|LEF Magazine June 1998 |
Continued from Can Calorie Restriction Work on Humans?
People often speak of hunger as being a barrier to practicing CRAN, but people often eat for reasons other than hunger. People eat out of habit, often because it is "mealtime," a social ritual. Also, people regularly eat for enjoyment, to entertain themselves, as well as because of appetite, something very distinct from hunger. And people eat until they are "full." Eating to satiety is very difficult to avoid, although resisting the temptation to start eating is much easier than ceasing to eat once eating has begun, says author Best.
"I am not afraid to experience hunger," he notes. "If a person wants to seriously restrict calories, then will power and a willingness to experience feelings of hunger must eventually enter the picture. It is remarkable to me how absolutely unwilling people can be to allow themselves to feel even the slightest amount of hunger. Often, all that is needed is to wait a few minutes for the feeling to pass. But even if the feeling does not immediately pass, I think it is a discomfort that a person can learn to live with, like the necessity of getting up in the morning to go to work, or engaging in exertions required for exercise. Learning to accept various levels of hunger is like building a muscle. It takes practice."
Nonetheless, Best is still trying to find gimmicks he can use to reduce his calorie intake while minimizing his discomfort. "Changing eating habits involves training. Once skim milk tasted like water to me, and I avoided it. However, I trained myself to drink skim milk rather than 2-percent milk until I finally accepted skim. Now 2-percent milk tastes like overly rich cream to me. I have trained myself to eat low-calorie vegetables when my appetite might incline me to eat something else. And I have learned not to buy or keep high-calorie foods in my kitchen."
Best says a useful practice he has found is to refuse to eat any food that he has not first weighed and calculated the calorie content for. The book Food Values by Jean Pennington contains the calories per gram of all the foods he eats. These results are summarized in sheets of paper taped to his cupboard doors.
"Calculating the caloric content of all eaten foods does a great deal to increase awareness of calories, and the process is essential for anyone restricting themselves to an upper limit of calories per day. For six months I weighed all my food and calculated calories to ensure that I would not exceed 1,600 calories per day."Charting One Man's Physical Examinations
Ben best in experimenting with calorie restriction over the past several years has recorded dramatically changing vital bodily measurements in that time
|Year ||Weight (Pounds) ||Blood Pressure ||Glucose (MMOL/L) ||Leucocytes (X10*9/L) ||Uric Acid (UMOL/L) ||Triglyceride (MMOL/L) ||HDL (MMOL/L) ||LDL (MMOL/L) |
|1989 ||158 ||130/96 ||4.8 ||9.0 ||339 ||1.82 ||N/A ||N/A|
|1991 ||168 ||124/90 ||4.8 ||7.3 ||358 ||2.10 ||1.31 ||1.95|
|1992 ||157 ||130/94 ||5.1 ||6.3 ||308 ||0.83 ||1.12 ||1.76|
|1993 ||150 ||120/80 ||5.5 ||7.8 ||349 ||1.94 ||1.20 ||2.41|
|1994 ||130 ||110/80 ||4.7 ||5.1 ||215 ||2.02 ||1.45 ||1.03|
|1995 ||120 ||106/70 ||4.4 ||5.1 ||233 ||1.00 ||1.26 ||1.43|
|1997 ||112 ||100/80 ||4.4 ||5.1 ||186 ||0.71 ||1.52 ||1.31|
Some CRAN Caveats
CRAN is not without its hazards, above and beyond the inability to indulge all the pleasures of the appetite. Nearly all CRAN practitioners experience an increased sensitivity to cold, particularly in the extremities. Author Ben Best reports that his feet are usually cold if he take no precautions. He wears at least two or three pairs of heavy socks, even when sleeping.
"Another hazard is hemorrhoids," Best says. "During various stages of my food restriction experiments I noticed that my stools would become small, dry and hard. Eventually I got hemorrhoids. I now know that adequate nutrition for CRAN must include adequate fiber. Eating many vegetables doesn't necessarily guarantee adequate fiber. The best fiber to prevent hemorrhoids is a mixture of psyllium and wheat bran. This mixture has the added benefit of having been shown to reduce the incidence of colon cancer in experimental animals to a quarter of that seen in controls. Colon cancer is second only to lung cancer as a cause of cancer death in humans.
The very worst hazards Best experienced in practicing CRAN were toward the end of his 6-month period on fewer than 1,600 calories per day. His weight had dropped below 115 pounds and he was experiencing lightheadedness, physical weakness, periodic cardiac acceleration and gastrointestinal pains. His lightheadedness was so extreme at one point that he fainted-not while driving, luckily. He experienced his first flu in more than two years, and had difficulty shaking it off. He was down to 112 pounds when it was time for his annual physical examination.
"My 15-hour fast in preparation for my examination caused me great discomfort, possibly including symptoms of hypoglycemia (low blood sugar). When my physician put me on an EKG he found bigeminal rhythm-extra systoles (heartbeat irregularities). He didn't rush me to the hospital, but he did warn me that I should gain some weight. Extra systoles are not usually life-threatening, but they can be. I immediately went on an eating binge. It took me a while to regain my stability and pursue a more 'moderately stringent' version of CRAN. Currently, my target weight is 120 pounds, and I rarely go above 123."
