and processed foods (cooking oils, sugars)

Aside from that they are pretty varied. Some vegetarian thinkers claim whole grains aren’t very good for you (since we didn’t evolve to eat them), others think they are. The paleo diet promotes various meats, some discourage them. Atkins is pretty much all meat. All claim to be good for physical and mental health.

Even as far as eating fruits and vegetables (which most nutrionists and people promoting eating for health promote) there is diversity on which ones and how to eat them. Some say juice them (to pre-digest them by breaking cell walls), some say smoothies, some say raw. Beans and nuts have varied responses from various writers.

Some say phytochemicals are important, others seem to discount their health benefits. Some claim artificial sweeteners are fine, some don’t. Cooking oils like olive oil are featured heavily in the mediterranian diet for health benefits while others criticize cooking oils, etc.

So when it comes to eating for physical and mental health, is there a strong consensus on a handful of concepts (avoid refined foods, eat vegetables) and everything else is a fad diet? Or are there really no strong points of consensus that run along the ideas?

I don’t believe there needs to be a single “healthy diet”. There may be many different diets, all of which can work fine for a subset or even a majority of people.

The Atkins diet is popularly portrayed in the media as being all about meat. In truth, low carb fruits like berries as well as vegetables are also a big part of the Atkins diet.

I think carbs, especially simple carbs such as sugars and white bread are big culprits in unhealthy diets. I especially laugh at the high fructose corn syrup commercials that say it is just as ggod for you as sugar. That’s like saying that being hit with a hammer is just as good for you as being hit with a 2x4. Their both equally bad for you.

Behold the USDA’s new Food Plate!

It actually gives pretty decent dietary advice.

Also, Walter Willett’s version of the food pyramid, which is very useful:


You know, when I heard they were ditching the pyramid for a plate metaphor, I thought they were daft. But that’s actually a really good graphic depiction of how to balance your diet.

This is a really great website, thanks!

Though a bit protein heavy for my taste, but I have seen measuring bowls for portion sizes online that look interesting.

Seems to be a simple pie chart.

Although it’s focused on weight gain/loss, there’s an interesting article in the NYT about a 20 year study that recently concluded.

So you can feel free to have a side of yogurt and nuts with your fruit, vegetables, and whole grains. And if you want to snack on something a bit more decadent, a little cheese won’t hurt.

It’s not. A pie chart uses the size of angles to convey information. The “plate” uses a clever mix of angles and sizes to nicely convey ideas like “half of this, half of that”, “less than a quarter”, “eat the most of this” and “eat the least of this”.

Dr. Kurt Harris has an excellent set of guidelines of what constitutes a healthy diet from a scientific perspective:


So… basically, no bread or grains, right?

In other words, no grains.

This is actually hazardous advice for someone with a dairy allergy - there is no way to ensure there is no milk protein in butter, and there is certainly milk protein in cream. This point alone makes me doubt this guy knows what he’s talking about. I’m aware that not everyone with an MD after their name is an allergy expert, but that’s really basic stuff about food allergy. And if this is supposed to be a diet emulating what our distant, pre-agricultural ancestors ate why is there dairy at all in it? Does he think that our distant ancestors were attempting to milk lactating wild goats or something?

The site is… interesting, but I have real issues with some of what he says.

Do Atkins aficionados really make this claim? (I know it’s not “all meat,” I mean the health claim.) I thought it was meant strictly as a weight-loss (and then maintenance) technique.

Broomstick, a few months ago I started eating the way Harris recommends, and it has dramatically improved my health and body. I look and feel pretty great all the time now, my skin and energy has improved, basically my whole life is better. Before I started, I was only about 10 lbs overweight, but that was struggling all the time on a diet like the one initech’s link suggests (I ate almost zero processed or fast food before I started, but still wasn’t doing all that well). I no longer obsess about food, the food I eat tastes fantastic, and I don’t get cravings or have trouble resisting a plate of cookies anymore. I highly, highly recommend the Paleo/Archevore diet. I have no doubt I’ll be eating like this for the rest of my life.

If anyone is interested, I find Stephan Guyenet’s blog to be well researched and not-crazy.

Look, there’s a lot of good there about reducing excess sugar and such, it’s a diet that may well work for some people but when he whips out “people with milk protein allergy can substitute butter and cream” he’s spreading misinformation, nonsense, and, as I said, hazardous advice. This is such a basic mis-step in regards to allergy that it makes me wonder about the rest of his theory of diet.

Sure, you can always lose weight by eliminating large categories of food - some people eliminate all meat… his system eliminates all grains. Either way, you’re reducing calories in your diet. So there is nothing magical or particularly ground-breaking about what he proposes. Sure, you lost 10 pounds - you probably could have done that by some other diet that also eliminates large groups of food. Your health improved - well, losing weight usually has that effect. He emphasizes non-processed or minimally processed food - yes, that usually does taste fantastic.

If it works for you that’s fine, what I’m questioning here is the idea that it would work for everyone, and as I pointed out, for some people his advice could actually pose a threat to health.

