Don’t Eat Your Vegetables
Veggies are pretty healthy, but it’s not because of fiber.
It’s not an easy task to make vegetables tasty for a kid. Even if you are successful, the rebellious nature always prevails. No matter how much you talk about the vitamins or the antioxidants, it’s often just as hard to make veggies appealing to an adult. We’ve been so hung up on trying to make them cool, that we forgot why we’re even doing it.
Before handing away the problem to the marketing campaigns, shouldn’t we first make sure that there’s some merit to our claims? We know that broccoli is healthier than a pizza, but does that make plants bulletproof? Also, just because junk food lacks fiber, does that vindicate all foods that do not?
Fiber is not your friend
Before we go any further, there’s one realization that needs to happen. Fiber is not essential. If it was, then the Eskimos as well as the current “carnivores” would’ve died out. The soluble fiber can serve a purpose and degrade to short-chain fatty acids, but the majority of fiber has no benefits other than psychological (1).
When it comes to these fancy short-chain fatty acids nourishing our colon cells, they do so by converting to ketones. Albeit achieving ketosis through a nutritional approach might be tricky for some people, that would be much more advantageous for all the cells lining the intestine. Even if you’re not certain whether you’ve lowered your carb intake enough, it is shown that animal protein and collagen can also be fermented into these specific fatty acids.
The biggest problem with advocating for fiber is acquitting foods with “empty” calories at the same time. The American Heart Association recommends 25 grams of fiber or more, depending on age and sex. Not only does separating these groups of people makes no sense, but it also justifies fiber-rich foods such as granola, cereal, various bars, etc. Hence, trying to reach the recommended daily allowance can result in weight gain, nutrient deficiencies, metabolic dysfunction, and the list goes on.
Furthermore, being open-minded and self-experimenting is the best path to wellbeing. There’s a good chance that you will feel better psychologically by consuming more fiber but possibly at the expense of stool quality. Reprogramming your brain to stop worshipping vegetables takes time, as the propaganda machine has been in effect since you were just a baby.
Everyone poops
Are veggies, or fiber in them, necessary to poop? Well, if they were, then that would explain why hunter-gatherers did not have toilets. Turns out, everyone poops.
Believe it or not, when it comes to bloating, constipation, and similar symptoms, fiber is almost never the answer. In fact, if you want to poop more regularly and effortlessly, you might want to reduce it or eliminate completely (2). An Australian doctor Paul Mason gives a great analogy for this: “adding fiber to bulk out the feces makes no more sense than adding cars to clear out a traffic jam”.
Quite frankly, my conclusions are mostly based on one experimental study published in the World Journal of Gastroenterology and a bunch of anecdotal experiences. To this day, there’s not a single randomized control trial on this topic. I don’t want to get conspiratorial, and I do understand that finding funding is the most difficult part, but I really don’t see any ethical or other problems to make such a study.
Importantly, peristalsis (automatic muscle contractions that move food) works with fiber and without. While vegetables certainly add bulk, they do not protect you from distension, pain, bleeding, and other constipation related symptoms. To many people’s surprise, fiber is often the main cause of their bloating, since it cannot be digested in the small bowel. When it is being fermented into the magical short-chain fatty acids, gasses are produced and abdominal pain can occur.
All your poops are is dead gut bacteria plus the insoluble fiber. The idea that fiber is a “free” nutrient that contributes to satiety and helps move things along is too good to be true. It may be filling, but so is drinking water or eating paper.
What about the microbiome?
This one is a hail Mary of the pro-fiber people. Why not claim something that is unproven in humans and revolves around a topic that we barely understand? A healthy gut microbiome is incredibly important for the immune system, digestion, and a plethora of other things. The science around it is indeed cloudy, but it does not portray fiber as the hero.
Besides folklore, these discussions accelerated with a study published in the Journal of Cell (3). The problem with this highly cited study is that it was done in mice. What is more, the mice were raised to have a 14 species microbiome that was entirely fiber dependent. Once the researchers deprived them of it, the mucus layer went down but did not indicate any damage to the gut. While several conclusions can be made from the paper, mice are not humans, and a microbiota that has 70 times fewer species than ours is not a good starting point, to begin with.
Because the microbiome is still a mystery and a pretty great one at that, claiming that fiber makes it robust is speculative at best. Some meta-analyses of observational studies do find fiber useful, but more often than not, those seem to be the result of reverse engineering (4, 5).
The saving grace
There’s one reason why going for the high-fiber vegetables may be of some benefit to you. In the case of your diet being high in sugar, or carbohydrates in general, fiber may be the only thing preventing you from diabetic-level glucose spikes (6). That said, unless you’re a trained athlete, I would not recommend a high-carb nutritional approach.
In addition, rarely do people include veggies in their diet without also adding some fruit. The latter is often the first thing that jumps to mind when someone thinks of improving his or her health. The phrase fruits and vegetables is, as a matter of fact, more popular than vegetables and fruits. Although that’s probably due to linguistic reasons, the wording of health messages does shape the way people perceive these two options (7).
If you are someone who can’t live without fruit, then ignore the parts where I bash on fiber. Your fasting blood sugar levels are still something to be worried about, but not limiting veggies can help. Also, remember that just like you can’t out-exercise a bad diet, putting spinach on a pizza will not make it healthy.
Takeaway
Vegetables are important, so far as they ward off high glucose spikes and less nutritious foods overall. However, if you’re not addicted to sugar, then fiber may be doing more harm than good.
Veggies are probably not the answer to the obesity and despair epidemic that we’re currently in, but they could be a step in the right direction. Lo and behold, you’ll still have to prioritize sleep, lack of stress, exercise, and other things that increase your healthspan.
