White bread is not devoid of nutritional value, because it is the cheapest source of proteins known to mankind. Legumes like lentils, beans or peas have a cost per protein content at least 2 to 2.5 times higher than wheat flour. Chicken meat and plant protein isolates have a cost per protein content at least 4 to 5 times higher than wheat flour.

White bread is also one of the cheapest sources of energy, though depending on the geographical location either maize or rice may be slightly cheaper sources of energy, but which provide much less protein.

Among cereal products, wheat bread has the highest protein content, except for oats, but oats are much more expensive per protein content.

If you eat white bread in preference to any other starchy products, like those based on rice, maize or potatoes, this ensures a higher protein intake per a given calories content, which enables a lower consumption of more expensive sources of proteins, like those based on legumes or on meat.

White bread cannot be the only food that one eats, because other kinds of foods must provide other nutrients, but it can provide at a minimum cost major fractions of the daily intake of proteins and energy.

After experimenting with many different healthy diets, I have settled on a variant that I consider optimal, where wheat bread that I bake myself at home typically provides about a third of my daily protein intake, so its nutritional value is quite important (and the fact that it is very tasty is a welcome bonus).

Does whole wheat bread made from the same grain not have the same protein, or does removing all that fiber, flavour, and micronutrients somehow enhance the protein content and render it less expensive?

White flour has a slightly higher protein content (e.g. I bake bread from flour with 13% protein), but the important difference is that it is much cheaper, e.g. at least twice cheaper than whole wheat flour.

The reason for the price difference is unlikely to be due to a more expensive processing technology, but mostly from the economies of large scale processing, because the production of white flour is much greater.

Whole wheat flour has slightly higher amounts of the more valuable nutrients, but due to its high price it is an inefficient way to get those nutrients. A both cheaper and healthier diet can include white bread and larger amounts of other vegetables that are better sources of fiber, vitamins and minerals than whole wheat flour. (E.g. the food that I cook usually includes ingredients like lentils, carrots, parsnips, onions or garlic, broccoli or cauliflower, bell peppers, parsley or dill etc. Spending less on those in order to make more expensive whole wheat bread would provide much less desirable nutrients, so it would be a bad allocation of funds.)

No, it has nothing to do with economies of scale.

Grains contain both starch and oil and when you mill the grains, the oil goes rancid much faster than the starch.

If you remove the oil you have a nutritionally worse product but it lasts longer on the shelves.

That does still sound related to economy of scale. Longer shelf life means you can have a larger inventory.

That highlights the oddity of your calculations. You say that wheat is cheaper, but little about why. If the economies of large scale processing makes more processed wheat cheaper than less processed wheat, then maybe something else would be cheaper if our habits were different. So it's dubious to use the cheapness of white flour to argue that we should eat more white flour products.

"if...were" means nothing today, because woulda, coulda, shoulda. Today white is cheaper, so the calculation stands as it is, and makes for a very interesting argument in today's flood of influencer diets/fads.

It's very unlikely to matter economically for you or me or the op that whiter flour is cheaper. Bringing it up suggests it matters in some other way - like we have an obligation to buy the cheaper option because that has least impact on the environment maybe? But that does not follow at all. I don't think we should award points for originality either.

> White flour has a slightly higher protein content

The bags of 13.5% protein whole wheat flour and 16% (!) protein whole khorasan flour in my pantry are not convinced this is a generally true statement.

Well, see, the problem for me is mostly that white bread is just unhealthy. If I eat white bread, my blood sugar spikes. If I eat while wheat bread, it doesn't. Given the difference in cost does not even appear as a rounding error in my food budget, and that white bread has long-term negative health effects for this diabetic, I'll go with the more nutritious choice over the marginally cheaper one and get almost all my protein from better sources than grain seeds.

Make no mistake: I dream of gorging on delicious chunks of white sourdough bread hot and steaming from the oven. I just have good and indisputable evidence from my test strips that it is not good for me.

The wheat we eat was bred specifically to grow without nutrients.

