Roy L. Walford, M.D. has been Professor of Pathology at the UCLA School of Medicine since 1966. His scientific career has been focused largely on research into the biology of aging. With pre-medical training at the California Institute of Technology and a M.D. from the University of Chicago, he is licensed to practice medicine in California and in Arizona, and is board certified in Pathologic Anatomy and Clinical Pathology.

Previous positions have included: from 1962-72, Director of the School of Medical Technology, UCLA Hospital, 1971-80, Director of UCLA Blood Bank, 1990-94, Chief of Medical Operations, Space Biospheres Ventures (Biosphere 2), Oracle, Arizona, and visiting Professor of Surgery, University of Arizona. Advisor to the World Health Organization in Immunology; Counselor to all the International Histocompatibility Workshops; Senatorial Delegate to the White House Conference on Aging in 1981; Fulbright Research Scholar (for study in Germany, 1960, laboratory of Otto Westphal), and a Commonwealth Fund Fellow (for study in France, 1968, laboratory of Nobelist Jean Dausset). He was the physician inside Biosphere 2 during its first two years of closure, 1991-93.

Get the recipe for Dr. Walford's Supreme Vegetable Salad in The FRONTIERS Cookbook.

5.18.01 Melissa asked:
Can you address the concept of "set weight"? I'm assuming that things like childbirth, nursing, etc. affect one's body metabolism over a lifetime. How do you find your set weight?

Walford's response:
"Set weight" or "set point" refers to what you weigh when you eat a reasonably healthy but not necessarily super-healthy diet but as much as you want. It may also be what you weighed when you were in your low 20's. For example, I was Captain of the wrestling team for 2 years in college. I weighed 150 and had to train down to 147 to make my weight class. I was trim at 150. I stayed at 150 for many years, until starting calorie restriction. Now I'm much less. But 150 is clearly my "set point". For other persons, determining "set point" may be more difficult, if their weight has varied a lot. You have to make an estimate.

5.18.01 Patricia asked:
Dr. Walford, do you have any suggestion on how to clean out your system to help prevent free radicals and eliminate food particles that may be stuck to you intestine walls? Also, how do you feel about fasting? Thank you.

Walford's response:
Free radicals are a necessary part of many normal chemical reactions in the body, but the overflow may be damaging. They are produced more or less instantaneously in the course of normal metabolism and are beneficial or damaging right at that time.

In other words, they do not accumulate, and there is no way and no need to "clean out" the system from these agents. However, less free radical overflow is produced, and the damage-repair machinery is better, on a low-calorie diet. There is a great deal of scientific evidence for this statement.

As to food particles stuck to intestinal walls, food may be impacted in diverticulae (abnormal outpouchings from the intestinal wall), but that's a straight medical problem for your doctor. Food particles do not "stick" to a normal intestinal wall. Short-term fasts of a few days are healthy, long-term fasts maybe not; but that's just an opinion. I have not studied carefully the literature on fasting.

5.18.01 Monica asked:
Dear Dr. Walford, What computer program were you using to calculate nutrition? Does the public have access to it? If so how? Thank you for the opportunity to contact you.

Walford's response:
The software is the Interactive Diet Planner. I devised it for our use for the 2-years inside Biosphere 2, where I was the physician crew-member, so we could be sure our low-calorie diet remained nutrient-dense (maximal nutrient content per calorie). A greatly improved version of the Diet Planner is available from my Web site (LINK to www.walford.com). At the moment, it's only available for PC's. A Mac version may be out in the future.

5.18.01 Joseph asked:
Dear Dr. Walford Your segment on Scientific American Frontiers fascinated me. However I am interested in your views on exercise and physical activity in general. It would seem that a low caloric diet might not provide the necessary fuel for an extremely active person. I run and cycle and sometimes find myself out of energy if I don't eat a proper meal beforehand, and for me that means a lot of calories. Thanks!

Walford's response:
Exercise by itself is health enhancing and will help prevent disease, like cardiovascular disease, but it does not retard the rate of aging. However, a low-calorie nutrient-dense diet will do both, will markedly lower susceptibility to cardiovascular disease, diabetes, auto-immune disease, cancer etc., and also retard the rate of aging. Exercise and a good diet are not in opposition, but, at least for disease prevention, complimentary. But if you simply eat less (to decrease your calories) of the usual fast-food intake of the "normal" American (fast foods etc.) diet, you will get into nutrient deficiencies, and that won't work for either disease or longevity. High quality diet, low in calories, and moderate exercise make the best combination.

5.18.01 Gillian asked:
Dr. Walford, Are you a vegetarian? Is it healthier to just eat veggies? How do you supplement essential amino acids when you omit red meat? What are the pros and cons of eating meat? Thank you.

