The following is a guest blog posting that I did for the PeerTrainer blog. Thank you for the opportunity PeerTrainer! In case you didn't catch the early showing, here it is . . .
When I started to blog a year ago about my weight loss a few friends of mine who I haven't seen or talked to since long before high school graduation got wind (no pun intended) of what I was doing. They were very supportive, interested and inspired by how I had lost weight. So they too started to incorporate a lot more vegetables, fruits and beans into their diets (a la Eat to Live, Volumetrics, Prevent and Reverse Heart Disease, The Peer Trainer Cheat System and The Engine 2 Diet . . . talk about a fusion!).
Immediately, reports of digestive changes started to roll in. Let's just say their systems started to work a lot better. They weren't used to that with the Standard American Diet. But I wasn't sure if they were comfortable with the changes in their body brought about by their increase in fiber.
The amount of dietary fiber in the average North American diet is really very low. It ranges from about 9-18 grams of dietary fiber per day. This diet is however, very high in fat and processed foods that have been depleted of much of their original fiber and nutrients. As a result, we consume about 80% less of the fiber our ancestors consumed just 100 years ago. Current recommendations from the United States National Academy of Sciences, Institute of Medicine suggest that adults should consume 20–35 grams of dietary fiber per day. But I would hardly consider those recommendations a "high-fiber diet."
The benefits of a high fiber diet are so well known that they hardly bear repeating here. But just in case you are not on the up and up about fiber, just do a Google search for "benefits of a high fiber diet" and read until your eyes glaze over! Fiber is amazing.
A few weeks ago I posted a YouTube video of Dr. Lustig about the science of sugar. It was awesome. It made me think long and hard about my sugar habit. One of the most fascinating things that came out of Dr. Lustig's mouth was the following comment, which I memorized (it wasn't too hard) and can frequently be heard repeating:
"Fart or be fat."
Immediately, I thought of my old friends and how they had reacted to their change to a high fiber diet. They kind of acted like flatulence and bowel movements were weird. And even I thought flatulence was bad, a signal that you've overdone something or that a certain food doesn't agree with you. That same Google search on "benefits of a high fiber diet" will also yield you endless results on how to tame the gassy monster. So gas must be a bad thing, right?
Well, not so fast. What if what Dr. Lustig said was true, and what does "fart or be fat" really mean? What if it means "if you are not farting, you are not eating enough fiber" (you can quote ME on that!)? Maybe that's the angle we should be looking at this from.
What Is Dietary Fiber?
Dietary fiber is found in the structural components of plants and cannot be digested by humans in the small intestine. Because it passes through the small intestine undigested, and then into the large intestine, it is not used for energy, but plays an important role in digestion and disease prevention.
Dietary fiber is divided into two categories, soluble fiber and insoluble fiber. Most foods that contain fiber have a mixture of the two types. "When mixed with liquid, soluble fiber forms a gel,” says Lanah J. Brennan, RD, a dietitian in Lafayette, La. “In your digestive tract, this gel helps to keep you feeling full and slows down digestion. Insoluble fiber does not form a gel. Instead, it passes through the intestinal tract intact, keeping things in motion."
Soluble fiber comes mainly from the insides of fruits and vegetables. Insoluble fiber comes from the skins of fruits and vegetables, and from whole grains, nuts, and seeds.
Why does fiber consumption cause flatulence?
Your body does not digest and absorb fiber in the small intestine because of a shortage or absence of certain enzymes there. So this undigested food then passes from the small intestine into the large intestine, where normal, harmless bacteria break down the food, producing hydrogen, carbon dioxide, and, in about a third of all people, methane. Eventually these gases exit through the rectum.
Everyone has intestinal gas and that is a good thing. The normal amount of flatus passed each day depends on whether you are male or female (men fart more) and what is eaten. Foods that can cause flatulence (gas) in some people may not produce flatulence in others. It all depends on the amount and type of bacteria each person has in the large intestine. Some types of fiber are digested to a greater extent by colonic bacteria than other types of fiber. The better-digested fiber produces more gas.
"All fibers, no matter their source, can cause flatulence; however, since bacteria vary in their ability to digest different types of fiber, different sources of fiber may produce different amounts of gas. To complicate the situation, the ability of bacteria to digest one type of fiber can vary from individual to individual. This makes the selection of the best type of fiber for each individual (i.e., a fiber that improves the quality of the stool without causing flatulence) more difficult. The choice becomes a matter of trial and error." Dr. Jay W. Marks
Fiber alone contains no calories, and it provides the bulk to your diet that gives you the satisfaction of chewing. Fiber gives us the feeling of a full stomach sooner and stays in our stomach longer than other substances we eat, slowing down our rate of digestion and keeping us feeling full longer. Foods with fiber are satisfying so you don't feel hungry between meals. Click here to see the fiber content of a large variety of foods.
Be sure to drink plenty of fluids when adding fiber to your diet. While fiber is normally helpful to your digestive system, without adequate fluids it can cause constipation instead of helping to eliminate it.
What's the moral of the story?
Don't fear the fiber! And if it does cause flatulence, embrace it. Like Martha Stewart says, "It's a good thing!"
For the truth about whole grains and their relationship to a high fiber diet, catch this phenomenal post from The Sweet Beet.