The Scientifically Proven Approach to Nutrition

by Jeffrey R. Stout, from

The millions that view flab as the most disgusting ingredient of human flesh have, for years, waged war against its presence. Yet, through all their clashes, fat has emerged victorious a dreadful number of times, only to foster the same frustration that ignited so many ill-advised attempts to destroy it. This inevitably has led dieters down two seemingly different paths - one of indulgence, the other, starvation.

The destructive forces of overeating are well chronicled. After numerous failed attempts with dieting gimmicks and bogus potions, succumbing to fast-food fantasies casually becomes a justifiable alternative. In time, a healthy meal plan is as automatic as Homer Simpson's exercise regimen, and a steady diet of McDonald's combo platters is an insurmountable addiction. Thus, it is not surprising that America exhibits such extraordinary health problems, the likes of which have done little to avert those whose diets contribute to the soaring obesity that shackles an appreciable physique. If you truly are what you eat, then 50 million Americans are a Big Mac with extra cheese and a large side of fries.

Deceive the Body, and the Body Strikes Back

Though the above example reaches the extremes of a hopeless, carefree cuisine, the results of a starvation diet can also be a disaster of catastrophic proportions. The logic behind it is intuitive: fat is hideous, so eliminate it (and all calories for that matter) from the diet. By this rationale, the dieter assumes that the body has no choice but to begin slashing inches off its carcass. In reality, this is hardly the case. In fact, just the opposite is usually true, such that the body responds by administering its fat strangle-hold even tighter, making the process of weight loss almost impossible.

If the human body could list its top ten most efficient processes, adaptation would probably rank number one. Evolution's millions of years have shaped the body into a species that is geared not for the production of a slim waist or muscular arms, but for survival. In ages prior, when restaurants were about as plentiful as the wheel, periods of famine prevailed. Yet, so did the human race. The catch, unfortunately, is that those with a considerable propensity to store fat survived. Thus, the twentieth-century version of our ancestors is one that has adapted to years of food shortages through a nauseating ability to maintain a pear-shaped torso. So much for "Survival of the fittest."

When the innocent dieter initiates a restrictive diet, the conditioned response by the body is to kick into the aforementioned survival mode. This, in essence, is a signal to store fat to offset an anticipated period of deficient caloric intake. Compounding matters is a gradual decline of the body's metabolism, rendering the process of fat loss even more difficult. The process is no different than any other the body performs when encountering change - it adapts. Instead of perceiving food as the culprit, it should rather be viewed as fuel. Food is fuel for an increasing metabolism, fuel for the release of fat-burning and muscle-building hormones, and finally, fuel for a healthy diet and a normal lifestyle. When food is eaten in the precise amounts, the body again must adapt. This time, however, it adapts to the notion that its needed energy will be granted. When this gift is awarded, the body responds with its own goodwill gesture, a liberation of its suddenly unnecessary fat stores.

Facts and Fallacies of Food

The constituents of all food can be separated into three types: protein, carbohydrates, and fats. Together they form the basis of all diets and, along with exercise, ultimately determine changes in body composition. This is achieved through hormonal release, an increase in metabolism, and the preservation and enhancement of muscle tissue.

Proteins are considered the body's building blocks for repair, maintenance, and muscular growth. Adequate protein intake ensures the preservation of muscle tissue and enhances recovery from both strenuous workouts and daily activities. Since exercise causes significant damage to muscular tissue and subsequent growth requires adequate recovery, a lack of protein is often the missing factor. Without it, muscle may be spared and appreciable decreases in metabolism will soon follow. This, as illustrated previously, is a splendid method for accumulating a fatty midsection.

Fallacy #1: The RDA for Protein is Sufficient

The recommended daily allowance (RDA) for protein is approximately .36 grams per pound of body weight. Therefore, according to the RDA, a 200 lb. man would require a mere 72 grams of protein daily. This may be sufficient for a sedentary individual like the vice president, but when factoring in strenuous activity such as endurance or weight training, the RDA is grossly inadequate. In fact, research studies have suggested that consuming the RDA for protein during periods of intense training may lead to loss of muscular tissue (17, 10). It is apparent that protein requirements depend on an individualĘs activity level, such that a range between .64 and .91g of protein per pound of body weight is appropriate (17, 10).

