The Prohibited Fruit… Or Is It?

By Xavier Fox

There have been numerous occasions when the subject of fruit has come up in conversations about dieting. The focus quickly turns to the fact that fruit contains a form of sugar known as fructose that readily converts to fat, and whether eating fruit is a good idea for those wanting to lose those extra pounds. Well, fruit has many nutritional benefits and eating fruit can never be considered “bad.” However, depending on your physique goals, there may be times when you want to eliminate fruit from your diet for a temporary period.
Fruit contains many vital nutrients such as fibre, vitamins, minerals and antioxidants. If you are taking the time to exercise and watch what you eat, it is obvious that you are concerned for your health and your physical appearance. The nutrients that you put into your body play an important role in the ability of your body to stay healthy, produce energy, lose fat, get rid of waste products and recuperate from exercise. Consuming fruit on a daily basis can help you achieve all of your fitness goals as well as build a foundation for a long and healthy life.
Probably the most important reason for people that work out to consume fruit is that it contains antioxidants, and these antioxidants are vital in combating free radicals. The atoms in our bodies search to maintain stability and those atoms that are bonded to each other by sharing an electron are normally stable. However, sometimes the bonds are weak and an electron is lost… now there is an atom or molecule floating around that is missing an electron in its outer shell and it becomes unstable and in search of another electron. This is a free radical. Well, guess what happens? The new free radical steals an electron so that it can become stable, then the free radical it created does the same thing, and the chain reaction continues. This continual creation of free radicals can end up disrupting the behaviour of the entire cell, because they steal electrons from the nucleic acids, proteins, or enzymes. The cell itself cannot stabilize due to all of the free radical commotion that is going on inside of it.

