Fitness for One and All Home Page

Books and eBooks by the Director

Part One of this series looked at healthy plant foods. Part Two looked at healthy animal foods. The foods discussed in those two articles should constitute the building blocks of a healthy diet. But what foods are unhealthy and best avoided? That question will be address in this final installment of this series.

Probably one of the unhealthiest inventions of the modern food processing industry is trans fat. Trans fats are formed when unsaturated fats are "hydrogenated" with hydrogen atoms. But the problem is, the placement of hydrogen atoms on fatty acid molecules in nature are in a "cis" configuration while on these artificially generated fats the hydrogen atoms are in a "trans" configuration. The meaning of these terms is not important. The important point is, trans fats are an unnatural fat, and your body simply is not prepared to deal with them. As a result the consumption of them is increasing being shown to be associated with various health risks.

The consumption of trans fats has been shown to increase the risk of heart disease. One study states, "Concern that trans-fatty acids formed in the partial hydrogenation of vegetable oils may increase the risk of coronary disease has existed for several decades, but direct evidence on this relation in humans is limited." So this study looked at the diets of 239 heart attack patients and compared their diets to 282 control subjects.

After adjustment for other factors, the study found, "Intake of margarine--the major source of trans-isomers--was significantly associated with risk of myocardial infarction. CONCLUSIONS: These data support the hypothesis that intake of partially hydrogenated vegetable oils may contribute to the risk of myocardial infarction" (Ascherio).

So the recommendation to replace butter with margarine of the past few decades is completely wrong-headed. The trans fats in margarine are just as dangerous to the heart as the saturated fats in butter.

Another study followed 80,082 women over a period of 14 years. In that time, 939 of them suffered heart attacks. The study found that the intake of both saturated and trans fat correlated with an increased risk of heart disease, but total fat intake did not. In fact, the consumption of polyunsaturated and monounsaturated fats were correlated with a reduced risk.

So the study concluded, "Our findings suggest that replacing saturated and trans unsaturated fats with unhydrogenated monounsaturated and polyunsaturated fats is more effective in preventing coronary heart disease in women than reducing overall fat intake" (Hu). So again, it is not total fat intake that is important but the type of fat.

Looking at a completely different health matter, a study looked at fat intake and the risk of developing Alzheimer disease. The study followed "815 community residents aged 65 years old who were unaffected by Alzheimer disease" for 3.9 years. During this time 131 of them developed Alzheimer disease.

Looking at their diets, "Intakes of saturated fat and trans-unsaturated fat were positively associated with risk of Alzheimer disease, whereas intakes of omega-6 polyunsaturated fat and monounsaturated fat were inversely associated" (Morris). So once again, saturated fats and trans fats proved detrimental while polyunsaturated and monounsaturated fats are beneficial.

On yet another matter, a recent issue of Men's Health reported:
… trans fats also add inches to your waist, according to a recent study published in the American Journal of Clinical Nutrition. In the 9-year study of more than 16,5000 men, researchers found that for every 2 percent increase in trans fat intake, men added one-third of an inch to their waists. "Mono- and polyunsaturated fats had no effect. Saturated fats seemed to affect total weight, but not the waist (p. 48).

So trans fats add body fat to the most dangerous place, the mid-section, while saturated fats add fat to the body in general. But poly- and monounsaturated fats do not have these problems associated with them.

And finally, "Preliminary evidence suggest that trans fatty acids may adversely affect infant and fetal development, may lower testosterone levels in men, and may heighten breast cancer risk" (Faigin, p. 175).

It's relatively easy to keep tabs on ones saturated fat intake as values for it are listed in the "Nutrition Facts" label of most foods. But currently, there is no such listing for trans fat. But this is due to change in 2006. But until then, if any kind of hydrogenated oil is listed in the ingredients you can be sure there are trans fats in the food, and it is best avoided.

Moreover, the generally accepted limit for saturated fat intake is 10% of total calories. And this percentage is used on food labels as the "Daily Value" for saturated fat intake. But once trans fats are listed, there will be no Daily Value given for them. The reason for this is that researchers were not able to come up with a "safe" level of trans fat intake. The intake of trans fat in any amount is deleterious.

The above information ties in nicely with the recommendation in Part One of this series to consume nuts and seeds and in Part Two to consume fish. Nuts and seeds are high in mono- and polyunsaturated fats while fish is high in monounsaturated fats. These foods also contain many other beneficial nutrients, so they are your best source for these healthy fats.

Part One of this series discussed the benefits of whole grains. In the process it also discussed the problems with refined grains. In short, refined grains are devoid of most of the beneficial nutrients and fiber found in whole grains. Moreover, refined grain consumption is associated with an increased risk of colorectal cancer, while whole grains were associated with a reduced risk. And it is not just colorectal cancer, "refined grain intake was associated to increased risk of different types of cancer" (La Vecchia).