My view is that humans are omnivores, that means there is likely no ONE diet that is healthy. There are likely several approaches that result in a healthy human being, and given some of the known diversity of the human race (the ability or lack of it to digest lactose past the normal weaning age being one well known example) it is also entirely possible that a diet healthy for one person would not be so for another. On top of that, adding in disorders like food allergies and diabetes and lipid processing problems and you’ve got a minefield.

I’ll at least give him credit for mentioning that for healthy individuals his system poses no threat but we have a LOT of people in the world with chronic issues. Some of these probably aren’t really new… it’s just that in the past people died young from them, or complications of them.

Well, I’m not going to argue with you about it, I’m just saying what worked for me. I’m absolutely eating more calories and way more fat than I used to, and continue to lose weight despite my general gluttony. Specific health issues I’d struggled with my whole life cleared up completely, and like I said, I was eating very much according to USDA guidelines before. YMMV, but for me, this works, and I’m advocating it because other people may not have heard of this way of eating. I had not before a few months ago, and wish I’d started much earlier.

My problem is that I can find people who have totally different opinions.

A major problem I have is that diet and exercise are mostly treated as vehicles for weight loss in this fat phobic culture of ours, not as health promoting tools in and of themselves. So I wonder how much are healthy diet and exercise overhyped by medicine (because they are seen as vehicles for weight loss), and how much of the advice is based on the impact on weight loss rather than physical/mental health independent of BMI.

Not only that but I get the impression that many nutrition experts have their own biases or philosophies they want to push (such as anti-modernism or anarcho-primitivism), which I do not subscribe to.

  1. Eliminate sugar (including fruit juices and sports drinks that contain HFCS) and all foods that contain flour.

Some promote whole wheat flour. I don’t know if anyone supports a diet high in HFCS or white flour though, so there seems to be a consensus there.

  1. Start eating proper fats - Use healthy animal fats to substitute fat calories for calories that formerly came from sugar and flour.

I’ve heard some say plant fats are far healthier than animal fats, etc.

  1. Eliminate gluten grains. Limit grains like corn and rice, which are nutritionally poor.

Whole wheat is considered healthy by some due to its fiber content and ability to lower glycemic index.

  1. Eliminate grain and seed derived oils (cooking oils) Cook with Ghee, butter, animal fats, or coconut oil. Use no temperate plant oils like corn, soy, canola, flax, walnut, etc.

Walnut oil is high in omega 3s, the health benefits of olive oil are a major selling point of the meditterranian diet. Canola, avocado, sunflower, etc oils are also considered healthy. Some consider butter and animal fats unhealthy.

  1. Favor ruminants like beef, lamb and bison for your red meat. Eat eggs and fish.

Some favor no meats. Some like the paleo diet only favor foods our ancestors would’ve eaten. So no eggs or beef.

  1. Make sure you are Vitamin D replete. Get daily midday sun or consider supplementation.

I haven’t heard any criticisms of that.

  1. 2 or 3 meals a day is best. Don’t graze like a herbivore.

I’ve heard some say health benefits come from grazing 6 or more times a day. I’ve heard other say intermittent fasting (going up to 72 hours at a time without food) is best for health.

  1. Attend to your 6s and 3s. Pastured (grass fed) dairy and grass fed beef or bison has a more optimal 6:3 ratio, more vitamins and CLA. If you can’t eat enough pastured products, eat plenty of fish.

I haven’t heard anyone criticize proper omega 3 content. So that is a point that doesn’t seem to be contentious.

  1. Get proper exercise - emphasizing resistance and interval training over long aerobic sessions.

  2. Most modern fruit is just a candy bar from a tree. Go easy on bags of sugar like apples. Stick with berries and avoid watermelon which is pure fructose. Eat in moderation. If you are not trying to lose fat, a few pieces of fruit a day are fine.

Some say eat any fruit, some say eat only some. Some say eat organic, some say it doesn’t matter. Some say eat it raw, some say cook it. Some say juice it, some say use smoothies. So the ideas are all over the place.

  1. Eliminate legumes

Some say eat them. Peanuts can help with type II diabetes and cardiovascular disease.

  1. If you are allergic to milk protein or concerned about theoretical risks of casein, you can stick to butter and cream and avoid milk and soft cheeses.

Some say avoid all dairy products. Some say eat the whole fat. Some say the skim.
Anyway, I’m not trying to be rude by all that. But my point is that I really don’t know if there is a general scientific consensus about eating for health (rather than weight loss) when the advice usually contradicts other advice. Not only that, but much of the advice is for lifestyle change so radical most people can’t possibly maintain them for life. I’m not going to give up grains for life for a variety of reasons.

Something as simple as eating breakfast every day and making sure the breakfast is high in fiber and protein can have health benefits for blood sugar, mood and cardiovascular health. Plus it is a realistic lifestyle change a person can maintain.

Or switching to healthier cooking oils. Or using whole wheat grains instead of white. Those are realistic lifestyle changes I can make.

I don’t agree. Like with religion, I think there is only one true path and everyone else is either misinformed or ignorant.

Oats would be better than most other grains, though buckwheat purportedly is good for high blood pressure, high cholesterol, diabetes, PCOS …

perhaps a breakfast of oatmeal and buckwheat groats would be good, buckwheat pancakes/crepes/blini instead of wheat, oat based breads and cookies.