The focus here is on meat substitutes like Beyond and Impossible… and while it’s true some of their plant based ingredients are for taste/texture rather than nutritional content… Is there anything scientific about being more or less processed? Or is this just classic dietitian mythology?
I think (but I am not a dietician or food scientist or whatever) that processed food is generally frowned on because historically, when people make processed food, the goal is to get the most flavor for the lowest cost. Empty calories from sugars and fats are the best way to get cheap flavor, so as a result processed food has generally been unhealthy to eat.
Soylent is obviously heavily processed but is made with a goal of good nutrition, so the normal “processed foods will kill you” belief doesn’t apply. My understanding of Beyond and Impossible is that their main goal was to be meaty, nutrition wasn’t much of a concern, so they aren’t terribly healthy. I have eaten both and like them, but I expect that if I replaced my 10-15 Soylents per week with impossible burgers, it wouldn’t be best for my well being!
There’s nothing inherently wrong with “processing”. Nearly all foods are processed so some degree. Processing is just whatever you do to ingredients to turn them into a food, and that includes stuff like washing and heating.
The problem with “processing” is there is a correlation between highly-processed foods and added salt & sugars, exposure to harmful substances (such as BPA in food containers, fragments and microorganism contaminants from machinery, et al.), and reduced or degraded nutrients & fiber.
Speaking to your last question, there was a great, older episode of The Nutrition Diva (a science-based nutrition podcast) where the host says she was called out as she too fell into this trap of saying “avoid processed foods”; that as a professional in her field, she and others need to do better with clarifying what they mean. Processing can be good, and it can be bad. In America, the correlation is clear: the more processing, the less healthful; but this is not a scientific law - just a general rule of thumb.
Heating, for example, reduces some nutrients but makes other more bioavailable. If your diet is overwhelmingly highly-processed foods, you’d have a higher risk of developing nutritional deficiencies. But this is easily mitigated by having a varied diet that also includes minimally-processed foods.
A product like Soylent is a bit of an outlier. It is extremely processed, but also includes the majority of nutrients one needs to be healthy. It doesn’t include 100% of what your body likes (neither do the published DRIs the American diet is based off of), but it’s closer than probably any other single food item.
The idea that processed foods are bad is isn’t entirely true, but it is true to an extent. It depends on specifics.
When people say “processed foods” there are a lot of things they can mean. They might mean things like hot dogs, Spam, or potted meat product, where the food is ground up into something unrecognizable, maybe with added flavors and preservatives. They might mean products derived from food through extraction and purification, which includes white sugar, Vegemite, and such (but not salt, because salt isn’t an extract from food products). They might mean any food with additives that don’t come from food products, which includes stuff like salt, preservatives, flavor protection agents, some texturing agents, and often even added vitamins and minerals. Whether a particular kind of “processing” is good or bad depends largely on what it is and often on specific details.
The original food processing was merely cooking. Cooking alters food by making calories more available, but it also tends to destroy nutrients. The more a food is cooked, the more the nutrients it contains are destroyed. This effect varies with different food products, but it is not so dramatic that it is generally a serious problem. It does mean, however, that home cooked meals are generally a little bit more nutritious than store bought canned foods, which have generally been cooked significantly more. If you eat a variety of foods though, it really won’t make a huge difference. Also, the majority of nutrients humans need can be obtained merely by eating meat. If you eat meat regularly, you probably don’t need to worry about nutritional losses in precooked food.
Purified food products are a bit more problematic, but they are rarely as bad as people make out. The biggest culprit here is sugar. I am not aware of any extract that is as potentially harmful as processed sugars. (Things like Vegemite are often healthier than their sources, because they are specifically concentrating the nutritious part, while discarding the parts that are less healthy.) Processed white sugar, as well as brown sugar and various “raw” sugars (not really raw though, since they have been extracted from the cane/beet) are actually not that bad. To understand the issue with processed sugars, you need to understand blood sugar and glycemic index (GI). A very basic rundown is this: High GI foods cause spikes in blood sugar. When these spikes are only occasional, no harm is done. When they are frequent or constant, it eventually trains your cells to ignore insulin, which a hormone the body uses to tell cells they can take sugar from the blood to use it as energy. This can result in blood getting thick (think light syrup) as the sugar content gets out of control, which will kill you if untreated and which is known as Type 2 Diabetes. Note, however, that it can take 20 to 30 years for frequent high blood sugar to lead to this, which makes it especially dangerous in a society that almost worships sugar. Anyhow, table sugar has a moderate GI. You would have to consume a lot of it pretty regularly to lead to diabetes. High fructose corn syrup has a very high GI, which means if you merely replace a significant portion of your water intake with soda, you can put yourself at serious risk for Type 2 Diabetes. Now, added sugars in foods, even HFCS, isn’t that bad. It depends on the food. Breakfast cereals are pretty bad, because they are made from corn, which is already at the high end of medium, so a bit of HFCS for flavor can make it pretty bad for you. A bit of sugar in foods like pork and beans though, isn’t going to harm you, because the fiber slows the sugar uptake preventing the spike. (In theory, if you added something like Metamucil to your soda, it would be far less dangerous.) So basically, added sugars are actually not dangerous, if the base food they are added to isn’t already very unhealthy. It’s when they are added to foods that are unhealthy or when they are added to neutral foods in very large quantities that they are a problem. (Note, however, that some basic, unprocessed food products are worse even than HFCS. For example, Russet potatoes and white bread have extremely high GIs, significantly higher than HFCS.)