So substituting whole grains for refined grains is a very beneficial step to take.

The average American consumes his or her bodyweight in sugar each year. And this high consumption of sugar is one of the main causes of the growing obesity epidemic in the USA. And obesity is an underlying factor in many degenerative diseases, such as heart disease and diabetes. The reason why sugar consumption is associated with increased body fat concerns how sugar and carbohydrates are metabolized.

Carbohydrates serve three main functions in the body. First, they can be burned for fuel. Second, they can be stored as glycogen in the liver and muscles. Glycogen is the body's primary stored form of energy. Third, carbs can be stored as body fat.

Complex carbs (like those found in whole grains, vegetables, nuts and seeds, and legumes) are broken down in the body into glucose molecules. Glucose can then be used for any of the above three functions. Moreover, since each of these foods contains a high amount of fiber, they are digested relatively slowly. So this increases the chance they will be burned for fuel.

However, common table sugar (sucrose) is a disaccharide, composed of one molecule of glucose and one molecule of fructose. And it is with sucrose being half fructose that one of the many problems with sugar comes in.

Fructose cannot be used to restore muscle glycogen. So when it is consumed, if it is not immediately needed for fuel, it will be stored as body fat. Moreover, foods high in sugar are generally low in fiber. As a result, the food is metabolized very quickly. This decreases the chance it will be burned as fuel. So the only place left for it is to be stored as body fat. And making matters even worse, people tend to consume high-sugar foods late in the day, when activity is low. And this further decreases the possibility of it being burned for fuel.

Even worse than sucrose is high fructose corn syrup (HFCS). As the name implies, HFCS is mostly fructose. And, as with sugar, HFCS generally appears in foods that are low in fiber. In fact, over the last 20-30 years, food manufacturers have switched from using primarily sugar to using primarily HFCS in processed foods. The reason for this is that HFCS is cheaper than sugar. But there are many health researchers who believe that this switch is one of the reasons for growing American waistlines.

However:
Having said that, don't be deterred from eating fruit because it contains fructose. Although fruit contains a high percentage of fructose, the total amount is relatively low because the total amount of carbohydrate is relatively low … This is in contrast to cake or cookies, which contain tremendous amount of sucrose (remember, sucrose is made up of half glucose and half fructose). Therefore, although desert foods may contain a lower percentage of fructose than fruit does, they yield a greater amount of fructose per ounce (Faigin, p. 145).

Moreover, with most fruits you are getting a large amount of vitamins, minerals, fiber, antioxidants, and other beneficial food elements. And the consumption of fruit is associated with a variety of health benefits, as was discussed in Part One. And again, the fiber in fruit slows digestion thus increasing the likelihood of the carbs being burned for fuel. Meanwhile, most foods high in sucrose and/ or HFCS tend to be very low in nutrient and fiber content.

But it should be noted that these comments only apply to whole fruits not fruit juice. With fruit juice, you do get a high concentration of sugar, and thus a higher caloric level. There is also the loss of most of the nutrients and fiber and a greatly increased rate of digestion.

This discussion takes us back to Part Two and the discussion on dairy products. There it was mentioned there were potential problems with people being lactose intolerant. But even without intolerance, another problem with lactose is that it is a disaccharide, composed of one molecule of glucose and one molecule of galactose.

Like fructose, galactose cannot be used to replenish muscle glycogen. So like fructose, unless it is burned immediately, it will be stored as body fat. That is why I said I stick with protein powders that have the lactose removed. But I do consume yogurt, even though it contains lactose, as discussed, it is particularly healthy.

In addition to the tendency for sugar to deposit body fat, the consumption of sugar is also associated with various other health problems. For instance, a study compared the diets of women with breast cancer to the diets of those without.

It found:
There was no association between breast cancer risk and intake of calories, macronutrients, or types of fat. Risk of breast cancer was unrelated to intakes of a variety of food groups, including red meats, dairy, high-fat snacks and desserts, or foods high in animal fat. Increased risk was observed for high intake of a food group composed of sweet items, particularly sodas and desserts. Risk increased linearly with percent of calories from sweets and frequency of sweets intake.

Much more could be said on the problems of sugar and HFCS. But this section will just conclude with the recommendation to satisfy your "sweet tooth" with the consumption of whole fruits and to avoid fruit juice and foods high in added sugar and HFCS.

Artificial sweeteners, artificial flavorings, artificial colorings, flavor enhancers, emulsifiers, preservatives. Our food supply is filled with a wide variety of artificial food ingredients. And by definition, these ingredients are, well, artificial. The human body was never designed to metabolize any of them. Making matters worse, many such ingredients are still allowed in foods despite the fact that their safety is questionable. Generally speaking artificial food ingredients can be classified into three categories.

The first category is those artificial food ingredients for which some studies have found potential adverse health effects and/ or for which people have reported adverse effects from their consumption. But despite these potential problems they are still allowed in our food supply.

