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The Super Fiber that Controls your Appetite and Blood Sugar

The Super Fiber that Controls your Appetite and Blood Sugar

IMAGINE EATING 12 POUNDS of food a day — and still staying thin and healthy. That may sound crazy, but it’s exactly what our hunter-gatherer ancestors ate for millennia! And they didn’t have any obesity or chronic diseases like heart disease, diabetes, cancer, or dementia.

Of course, I wouldn’t advise anyone today to eat 12 pounds of food, because the food in our society lacks one major secret ingredient that our ancestors ate in nearly all their food — fiber!

Fiber has so many health benefits that I want to focus on it in this blog. I’ll explain some of its benefits and give you 9 tips you can begin using today to get more fiber in your diet. I’ll also tell you about my favorite “super-fiber” that can help you increase your total fiber intake overnight.

But before I tell you about what fiber can do for you, let’s a look a little more at the history of fiber.

Why Bushmen are Healthier than the Average Westerner

Dr. Dennis Burkitt, a famous English physician, studied the differences between indigenous African bushmen and their “civilized” western counterparts. The bushmen seemed to be free of the scourges of modern life — including heart disease, cancer, diabetes, and obesity.

Dr. Burkitt found that the average bushman had a stool weight of 2 pounds and the “civilized” men had a stool weight of only 4 ounces – that’s 87.5% smaller! The difference was in the amount of fiber they ate.

Today, the average American eats about 8 grams of fiber a day. But the average hunter and gatherer ate 100 grams from all manner of roots, berries, leaves and plant foods. And the fiber is what helped those ancestors of ours stay healthy. Just take a look at all the good things that fiber can do for your body.

You need fiber to keep healthy from top to bottom, as well as to provide food for the healthy bacteria that work within you to promote health.

Glucomannan is an ancient fiber source that can help you lose weight, lower your cholesterol, reduce your appetite, and lower your blood sugar more effectively than ANY other fiber.

In fact, fiber can actually prevent obesity and all the chronic disease of aging. This is because fiber slows the rate at which food enters your bloodstream and increases the speed at which food exits your body through the digestive tract. That keeps your blood sugar and cholesterol in ideal balance — and quickly eliminates toxins from your gut and reduces your appetite.

There’s good science to back this up. Research shows that fiber can lower blood sugar as much as some diabetes medications, lower cholesterol, and promote weight loss. It’s clear, fiber is a great ally in the battle of the bulge.

But it’s also a hero in more serious battles.

For example, one recent study showed how butyrate made by gut bacteria from certain types of fiber acts as a switching molecule that turns on an anticancer gene — and turns OFF colon cancer. In fact, fiber has been shown to reduce the risk of colon cancer by as much as a third and breast cancer by almost 40 percent.

It also lowers cholesterol and reduces the risk of heart disease by as much as 40 percent. And if you have diabetes, adding fiber to your diet may even help you use less insulin. Plus, it’s a great natural cure for constipation and irregularity.

Now that you know how beneficial it is, let’s look at how you can begin taking advantage of fiber’s health benefits.

Getting Enough Daily Fiber

You should shoot to get 30 to 50 grams of fiber into your diet every day. The type of fiber you choose is important, too.

Most people think that bran is the best type of fiber to eat. But bran (wheat fiber) is mostly insoluble and doesn’t get digested. Think of it as more of a scouring pad for your intestines. That’s good for getting you regular, but it just can’t help your health the way that soluble fiber can.

You’ll find soluble fiber in fruits, vegetables, beans, nuts, seeds, and most whole grains. The bacteria in your gut metabolizes the soluble fiber in these foods, and that’s when the benefits start.

Soluble fiber can help lower cholesterol, blood sugar, and insulin, prevent cancer, balance hormone levels, remove excess estrogen and reduce the risk of breast cancer, make vitamins and minerals, provide food for the colon cells, and more. So it’s easy to see just how crucial soluble fiber is to good heath!

