Fibre

By Xavier Fox

Since BodyFitness readers are very health conscious, it is safe to assume that you spend a lot of time at the grocery store checking the labels of the food products that you buy. How many times have you noticed that the nutrition labels list the amount of carbohydrates, and then they list fibre as a sub-category of the carbohydrates? We all know that we are supposed to get some amount of fibre in our diet, but what exactly is the nutritional label trying to tell us? If a food has 15 grams of carbohydrate per serving, and 10 grams of that carbohydrate are fibrous, what should we interpret from that, being that we are trying to add muscle and burn fat?
As fibre is a type of carbohydrate that means that it is found in plant food sources. By eating proper proportions of fruits, vegetables, grains and legumes on a daily basis you are certain to get the amount of fibre that your body requires. Most dieticians will tell you to consume about 20-30 grams of fibre each day. The average person normally eats about half that much. Although fibre is a carbohydrate, it has a different effect on your body than the typical carbohydrate sources that are used to provide energy for the intense workouts that you have in the gym.

Fibrous carbohydrates do not get digested, and therefore are not used as an energy source. Fibre is the rough plant matter that is made mostly of polysaccharides, and it stimulates the digestive system to contract the muscles and move food through the intestines. If the food that you choose to eat has 20 grams of carbohydrates per serving, and it also has 8 grams of fibre per serving, then your body will actually only be able to use 12 grams of carbohydrate (20 – 8 =12) to produce glycogen. There are both advantages and disadvantages to this. Fibre has a lot of positive health benefits such as lowering the risk of heart disease and certain cancers, improving cholesterol profiles, lowering blood pressure and controlling blood sugar levels. But, since the fibrous carbohydrates will not be converted into energy, you must be aware that you consume enough of the food source to provide you with the fuel for those gruelling training sessions. And, not only will certain forms of fibre not provide energy, they will go right through your system, and you will not get the calories that the fibrous portion of the food contains.
For example, a guy at our gym was dieting for a bodybuilding show, and for some reason he decided to consume green beans as his only carbohydrate source. I assume he was thinking that he would be able to eat a lot of food and get full without taking in a ton of calories, since three-quarters of a cup of green beans only has 25 calories. Now, the reason I know he was doing this is because after dieting for a couple of months he couldn’t figure out why he felt tired all of the time and looked flat, so he approached me to see if I had any suggestions. Well, after he told me what he was eating, the answer became obvious. Sixty percent of the carbohydrates in green beans are fibre, so he basically was getting hardly any usable carbohydrates from his meals. He had calculated the correct amount of calories he needed from his carbohydrate source, but he was actually only able to use 40% of the carbohydrates as calories and an energy source. Therefore, he was not getting enough to sustain energy and keep the muscles full of glycogen and water. In addition, the lack of carbohydrate calories made his diet too restrictive, and his body broke down muscle to create an energy source. We made some small modifications to his diet so that he could eat the same amount of calories and get the carbohydrates he needed for energy, and he still consumed some fibre. The point is this: you need to account for the fibre that you consume, so that you still get enough carbohydrates to provide the energy that you need.
There are two types of fibre, and both of them play important roles in keeping us healthy. The two types are water-soluble fibre, and water-insoluble fibre. Examples of water-soluble fibre are gums, pectin and mucilage. Oat bran, dried beans, peas, some nuts, barley, flaxseeds, oranges, apples, carrots, and psyllium husks are all good sources of water-soluble fibre. Cellulose, hemicelluloses and lignin are forms of insoluble fibres. Green beans, dark green leafy vegetables, fruit skins, root vegetable skins, whole-wheat products, wheat bran, oat bran, corn bran, and some seeds and nuts contain insoluble fibre.
Water-soluble fibre gets its name, because it dissolves in water (surprise!). It can be found in oat bran, legumes, psyllium, nuts, beans, pectin, and various fruits and vegetables. When this type of fibre combines with water, it forms a gel-like substance in the intestine, and it will manage the flow of waste through the digestive tract. Water-soluble fibre also binds with bile acids and transports them out of the body, and this causes cholesterol levels to lower, because bile acid is manufactured from cholesterol. Therefore, when the water-soluble fibre binds with the bile acids, the liver is forced to gather more cholesterol out of the blood to produce more bile acids.
Psyllium is a type of water-soluble fibre that is believed to reduce the risk of coronary heart disease. It is very effective at lowering cholesterol, because it has tremendous ability to combine with bile acids and reach comparatively large volumes. This way, it can remove much larger amounts of cholesterol from the body than most other types of fibres can. It has been shown to be eight times more effective than oat bran at removing cholesterol.
Insoluble fibre is, just as its name says, not soluble in water. This means that we do not have the ability to digest it. It is mainly found in cereals, bran and vegetables. As my grandmother used to say, “It keeps you regular”. In other words, it collects water as it travels through the intestines, and it moves waste through the system so that you have bowel movements. This is always a fun subject to bring up during dinner at family get-togethers. By moving toxic waste materials through the intestines, insoluble fibre will reduce the risk of colon cancer and other problems. It also balances the acidity in your intestines.
