High fiber diet for weight loss

man with a bunch of fibrous foods in front of him
November 23, 2016 (Updated: August 16, 2018)
Lily Moran

Most of us know that fiber is good for us. But few people realize just how essential it truly is. Not only is a high fiber diet good for digestion—and firming or softening stool. But it’s also the key to weight loss. It’s one of the best tools we have to fight cardiovascular issues, mood problems, strengthening our immune systems, even controlling our metabolism.

But not all fiber is created the same, as we’ll soon see.

But before we get there, it’s important to answer—what makes fiber so special?

The best indigestible thing you can put in your mouth

Here’s the crazy secret about fiber: We can’t digest it.

Fiber is basically a carbohydrate that your body can’t digest.

That sounds bad, right? Think again.

For one thing, fiber is a displacing agent.

That means that it fills you up, but doesn’t add any calories to your diet. Eating foods rich in fiber will leave you feeling full, while helping you shed pounds.

For another, fiber is a bulking agent. That means it helps your stool take shape, and prevents the runs.

Fiber also generally aids in digestion—in two different ways.

It’s also essential for a healthy gut microbiome.

Your best friends

Right now, about 100 trillion bacteria—categorized in 10,000 species—live in your gut.

And that’s a great thing.

You microbiome is responsible for all sorts of workings in your body. Your gut flora aids digestion, and helps you extract necessary nutrients from your food.

Your gut microbiome tells you when you’re full. 80-90% of your serotonin—one of the body’s natural happy hormones—is secreted in your gut. And yes, you guessed it, your microbiome is responsible for sending out those signals.

Your insulin sensitivity is controlled by your gut flora, as well. If you want to avoid Type II diabetes, you need to keep those bacteria healthy.

And problems with gut microbiomes have been linked to everything from heart disease to cancer. I can’t overstate how important your gut microbiome is.

However, a lot of modern food—high in sugar and fat, refined and processed—is bad for your gut microbiome. That’s not the fuel that your beneficial bacteria need.

Instead, the flora in your gut have one primary source of sustenance: fiber.

If you want a healthy microbiome—and, by extension, a healthy body—you need plenty of fiber. At least 25 grams a day for women, and 38 grams a day for men.

That’s way more than most of us eat.

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A tale of two fibers

Fiber comes in two basic forms.

One is insoluble—meaning it doesn’t dissolve in water. Think of roughage, like leafy greens.

This type of fiber passes through you quickly, speeds up digestion, and adds bulk to your stool. It helps you feel full, but the effect is relatively short-lived.

The other basic form of fiber is soluble, which dissolves in water. You’ll find this in juicy fruits, like oranges. You’ll also find soluble fiber in some vegetables—like Brussels sprouts—and many whole grains.

Metamucil is basically just soluble fiber, and many other digestion aids contain it.

What makes soluble fiber so special—and the most powerful type of fiber you can consume—is what it does when mixed with liquid.

Soluble fiber mixed with water turns into a gel-like substance. Unlike insoluble fiber, this actually slows digestion down.

But that’s not a bad thing. The gel-like substance moves slowly, but very slickly. It makes digestion smoother.

And since it moves slowly, it leaves you feeling fuller, longer. Meta-studies done on fiber find that, while both soluble and insoluble fiber leave you feeling satiated, only soluble fiber actually reduces caloric consumption.

That’s because it can fill up your gut for such a long time.

And, while insoluble fiber is good for solving constipation, soluble fiber performs even more functions. By slowing digestion down, it eliminates worries about anything like the cabbage runs. It also gives your body the chance to absorb all the vitamins and nutrients in all your food.

And, by becoming a gel-like substance that helps everything move, it works wonders curing constipation. It won’t work as fast as insoluble fiber for this particular problem, but it does the job.

Meanwhile, soluble fiber is just as beneficial for your gut flora as its insoluble sibling.

How to add fiber to your diet

The most important takeaway for today is this: Get more fiber into your diet. Both the soluble and insoluble.

That means more fruits and veggies—especially the watery sort that contain soluble fiber.

It means eating lots of unprocessed and whole grains. The refining process actively strips fiber from grains, greatly reducing their benefit. That’s why you should always replace white rice with brown, and white bread with 100% whole grain (it MUST say 100% or you’re not getting real whole grain benefits).

Reducing the amount of sugar, fat, and processed foods you eat will be a big favor to your microbiome.

And adding plenty of fiber will ensure you don’t feel like you’re being deprived of nutrition or satisfaction. Fiber is the healthiest appetite suppressant that exists.

There simply is no downside to a high fiber diet—but there’s tons of upside. From digestive health, to weight loss, to protection against disease, to hormone regulation—fiber is the key to all of it.

Make sure you’re getting enough. And, if you’re falling short, find ways to add it to your life.

This should be one of your most important nutritional goals. Don’t just chase vitamins and minerals. Make sure your body knows what to do with them when they get there. Eat more fiber.


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