In just a minute, I’m going to tell you how to increase your fiber intake. But first, I want to tell you about some recent discoveries regarding an ancient fiber source that can help you lose weight, lower your cholesterol, reduce your appetite and lower your blood sugar more effectively than ANY other fiber. It’s called glucomannan, but I call it super fiber!

Glucomannan: The Benefits of Super Fiber

Glucomannan (GM) is a soluble, fermentable, and highly viscous dietary fiber that comes from the root of the elephant yam, also known as konjac (Amorphophallus konjac or Amorphophallus rivieri), native to Asia. The konjac tuber has been used for centuries as an herbal remedy and to make traditional foods such as konjac jelly, tofu, and noodles. More recently, purified konjac flour, or GM, has been used as a food stabilizer, gelling agent, and supplement.

What makes this fiber so super is the fact that it can absorb up to 50 times its weight in water — making it one of the most viscous dietary fibers known. That means that GM can help you shed pounds. In many studies, doses of 2 to 4 grams of GM per day were well-tolerated. This amount also resulted in significant weight loss in overweight and obese individuals.

GM works by promoting a sense of fullness. Plus, it pushes more calories out through your colon, rather than letting them be absorbed. It also lowers the energy density of the food you eat. In other words, it bulks up food in your gut — creating a lower calorie content per weight of food you eat.

And since fiber has almost no calories but a lot of weight, adding it to your diet lowers the energy-to-weight ratio of the food that you eat. Studies show that the weight of food controls your appetite, so the fiber increases the food’s weight WITHOUT increasing calories — a critical factor in weight control.

This powerful fiber may also control your appetite in other key ways. For example, it sends signals to your brain that there is a lot of food in your gut and tells it to slow down on stuffing food in there.

GM also leaves your stomach and small bowel slowly because it is so viscous. By slowing the rate of food absorption from the gut to the bloodstream, GM reduces the amount of insulin produced after a meal, which also controls your appetite.

It may also increase the level of hormones in the gut (such as cholecystokinin), which is another way to control your appetite. And finally, you lose more calories through stool because GM soaks up all those extra calories!

GM can also help your health in other ways. In addition to weight reduction, GM has been studied for its effects on constipation, serum cholesterol, blood glucose, blood pressure, and insulin resistance syndrome.

With all those benefits, there’s no doubt you should eat more fiber. No, you probably won’t be eating 12 pounds of food like your ancestors did! But you can increase your fiber intake, just by being smart about what you eat. Here are some simple suggestions for increasing fiber in your diet.

9 Tips for Increasing the Fiber in Your Diet.

  1. Get the flax.Get a coffee grinder just for flax seeds, grind 1/2 cup at a time, and keep in a tightly sealed glass jar in the fridge or freezer. Eat 2 tablespoons of ground flax seeds a day. Sprinkle on salads, grains, or vegetable dishes or mix in a little unsweetened applesauce.
  2. Load up on legumes. Beans beat out everything else for fiber content!
  3. Bulk up on vegetables. With low levels of calories and high levels of antioxidants and protective phytochemicals, these excellent fiber sources should be heaped on your plate daily.
  4. Go with the grain. Whole grains like brown rice or quinoa are rich in fiber, too.
  5. Eat more fruit. Include a few servings of low-sugar fruits to your diet daily (berries are the highest in fiber and other protective phytochemicals).
  6. Go nuts. Include a few handfuls of almonds, walnuts, pecans, or hazelnuts to your diet every day.
  7. Start slowly. Switching abruptly to a high-fiber diet can cause gas and bloating. Increase your fiber intake slowly until you get up to 50 grams a day.
  8. Consider a good fiber supplement. If you’re have trouble getting your fill of fiber, choose a supplement that contains both soluble and insoluble fiber and no sweeteners or additives.
  9. Choose GM. By now, you know that my favorite kind is glucomannan (GM), or konjac. Many companies sell it in capsule form. Although I don’t normally recommend specific brands, I like the one produced by Natural Factors called WellBetX. You can take 2 to 4 capsules with a glass of water, 30 to 60 minutes before eating. Don’t take any medications within 1 hour before or 2 hours after taking it because the fiber may absorb the medication.

