The Effect Of Diet On Body Composition

Dr. Peter J. Lord

One of the concepts we continually teach at HealthQuest is the power of diet and exercise, when approached in a consistent, science based, and systematic program. For the most part, the consumption of carbohydrates and proteins in the right amount and type, will dictate how your body will respond and determine it's composition. More importantly, since all carbohydrates are not created equal, the type of carbohydrates we ingest has a more than substantial effect on our results.

First let's cover the concept of protein. Since many of the hormones we produce, including growth hormone, DHEA and testosterone are myogenic (muscle building) hormones, the importance of plenty of good quality protein is simply to supply these hormone levels with the building blocks they need to improve our muscle size and strength. This is not only for body builders and fitness folks like yourself in the realm of skeletal muscle, but it also takes place in the MYOCARDIUM to make it STRONGER and INCREASE THE VOLUME OF BLOOD PUMPED with each heart beat (stroke volume). Increased stroke volume increases our cardiac output without changing our heart rate. Our rate is determined by our oxygen needs and the efficiency of the heart. As our heart becomes more efficient, by increasing it's stroke volume, our heart rate will be lower, given the same level of exercise. This is the same process that takes place in a well-trained athlete - a slower heart rate both at rest and with exercise.

Furthermore, as our muscle mass increases, our body composition changes in that the ratio of muscle to fat goes up. This increases the number of calories we consume with activity and at rest, and therefore adds further to helping keep body fat down. Keeping body fat down decreases our risk of certain cardiovascular and pulmonary diseases. Needless to say, we also LOOK AND FEEL BETTER, WITH ADDED STRENGTH, ENERGY, AND SELF-CONFIDENCE. This is part of what contributes to the feeling of well-being.

The effect on our health of the carbohydrates we ingest is a little more complicated, but I believe even more important. Here we have the opportunities to literally manipulate not only hormone levels, but also our level of body fat, minute to minute energy, and the robustness of our immune function. The carbohydrates in our diet provide us with an immediate source of energy, much like gasoline for an automobile. All carbohydrates are ultimately broken down in the digestive system and absorbed as sugars, primarily glucose. After glucose is absorbed from the intestine, it travels in the bloodstream and is available for cellular uptake. Our cells take up glucose from the blood and burn it as fuel or energy. Cells cannot do this without the help of a hormone called insulin.

Insulin is a polypeptide hormone secreted by the pancreas, a digestive organ lying beneath the stomach. Insulin attaches to receptor sites in our cells and opens the gates to allow glucose to flow from the bloodstream into the cell. Without insulin, we could not live. However, although we need steady supplies of glucose and insulin for normal cellular function, WE FUNCTION BEST AND AGE MORE SLOWLY IF THESE STEADY SUPPLIES REMAIN AT VERY LOW LEVELS.

High levels of glucose and insulin are associated with diabetes and other diseases such as peripheral vascular disease, coronary artery disease, retinopathy (a type of blindness), kidney disease, obesity, and strokes. Why? Glucose in the bloodstream has a propensity to attach itself to protein molecules. Proteins carry out ninety-five percent of the biological processes in our cells. The attachment of glucose to these proteins is a process called glycation. Glycation of proteins is detrimental to protein function because glucose, just like molasses, is sticky. So when this sticky glucose attaches to our proteins, it causes the protein strands to stick together in odd shapes, a process called cross-linking. Cross-linking of proteins causes protein dysfunction because these molecules need to be sleek and slippery to pass by each other frequently in order to perform their intended function. When glycated, these proteins become much like a football team whose players have their legs all glued together. This protein dysfunction, within the cell, causes cellular dysfunction and leads to premature aging. This is a very slow process that takes it toll over decades but ultimately makes a dramatic difference in our quality of life and can actually subtract 10 to 15 years from our life span. The higher our blood sugar is, the more glycation takes place.

IT IS IN OUR BEST INTEREST TO CHOOSE OUR CARBOHYDRATES WISELY. The key to choosing the right carbohydrates can be determined by using what is called the glycemic index. The glycemic index refers to the speed with which carbohydrates are digested and absorbed into our blood stream as glucose. The speed at which sugar goes through this process is arbitrarily given the number 100. Sugar is one of the fastest digested and absorbed carbohydrates. All other carbohydrates are then measured in this capacity and assigned a number relative to sugar. Therefore, the higher the glycemic index of a particular carbohydrate, the closer it is to sugar and the less healthy it is to eat.

