THE DIET MAZE I:  THE FACTS AND THE FLUFF

     Of all the topics in daily conversation, articles in magazines, and discussions on TV, there probably isn’t any given topic more talked about than diets.  There are at least 20 different books addressing named diets such as the Atkins diet, the Pritikin diet, the Scarsdale diet, the Beverly Hills diet, the South Beach diet, etc., etc., etc.  The real truth is if there were one that really worked, we wouldn’t need books about 20 of them that didn’t.

     With some trepidation I am writing this column because one of the most common questions I am asked as a physician is, “Which diet should I use?”  Over the years, there has been remarkably little scientific evidence produced to answer that question.  In other words, there is very little fact, but there sure is a whole a lot of fluff.  Fluff can be defined as something that takes up a whole lot of room but has very little substance.  In this and the next three columns, the topic of the Atkins diet, the Mediterranean diet, and the several low-fat diets will be discussed.  There are many articles in the medical literature that address what happened to a number of patients when they tried one dietary measure or another.  This is information that is called evidence based or fact.  The baseless claims made by a number of different diets will be pointed out as fluff for which there is no demonstrated truth to the claim.

     Question #1.  Why do people diet?  Some diets have life saving importance.  As a simple example, there is a hereditary disease called phenylketonuria.  Babies that are born with this disease will become critically ill and develop mental retardation if their diets are not depleted in an amino acid called phenylalanine.   Now we test babies at the time of birth to see if this problem is present so the diet can be started early and prevent damage.  Other life saving diets include those that are used for patients that have liver failure or kidney failure.  They need especially low protein diets because they cannot get rid of the waste products when a normal amount of protein is consumed.  Another example is those individuals that have wheat sensitive diarrhea.  They must remove almost all wheat products from their diet in order to avoid having diarrhea and eventual malnutrition.  These are all special situations in which adherence to the diet pays immediate and high benefit returns.

By far, the vast majority of people who ask about diets are those that want to lose weight.  Most of these individuals have a cosmetic motive and want to “look better”.  Some feel that their clothes are too tight and they don’t want to buy a new wardrobe.  Relatively few individuals queried about why they want to lose weight volunteer that it is for health reasons and longevity.

     Question #2.  Why is overweight so pervasive in our society now effecting 60% of our population?  It is a fact that heredity is a major factor.  There is no question that there are many members of our society who are “easy keepers”.  There are the long thin body builds and the short squatty body builds that in many years of our evolution have been favored by different environments.  Individuals who had a heavier layer of fat were given a survival benefit in cold climates where foods supplies were scarce at certain times of the year.

 Equally important are the environmental factors that have developed in our society over the past many years with overweight being a massive epidemic in the United States at this time.  It is a fact that the use of sugar-sweetened beverages such as Coca Cola and the inactivity that has come with our computers and TV sets has been a major factor in producing overweight in many of the otherwise normal weight population.  Thus, being overweight may be permitted by our genetics. But overweight most certainly blossoms in response to the plentiful, cheap supply of highly concentrated carbohydrate rich diets provided by our society today.

     Question #3.  What is the data indicating that different dietary habits affect the population?  There is now abundant factual data available from cultural observations showing that different eating styles affect the general health and personal appearance of the population.     Mediterraneans as a group are relatively thin, have a low incidence of alcoholism and a low incidence of heart attack. Their dietary habit is called the Mediterranean diet.  The Mediterranean diet is not something that somebody thought up but rather a naturally occurring life style adopted by the Mediterranean population based upon the food available and their lifestyle.  As a counter example the major food of the Eskimo is whale blubber and fat obtained from ocean dwelling seals.  An Eskimo’s blood cholesterol may be 2000 mg% (normal up to 200 mg%).  Yet Eskimos have one of the lowest incidences of heart attack in the world.  This is a fact.  The supposed reason is that their food base is fish as opposed to a red meat based diet such as occurs in the United States.  Oriental diets have a much higher salt content than those in the Western world.  Orientals have a much higher incidence of stroke than does the Western population. But if Orientals move to the United States and adopt our dietary lifestyle their incidence of stroke goes down and their incidence of heart attack goes up. Citizens of the United States are the most genetically diverse population in the world and yet homogeneously across the genetic spectrum we have one of the highest incidences of heart attack related to our fat rich American diet.  The fact is that genetics play a part in overweight but the cultural dietary habit is a major player in the disease spectrum of any population.

     Question #4.  Can a self-imposed diet have a long-term impact on a patient’s body weight and general health?  To this time, claims regarding usefulness of weight loss diets to improve general health are all fluff.  The average lifespan in the United States for both women and non-smoking men is over 77 years of age.  Other than the experiments of nature described above, effects of diets such as the Atkins diet, etc. have no significant data documenting longevity benefit, overall health benefit, or cosmetic benefit over the long run.  In the next three columns, the Atkins diet, the Mediterranean diet and a low fat diet will be analyzed in regard to factual expectations, potential dangers, and what is mostly fluff.