Central  South  Dakota  Medical News
The Clinical View
by Phillip Hoffsten
27 OCTOBER 2004

THE DIET MAZE:  LOW FAT DIETS

     The last two columns have been devoted to the Atkin’s Diet and the Mediterranean Diet.  The Atkin’s Diet advocates 40% of calorie intake as being fat. The Mediterranean Diet advocates approximately 20% of calorie intake as being fat.  The low fat diets are illustrated by the “Ornish Diet” and the “Pritikin Diet”.  The Ornish Diet advocates that all fat taken in be vegetable origin while the Pritikin Diet allows some animal fat but still only 10% of total calories coming from fat.

     Question #1:  What is the origin and purpose of a low fat diet?
     It was observed many years ago that vegetarians had a distinctly low incidence of heart disease, stroke, or high blood pressure.  A vegetarian’s cholesterol is characteristic quite low.  The longevity and health of vegetarians exceeds that of the general population.  Doctors Pritikin and Ornish took advantage of this observation and reasoned that the success of the vegetarian diet resided in the low fat content.  Thus was born their diet plan.  It depends upon a very high intake of vegetables and fiber with the Ornish Diet markedly diminishing the intake of standard American meat products.

     Question #2:  Does the low fat diet contribute to weight loss?
     If adhered to, the answer is a definite yes.  Probably more than effective weight loss program, the low fat diet appears to be very effective for a weight maintenance program.  However, clinical studies putting one group of individuals on an Atkin’s Diet program and another group of individuals on a low fat diet has clearly shown that the low fat diet is not as effective a weight loss program as an Atkin’s Diet plan.  Over a six-month period the Atkin’s Diet plan results in almost double the weight loss as opposed to the group of people on a low fat diet.

     Question #3:  What is the “gimmick” that makes the low fat diet work?
     If an individual is able and willing to adopt an essentially vegetarian lifestyle, weight loss, decreased cholesterol, decreased blood pressure and longevity are a predictable result. While the original plan of the low fat diet was to decrease the amount of cholesterol consumed, this probably plays very little part in the effectiveness of the vegetarian low fat diet.  In fact, your body produces about 1200 mg of cholesterol per day.  A normal dietary intake is around 300 mg per day.  When a diet gets to 200 mg a day of cholesterol or less, it begins to taste more or less like cardboard and is very unsatisfying.  Thus, the cholesterol lowering effect of the Pritikin Diet is a very minor contributor.  This is because whatever cholesterol the body needs is quickly made up when the dietary intake drops.  Thus, if a person cuts their diet from 300 mg of cholesterol a day to 200 mg of cholesterol per day, the liver will simply make extra cholesterol to make up for what is not eaten and there will be no net change in the amount of cholesterol presented to the body each day.

     Thus the real gimmick of the low fat diet is the calorie limitation imposed by this program.  You just can’t eat enough vegetables to get a lot of calories in and the calorie limitation is what lowers the blood cholesterol.

    Question #4:  Is a low fat diet safe?
     The answer is a very clear yes.  It is recommended that people on a low fat diet take a vitamin pill and an adequate amount of low fat dairy products to ensure adequate calcium and protein in the diet.  However, vegetarians do not die young and they don’t become incapacitated from degenerative disease at anywhere near the rate the general population does.  Thus, the low fat diets do appear to be safe.

     Question #5:  What is the problem with low fat diets?
     The biggest problem with low fat diets is adherence to the program.  Carrots, celery, tomatoes, spinach, cauliflower and broccoli, etc. just seem to get old after awhile.  In addition, those who have conditioned themselves to enjoy rich, creamy, smooth foods don’t get much satisfaction from a low fat diet.  It is fat that makes cheesecake, ice cream, eggnog, gravy, etc. taste so good.  Once a person gets used to this taste sensation, deleting it from the diet is not a satisfying situation.  Thus, the biggest problem with low fat diets is adhering to them.

     Question # 6: For whom would a low diet “Ornish” or “Pritikin” Diets be recommended?
     Adoption of a low fat diet program requires substantial discipline.  This type of diet plan would be recommended for a highly motivated individual who has major risk factors for development of coronary artery disease or someone who has already had their first heart attack.  A low fat diet correctly adhered to will lower cholesterols and lower blood pressures in most people.  Individuals who are disciplined enough to follow this type of program can expect significant benefits.  However, to this time, I am not aware of a comparative study showing that a low fat diet prescribed for a group of individuals is shown to have long term benefit.  My prejudice is that the reason this is so difficult to show is that adherence to the diet is so difficult.

     Question #7:  How can a person find detailed information about the foods allowed in the various diet plans?
     Bookstores, libraries, and the Internet have an almost endless supply of books about various diet plans.  The Atkin’s Diet book is almost 300 pages long and requires extensive reading if a person is to adopt this plan.  The same is true for the South Beach Diet, the Mediterranean Diet, and the various low fat diets.  Readers are referred to the greater detail available in these books to provide meal-to-meal and day-to-day listings and suggestions of what might be eaten.

     If a diet plan is to be effective, there is no question that the most critical consideration has to do with the quantity of food taken in.  Regardless if whether a diet is low fat or high fat, or modified in any other composition, the bottom line has to do with how many calories are consumed.  If a person takes in more calories than they burn, fat accumulation, the tendency for higher blood pressures, the tendency to higher blood cholesterols and the impairment of health are an expected and predictable result.  When all is said and done, quantity of food is much more important than quality of food.