The body's primary fuel for energy is derived from carbohydrates. They are especially important for aerobic activities and high-volume weight training, and are also utilized during periods of recovery. As was the case with protein, inadequate intake of carbohydrates can compromise exercise performance and duration. However, carbohydrates have also demonstrated an air of infallibility in the recommendations of most dieticians, though perils do exist even with this vaunted energy source.

Fallacy #2: The More Carbs the Better

Contrary to what is often uttered about the wonderful merits of carbohydrates, the fact remains that excess carbs lead to excess inches. With the exception of the overly lean individual with a speedy metabolism, where weight gain is often the goal, overindulgence of high carbohydrate foods can be as detrimental to waistlines as excess fat. It is often stated that spare carbohydrates are, in large part, stored for energy. However, it is more likely that excess carbohydrates will be converted to body fat (3). Furthermore, studies have shown that identical improvements in body composition, strength, and muscular endurance can be achieved with diets that derive as little as 40% of their calories from carbohydrates versus those that contained over 60% (15, 19). Studies have also repeatedly demonstrated that the sum caloric intake is the predominant factor in weight loss and an elevated carbohydrate intake is not advantageous (1, 7).

It is obvious that fats have endured more than their share of abuse. Saturated fats, in particular, are considered a key contributor to heart disease, an epidemic that has claimed more lives than the flood in Genesis. Fats also carry over twice as many calories per gram than both carbohydrates and protein. Though it is true that an excessive fat intake is the best way to resemble a blimp, it's also a fact that fat is necessary for proper metabolic function, hormone production, and as an energy source.

Fallacy #3: Avoid Fats Entirely

Most American diets are either too deficient or too abundant in fat intake. As stated previously, neither method is a successful tactic for weight loss. When examining the habits of most restrictive diets, there is a prevailing assumption that all dietary fat can only be deposited to adipose tissue. This is an absurd misconception. In reality, the body utilizes dietary fat for energy in a state of negative energy balance (21). As long as the total caloric intake is less than what is expended, the percentage of fat in the diet is not as significant as once thought. Studies have also affirmed that equivalent differences in weight loss can be achieved with diets consisting of approximately 10-50% fat, as long as the total calorie consumption was identical (1, 7).

With these menacing fallacies of food exposed, it is evident that the low calorie, low fat, high carbohydrate diets that have been advocated for years are in fact fallacies themselves. A long-standing, correct approach to weight loss is the procedure whereby more calories are expended than ingested. Unfortunately, this has formed the basis of extremely low calorie diets, diets that result in the loss of vital muscle tissue and a striking decrease in metabolism. Take, for example, the Slim-Fast diet. This is a nice, convenient drink that is akin to a small cup of milk and copious helpings of sugar. With few calories, a meager appearance by protein, and no fat, the body exhibits a ruthless preservation of adipose tissue, a greater propensity for fat accumulation, and a yearning for real food and a normal life. The low-calorie deception offered by such diets is further augmented by an overload of sugar and similar carbohydrates, yet another frustrating contributor to ballooning belt sizes.

All Carbohydrates are not Created Equal
Now that it's intuitive to avoid excess carbohydrates, the type of carb must also endure similar scrutiny. Though all carbohydrates are broken down into glucose and released into the bloodstream, the speed at which this process occurs varies drastically with different carbohydrates. Interestingly, this absorption rate is a critical factor in energy levels, fat reduction, and overall health. Fortunately, foods have been assigned a glycemic index, a measure of how fast their carbohydrates enter the bloodstream to be utilized as energy or stored as glycogen (a preserved energy form). High-glycemic foods, therefore, are available quickly for use as energy. Though this may seem optimal, in actuality they trigger a hormonal reaction that has reverse effects.

High-glycemic carbohydrates produce a rush of glucose into the bloodstream, elevating blood sugar levels dramatically. This sudden rise stimulates a release of the hormone insulin, which essentially negates the high-energy effects of glucose. The rapid surge of insulin shuttles the glucose out of the bloodstream, effectively dropping energy levels to lethargic lows. To make matters worse, the insulin also takes the fatty acid energy source with it, shoveling it into fat cells for storage. High-glycemic foods, therefore, exhibit a double curse, keeping consumers fat and lazy.