FORTUNATELY, THOSE CARBOHYDRATES THAT ARE NUTRIENT DENSE IN VITAMINS, MINERALS, AND ANTI-OXIDANTS ARE ALSO THE LOWER GLYCEMIC INDEX CARBOHYDRATES. By eating only the lower glycemic index carbohydrates, we insure ourselves of getting more vitamins, minerals, and anti-oxidants, but more importantly, keeping glucose and insulin levels low.

Another physiologic aspect of insulin that is highly important is its propensity to store and lock up body fat. Insulin earned its place in human physiology through evolution, just like all other physiologic and anatomical characteristics of any organism. Insulin's job through evolution was to get us through times of famine and it did this job very nicely. Insulin succeeded in this role by having a unique ability to store and lock up body fat.

Insulin is extremely efficient in moving sugar from the bloodstream into the fat cell, where it is immediately converted into fat and stored for a time when the hunting was slow and the food supply was low. Insulin also functions to block the oxidation (breakdown) of fat, in a constant effort to keep it in storage. Since the oxidation of fat is actually a calorie burning process, we actually consume calories in burning our own body fat (a doubly wonderful scenario), which insulin does its best to prevent!

IN THE PRESENCE OF HIGH INSULIN LEVELS, BODY FAT IS UNAVAILABLE for oxidation and we not only miss the opportunity to break it down, but fail to burn those calories that would normally be consumed in this oxidative breakdown. High insulin levels, therefore, not only prevent us from using our own body fat, but prevent us from burning the calories that it takes to use that body fat. This becomes extremely important in how we feel, hour-to-hour, during the day. In the presence of high insulin levels, sugar is rapidly taken into the fat cell and the level of sugar left in the blood drops. This combination of high insulin and low blood sugar makes us immediately very tired and hungry. You may have found this to happen to you an hour or so after a heavy meal that included bread, pasta, potatoes, or sweets. Normally, the presence of low insulin levels, a drop of blood sugar would not do this.

When insulin is low, fat is oxidized into free fatty acids, which are delivered into the blood stream to supply our cells with energy. We remain satisfied and alert. When insulin levels are high, however, lipolysis (fat breakdown) is blocked and no free fatty acids are available for our hungry and tired cells. The result is hunger and fatigue, which frequently leads to ingesting more high glycemic carbs, and the vicious cycle of widely fluctuating sugar levels and persistent high levels of insulin. We spend the day in what Dr. Barry Sears calls "carbohydrate hell", with fatigue, frequent hunger, and mood swings. On the other hand, EATING A BALANCED DIET WITH LOW GLYCEMIC CARBS ALLOWS US TO OXIDIZE BODY FAT ALL DAY, GIVING US BOUNDLESS ENERGY, KEEPING US FREE OF HUNGER, AND EVEN-TEMPERED.

Still want to eat sweets and starches? It gets worse. The cells of our body have a given sensitivity to insulin. This sensitivity determines how much insulin is required to open up the gates of our cells and allow sugar to pass from the blood into the cell. In some of us, the cells are very sensitive and only a small amount of insulin is required. In others, a phenomenon called insulin resistance takes place, requiring a truckload of insulin to induce the same response.

Insulin resistance results from three main factors. One is our genetic makeup, about which we can do nothing. The second is the amount of insulin to which the cells are accustomed to being exposed. Constant high levels of insulin cause the cells to get "numb" at the receptor site and they begin to ignore the insulin, requiring higher levels of insulin to open the glucose gates. The third is body fat. The more body fat we carry, the more resistant our cells are to insulin. As we increase our insulin resistance, our pancreas is happy to oblige us by secreting more and more insulin. As our insulin levels go higher, it causes us to build and store more body fat, causing further insulin resistance, and the vicious cycle ensues. Fat begets insulin and insulin begets fat. The result is frequently the onset of Type II diabetes. Eventually the cells are so resistant to insulin that medication is required. A vicious cycle has been created.