The second category is those artificial ingredients that have not been extensively studied and which have not been used for long enough or in enough of a widespread fashion to determine if they are safe or not. The "jury is still out" so to speak.

The third category is those artificial ingredients that even with extensive research and widespread usage, no adverse health effects have been reported.

By way of example, looking at artificial sweeteners, saccharine and aspartame would fall into the first category. Some studies in the 1970's found a high consumption of saccharine to be associated with an increased risk of bladder cancer. It was banned for a period of time but was later allowed in foods, but with a health warning on the labels. Meanwhile, many people have reported a variety of adverse effects from aspartame, but it also still remains on the market.

Acesulfame, a newer artificial sweetener, would fall into the second category. The number of studies on it has been very limited, and it is so new to the food supply that not enough people have been using it for long enough for adverse effects to be noted from it. So at the present time, it appears to be safe, but this could change with more testing and widespread usage.

Sucrolose would fall into the third category. It has been extensively studied and has been used for a long time, but no adverse effects have been reported from it. So all indications are that it is safe (Schardt, pp. 8-11). So if one were going to use an artificial sweetener, then sucrolose would be your best choice, and acesulfame might be a good second choice.

But still, as a general rule, it is best to limit the consumption of artificial food ingredients, including artificial sweeteners, as much as possible. Avoiding highly processed foods would be the best way to do so. And an even better option for a non-caloric sweetener than any artificial sweetener would be to use stevia, a natural, non-caloric sweetener.

Stevia is an herb that is 300 times sweeter than sugar. So only a very small amount is needed. Such a small amount in fact that in powder form it can be hard to measure out. So I would recommend it in liquid form. Only a couple of drops are needed to give the sweetening effect of a teaspoon of sugar. The best such product I have found is Wisdom of the Ancients liquid stevia. I prefer this brand as it does not use alcohol as most liquid stevia products do.

Part One of this series stated that foods can be classified as those that reduce the risk of one or more degenerative diseases and those that increase the risk.

In the decrease risk category would be: vegetables, fruits, nuts, seeds, whole grains, legumes, fish, skinless baked chicken and turkey, low fat or non-fat dairy products (especially yogurt), and egg whites.

In the increased risk category would be saturated fats, trans fats, refined grains, sugars, high fructose corn syrup, and artificial food ingredients.

Limit your consumption of the latter while eating copious amounts of the former. Lean red meats and whole eggs could also be added for additional protein and other nutrients without adverse health effects if they are used in limited amounts. That is the prescription for a healthy diet.

References:
The following items are listed in order of reference. PMID refers to the PubMed Identification Number. The easiest way to find these abstracts is to search on the PMID on PubMed:

Circulation. 1994 Jan;89(1):94-101. Trans-fatty acids intake and risk of myocardial infarction. Ascherio A, Hennekens CH, Buring JE, Master C, Stampfer MJ, Willett WC. PMID: 8281700.
N Engl J Med. 1997 Nov 20;337(21):1491-9. Dietary fat intake and the risk of coronary heart disease in women. Hu FB, Stampfer MJ, Manson JE, Rimm E, Colditz GA, Rosner BA, Hennekens CH, Willett WC. PMID: 9366580.
Arch Neurol. 2003 Feb;60(2):194-200. Arch Neurol. 2003 Aug;60(8):1072. Dietary fats and the risk of incident Alzheimer disease. Morris MC, Evans DA, Bienias JL, Tangney CC, Bennett DA, Aggarwal N, Schneider J, Wilson RS. PMID: 12580703.
Men's Health. "Weight-Loss Bulletin: Fat that makes you fat." March 2004, p. 48.
Nutr Metab Cardiovasc Dis. 2001 Aug;11(4 Suppl):10-5. Nutrition and health: epidemiology of diet, cancer and cardiovascular disease in Italy. La Vecchia C, Chatenoud L, Altieri A, Tavani A. PMID: 11894740.
Faigin, Rob. Natural Hormonal Enhancement. Extique Publishing: Cedar Mountain, NC, 2000.
Schardt, David. Nutrition Action. "Sweet nothings: not all sweeteners are Equal." May 2004, pp. 8-11.

Basics of a Healthy Diet. Copyright © 2004 By Gary F. Zeolla.

Disclaimers: The material presented in this article is intended for educational purposes only. The author is not offering medical or legal advice. Accuracy of information is attempted but not guaranteed. Before undertaking any diet, exercise, or health improvement program, one should consult your doctor. The author is in no way responsible or liable for any bodily harm, physical, mental, or emotional, that results from following any of the advice in this article.

The above article was posted on this site May 27, 2004.
It was updated August 22, 2005.
It originally appeared in the free email newsletter FitTips for One and All.

Nutrition
Nutrition: General Nutrition

Text Search     Alphabetical List of Pages     Contact Information

Fitness for One and All Home Page

Books and eBooks by the Director