In the past, it was recommended that foods high in simple sugars (candy, cookies, soft drinks) be avoided for the aforementioned reasons. This is true; however, many revered energy sources are also considered high-glycemic foods. Surprisingly, many kinds of pasta, rice, and potatoes rank rather high on the glycemic index. Many breads and cereals are also offensive, fast enough to zap energy levels and hoard fat like the good-ol' days of famine and starvation.

The opposite results, fortunately, are available with the ingestion of low-glycemic foods. They provide for more stable energy levels and an attenuated insulin response, favoring the probability of productive workouts and sustained vitality. These foods rank in the below 70 category on the glycemic index chart, which is provided below. All foods are rated according to white bread, which receives a very speedy score of 100. The following is a list of common foods and their respective scores, categorized into three accommodating lists:

High Moderate Low
Instant Rice (128) Ice Cream (87) Grapefruit juice (69)
Crispix cereal (124) Cheese Pizza (86) Green peas (68)
Baked Potato (121) White Rice (83) Grapes (66)
Cornflakes cereal (119) Popcorn (79) Linguine (65)
Rice Krispies cereal (117) Oatmeal Cookies (79) Macaroni (64)
Pretzels (116) Brown Rice (79) Orange (63)
Total cereal (109) Spaghetti, durum (78) Peach (60)
Donut (108) Sweet corn (78) All-Bran cereal (60)
Watermelon (103) Oat Bran (78) Spaghetti, white (59)
Bagel (103) Sweet Potato (77) Apple juice (58)
Cream of Wheat (100) Banana (77) Apple (54)
Grapenuts cereal (96) Special K cereal (77) Vermicelli (50)
Nutri-grain bar (94) Orange juice (74) Barley (49)
Macaroni and Cheese (92) Cheese tortellini (71) Fettucine (46)
Raisins (91) Chocolate (70) Lentils (41)

Table adapted from reference 6.

Since foods are usually eaten in combinations, note that the glycemic index of a meal is usually lower than the glycemic index of the highest constituent. For instance, if equal calories of a bagel and an apple are combined, the glycemic index of that meal becomes a more acceptable 79. Protein also helps matters, such that they efficiently decrease the total glycemic index by slowing the absorption rate of carbohydrates. This emphasizes the importance of combining protein and carbohydrates in each meal.

Food: A Potent Hormone Trigger

As stated, the hazards of one hormone, insulin, are encouraged by the ingestion of high-glycemic foods. While insulin promotes fat storage, a substance known as growth hormone (GH) effectively burns fat, builds muscle, and improves the immune system. This provides another advantage to low-glycemic foods. If low-glycemic foods are emphasized and blood sugar levels remain stable, a positive environment exists for GH to exert its effects (13).

The exploits of the muscle-building hormone testosterone are even more profound. Studies have demonstrated that testosterone is chiefly influenced by the ratios of food in the diet. Therefore, the percentages of protein, carbohydrates, and fat can have dramatic effects on changes in body composition. For instance, for the individual seeking added muscular mass, a low protein to carbohydrate ratio and a moderately high-fat intake are necessary for maximal testosterone output (20, 14). This is not to suggest a reduction in protein intake; rather the percentage of carbohydrates in the diet should be much greater than protein (20). Furthermore, the source of food also influences testosterone concentrations, such that a vegetarian diet produces much lower testosterone levels than a meat-rich diet (12).

A diet high in red-meat, however, is also an abundant source of saturated fat. Though the reasons for avoiding saturated fats are well established, such as their contribution to heart disease, other forms of fat can be quite beneficial for normal metabolism and hormone production. The fats contained in fish, for example, should be emphasized in the diet. In addition, olive, sunflower, and canola oils are rich in monounsaturated fatty acids, a form of fat that is a powerful stimulant of testosterone (20).