What can we possibly do to break this cycle? ELIMINATE HIGH GLYCEMIC CARBOHYDRATES FROM THE DIET AND EXERCISE. Sugar levels stay low, and with low sugar levels come low insulin levels. With low insulin levels comes the oxidation of fat and resulting loss of body fat. With this loss of body fat our cells become more sensitive to insulin and we need less. Our pancreas then secretes less, allowing us to oxidize more body fat, and now the vicious cycle has turned the other way!

Therefore, we see two very profound ways of manipulating this system to our advantage. One is to exercise regularly and the other is to limit our carbohydrate intake to those which are of low glycemic index. Since the list of carbohydrates that are of low glycemic index is nearly endless, it is much easier to list those that are of high glycemic index, which fortunately is very short. They are to be avoided to the extent possible.

Carbohydrates to be avoided:
1) Sweets - This includes all sweets, i.e., sugar, molasses, honey, corn syrup, candy of all kinds, etc. Note that this includes many sweets that are marketed as "healthy", such as low fat and non-fat cookies, which generally have extra sugar added to compensate for the reduced fat. Be wary of health bars such as 40/30/30 Bar, etc..., because they generally contain substantial amounts of sugar.

2) Refined Carbohydrate Snack Foods - Rice cakes, pretzels, crackers, and baked goods, including muffins and cakes.

3) Starches - Bread, bagels, rice, potatoes (Exception: it's an oxymoron, but sweet potatoes are low glycemic), pasta, and breakfast cereals (with the exception of rolled oats that you must cook from scratch, and All Bran). Whole grain bread, rice and pasta, although somewhat better than the white flour varieties, are still not very good and are better avoided if possible.

4) Certain Vegetables - Corn and raw carrots. Cooked carrots are somewhat better because much of the sugar is extracted by the hot water.

5) Certain Fruits - Bananas, watermelon, mangos, raisins and other dried fruits (except apricots, which are very low in sugar), and pineapple.

6) Alcohol - Alcohol is metabolized in our bodies more as a fat than a carbohydrate, although it is a combination of the two. Alcohol, therefore, does not have a high glycemic index. However, alcohol mixed with any sweet drink will be extremely high in its glycemic index. Therefore, mixed drinks should be taken only with water or club soda. Beer is particularly high in its glycemic index because it contains the sugar maltose, which is absorbed even faster than table sugar. The healthiest alcoholic beverage is dry, red or white wine, such as Cabernet, Merlot, Chardonnay, and others. If the wine tastes sweet, you can be sure it is high glycemic index. Finally, any alcohol consumption should be limited to two drinks per day.

Bullets to Better Eating:

Base your meals on a lean protein (fish, chicken, lean meat). Even eggs are good, occasionally.

Try to eliminate breads, grains, and processed foods. Choices like these elevate blood insulin levels above optional levels.

Supplement your diet with natural foods. Fruits, nuts, berries, and vegetables make excellent snacks. Grapefruit especially.

Drink lots and lots of water. Sodas, carbonated beverages, and fruit juices can also lead to elevated insulin levels.

Armed with this knowledge, one begins to see how diet and exercise is such an effective science. Since insulin (the fat builder) competes with growth hormone and androgens (the fat oxidizers), keeping glucose and insulin levels low allows our hormones free access to our fat stores so they can accomplish their tasks unimpeded. It virtually doubles their effectiveness. Exercise not only lowers glucose and insulin levels, but also burns calories, resulting in the oxidation of more fat.

The last important effect to mention is the negative effect of glucose on our immune system. Clinical studies show that ingestion of high glycemic carbohydrates and rapid rise in blood sugar cause an immediate and direct negative effect on our cellular immunity. This, of course, increases our risk of infections and cancer in that the immune system is our front line of defense against these diseases.

In summary, we can enhance our quality of life and possibly our longevity by keeping our glucose and insulin levels low. All it takes is regular exercise and an intelligent diet, relatively high in protein and restricted to nutrient dense, low glycemic index carbohydrates, such as fruits and vegetables. The health implications are profound. For those of you who would like more details on this subject, four good sources are Sugarbusters!, by H. Leighton Steward, et al., Protein Power, by Michael and Mary Eades, The Glycemic Index, by Dr. Ann de Wees Allen, Syndrome X, by Jack Challem, The Perricone Prescription, by Nicholas Perricone, M.D.

As always if you have any questions or comments, or would like us to do some research for you, we are open for suggestions. Please email us with your request or if you would like to join our newsletter.