Well, you are probably wondering why fibre is so freaking wonderful. First of all, as we mentioned above, insoluble fibre collects water and moves materials through the intestine. This makes it kind of like a pipe cleaner. As the bulky mass binds together and moves, it pushes materials forward and out of the intestine. This includes the materials along the walls of the intestines. Therefore, the intestines are kept “clean” and are able to digest more nutrients, since there is nothing blocking the nutrients from being absorbed. If you are able to absorb more protein and high-quality carbohydrates, you will be able to gain more lean muscle mass. That sure is better than a stick in the eye.
Fibre does not only bind to bile acids, it also binds to fatty acids. This means that a lot of that saturated fat is being removed from your body by fibre. For those of you that consume red meat and yogurt to help you get bulked up, it is obvious that this will help keep those abdominals looking tight. It will also keep your risk of heart diseases minimized. When there is less fat circulating through your system, your body will remain in more of an anabolic state. So, the increased ability to stay lean, build muscle and live a longer life is a side effect of eating proper amounts of fibre. Which characteristic is most important? Well, that depends on how hard-core you are.
In many past articles concerning carbohydrates, you probably remember BodyFitness explaining the importance of consuming low-glycemic carbohydrate sources. Water-soluble fibre slows down the digestion of carbohydrates, then providing energy at a slower and steadier pace. Even a carbohydrate that is typically a high-glycemic carbohydrate can act more like a low-glycemic carbohydrate if the right type and amount of fibre is present when it is being consumed. Therefore, the carbohydrates that you consumed will not only provide fuel for longer periods, they will keep your blood sugar levels from rapidly increasing and forcing your body to spike its insulin production.
When you consume high-glycemic carbohydrates that cause your insulin levels to elevate rapidly, your liver will begin to produce triglycerides that end up being stored as fat. Too much insulin can also cause high blood pressure and water retention. If insulin spikes become a regular occurrence, it is possible that you can become a Type 2 diabetic, or even become hypoglycaemic. The reason this happens is because when high glycemic carbs are ingested on a consistent basis, the body releases high levels of insulin. As more and more insulin is released, the cells become resistant to it as a protective mechanism, because they do not want to become overloaded with insulin. Well, as the cells reduce the number of receptors, less insulin gets in them, and this reaction fools the body into thinking it is not getting enough insulin. It does exactly the opposite of what it needs to do: it produces even more insulin. The cells in the liver become resistant first, then the muscles, and finally the fat cells. As the body is bombarded with insulin, the cells continue to lower the amount of receptors. However, soon the pancreas must lower the amount of insulin it produces, and now the cells have shut down most of their receptors. Thus, a large amount of insulin receptors are shut down and the pancreas is not producing insulin at required levels, then blood sugar levels skyrocket, and the person becomes a Type 2 diabetic. Eating fibre will help keep the effective glycemic levels of foods lower, so that carbohydrates are digested more slowly. Sweet potatoes, red potatoes, peas, pears, black beans and oatmeal are good choices. You may also want to use a psyllium supplement to slow down the absorption of carbohydrates into the blood.
Foods with fibre help keep you from overeating. The fact that fibre binds to water and other substances is good, because all of the food and water bound together will make you feel full. However, that is not the only reason that fibre makes you feel full. The presence of fibre makes your body release a hormone called cholecystokinin that sends a signal to your brain that you are full. Green vegetables are very adept at performing this function. Many green vegetables contain insoluble fibre, so you can consume a large amount without getting punished with calories. For example, if you eat three cups of broccoli, you will only absorb 75 calories. That is a lot of bulk sitting in your stomach that does not contribute many calories. Having fibrous carbohydrates during each meal will help keep your appetite under control.
Cabbage, broccoli, cauliflower and spinach include compounds called indoles that are proven to reduce oestrogen levels in men. Oestrogen is the antithesis of testosterone, and too much will inhibit muscle production, increase fat storage and make you retain water. Eat fibre in order to keep oestrogen levels low. This will help you keep your skin thin and it will also keep water from sitting underneath it. That will make you look harder and fitter.
The only time that you should avoid fibre is directly following your workout. You want the carbohydrates that you consume immediately following your training session to get into your system quickly and replenish glycogen stores in order to optimise muscle recovery and growth. This is also the only time that it is recommended you consume higher glycemic carbohydrates. White rice and white potatoes are good sources of post-workout carbohydrates.
In order to increase the amount of fibre you consume, eat whole fruits instead of drinking fruit juices, eliminate processed carbohydrates (white rice, breads, and pastas) and eat brown rice, whole-grain products and whole-grain cereals. Eat raw vegetables instead of potato chips, crackers, or other types of fried snacks. Add whole grains and legumes to your meals, or put them in salads. Doing so will keep your blood sugar down, lessen your risk of certain cancers, lower oestrogen levels in men, help you maintain a healthy colon and help you increase your ability to digest protein and carbohydrates so you can maximize muscle and minimize fat.