Planning the Metamorphosis

Before an appropriate, individualized diet can be incorporated, an accurate reading of body fat percentage must first be performed. Since daily calorie requirements depend both on the amount of lean body mass (all bodily constituents except fat) and activity level of an individual, this is a necessary estimation. This is because of the radically different metabolic processes required to maintain muscle as opposed to fat. Specifically, muscle requires a great deal of energy to sustain it, while fat basically sits (or hangs) there. As a result, the daily calorie intake should be sufficient to maintain muscle, not fat. Therefore, the differences in protein and calorie requirements of two men of the same weight, one at 10% fat and the other at 20%, are astounding.

Once body fat percentage is known, there are three primary stages in developing an ideal calorie level: 1) determine metabolic rate, 2) choose an appropriate protein intake depending on lean body mass, metabolic rate, and activity level, and 3) select a suitable nutrient ratio according to metabolic rate and body composition goals. The following tables provide the completion of all three stages.

Table 1. Fast, Moderate, and Slow Metabolic Rates.

1.Fast - Individuals with a fast metabolic rate exhibit low weight and body fat levels, have trouble gaining muscle, and can generally eat like pigs with no adverse consequences.

2.Moderate - These individuals generally desire to maintain body weight, decrease fat, and slightly increase muscle mass. Excess calorie intake usually results in mild weight increases.

3.Slow - A slow metabolic rate usually equates to a high propensity for weight and fat gain. These individuals desire extensive weight loss.

Note: These estimates are subjective and do not exactly encompass all types of metabolic rates. In reality, everyone is different. It should be emphasized also that varying degrees of all three rates exist. Namely, fast-moderate and moderate-slow metabolic rates are common and can be utilized as intermediaries in the following tables.

Grams of protein required per pound lean body mass Metabolic Rate No Exercise Light Exercise Strenuous Exercise Strenouus Exerices Intense Exercise Fast .6 .8 .9 1.0 1.2 Moederate .5 .7 .8 .9 1.1 Slow .4 .6 .7 .8 1.0

Percentage of Daily Caloric Intake
Nutrition Fast Metabolism Moderate Metabolism Slow Metabolism

Note: One gram of protein or carbohydrate equals four calories, while one gram of fat is equal to nine.

Two Examples

Example 1. This individual is a 5'9", 140 lb. male with 5% body fat. He exhibits a fast metabolic rate and utilizes intense weight training 4-5 times a week (activity level 4) in an attempt to gain weight. To determine his caloric requirements, simply calculate lean body mass and choose an appropriate protein intake and nutrient ratio.

1. 140 lbs. x 95% lean body mass = 133 lbs. lean tissue
2. This individual would require approximately 1.0g of protein per pound of lean body mass, or 133g daily.
3. Protein would therefore account for 532 calories (133g x 4 calories per gram). He would then utilize a nutrient ratio where protein consisted of 17% of his daily calories, such that 532 divided by 17% would result in the daily calorie intake.
4. 532/.17 = 3129 total calories/day. To determine the amount of carbohydrates and fat, simply multiply this number by their respective percentages. For example, the daily carbohydrate intake would be 1814 calories (3129 x .58), or 454 grams (1814 calories/4 calories per gram). The daily fat intake is 782 calories (3129 x .25), or 87 grams (782 calories/9 calories per gram).
5. Optimally, this person should eat 5-6 meals per day. If 5 meals are consumed, each meal would average approximately 626 calories, in the same ratio of nutrients as described above. Of course, this number will vary, especially since post-workout meals should contain more calories.

Example 2. This individual is a 6'0", 190 lb. male with 18% body fat. He desires to lose a little weight and a lot of fat to become "toned." Since he gains weight rapidly if his calorie intake soars too high, he is considered to have a moderate-slow metabolism. He currently trains with weights and runs for thirty minutes five times per week. He would therefore fall between activity levels four and five, requiring approximately .85-1.05 grams of protein per pound of lean body mass.

1. 190 lbs. x 82% lean body mass = 156 lbs. lean tissue
2. 156 lbs. x .95g protein = 148g protein daily
3. Protein would therefore account for 592 calories (148g x 4 calories per gram). A nutrient ratio for an individual with a moderate-slow metabolism would be 24.5% protein, 53.5% carbohydrates, and 22% fat (percentages derived from using the average of moderate and slow metabolism ratios). This individual's daily calorie intake is determined by dividing 592 by 24.5%, resulting in 2416 calories.

