TCS Daily

Are You What You Eat?

By Jonathan Robison, PhD, MS - December 10, 2003 12:00 AM

You Are What You Eat is one of the most widespread and troublesome myths about food that exists in our culture today. According to the American Dietetics Association, it implies that "everything from mood and behavior to intellectual capacity is determined by diet,"(1) that food is the crucial determining factor for healthy living. If we eat the right foods we will live a long, healthy life. But, does food really make the man (or woman)? Are vegetarians really different from meat and potatoes people? Is food really a cure for all that ails us? Is this kind of thinking helpful for people?


Aside from the obvious fact that people do not in any way resemble the salad or plate of spaghetti they had for lunch, (unless they have spilled some on their shirt or tie you can't tell who has eaten what) the you are what you eat perspective on food is not only misleading, but potentially dangerous as well.


Now You Eat It, Now You Don't


In reality, it turns out that there is a wide range of dietary patterns that can be associated with a healthy lifestyle. Consider the following well-known facts about dietary fat, alcohol and heart disease:


·        The Japanese eat a very low fat diet and suffer fewer heart attacks than Americans

·        The French eat a high fat diet and suffer fewer heart attacks than Americans

·        The Japanese drink very little red wine and suffer fewer heart attacks than Americans

·        The Italians drink a lot of red wine and suffer fewer heart attacks than Americans


Certainly trying to lay blame for increased heart attacks in Americans on either of these particular foods would be futile. (Actually, some have suggested that it may be speaking English that is the culprit.)


The disease conditions that are commonly linked to diet, such as heart disease and cancer are complicated and multifactorial in etiology. This is not to say that diet does not play a role in the development of these diseases. But, while research suggests links or associations between diet and disease, there is ongoing and often rancorous controversy, even within the scientific community, regarding specific nutrition recommendations. Just think about what we have been told just in the past few years. First we were told to eat margarine instead of butter. Then we were told it is better to eat butter. (2) We were told that pasta would make us all thin. Now we are told it is making us all fat.


Although most of the time these fluctuating recommendations just end up causing confusion, they have the potential to cause significant harm as well. In the 1970's and early 1980's the antioxidant supplement beta-carotene was routinely recommended as a preventative measure against heart disease and cancer. Unfortunately, when the United States government conducted research to examine the impact of actually giving these supplements to people, two large, well-controlled studies had to be terminated because some of those taking the supplements experienced an increased risk for the diseases they were trying to prevent. The end result was that beta-carotene supplements are no longer recommended. In fact, for a time there was talk of regulating beta-carotene as a carcinogen. (3)


As another example, fat in the diet has been portrayed as no less than the devils handiwork -- something to be shunned at all costs. Ironically, considerable research suggests that good health is compatible with a much wider range of fat intake than has been previously preached. As Walter Willett, Professor of Epidemiology at Harvard and one of the world's leading researchers on nutrition and health stated almost ten years ago:


The recommendation to eat a 30% fat diet to protect against heart disease is not based on facts. Research has not proved that there is an ideal amount of fat to be aimed for in the diet


More recent findings, reported by the American Heart Association, have even suggested that very low fat diets may benefit only about one-third of the population and may actually have detrimental health effects on another third! (4)


As the following list reveals, in just the last five years, new research has uprooted many of the most widely cherished and long-held beliefs about the relationship between various foods and disease:


Fiber and Colon Cancer                                      " association between the intake of dietary fiber and the risk of colorectal cancer." (NEJM, 1999) (5)


Eggs and Hypercholesterolemia                          "... no evidence of an overall significant association between egg consumption and risk of CHD in men or women." (JAMA 1999) (6)


Sugar and Diabetes                                            "...the most widely held belief about the nutritional treatment of diabetes has been that simple sugars should be avoided and replaced with starches... There is, however, very little scientific evidence that supports this assumption." (Diabetes Care) (7)


Salt and Hypertension                                                    "...although diet can strongly influence blood pressure, salt may not be a player." (Science 1998) (8)


