Soylent 1.6 meets the minimum FDA guidelines for fiber. You only have problems from excessive fiber if you take crazy large doses of it. Your worries about Soylent’s fiber content are unfounded.
I’m generally on a 2-3 week travel; I can have a 7-10 day schedule if I’m overeating (and I gain a lot of weight!).
So imagine you eat 25g of fiber every day, and you poop out this mostly-cholesterol brown log. That’s great.
Now imagine you eat 250g of fiber every day.
To make this perfectly clear: all of the fiber I eat for two to three weeks comes out in something eight to ten inches long. Maybe a week if I’m eating multiple large meals every day.
Food contains a lot of water. Meat is about 75% water; it’s made of protein and fat, otherwise, for the most part. Starches are broken down by amylase and gut flora into water and sugar. Sugars are absorbed. Yeast and bacteria die and autolyse, rendering themselves into a nutrient slurry other bacteria can consume, or your intestines can absorb.
Given a long enough fermentation, it all turns to water.
That’s the point of fiber: it comes out as a grainy powder, unchanged, unabsorbed. It’s hygroscopic, absorbs water, and bulks up. Too much fiber becomes a stiff, dry log.
At 4g/day, I might take in 80-90g of fiber, if that, between movements. At 14g, it’s 280-300g. At 25g, it’s over 500g.
I challenge you to eat 500g of fiber between each bowel movement.
Your entire “foundation” for that much fiber being okay is that the USDA recommends 25g per day. The USDA recommends 25g per day essentially because it recommended “adequate fiber intake” in 1980. This is often-assumed by alt-right crazies to be at the influence of conspiracies headed by Graham or Kellogg; in truth, it’s a simple hand-me-down of long-term cultural belief: the British have historically attributed many health benefits to “roughage”, fiber in the diet.
The British obsession with fiber was a culture-specific trait. The Japanese historically have believed that Miso and Shiitake impart great health and should be eaten every day. The French and Germans have their own ideas. Ben Franklin used to note that Americans believed strong alcoholic drinks would make them strong–something we rank up there with doctors prescribing cigarettes for their health benefits, or the common notion of taking a small dose of Strychnine for its health benefits.
The problem I have with the study you posted is it doesn’t mention how much and what kind of fiber the patients were getting before the study nor does it mention how much fiber or what kind they where getting during the study. Not to mention the fact that the patents had to change their diets to accomplish the levels of fiber requested. It’s not impossible that the change in diet is what helped their symptoms not the reduction in fiber.
Have you taken a statistics course? You should.
You essentially just managed to argue that the field of statistics itself is wrong about statistics. Much of your argument claims that variables other than fiber changed in ways which might have differed between patients, and thus that we would know more about changing the amount of fiber if we simultaneously changed other variables in controlled ways.
I cannot concisely explain why statistics uses randomization; it would require explaining all of statistics. I can point out that selecting a straw set of complaints about anything is possible, and is a common political tactic used by the dishonest in the hopes that the audience is made of idiots.
High-quality studies on the health benefits of fiber are thin. Some point out that children who are picky eaters have more constipation problems than children who eat a broad range of food, and conclude that more vegetables means more fiber, and thus fiber is the active agent. Some simply assume that every 1g average increase in fiber intake will produce a 1.8% reduction in constipation (without citing any supporting studies!), and show the great economic benefit of reducing healthcare costs by increasing fiber intake. Some survey populations and report on their estimated fiber intake, and their health state. That’s a lot of uncontrolled variables.
The problems with these studies is the groups are not sufficiently-random. When you compare “Picky Eaters” to “Non-Picky Eaters”, you have a lot of variation; and you also have a common dietary behavior, which may imply many things. When you compare population surveys and their fiber intake levels, you don’t identify the cause of their fiber intake levels–are they overeaters, vegetarians, or tightly-controlling their diets? These have different degrees of likely confounding.
As you so astutely pointed out, the study I linked found a bunch of people with constipation problems, excluded people with certain medical histories indicating a potential cause, and then told them to eat no fiber. They only surveyed at 1 month and 6 months. The study was an open study, not a double-blind with placebo and crossover using fiber supplements and controlled diets. Not the best study in the world.
In the world of fiber studies, it is the best study in the world. That particular study has few-enough methodological flaws to control for confounding variables. 63 subjects provides a lot of statistical power; a 200+ subject study could have detected much-smaller effects, and the large change in subject classes coupled with the narrow variance is the only thing that gave this study statistical weight.
In other words: the changes were so striking and so consistent among such large groups as to give an extremely high confidence in the study. That “P < 0.001” indicates how likely their observation should be if they’re wrong. When you get 41 patients moving from a range of 2.16-5.34 to a range of about 1.0 on a resolution of 1.0, something changed. When you have 41 unrelated patients told to “eat less fiber”, their diverse, uncontrolled diets are a source of randomization, which should broaden your outcome range if some other confounding effect is producing the results.
No, it’s not a perfect study. I pointed out the methodological shortcomings. The fact that it doesn’t control what kind of fiber or how much they originally consumed but does control how much they consume in experiment adds statistical power. The fact that it doesn’t control what their diet contains also adds statistical power, by means of changing other variables differently between subjects rather than making a separate, consistent change.
The only sensible part of your argument on why the study has flaws is that any change in diet might produce those results; and that isn’t actually valid, because we have a group with no change, a group with a partial change, and a group with a complete change, with the primary controlled variable being amount of fiber, and with all other variables uncontrolled and thus potentially-chaotic. The likelihood of a consistent, linked variable changing in proportion to the change of the primary controlled variable (fiber intake) is diminished.
Whereas one study might use picky eaters versus non-picky eaters, this study used “people with idiopathic constipation”, and instructed a vague dietary change. The experiment and control groups are the same because you’re making a broad change without placebo; subgroups are diverse, and so have differing characteristics, thus are less-likely to deal with linked variables and the confounding thereof.
It would seem that there is a 1 in 1,000 chance that no subset of the population is sensitive to dietary fiber in such a way that consumption of dietary fiber leads immediately and directly to constipation. We can generalize this to say that it’s almost-certain (99.9%) that people experience varying degrees of fiber sensitivity, with effects on digestive discomfort leading to bloating and constipation.
It is unlikely that normal people need fiber for healthy bowel function if the reduction of fiber reduces negative impacts of fiber intake in a dose-dependent manner as shown in this study all the way to zero intake. That’s a good hypothesis; we should repeat this experiment on healthy individuals and see if they develop digestive problems–notating their initial fiber intake.