4. Utilizing the same method as outlined in example 1, the daily carbohydrate intake is 1292 calories, or 323 grams. The daily fat intake is 531 calories, or 59 grams.

The Importance of Nutrient Timing

The number and content of daily meals is an extremely important but overlooked facet of proper nutrition. The timing and quality of foods ingested, especially pre- and post-workout, is often the difference between a successful diet and another failed attempt at physique enhancement. Skipping breakfast, avoiding post-workout meals, and consuming high-glycemic carbohydrates before workouts can easily transform a sound meal plan into an unwitting disaster. Interestingly, however, even the most sensible diets ignore the crucial nature of nutrient timing.

As stated numerous times, elevating the metabolic rate is one of the most efficient ways to burn fat. The digestion of meals requires calories by itself, so the more often the body must break down food, the more efficient it becomes. Therefore, small meals should be consumed throughout the day to maximize the metabolic response. Related to this is breakfast, the "most important meal of the day." Though the post-workout meal may be equally important, the consumption of a large breakfast has been shown to result in significantly greater fat losses than diets that avoided it (8). Since the metabolic rate is fastest in the morning and slows throughout the day, it is more likely that the calories consumed during breakfast will be utilized by the body and not stored as fat. Skipping breakfast, on the other hand, may result in vital losses of muscle and a subsequent decrease in metabolism.

For much the same reason, the post-workout meal is equally essential. Following exercise, the body exhibits an elevated metabolic rate, much like it does upon awakening. A lack of food following exercise, therefore, results in muscle tissue breakdown and, of course, a corresponding tumble of the metabolic rate. Research has proven that the synthetic rate of protein doubles following exercise and remains elevated for over 24 hours (11, 4). In other words, the body is primed for the acceptance of protein for muscle maintenance and growth. Equally important is the ample consumption of carbohydrates. Following exercise, the body is somewhat depleted of its glycogen stores. Remarkably, it has been shown that high-glycemic carbohydrates post-workout are the preferred source to replenish the body's energy stores (5). Not only does this result in greater storage for recovery and subsequent workouts, but it also significantly decreases muscle breakdown (16).

To obtain the most optimal effects of the previous findings, post-workout meals should contain about twice the normal amount of carbohydrates and protein and should be ingested immediately following exercise. For example, an individual eating five meals per day and 3000 calories would consume a post-exercise meal of approximately 1000 calories, while the other four meals would average 500. All subsequent post-workout meals should also contain a larger percentage of protein than pre-workout meals to comply with the body's elevated protein synthetic rate.

A final fitness faux pas is the pre-workout meal. How many fitness enthusiasts eat a bagel before exercise? It seems that this is one of the most common pre-workout foods due to its alleged energy benefits. However, look at its glycemic index - it's a whopping 103. The detrimental effects of this are monumental. The corresponding insulin response will not only decrease energy stores for exercise; it will also prevent fat breakdown at the same time. Fortunately, low-glycemic foods have much the opposite effect. They exhibit the ability to improve exercise performance without significantly compromising energy stores after a workout (9, 18). This, in turn, leads to enhanced recovery and accelerated progress.

A Word About Consistency

A suggested meal plan is not perfect, and individual tinkering will be required to determine the ideal diet. Losing weight too quickly is a sign of muscular and water loss, not necessarily fat loss. Therefore, those individuals should increase their caloric intake slightly. The same is true for similar imperfections; slight modifications are required and variety is encouraged. Remember that the body adapts to all changes, so an identical food and daily caloric intake will not only drive one to insanity, but also to stagnation.

If there is one truth about building an improved physique, it's that it takes time, dedication, and consistency. Losing or gaining weight should be a slow, gradual process to ensure the changes are of the appropriate type. This is one of the reasons so many diets fail and the gimmicks appear. In the future, everything short of chemotherapy will be offered as the new miracle in weight loss. In time, it too will fall by the wayside and fat will settle hideously to the waistline. And all the while, lurking in reality, is everything short of quitting, the true miracle in physique excellence.