Added non-food chemicals are actually an unanswered question, largely because there are so many. We know that aspartame is really unhealthy (avoid diet sodas…). Most artificial sweeteners, however, don’t seem to be very bad. All of them trigger an insulin release, which may cause immediate low blood sugar, but no negative long term effect have been observed, aside from aspartame (which interferes with reproduction and can cause sickness in large amounts, and which turns into formaldehyde when exposed to high heats, for example, in the back of semis in hot climates). Preservatives are also up in the air. Those that have been discovered to be bad have generally been phased out or prohibited by law. There may be other side effects that are really hard to detect though, for example, some people blame certain mental disorders on preservatives, and there is some evidence that people who have removed them from their diets have recovered from those disorders. It doesn’t work for every case though, and no one has proven that it wasn’t something else in the foods causing the illnesses. So it might be wise to avoid excessive preservatives, but no one has proven that they are harmful. This also applies to non-stick/non-clumping agents, flavor protection agents, and texturing agents, as well as artificial flavors and colors. There is limited evidence that some people may be sensitive to specific ones, but there is no evidence that quitting them will be good for everyone. (This also applies to certain things like gluten, a food product, and non-food flavorings, like MSG as well. A very small portion of the population is sensitive, but most people won’t benefit from avoiding them. And frankly, they actually provide legitimate nutrition, so avoiding them for people who are not sensitive could actually be bad, depending on whether or not they get those nutrients elsewhere in their diet.)
The last thing worth knowing about this is that certain nutrients can interact with each other in ways that make it better to get them separately. For example, calcium interferes with iron uptake. This means that when consumed together, your body will absorb significantly less of the iron, and since it can be hard to get enough iron in the first place, this can lead to iron deficiency. Processed foods are more likely to mix nutrients that interact in these ways than home made foods, because processed foods have so many more ingredients. Something like adding milk solids or whey to a food product, for flavor or texture, can significantly affect how the body responds to the nutrition in that food, and this won’t be reflected in the nutritional content label, because the testing used to determine the nutritional content of foods is merely a chemical analysis, and thus it does not account for interactions. A product that says it can satisfy 5% of your daily iron needs might actually satisfy significantly less, because it has a high calcium content. Cooking at home though, a person is far less likely to add milk solids or whey to improve flavor or texture, especially in meat dishes (meat being one of the biggest sources of iron for most people).
Processed foods are not inherently bad for you. Specific processing can decrease the nutritional quality of foods or add things that might be harmful, but processing on its own doesn’t harm food. There are some really good guidelines one can take to avoid the most harmful processed foods. One is to look at the ingredients. If the list is long, it might be good to reconsider. Treat foods with a lot of ingredients as foods that should only be consumed occasionally. Looking up ingredients you don’t recognize and learning about them is also a good idea, but it is not critical to eating reasonably healthy. Even known harmful ingredients, like aspartame, won’t do significant harm if they are consumed only once in a while. Cut out HFCS sweetened soda. Again, once in a while won’t be a problem, but don’t drink it regularly, and look for table sugar sweetened alternatives. (Mexican sodas are generally sweetened with table sugar.) Eat at least a few home cooked meals a week, to cover nutritional deficiencies that processed foods may have. Also eat a variety of foods. Sit down “slow food” restaurants that cook their food to order can be an alternative to home cooked meals, but they are also more expensive. They also tend to have limited variety though, so don’t go to the same place every time, and don’t order the same thing every time. If you don’t have a moral or health related reason for not eating meat, eat meat regularly. You don’t need a lot of meat to be healthy, but meat is the richest source of vital nutrients of any food. The nutrients that meat does not have can be obtained by eating a variety of vegetables. If you can’t or won’t eat meat, learn about nutrition. Many people who decide to go vegetarian or vegan end up sick from malnutrition, because they didn’t bother to learn how to replace all of the nutrients they would be getting from meat. If you are going to chose that lifestyle, you must do the work that comes with it, otherwise it is significantly less healthy than a diet that includes meat.
The claim of Soylent isn’t that it is more healthy than a well balanced diet. The claim of Soylent is that it is convenient and that it is significantly healthier than the average American diet. And this is almost certainly true, as the average American diet is quite unbalanced and is significantly lacking in certain nutrients. Soylent is indeed a processed food product. Even the creator admits that we don’t know everything about nutrition and thus it is likely that Soylent is missing important things. It is not recommended to consume Soylent exclusively, but if Soylent is missing anything critical, eating one or two real food meals a weak, with decent variety, should cover it easily. Unlike most processed foods, Soylent was designed specifically to cover all known nutritional needs, so you are far more likely to have problems eating common processed foods exclusively than consuming Soylent exclusively.
What it all comes down to though, is that the human body is resilient. It is more important that you get what you need than that you avoid what your don’t need. This means that eating a variety of foods to cover your nutritional needs is more important than avoiding presevatives and additives that might be mildly harmful. Thus even on Soylent, you should still eat other stuff now and then.
The replies above cover the detail way better than I could, but the very short version is that phrases like ‘processed’ and ‘GMO’ refer to a massive scope of things. Cooked food is ‘processed,’ for instance. And it’s important to evaluate what the claims are of a food on its own terms. The new fake meats aren’t making health claims [that I’m aware of], they’re making flavor/experience claims, so no reason to be dismayed at the high fat and calorie content, for example. And a ‘burger replacement’ that isn’t claiming to be healthier probably shouldn’t be judged on whether it meets any dietary requirements outside of those on the packaging.