Dietary Fiber: Carbohydrates’ Wrapper and Instruction Manual

Unfortunately, many of us get the majority of our carbohydrates stripped of their natural fibers. Modern processed grains like white rice and white flour as well as many ultraprocessed foods like some sugary breakfast cereals, packaged snacks and juices have removed these fibers. They essentially come unwrapped and without instructions for the body on how much it should absorb and how it should process them.

One popular approach to mitigating some of the ill health effects of low fiber and high refined carbohydrates has been to limit carbohydrate intake. Such approaches include the low-carb, keto, paleo and Atkins diets. Each diet is a variation on a similar theme of limiting carbohydrates to varying amounts in different ways.

There is scientific backing to the benefits of some of these low-carbohydrate diets. Research shows that limiting carbohydrates induces ketosis, a biological process that frees energy from fat reserves during starvation and prolonged exercise. Low-carbohydrate diets can also help people lose weight and lead to improvements in blood pressure and inflammation. That said, some keto diets may have negative effects on gut health. It is also unknown how they may affect heart health, some forms of cancer and other conditions in the long term.

Even more confusing, research shows that people with diets high in plant-sourced carbohydrates, like the Mediterranean diet, tend to lead the longest and healthiest lives. How can this be reconciled with studies that suggest that low-carbohydrate diets can benefit metabolic health?

The answer may have to do with the types of carbohydrates that studies are evaluating. Limiting simple sugars and refined carbohydrates may improve certain aspects of metabolic health, as these are some of the most easily digested and absorbed calories.

But a more sustainable and comprehensive way of improving health may be increasing the percentage of unprocessed, more complex and slowly absorbed carbohydrates that come with their natural packages and instructions intact – those that have fiber.

Unprocessed, more complex and slowly absorbed carbohydrates come in ratios of total carbohydrate to fiber that rarely exceed 10-to-1 and are often 5-to-1 or lower. Eating mostly whole foods is a simple way to ensure we’re consuming quality carbohydrates with the right ratios.

Focusing on packaged processed foods that maintain carb-to-fiber ratios of at least as low as 10-to-1 or ideally 5-to-1 can help us make the best choices when picking more processed foods at the store. Take a look at the nutrition facts label and simply divide total carbohydrates by dietary fiber.

While almost all fiber is generally good for health in most people, not all fiber affects the body in the same way.

Certain medical conditions might preclude consuming certain types of fiber. For example, some people can be particularly sensitive to one class of fiber called FODMAPs – Fermentable Oligosaccharides, Disaccharides, Monosaccharides And Polyols – that are more readily fermented in the upper part of the gut and can contribute to symptoms of irritable bowel syndrome like bloating and diarrhea.