This series of events happens quite often in the mitochondria and the DNA. The mitochondria are the main suppliers for energy in the system, so if their structure is altered they will no longer be able to be an effective energy source. Chronic fatigue and fibromyalgia will result if this process is permitted to maintain itself. If the DNA is altered and not functioning the way it should, then the body cannot carry the genetic information necessary for cell functions, including making the proteins needed for cell maintenance and repair. If your system cannot properly produce proteins, then you will not be able to effectively repair and grow muscle tissue. That adds up to a lot of wasted time in the gym.
Fortunately for us, fruit contains a large amount of antioxidants that are always willing to act as sacrificial lambs. Antioxidants are compounds that have the ability to donate an electron from their outer shell without becoming unstable. This enables them to neutralize free radicals and stop the potential chain reaction of free radical production, which can lead to cell damage. Keeping fruit in your diet will help you recover from intense workouts much more efficiently, which means that you will realize your gains much faster and to a larger degree.
Another important nutrient found in fruit is fibre. Fibre is a carbohydrate that is indigestible in your system. Fibre does not have any calories. Fibre’s main function is to move waste through your intestines rapidly, and most people describe it as “cleaning you out.” There are two classifications of fibre; it can come in “insoluble” or “water-soluble” form.
Insoluble fibre will move bulk through your intestines quickly as well as help maintain the balance of the acidity in your intestines. By moving bulk through you it helps to remove the toxins from your intestines. However, the fact that insoluble fibre keeps the acidity balanced in your intestines allows it to prevent the microbes in your intestines from developing cancerous matter. Eating fruit will help prevent the development of colon cancer as you age.
Soluble fibre’s main function is to bind with fatty acids. This important property keeps the ratio of LDL cholesterol (also known as “bad cholesterol”) to total cholesterol levels very low. The result is a much lower risk of clogged arteries and heart disease. Soluble fibre will also extend the time it takes for food to empty from the stomach, which causes sugars to be absorbed and released more slowly. By slowing this process, insulin levels will not spike after eating and create a situation where fat is stored more readily and blood sugar levels are bouncing all over the place. Apples and oranges are a good source of soluble fibre.
Another good thing about fibre is that it is much denser than other foods. Therefore, you can eat a lesser amount of a fibre rich food and it will make you feel as full as a larger amount of non-fibre food. This will cause you to eat less and thus consume fewer calories and this could help you lose more fat over time. Although you lift weights and exercise to look your best you should also stay concerned about your long-term health. Eliminating fruit completely may help you burn some fat a little quicker, but that won’t do you much good if you die 20 years before you were supposed to because you did not include fibre in your diet. You should try to get at least 25-30 grams of fibre in your diet each day, and you can do this by making fruit a part of your regular diet.
Now we will cover the topic of sugars and how our body uses them. This will give us a better understanding of how fruit affects us and why some people recommend staying away from them. When we ingest a carbohydrate our body must break it down into a single unit of sugar in order for it to be absorbed. These units are known as monosaccharides, which come in the form of glucose, galactose and fructose. Once broken down and absorbed via the small intestine and liver, the broken down sugars will circulate into the bloodstream in the form of glucose.
Once glucose is circulating in our blood there are a few things that can happen. If we are lucky, the glucose will immediately be used as a source of energy. If it is not required for instant energy, the body will convert it to glycogen where it will be stored in either the liver or the muscles, depending on how the body needs it. Muscle glycogen fuels only the muscles while liver glycogen fuels the rest of the body for its everyday functions. The liver is able to store up to 100 grams of glycogen whereas the muscles can store anywhere from 250-400 grams of glycogen depending on the amount of muscle mass the individual carries. Finally, if there is too much glucose in the system and the glycogen stores are already full, the excess glucose gets stored as fat by the liver and adipose tissue (body fat) everywhere else. Although carbohydrates are necessary for overall health and building muscle, this is why too many will cause you to gain unwanted fat.
Fruit contains the sugar known as fructose. Unfortunately for us, our bodies are designed in such a way that our muscles only contain enzymes that convert glucose into glycogen. However, our livers are able to manufacture glycogen from fructose, lactate, glycerol and a few other metabolites. Muscle glycogen, which is similar in structure to starch, is what is known as an amylopectin (branched chained polymer containing hundreds of glucose units). Muscles can only supply energy to themselves from the stored 250-400 grams of glycogen but the liver is responsible for supplying energy to the rest of the body.
Do not worry… I am getting to the point. In the event that blood glucose levels are where they should be, which is safe to assume, because we all know that BodyFitness readers are very disciplined and follow a proper diet, then any more fructose sugars that are ingested will be stored as glycogen in the liver. It does not take much fructose to allow the liver to reach its limit of glycogen (about 24 ounces of orange juice). Once the limit is reached, the body signals itself that all glycogen stores are full and the excess fructose is immediately stored as fat, either in the form of fatty acids or as adipose tissue. Since the liver does not store as much glycogen as the muscles do, it is easy to see why fructose can readily be converted into fat.
The question often comes up concerning the fact that fruit is low on the glycemic index, and low glycemic carbohydrates are supposed to be superior, so how can low glycemic fruit be bad? The reason that fruit is low on the glycemic index is that it is converted as fat in the liver (once liver glycogen levels are maximized), so it is released into the blood stream as fat and not sugar. Therefore, insulin levels are not spiked due to a rapid absorption of sugar. Even though fructose is low on the glycemic level it can be deceptively more fattening than high glycemic sugars.
So, should you eat fruit or not? The nutritional benefits of fruit far outweigh the fact that fructose can convert to fat if your liver glycogen levels are too high. Fructose is like everything else, if you consume it in moderation and eat small amounts every day then the benefit of the vitamins, minerals, fibre and antioxidants are far more important than the fact that you may have a small amount of fatty acids stored in your body. The only time you may wish to restrict fruit in your diet is during contest diet time, but you should be sure to eat fibrous vegetables as well as take supplements with multivitamins and antioxidants. Fruit is also a great way to stop those late night sugar cravings. A piece of fruit after dinner, or an hour before bedtime, will keep you from wanting to run to the corner shop for ice cream or chocolate.
Feel free to enjoy the various delicious fruits as part of your daily diet and still keep your body looking fit. Fruit will help you combat fatigue, muscle loss, damage caused by free radicals and excessive LDL cholesterol levels. You do not have to worry that if you eat a pear you will end up being built like one.

Here are some examples of common fruit vitamin contents

Fruit (100 grams)	A IU	C mg	B1 mg	B2 mg	B6 mg	E IU
Apple	2	15	0.02	0.01	0.05	0.5
Banana	3	10	0.04	0.03	0.36	0.3
Grapefruit	0	40	0.07	0.02	0.03	0.5
Kiwi	5	70	0.01	0.02	0.12	1.9
Orange	2	49	0.07	0.03	0.06	0.1
Pear	15	7	0.01	0.02	0.02	0
Peach	0	4	0.01	0.01	0.02	0.1
Strawberry	10	60	0.02	0.03	0.06	0.4
Tomato	140	15	0.05	0.02	0.08	0.7