As you can see, fiber has big benefits for your health — from encouraging weight loss to preventing chronic diseases. I hope you’ll start adding more of this important compound into your diet today!

Now I’d like to hear from you …

Have you noticed any ill-health effects from having a low fiber intake?

How much fiber do you think you currently eat every day?

What high-fiber foods do you enjoy?

What steps are you taking to get more fiber in your diet?

Please leave your thoughts by adding a comment below—but remember, we can’t offer personal medical advice online, so be sure to limit your comments to those about taking back our health!

To your good health,

Mark Hyman, MD


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Mark Hyman MD is the Medical Director at Cleveland Clinic’s Center for Functional Medicine, the Founder of The UltraWellness Center, and a ten-time #1 New York Times Bestselling author.

Comments (33)

  • I wish upon a star that I could eat this way. Radiation therapy has damaged my intestines. I do eat a low fiber diet now. I use to eat high in fiber before so I DO know what I am missing. If I do not want to stay in the house day after day and just live to use the bathroom I can’t afford to eat this way. But I have made this change to my life. I have this little part-time job that I do so the days I don’t work I am now trying to eat some vegetables to see what effects they will have on me. Sometimes it works now…sometimes it doesn’t work. I have a very low tolerance for fiber now. I know that my body is setting me up for more disease. I know. But…I do keep trying to eat well. I’m frustrated about this!

  • Very interesting! I just purchased glucomannan to use in cooking for thickening – perhaps I should try using it a la Sensa and sprinkle on my food as well, lol!

  • Hi, I am one of your 2013 beta testers. I am wondering if this is the same as pgx, or something to consider in addition. Also the bit about taking it 1-2 hours from medications, does that suggest I have been taking my other vitamins incorrectly witht the pgx (if they are the same product.) I am overall confused about the taking of the daily supplements. I do the advanced wellness pack from you all. let me know.

    • Hi Gail,

      This is the same as PGX. You can take your supplements with your meals. Take the PGX 15 minutes before.

      For more personalized nutrition advice, Dr Hyman’s nutrition coaching team would be happy to work with you on an individual level to help you reach your goals. To work with the nutrition coaching team please go to: OR call (800) 892-1443 to get started.

      In good health,
      The Nutrition Team

  • Hello Dr. Hyman,

    First of all, I want to thank you for all you do and all you are providing in the area of health related to DM, and other gut disorders. I know that you cannot offer specific health advice, but perhaps you can address the answers to my questions in the form of an article based on research. You mentioned not taking fiber near or at the same time as medications. I am wondering if the same is true for supplements. If people take supplements with their food at the same time as increasing the fiber, will the fiber absorb the nutrients from the supplements. Also, isn’t it really important to drink plenty of water when you increase fiber to help move it through and doesn’t drinking more water dilute the digestive juices, causing the body to work harder to replace them. It seems that all nutritional suggestions come with disclaimers and are varied depending on the person. Because so many people have Gluten intolerance and Celiac Disease, ( I am one of them) I would love to have you address this issue along with whatever other nutritional suggestions you are giving us. According to Dr. Wm Davis )(Wheat Belly) 60,000 people are walking around with this undiagnosed. Several advocates for banning GMO’s have shown in Rat studies that the pesticides used by Monsanto and related companies, are causing holes in the Rats intestines. Interesting that Celiac is on the rise and that is exactly what happens in our intestines. (Celiac=holes in small intestines, and Leaky Gut= holes in large intestines) All since the increase of GMO’S in our diet. This must be stopped, it is poisoning the food supply all over the world.
    Dr. Mercola is very vocal about this issue and I feel that if you and other Dr.s (like Dr. Oz, Dr. Sara Gottfried, etc. formed a panel of advocates for safe food and water, real progress could be made.
    Thank you for allowing me to share my ideas and passions with you.
    One more thing, about Vitamin P, I have a question. What about the worm and parasite issues
    with dogs and cats, they can also be the source of allergies.