About the Author
Dr. Stout has a diversified background in exercise science. His primary fields of expertise are sports supplements, neuromuscular fatigue, and body composition analysis. He has over 70 published manuscripts, abstracts, and national presentations in nationally and internationally recognized journals. Dr. Stout currently serves as assistant professor at Creighton University and is the director of the Human Performance Research Laboratory. His current teaching responsibilities include courses in exercise physiology, statistics, research design, and biomechanics.

1. Alford, B., A. Blankenship, R. Hagen. The effects of variations in carbohydrate, protein, and fat content of the diet upon weight loss, blood values, and nutrient intake of adult obese women. J Am Diet Assoc. 90(4):534-540. 1990

2. Anderson, K., et al. Diet-hormone interactions: protein/carbohydrate ratio alters reciprocally the plasma levels of testosterone and cortisol and their respective binding globulins in man. Life Sci. 40: 1761-1768. 1987

3. Baechle, T. Essentials of Strength Training and Conditioning. Human Kinetics: Champaign, IL. 1994. p. 215

4. Biolo, G., et al. Increased rates of muscle protein turnover and amino acid transport after resistance exercise in humans. Am J Physiol. 268(3 Pt 1): E514-520. 1995

5. Burke, L., M. Hargreaves, G. Collier. Muscle glycogen storage after prolonged exercise: effect of the glycemic index of carbohydrate feedings. J Appl Physiol. 74: 1019-1023. 1993

6. Foster-Powell, K., J. Miller. International tables of glycemic index. Am J Clin Nutr. 62(1): 871S-890S. 1995

7. Golay, A., et al. Similar weight loss with low- or high-carbohydrate diets. Am J Clin Nutr. 63(2):174-178. 1996

8. Keim, N., et al. Weight loss is greater with consumption of large morning meals and fat-free mass is preserved with large evening meals in women on a controlled weight reduction regimen. J Nutr. 127(1): 75-82. 1997

9. Kirwan, J., et al. A low glycemic meal 45 minutes before exercise improves performance. Med Sci Sports Exerc. 28(5 S): S768. 1996

10. Lemon, R. Protein and amino acid needs of the strength athlete. Int J Sport Nutr. 1:127-145. 1991

11. MacDougall, J., et al. The time course for elevated muscle protein synthesis following heavy resistance exercise. Can J Appl Physiol. 20(4): 480-486. 1995

12. Raben, A., et al. Serum sex hormones and endurance performance after a lacto-ovo vegetarian and a mixed diet. Med Sci Sports Exerc. 24: 1290-1297. 1997

13. Rabinowitz, D., L. Ziebler. Suggested variations in plasma insulin and HGH concentrations during one feast-famine cycle. Nature. 199: 913-915. 1963

14. Reed, M., et al. Dietary lipids: an additional regulator of plasma levels of sex hormone binding globulin. J Clin Endocrinol Metab. 64: 1083-1085. 1987

15. Rinehardt, K. Effects of diet on muscle strength gains during resistive training. In: Muscle Development: Nutritional Alternatives to Anabolic Steroids. Columbus, OH: Ross Laboratories, 1988. pp. 78-82

16. Roy, B., et al. The effect of oral glucose supplements on muscle protein synthesis following resistance training. Med Sci Sports Exerc. 28(5 S): S769. 1996

17. Tarnopolsky, M., J. MacDougall, S. Atkinson. Influence of protein intake and training status on nitrogen balance and lean mass. J Appl Physiol. 64:187-193. 1988

18. Thomas, D., J. Brotherhood, J. Miller. Plasma glucose levels after prolonged strenuous exercise correlate inversely with glycemic response to food consumed before exercise. Int J Sport Nutr. 4(4): 361-373. 1994

19. Van Zant, R., J. Conway, J. Seale. Effects of dietary carbohydrate restriction on high intensity exercise performance. Med Sci Sports Exerc. 24:S71. 1992

20. Volek, J., W. Kraemer, J. Bush, T. Incledon, M. Boetes. Testosterone and cortisol in relationship to dietary nutrients and resistance exercise. J Appl Physiol. 82(1): 49-54. 1997

21. Walberg-Rankin, J. A review of nutritional practices and needs of bodybuilders. J Strength and Cond Research. 9(2):116-124. 1995

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