Laboratory animals are in protected environments. However, people who are living workaday lives may be subject to stresses and vulnerable to conditions that could make hypoglycemia or weight-loss due to a disease more dangerous. Best believes that keeping his weight between 119 and 123 pounds provides him with a certain buffer against such events. He also suspects that there may be an important difference between CRAN that is imposed upon laboratory animals and CRAN that is a voluntary practice-in short, voluntary CRAN can create psychological stress. Beyond a certain intensity this stress may be physically damaging because of secretion of excessive amounts of stress hormone (cortisol). In fact, hypercortisolism is seen in CRAN animals and in anorexics, he notes. One theory of aging makes a strong case for the idea that stress and glucocorticoids play a key role.
"Another thing I learned from my physical examination," Best says, "was that my testosterone levels were well below the normal range. I had noticed a dramatic drop in my libido and was well aware that CRAN animals typically show reduced levels of sex hormones. Female anorexics often stop menstruating. A silver lining to my low testosterone levels, however, is the reduced risk of prostate cancer. My prostate specific antigen (PSA) level was 1.5 nanograms per milliliter of blood serum, well below the normal limit of 4.
"Sex hormones are produced from DHEA, which in turn is produced from cholesterol. My blood DHEA had been equal to the level of an average 95-year-old-which is pretty low for a middle-aged man like me. After learning that my testosterone was also low, I began taking 15 mg of DHEA three times daily in the hope that my DHEA and testosterone levels could increase. As a result, my libido has increased somewhat, and a more recent Life Extension Foundation measurement of my DHEA has shown me to be at the level of an average 75-year-old."
DHEA is known to oppose the actions of cortisol, so this might be a way to oppose the "stress response" and boost his immune system, Best says. He plans to increase his DHEA and see what his blood levels of cortisol and testosterone are at his next physical examination.Further Reading
"Dietary Restriction of Adult Male Rhesus Monkeys: Design, Methodology, and Preliminary Findings From the First Year of Study" Joseph W. Kemnitz, et al. Journal of Gerontology (Biological Sciences) 48(1):b17-b26 (1993)
"Diet restriction in rhesus monkeys lower fasting and glucose-stimulated glucoregulatory end points" Mark A. Lane, et al. American Journal of Physiology 268:(5 part 1):e941-e948 (1995)
"Dietary restriction increases insulin sensitivity and lowers blood glucose in rhesus monkeys" Joseph W. Kemitz, et al. American Journal of Physiology 266: (4 Part 1): E540-E547 (1994)
"The calorically restricted, low-fat, nutrient dense diet in Biosphere 2 significantly lowers blood glucose, total white cell count, cholesterol and blood pressure in humans" Roy L. Walford, et al. Proceedings of The National Academy of Sciences of The U.S.A. 89:11533-7 (1992)
"Biosphere Medicine' as Viewed From the Two-Year First Closure of Biosphere 2" Roy L. Walford, et al. Aviation, Space, and Environmental Medicine 67(7):609-617 (1996)
"Nutritional Methodology in Metabolic Research with Rats" Heather Greenfield and George M. Briggs Annual Review of Biochemistry 40:549-572 (1971)
"The Effect of Dietary Cellulose on Life Span and Biochemical Variables of Male Mice" G.C. Kokkonen and C.H. Barrows AGE 11(1):7-9 (1988)
"Satiation, Satiety and the Action of Fibre on Food Intake" J.E. Blundell and V.J. Burley International Journal of Obesity (Suppl.1) 11:9-25 (1987)
"The effects of high and low energy density diets on satiety, energy intake, and eating time of obese and non-obese subjects" Karen H. Duncan, et al. American Journal of Clinical Nutrition 37:763-767 (1983)
"Effects of dieting and exercise on lean body mass, oxygen intake, and strength" Konstantin Pavlou, et al. Medicine and Science in Sports and Exercise 17:466-471 (1985)
"Resistance weight training during caloric restriction enhances lean body weight maintenance" Douglas L. Ballor, et al. American Journal of Clinical Nutrition 47:19-25 (1988)
"Relation of Electrolyte Disturbances to Cardiac Arrhythmias" Charles Fisch Circulation 47:408-419 (1973)
"Effects of Self-Induced Starvation on Cardiac Size and Function in Anorexia Nervosa" John S. Gottdiener, et al. Circulation 58:425-433 (1978)
"Anorexia nervosa and bulimia nervosa" Kathryn J. Zerbe Postgraduate Medicine 99(1):161-169 (1996)