Walford's response:
I personally am not a vegetarian but I eat less red meat or poultry (maybe 1x/wk) and more fish (maybe 2x/wk) than the average person. However, it's not difficult to achieve full nutrition on a completely vegetarian diet. Complete nutrition data is given for all the meals in my several books, and many are without meat. Or nutrient-dense vegetarian meals can be calculated using the Interactive Diet Planner (see above). The essential thing is low overall calories (to achieve the age-retardation effect). The distribution (where the calories come from) is less important so long as you get at least the recommended daily allotment of each essential nutrient. Of course, you can't do that on popcorn, cake and fast foods, but you certainly can on a good vegetarian selection. You have to make choices. On a low-calorie nutrient-dense diet you will live longer, healthier, have more vitality, need less sleep, be more resistant to disease (including colds) etc.; but you have to limit your intake of bad foods.

5.18.01 Kathryn asked:
Dr. Walford, Are you a vegetarian? Is it healthier to just eat veggies? How do you supplement essential amino acids when you omit red meat? What are the pros and cons of eating meat? Thank you.

Walford's response:
I personally am not a vegetarian but I eat less red meat or poultry (maybe 1x/wk) and more fish (maybe 2x/wk) than the average person. However, it's not difficult to achieve full nutrition on a completely vegetarian diet. Complete nutrition data is given for all the meals in my several books, and many are without meat. Or nutrient-dense vegetarian meals can be calculated using the Interactive Diet Planner (see above). The essential thing is low overall calories (to achieve the age-retardation effect). The distribution (where the calories come from) is less important so long as you get at least the recommended daily allotment of each essential nutrient. Of course, you can't do that on popcorn, cake and fast foods, but you certainly can on a good vegetarian selection. You have to make choices. On a low-calorie nutrient-dense diet you will live longer, healthier, have more vitality, need less sleep, be more resistant to disease (including colds) etc.; but you have to limit your intake of bad foods.

5.18.01 Luke asked:
Hi Dr. Walford, After seeing you and the show on PBS about eating less to live longer, I have a question for you: can I eat just one meal (dinner) a day for months to lose weight and be healthy? Thank you.

Walford's response:
Yes, you can eat one meal a day for months and remain healthy; but you have to do it right. First, that one meal has to have all the non-calorie nutrients which the body needs. Second, if you are going for age-retardation, it's a long-term affair, and weight should not be lost too rapidly. One or two pounds a month, on the average would be OK

5.18.01 Amy asked:
I recently had an Iridology study completed. Is it true that your eyes are linked to each organ of the body and disease or weakness can be seen using this study? I was also told of foods that were "poisonous" to my body due to my blood type (A Pos). Is there any truth to this?

Walford's response:
Iridology is a form of so-called "alternative medicine", the evidence for which is almost entirely anecdotal ["I know someone who did it and it works!" -- that's anecdotal evidence]. Unfortunately anecdotal evidence is very untrustworthy. If you accept it, you end up believing in UFO's, miracles, ghosts, witchcraft, and so forth -- because these all have people who will testify to the experience. So I can't answer your question except to express skepticism. Fortunately, the National Institutes of Health now has a division devoted to evaluating the claims of the various forms of alternative medicine. I will wait for their evaluation of the various fields of alternative medicine. As for any relation between blood types and what food you should be eating (the "Eat for Your Type " book), my opinion is that that's baloney. The author is an M.D., but in my view either simply foolish or a disgrace to his profession.

5.18.01 Brian asked:
Dear Dr. Walford, I am very interested in nutrition as it relates to a long and healthy life. My question is: you stated that we may be able to prolong our life by reducing our caloric intake- resulting in a subsequent loss of about 10% of our normal body weight. Is this a realistic and healthy goal for young men and women who like to participate in sports and other physical activities? In your experience would this diet allow us to maintain our strength, and our ability to participate in vigourous sports?
Thanks for the very interesting information!

Walford's response:
Of course the 10% depends on where you start from, and how vigorous the sport. Generally, however, 10% loss if on a nutrient-dense diet should actually enhance ability to participate in sports. It will lead to better health judging by levels of blood pressure, blood sugar, blood lipids, and a feeling of general well-being.

5.18.01 Rob asked:
Hello Dr. Walford, I'm curious if there is one (packaged) food product available that is nutritionally balanced, quick, easy, and perhaps in measured portions, similar to the rhesus monkey diet? Thanks much.

Walford's response:
No, sorry, I know of no packaged food product that fulfills all the requirements. Weight Watchers, Pritikins, and similar products are pretty good, but should be mixed with fresh wholesome foods. We don't know enough about nutrition to make a one-product package. There are still doubtless undiscovered factors in whole foods that are health-enhancing. Phytochemical nutrients, for example, were almost unknown 12 years ago.