High-Fiber vs. Low-Fiber Breakfast: Does It Really Make a Difference?

When I was a teen, I had issues—and not the kind you can deal with by listening to Morrissey. I’m talking about stomach issues... constipation issues. I couldn’t shit, OK. Back then, my diet consisted primarily of chicken parm sandwiches and Clearly Canadian. For breakfast, I would eat a bowl of high-sugar, low-fiber cereal: Cookie Crisp comes to mind. Pooing was a chore that happened irregularly and bore unpredictable fruit. I accepted that I was never going to poo as well as other people. I had a friend who would regularly brag about the speed and efficiency of his shits. He was an outspoken one-wiper, and I envied him.

Then, in my late 20s, I made a commitment to myself: I endeavored to eat more fiber. My theory was that if I set a good base with a high-fiber breakfast, the meal would become the surfboard that the rest of my daily food intake could ride to the shore. Lo and behold, the plan worked, and for about the last decade, I’ve continuously accomplished what I thought was unachievable: I’ve been regular.

As someone who now writes about food, I've never forgotten my bloated childhood. Your digestive system changes as you get older, typically for the worse, and I recently found myself wondering what would happen if I returned to my terrible teenage habits. Not necessarily the chicken parms, but what if I traded the high-fiber breakfast cereal routine I have now for my teenage, low-fiber ways?

A plan took shape: For one week, I wouldn’t eat my Kellogg’s All-Bran. Instead, I would indulge in an icky-sweet low-fiber alternative. Then I would track the differences. For science. I went to the grocery store and settled on Cocoa Krispies, a well-known brand that’s low in fiber—it has two grams per serving. My stomach was already recoiling.

To get a sense of what might happen, I contacted some professionals. Though not repulsed by my experiment, Dr. Christen Cupples Cooper, Director of Nutrition Programs at Pace University, did seem to question its scientific validity. “To say whether I think you are likely to experience changes, I would have to know whether the cereals were comparable in other ways besides fiber levels… sugar levels, fat levels, carbohydrate levels, additive levels, serving size,” she told me via email. “Also, did anything else in your overall diet change during your experimental period?”

Alas, my control over these factors would certainly be considered below that of a scientific journal’s rigor. However, despite her apprehension, I did convince Dr. Cooper to give me her best off-the-cuff guess. “I would GUESS that there would be minimal, but perhaps already notable differences in your digestive system after eating a higher-fiber vs. lower-fiber cereal. You may have some stomach discomfort, you may poop more, and you may feel better,” she said. “That's about as much as I would think you would notice.” Though saddened that my academic prowess had been put to shame, I was at least happy to hear that Dr. Cooper and I were on the same page.

I began the experiment by following my usual diet for one week, starting each day with a bowl of high-fiber cereal. As could be expected, everything went normal. Business was taken care of before noon, and thankfully for you, reader, nothing noteworthy happened that I need to describe.

During week two, I started every day with Cocoa Krispies. My first bowl on Monday gave me a heady sugar rush like I was eating Cadbury Eggs on Easter morning. But as far as my bowels were concerned, everything seemed normal. By Friday, I literally wrote down the note, “Honestly, I haven't noticed any difference. And I had pizza for dinner the night before.” Pizza being the kind of starchy meal that would usually disrupt my system in awful ways.

For the first time in my life, I was disheartened that I wasn’t having digestion issues. But as I was warned by Dr. Cooper, any differences I “may” experience “would be minimal,” and that was about it. To be fair, I was a teenager for seven years. To think I could revert my digestive system back to its “awkward years” in one week was probably a bit ambitious.

But I have to wonder, what’s the point of eating fiber in the morning if I was fine eating Cocoa Krispies? Another expert I spoke with, Dr. Caroline Apovian, Director of the Nutrition and Weight Management Center at the Boston Medical Center, encouraged me not to give up on fiber just because I couldn’t block myself by cutting it out of my diet for a week.

“Eating a high-fiber cereal is generally a healthier choice than a low-fiber cereal,” Apovian wrote in an email. “Foods that contain high amounts of fiber take longer to digest than other foods, increase feelings of satiety, and raise our metabolic rate, meaning that we will burn more calories following a high-fiber meal. Consuming enough fiber in the diet also reduces blood sugar and insulin levels. Over time, this increases insulin sensitivity. The opposite condition, called insulin resistance, is a condition in which the body produces high levels of insulin, but does not use it properly. Insulin resistance results in a heightened risk for type 2 diabetes and obesity.” Additionally, beyond fiber, cereals with less sugar provide benefits as well. Consuming lower amounts of sugar prevents blood sugar spikes that can make you feel tired. Eating less sugar can even reduce acne. (If only my teenage self would have known!)

So despite how this article might make it seem, Iam apparently making better decisions now than when I was in high school. Yes, my little experiment failed, but as Dr. Cooper pointed out, it was probably a bit naïve to think of it as an experiment to begin with. More importantly, believing I could prove in a week what I’ve learned in a lifetime was shortsighted. A more adult approach is to realize that I've improved my digestion over the past decade thanks to eating a high-fiber breakfast, and the proof is in the pudding. LOL, pudding.