"Sudden death associated with very low calorie weight reduction regimens" Harold E. Sours, et al. American Journal of Clinical Nutrition 34:453-461 (1981)
"Sudden, Unexpected Death in Avid Dieters Using the Liquid-Protein-Modified-Fast Diet" Jeffrey M. Isner, et al. Circulation 60(6):1401-1412 (1979)
"The Historical Development of Very Low Calorie Diets" A.N. Howard International Journal of Obesity 13 (Sup.2) 1-9 (1989) "Very Low Calorie Diets" National Task Force on the Prevention and Treatment of Obesity Journal of the American Medical Association 270:967-974 (1993)
"Effects of voluntary exercise on longevity of rats" John O. Holloszy, et al. Journal of Applied Physiology 59(3): 826-831 (1985) "Interaction between exercise and food restriction: effects on longevity of male rats" J.O. Holloszy and K.B. Schechtman. Journal of Applied Physiology 70(4): 1529-1535 (1991)
"Mortality rate and longevity of food-restricted exercising male rats: a reevaluation" John O. Holloszy Journal of Applied Physiology 82(2):399-403 (1997)
"Biochemical Mechanisms for Oxygen Free Radical Formation During Exercise" Bertil Sjodin, et al. Sports Medicine 10(4):236-254 (1990)
"Vitamin E prevents exercise-induced DNA damage" Andrew Hartmann, et al. Mutation Research 346: 195-202 (1995) "Dietary supplementation of Vitamin E protects heart tissue from exercise-induced oxidant stress" Charles T. Kumar, et al. Molecular and Cellular Biochemistry 111:109-115 (1992)
"Exercise, Oxidative Damage and Effects of Antioxidant Manipulation" Eric H. Witt, et al. Journal of Nutrition 122:766-773 (1992) "The Effect of Intravenous Vitamin E and Menadiol Sodium Diphosphate on Vitamin K Dependent Clotting Factors" Lawrence Helson Thrombosis Research 35:11-18 (1984)
"Study on the effect of megavitamin E supplementation in man" Alan C. Tsai, et al. American Journal of Clinical Nutrition 31:831-837 (1978)
"Thinness and Mortality" Stephen Sidney, et al. American Journal of Public Health 77:317-322 (1987)
"Body mass index and patterns of mortality among Seventh-day Adventist men" Kristian Lindsted, et al. International Journal of Obesity 15:397-406 (1991)
"Variations in Mortality by Weight Among 750,000 Men and Women" E.A. Lew and L. Garfinkle Journal of Chronic Diseases 32:563-576 (1979)
"Body Weight and Mortality among Women" JoAnne E. Manson, et al. New England Journal of Medicine 333(11):677-685 (1995) "Body weight and mortality: a 27-year follow-up of middle-age men" I.M. Lee, et al. Journal of The American Medical Association 270:2823-2828 (1993)
"Association of Weight Loss and Weight Fluctuation with Mortality Among Japanese American Men" Carlos Iribarren, et al. New England Journal of Medicine 333(11):686-692 (1995)
"Potential synergism between wheat bran and psyllium: enhanced inhibition of colon cancer" O. Alabaster, et al. Cancer Letters 75:53-58 (1993)
"Chronic Food Restriction and the Circadian Rhythms of Pituitary-Adrenal Hormones, Growth Hormone and Thyroid-Stimulating Hormone" A. Armario, et al. Annals of Nutrition and Metabolism 31:81-87 (1987)
"Abnormal Hypothalamic-Pituitary-Adrenal Function in Anorexia Nervosa" Philip W. Gold, et al. New England Journal of Medicine 314:1335-1342 (1986)
"The Neuroendocrinology of Stress and Aging: The Glucocorticoid Cascade Hypothesis" Robert M. Sapolsky, et al. Endocrine Reviews 7:284-301 (1986)
Stress, the Aging Brain and Mechanisms of Neuron Death, by Robert M. Sapolsky (1992)
"Anti-glucocorticoid effects of dehydroepiandrosterone (DHEA)" Mohammed Kalimi, et al. Molecular and Cellular Biochemistry 131:99-104 (1994)
"Dietary Restriction Alone and in Combination with Oral, Ethoxyquin/2-Mercaptoethylamine in Mice" Steven B. Harris, et al. Journal of Gerontology (Biological Sciences) 45(5):B141-B147 (1990)
"Co-Enzyme Q-10 and Life Extension" L. Stephen Coles and Steven B. Harris, Advances in Anti-Aging Medicine, Volume 1, Dr. Ronald M. Klatz, Editor (1996)
"Carnitine status of lactovegetarians and strict vegetarian adults and children" Kenneth A. Lombard, et al. American Journal of Clinical Nutrition 50:301-306 (1996)
"Carnitine and Its Derivatives in Cardiovascular Disease" Michael A. Arsenian Progress in Cardiovacular Diseases 40(3):265-286 (1997)
"A Cluster Analysis Study of Acetyl-L-Carnitine Effect on NMDA Receptors in Aging" Massimo Castorina, et al. Experimental Gerontology 28:537-548 (1993)
"Acetyl-L-Carnitine: A Drug Able to Slow the Progress of Alzheimer's Disease?" A. Carta and M. Calvani Annals New York Academy of Sciences 640:228-232 (1990)
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