    Thank you,
    Dianne McCown

    • Hi Diane,

      Thank you for your interest in Dr. Hyman’s work. We will share your ideas with him! Supplements do not need to be treated like medications regarding PGX. You can take them with your food.

      For more personalized nutrition advice, Dr Hyman’s nutrition coaching team would be happy to work with you on an individual level to help you reach your goals. To work with the nutrition coaching team please go to: OR call (800) 892-1443 to get started.

      In good health,
      The Nutrition Team

  • Most informative. I have questions:

    1. “Don’t take any medications within 1 hour before or 2 hours after taking ‘GM’ because the fiber may absorb the medication.”
    I am guessing that besides medications, a person should include supplements with this advisory, as well?

    2. I am fine all day, it is during the evening time that I am more likely to overeat. So, to prevent overeating in the evening after 6pm — during dinner and all night, what time should I take GM?
    Start with 1 capsule with at least one glass of water, 60 minutes before eating?
    What difference does it make whether a person takes GM 30 or 60 minutes before?
    Then to eat less during lunch and the afternoon to skip the mid-aft snack, start with 1 capsule with at least one glass of water, 60 minutes before lunch?

    3. When does the GM capsule start to swell? I am not good at swallowing. Is there anything I can coat the GM capsule with so it goes down my throat easily and quickly without interfering with its ability to swell up? And I am scared about it swelling in my throat. Maybe I should first drink half a glass of water, then swallow the GM capsule with a full glass of water?

    I am diabetic — low numbers. I believe that eating more fiber will help me feel full to eat less calories, then lose weight, then lose belly fat and maybe reverse my diabetes. That would be great!

    Thank you Dr. Hyman for all your informative e-mails.

    • Hi Kay,

      Thank you for your interest in Dr. Hyman’s The Blood Sugar Solution. Supplements do not need to be treated like the medication re: PGX timing. You can take your supplements with your meals.

      For more personalized nutrition advice, Dr Hyman’s nutrition coaching team would be happy to work with you on an individual level to help you reach your goals. To work with the nutrition coaching team please go to: OR call (800) 892-1443 to get started.

      In good health,
      The Nutrition Team

  • excellent submit, very informative. I’m wondering why the opposite specialists of this sector do not understand this. You must proceed your writing. I’m confident, you’ve a great readers’ base already!

  • I just tried to call your support line but am outside your working hours. I have questions that are very important. I take Seroquel, Janumet, Klonopin, and various other meds. Believe me when I say that I have tried NOT to be on Seroquel which causes weight gain. I recently lost 45 pounds being off of Seroquel but have found out that it is the ONLY medication that will work for me. My Psychiatrist had previously been treating me for depression and Panic Disorder. By process of elimination, he has figured out that I have co-existing disorders of Bipolar and Panic Disorder with Anxiety. Sounds fun doesn’t it.
    I need professional help that is very accurate re: how long to wait before and after taking Seroquel. On the information label, it states that Seroquel MUST be taken on an EMPTY stomach or with less than 300 calories. Because I need this medication, I can not waste a dose if it gets hidden in the GM. I’ve been on the Seroquel for a month and have gained 20 pounds back already. Unbelievable. My Primary Doctor keeps saying…..calories in/calories out. Not true. I have been on too many meds and gone through too many scenarios of severe hunger to Seroquel that changes my metabolism. I need help and hope you can give it to me. Thank you so much for listening to my rant. I know there are others who suffer like I do. Roxanne

  • “And the fiber is what helped those ancestors of ours stay healthy. Just take a look at all the good things that fiber can do for your body.”

    Dr. Mark, with all due respect, what were the average life spans of our ancestors? Also, most Africans eat so mich yam fiber because it is their staple, there is nothing else, and it is the tropics where people tend to eat less due to the heat and humidity. There bodies have fewer fat cells. that being said, westerners, on average do need more soluble fiber in their diets, but more importantly, many of us simply need to eat less.