Nutrients are divided into micronutrients, most of which are needed in quantities much smaller than 1 gram per day, i.e. vitamins, minerals, essential fatty acids and a few amino-acid derivatives, and macronutrients, which form the bulk of what you eat, i.e. carbohydrates, protein and fat.

What you mean is that modern wheat was selected for high production per area, which can be attained only when the seeds contain smaller amounts of micronutrients, so that their limited availability will not inhibit growth.

On the other hand, all plant seeds, including wheat seeds, in their dry form consist almost only of nutrients, unlike the other plant parts, which usually have very little nutrient content.

So wheat seeds and also the white flour made of them are very rich in nutrients, but only in 2 kinds of nutrients, starch and protein.

Animals, including humans, need a great number of essential nutrients in order to survive, around 50 different chemical substances.

White bread provides energy and protein that has a good amino-acid profile, except for low amounts of the amino acid lysine.

For complementary proteins and for the very small amounts of micronutrients that are required for a complete food, one must eat something else.

There exists no natural food that has a perfect composition that would allow humans to live eating only that (except mother milk for small babies).

So anyone must eat a combination of different kinds of foods. People who are rich might choose to eat some paleo diet or some keto diet and it is possible to conceive such diets that are healthy.

However most of the humans must allocate a limited budget for food, and within these constraints there are large areas in various places of the Earth, including Europe, where any healthy diet of optimum cost must include a non-negligible fraction of wheat.

For those who unfortunately suffer of celiac disease, a higher cost of food is unavoidable.

While the macro discussion is very interesting you are completely leaving out any mention of micros.

- White bread is not devoid of nutritional value

But it is processed food, which means it has indeed lost some nutritional value. Moreover, the way white flour is processed by our body is different from the way wheat or oats is - in very simplistic terms, the reduction of fibre content in white flour means that when it is consumed and processed, glucose / sugar from it is released very quickly into our body. Our body can handle that, once in a while. But repeated sugar spikes (and falls) isn't good for the health. And that is why doctors today (especially in India) advise you to eschew white flour in favour of others (wheat, oats, millets etc.). But yeah, the way you consume it, with other foods, matters too (and from your other comment, it does appear you follow a reasonably good diet, with a healthy outlook - without unduly obsessing over it).

> But it is processed food, which means it has indeed lost some nutritional value.

This seems like a trivially false assumption.

If processing grains into bread represented a loss of nutritional value, why would every civilization have invested their extraordinarily scarce time and resources into milling and baking instead of just eating the raw grains?

I think there’s a disconnect here between someone talking about what Americans call “white bread” (the highly Wonderbread that reportedly can only be sold as cake in some European states) and someone talking about what Europeans call “white bread”, which is more traditional bread — baguettes are an example, and just one of the many shapes it comes in.

I rather suspect there is a difference between people using dictionary definitions and hard facts, versus people using "processed" = bad, which is similar to "chemicals" = bad.

We have established a correlation between degradations in health with high-processed food diets. That is a fact, but it really doesn't tell us much. From this, and ideas like "brown bread has more vitamins than white bread", people naively say generalizations like "white bread is unhealthy" and "all processed foods are bad for you".

Cooking is processing too, and does indeed cause some nutritional loss. Its benefit however outweighs that (for e.g. cooked food is tastier, we are able to digest cooked faster and better, thereby expending less energy for it), and we also compensate for the loss of nutrition by consuming different food at the same time (having created recipes with different basic food groups, and what is now popular and promoted as the 'balanced diet'). I was however particularly referring more to processing wheat flour to refined white flour, from which white bread is made. These food products are optimised for taste rather than nutritional value. The more you refine it, the more likely you are to strip some nutritions from it. For example, here is how modern refined white flour is made in many parts of the world - https://food.ndtv.com/food-drinks/how-is-maida-made-and-is-i... . That aspect also matters today when you compare it past food habits and food processing - today, we refine many food products more than we used to do in the past. (And apparently, we are now even growing with food with less nutritional values, because we are prioritising and optimising more for how the produce should look - https://www.nationalgeographic.com/magazine/article/fruits-a... !)

Have you compared it to pasta wrt cost? Intuitively I suspect pasta may come out cheaper if you consider the time+electricity requirements for preparing at home.