Fat and Breast Cancer                                                   " We found no evidence that lower total intake of fat or specific major types of fat was associated with a decreased risk of breast cancer." (JAMA 1999) (9)               



An Atmosphere of Confusion


With all of this contradictory and continually changing information and the high volume of media coverage about emerging nutrition science, is it any wonder that the American population is confused and worried about what to eat and unsure about whom to turn to for accurate nutrition information. In fact, recent surveys show that:


·        More than 1 of 5 adults are confused by reports giving dietary advice (10)

·        2 of 5 adults believe that healthy eating means giving up foods they like (11)

·        More than 1 out of 3 adults feel guilty when they eat foods they enjoy (11)

·        70% of adults do not want government to tell them what they should eat (12)


The incessant preaching of what should and shouldn't be eaten, what disease can be prevented or caused by certain foods, all of which changes regularly with the latest press release, causes people to feel perpetually anxious and guilty about something that should be one of life's greatest pleasures -- eating. What is called for here is a healthy serving of perspective, dished out this time by the editors of the New England Journal of Medicine:


Although we would all like to believe that changes in diet and lifestyle can greatly improve our health...many if not most such changes will produce only small effects. And the effects may not be consistent. A diet that is harmful to one person may be consumed with impunity by another. (NEJM - 1994) (13)



With A Grain Of Salt


Yes, nutrition has a place in human health, but it needs to be put back into a broader perspective. Food provides us with fuel and essential nutrients to help our bodies go and grow. And, if we allow it to, food also provides us with pleasurable experiences both personally and socially. Eating a wide variety of foods can help us to be all that we can be, so that we can get the most out of life. Beyond that, focusing on the latest press release about the pluses and minuses of individual foods is likely to lead to increased anxiety about eating which may well offset any potential health benefits of eating that particular food. When it comes to diet and health -- the keys are variety, common sense and moderation (in all things including moderation). Perhaps it would be wise to take most other nutrition recommendations with -- if you'll pardon the expression -- "a grain of salt."




1.         Position of The American Dietetic Association: Food and Nutrition Misinformation. Journal of The American Dietetic Association 2002;102(2):260-266.


2.         Goldberg JP. Nutrition and health communications: the message and the media over half a century. Nutrition Reviews 1992;50(3):71-77.


3.         Omenn GS. Chemoprevention of Lung Cancer: The rise and demise of beta-carotene. Ann. Rev. Public Health 1998;19:73-99.5.        Willett, 1995


4.         News. Very low fat diets may harm some people. BMJ 1998;316:571 ( 21 February )


5.         Fuchs CS, Giovannucci EL, Colditz GA, Hunter DJ, Stampfer MJ, et al. Dietary Fiber and The Risk of Colorectal Cancer and Adenoma in Women. NEJM 1999;340(3):169-176.


6.         Hu FB, Stampfer MJ, Rimm EB, Manson JE, Ascherio A, et al. A Prospective Study of Egg Consumption and Risk of Cardiovascular Disease in Men and Women. JAMA 1999;281(15):1387-1394.


7.         Nutrition Recommendations and Principles for People With Diabetes Mellitus. Diabetes Care 1999;22(S1):S42-S45.


8.         Taubes G. The (Political) Science of Salt. Science 1998;281:898-907.


9.         Holmes MD, Hunter DJ, Colditz GA, Stampfer MJ, Hankinson SE, et al. Association of Dietary Intake of Fat and Fatty Acids With Risk Of Breast Cancer. JAMA 1999;281(10):914-920.


10.       Nutrition and You--Trends 2000 Final Report. American Dietetic Association: October 1999.


11.       Just What is A Balanced Diet, Anyway? Tufts University Diet and Nutrition Health Letter 1992;9(11):3-6.


12.       Patterson RE, Satia JA, Kristal AR, Neuhouser ML. Is There A Consumer Backlasj Against The Diet and Health Message? Journal of The American Dietetic Association 2001;101:37-41


13.       Angell M., Kassirer JP. Clinical Research - What Should The Public Believe NEJM 1994;331(31):189-190.

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