  • Dr. Hyman. I have read that Quinoa should be avoided by people trying to heal leaky gut. Can you please clarify. Thank you.

  • Have you tried Arbonne’s new product, Full Control? It is made with GM and is a powder you mix with water, taken 1/2 hour before a meal.

  • Is there a school you would recommend for Functional Nutrition?
    How highly would you recommend Integrative Nutrition school?

  • Great information! But to be clear…insulin is not reduced by fiber for type one diabetics in fact it can require more. I am type one and one tablespoon of chia seeds requires a unit of insulin extra with good eaten with it.

  • what is the effect of mixing in GM with a protein shake? (presumably right before drinking).

    would that slow down the protein absorption, or would it prevent the protein from being absorbed?

    good/bad idea?

    • Hi Joda,
      Taking glucomannan with a protein shake will not affect the absorption of protein, and will help to increase your sense of fullness and balance your blood sugar.
      Wishing you the best of health,
      Dr. Hyman Staff

  • I saw that a french fiber capsule has 15 to 18 grams of fiber. Do we have any capsules that have that much fiber?


  • What about the amount of gas that would be produced by these type of food or fiber?
    I always have so much gas and that’s why extra amount of fiber or food like beans or some specific vegetable cause so much pain.

    • Hello Homa,
      When increasing the fiber in your diet, we recommend that you increase it gradually over time to allow your body to adapt to higher amounts of fiber. This will help minimize the gas.
      Wishing you the best of health,
      Dr. Hyman Staff

  • m

    “Studies show that the weight of food controls your appetite…” studies also show that an overstuffed stomach causes an insulin spike. Practice hara hachi bu and do not eat until you are bloated including fiber.

    “…you lose more calories through stool because GM soaks up all those extra calories!” and accompanying micro-nutrients. ANY fiber can do that.

    “Load up on legumes” legumes contain phytotoxins as do “Go with the grain.” Proper preparation is key and it is estimated that over 80% of the world’s population have sensitivities. Pound for pound, grains are not as nutritious as low carbohydrate vegetables nor as much as we have been told. You do not need them at all. You will get better overall nutrition and natural fiber from eating as many low carbohydrate vegetables as you want per day. The science is there.

  • Hi,

    This is great information, thank!

    I have psyllium husks, is it the same as PGX, can I use it for that? I have just started the 10 Day Detox and I am living in Switzerland. It is not easy to fing PGX here.

    I’d be veryy happy if you can let me know if I can use psyllium instead of PGX, how much and how?


    • Hello Ceylan,
      Psyllium seed or flax seed are alternative forms of soluble fiber that are beneficial for filling you up and lowering the glycemic index of your meal. If you choose to take psyllium husk, I’d start with 1/2 teaspoon in water before each meal and then increase to up to 2 teaspoons as tolerated.
      Wishing you the best of health,
      Dr. Hyman Staff

  • I found this article very interesting. I suffer from multiple auto-immune disorders and healing the gut has been a focus for quite some time now. I do not have an issue with being overweight. Is GM still a suitable product for those who are trying to add more fiber but are thin? Furthermore, I’m more inclined to under eat, rather than over indulge.


    • Hi Martha,
      Since you are not overweight and tend to under eat, it would be better for you to include a variety of fiber-rich foods in your diet than to take a fiber supplement prior to your meals. This way you will have plenty of room for nutritious foods to support your health.
      Wishing you the best of health,
      Dr. Hyman Staff

  • I find precious little guidance for one that is definitely not overweight (5’8″; 125#) but has type II diabetes. Have to fight to keep AlC below 7.0. I eat lots of veggies, little red meat, limit my fruit to berries…. and limit my carbs generally to low glycemic load foods. 2,000 mg metformin/day. I know you can’t be specific to my needs, but general help to type II diabetics who are not overweight would help. Thanks. Allen