Dear Ed Blonz: Because of some digestive abnormalities, my doctor has told me that I need to be on a very low-fat diet. Is there was a minimum amount of fat that anyone needs to eat on a daily basis?
What, exactly, is the definition of a very-low fat diet, and is there anything I will need to be looking out for with this type of eating? - S.F., Oakland, Calif.
Dear S.F.: The fat in our food is usually packaged as triglycerides. This is its primary form when it travels in our blood stream or when it’s stored in our body.
The structure of a triglyceride can be thought of as resembling the letter E, where the prongs are the three (“tri”) individual saturated or unsaturated fatty acids attached to a 3-carbon “glyceride” back bone. Although it all is called “fat,” whether it is good, bad or ugly depends on the nature of the individual fatty acids and what position they’re in on the triglyceride.
There is no minimum requirement for fat, per se, but there is a need for specific types of fatty acids. These essential fatty acids (EFAs) are found in the oil from seeds and nuts such as corn, soy, safflower, sesame, walnut, and fish oils.
The EFAs should make up about 2 percent of one’s daily caloric intake.
For an average adult, this translates to about 1 to 2 tablespoons from the above-mentioned oils.
It’s rare for an EFA deficiency to develop in anyone eating a mixed diet. However, there have been some cases in which infants and adults on hospital tube-feeding have been accidentally placed on EFA-deficient formulas and have developed deficiency symptoms.
As to your second question, a very-low fat diet is one in which fat makes up less than 10 percent of calories.
At present, the average intake of Americans hovers around 36 percent.
Current health recommendations point to 25 to 30 percent as being a reasonable dietary goal.
About the only group where a very-low-fat diet might be a problem would be in children under the age of 2. At this age, standard, recommended levels of dietary fat should be provided.
It’s believed that the higher levels of dietary fat - and even dietary cholesterol - may be needed for proper growth and development.
In adults, however, as long as the EFAs are supplied, there is no apparent health danger in adhering to a very low-fat diet. Given that only a small amount of your daily calories can come from fat, you will need to be thinking about all the other things you will be eating. Per unit weight, fat contains over twice the calories as carbohydrates or protein.
This means that there will be an increase in the volume of foods you will be eating.
Focus on whole grains, vegetables and fruits, and stay away from simple sugars, except those naturally present in fresh fruits.
If you need more guidance, have your doctor recommend a registered dietitian to provide some additional specifics. Information on basic characteristics for a restricted-fat diet can be found at tinyurl.com/3dzohm5, or you can refer to books on the subject, including “Volumetrics” by Dr. Barbara Rolls, or one of the very low carbohydrate diet books by Dr. Dean Ornish.
Ed Blonz, Ph.D., is a nutrition scientist and an assistant clinical professor at the University of California, San Francisco. Send questions to: “On Nutrition,” Ed Blonz, c/o Newspaper Enterprise Association, 200 Madison Ave., New York, NY 10016. For e-mail, address inquiries to: email@example.com. Due to the volume of mail, personal replies cannot be provided. Copyright 2011, Edward Blonz. Distributed by United Feature Syndicate, Inc.