Over the past couple weeks, I’ve shared two nutrition ideas that show how context influences what happens in our bodies after we eat.
Two weeks ago, we looked at how the body responds to sugar when it comes “packaged” in whole fruit compared to more processed snacks.
Then last week, we looked at how the order in which foods are eaten within a meal can affect blood sugar levels, satiety, and energy use afterward.
This week’s idea focuses on one of the biggest contributors to both of those effects: fiber.
What fiber does inside the body
Most people associate fiber with digestive regularity—and it does help with that—but many of its most useful benefits show up earlier than that, influencing appetite, blood sugar regulation, and long-term health markers throughout the day.
Soluble fiber dissolves in water and forms a viscous gel in the stomach. This lengthens the time it takes for the stomach to empty and has a couple noticeable effects.
First, it improves satiety. This often leads to naturally eating slightly less without needing to consciously restrict portions, which contributes to easier weight management over time.
Second, it delays nutrient absorption. This leads to more stable blood sugar levels after meals and, subsequently, energy levels throughout the day.
On the less noticeable but still practical front, soluble fiber also supports our gut microbiome and binds to bile acids, causing them to be excreted instead of reabsorbed. In practical terms, that means improved insulin sensitivity and appetite regulation (via the microbiome) and reduced LDL cholesterol (because the liver must use it to produce more bile acids).
Insoluble fiber is the type that contributes to digestive regularity. By absorbing water and adding bulk to stool, it speeds up transit time through the intestines and helps prevent constipation. (This may be one reason higher fiber consumption is linked to a lower risk of gastric and colorectal cancers.)
Most people aren’t getting enough fiber (and it matters)
General recommendations are that most adults should consume 25–35 grams of fiber per day. However, it’s estimated that the average intake in the United States is closer to about half that amount and that 90% of people don’t reach the recommended target on a daily basis.
Besides the fact that fiber helps with noticeable daily outcomes like appetite regulation and maintaining stable energy levels, that gap matters because higher fiber intake has also been consistently linked with lower risks of various diseases and negative health outcomes, including:
- Cardiovascular disease mortality
- Cardiovascular and coronary heart disease
- Type 2 diabetes
- Diverticular disease
- Pancreatic cancer
- Ovarian cancer
- Cancers of the digestive system (e.g. gastric, colorectal)
Based on the number of people who don’t reach the recommended daily targets and the benefits and risks associated with fiber consumption, it’s not hyperbolic to say that increasing fiber intake might be the most impactful nutrition upgrade we can make.
Where to find fiber (and how to increase it realistically)
Fortunately, increasing fiber intake doesn’t require a major diet overhaul as many common foods already contain meaningful amounts:
- Black beans and lentils: ~8 grams/half-cup
- Raspberries and blackberries: ~8 grams/cup
- Avocados: ~5 grams/half
- Peas: ~5 grams/half-cup
- Broccoli and asparagus: ~5 grams/cup
- Apples and sweet potatoes: ~4 grams
- Oatmeal: ~4 grams/half-cup (dry)
- Bananas and oranges: ~3 grams
- Whole grain bread: ~3 grams/slice (often more with high-fiber varieties)
- Psyllium husk powder: ~4 grams/tsp
Drastically increasing fiber intake (especially if not accompanied with fluids) can lead to uncomfortable side-effects such as gas, bloating, or abdominal cramps. So it’s a good idea to gradually increase consumption if you don’t usually hit the recommended daily target—not to mention that a gradual increase is usually easier to maintain.
In any case, adding even one of these foods to your day or, eventually, to each meal will bring you significantly closer to the recommended target, provide a number of both short- and long-term health benefits, and be rather tasty!
Putting it into practice
As I’ve mentioned before, it’s always useful to get clear about your starting point before trying to increase (or decrease) anything.
So this week, consider first spending a day or two tracking how much fiber you normally consume.
Once you have that number, decide which fiber-containing food(s) you’d be willing to add—or swap for a more processed snack—on a regular basis, and commit to doing it.
Then intentionally observe any changes to your appetite, cravings, and energy levels throughout the day.
It’ll be a simple change, but one that’s likely to provide a host of short- and long-term benefits.