Vegan diets in general are lower on calories than omnivorous diets, and as a result vegans are normally slimmer than their omnivorous counterparts. It was found that vegetarians weigh some 8 kg less than meat eaters who in turn are, on average, 5-7 kg over weight.[i] The lower weight of vegetarians has distinct health advantages in that slim people fall into lower risk categories regarding cardiovascular diseases and cancer.[ii],[iii] Obviously the body requires a minimum intake of energy to stay alive, and the number of calories required varies with sex, size and body weight. Adults require some 1000-1700 calories per day at rest (basal metabolic rate or BMR) whilst activity increases the energy expenditure. The average energy consumed per day is 2 000 calories for women and 2 700 for men, whereas heavy manual labour or sporting activity can increase the requirements to as much as 4 000 calories per day. The vegan diet has a lower fat and protein content and a higher carbohydrate content than most other diets, and particular attention must be paid to energy intake as the energy supply from fat is some 9,4 kcal/g, whereas carbohydrates and proteins supply only 4,2 and 4,3 kcal/g respectively.
Food guides in general are useful in teaching, but the average person will not pay much heed to them unless he can be educated to do so. The vegetarian tribes of the world also do extremely well without the use of dietary charts and lists of recommended daily allowances (RDA). The diets that have been established in these tribes have, however, arisen over time and have been practiced for generations, whereas Western societies must rediscover simple wholesome eating practices. Moreover, there are so many so-called health foods and metaphysically inspired health notions, that the health-food industry has become a veritable minefield of misinformation. Under these circumstances it is prudent to make a thorough investigation of the issue, and not to avoid the voice of science.
In general the Western societies adhere to the Basic-Four nutritional guide which correlates adequate nutrition with regular intake of the four basic food types: Dairy products, breads and cereals, fruits and vegetables and meat. It is interesting that even this Basic-Four Food Guide was found to be lacking in vitamin E, vitamin B-6, magnesium, zinc and iron.[iv] In the past, these four food groups were depicted as of equal importance, and the plate was divided into four quarters each with one of these food groups. This Basic-Four diet has recently come under attack from health circles, but intensive lobbying by the meat and dairy industry has managed to keep it at least partially afloat in the minds of the general public. In the past American school children were taught that a healthy diet included meat every day, but now the US government has recognized that a vegetarian diet can be healthy. In 1992 the USDA issued a revised recommendation in which the “food pyramid” was used for the first time. It was now suggested that grains and cereals form the bulk of the diet, vegetables and fruits were suggested as next in importance followed by animal product and finally fats, oils and sugars which were to be used sparingly. The 1996 guidelines are a further advance on this, and the inclusion of vegetarianism as a healthy alternative may almost be considered bold. The 1996 guidelines state “Most vegetarians eat dairy products and eggs and, as a group, these lacto-ovo-vegetarians enjoy excellent health”. The guidelines, however still warn against a strict vegan diet and supplementation of iron, zinc, and B-vitamins is suggested.[v] The change of heart comes from an overwhelming body of evidence that the consumption of animal products is a health risk, and it can be expected that more changes in lifestyle will be recommended in the future. Already, Michael Jacobson, executive director of the “Centre for Science in the Public Interest” criticized the US government for not coming out more strongly against meat in the 1996 guidelines.5 Vegan vegetarians need different guidelines to those commonly accepted in Western societies, and they need to plan their eating regimes carefully, nevertheless a balanced vegan lifestyle is not only possible, but can indeed be desirable in terms of health.
Ovo-lacto- and lacto-vegetarians have less of a problem in meeting caloric needs than do vegan vegetarians, and that is why the safety of lacto-ovo-vegetarian eating patterns is normally emphasized in dietetic recommendations, whilst specialized dietary planning is recommended for vegan type diets.[vi],[vii] The energy component of ovo-lacto-vegetarian diets is boosted by the animal fats included in these diets and is therefore not to be regarded as a positive aspect of these diets. Vegan vegetarians must plan diets that will compensate for the omission of dairy products, by ensuring that they include adequate quantities of high energy foods in their diets, which must also meet all the other basic needs of the body. Provided this is done, it has been shown that a vegan diet can provide all the body’s needs and can be followed without fear. A number of suggested vegan diet patterns have been analyzed, and it was found that the diet suggested by Selma Chaij-Rhys came closest to satisfying daily nutritional needs of adults.[viii],[ix] In addition this diet uses a simple numerical formula and starts off by using grains, fruits, nuts and vegetables, and adds vegetable-protein foods fortified with vitamin B-12, such as fortified soy milk or simply a B-12 supplement. The numerical formula used in this diet guide is the 1-2-3-4-5 pattern, to help the user remember the number of servings to be used in each food category per day.
This eating pattern will supply more than double the RDA of iron, particularly as the high vitamin C content will enhance the utilization and absorption of non-haem iron.[x] Riboflavin and niacin needs are also met. The pattern, however, falls short in protein and energy, particularly in men, but the use of a larger serving size would help to bridge the energy gap. In women the Chaij-Rhys diet plan will supply adequate nutrition in all the nutrients with the exception of calories. Again a somewhat larger serving will cater for all the needs, including energy needs.
To
satisfy protein needs, correct food combinations are essential, as various
plant-protein sources complement one another. Legumes are high
in lysine but low in the sulphur-containing amino acids methionine and
cystine, and the combination of legumes with grains, which are high in
methionine and threonine and low in lysine, will provide an excellent
protein.[xi] To
achieve a proper amino acid balance is thus not nearly as complicated
as it sounds, and the ordinary peanut butter sandwich will supply complete
proteins as it is a combination of a grain (wheat) and a legume (peanuts).
The above has been excerpted from the book Diet and Health by Professor Walter J. Veith available through our webstore.
Resources:
[i] Register, U.D. and Sonnenberg, L.M. 1973. The vegetarian diet. J.Am.Diet.Assoc. 62: 253-261.
[ii] Beil, L. 1988. Lean living. Science News 134: 142-143.
[iii] Butrum, R.R., Clifford, C.K., Lanza, E. 1988. NCI dietary guidelines: rationale. Am.J.Clin.Nutr. 48: 888-95.
[iv] King, J.L., Cohenour, S.H., Corruccini, C.G. Schneeman, P. 1978. Evaluation and modification of the Basic Four Food Guide. J.Nutr.Educ. 10:27-9.
[v] Kleiner, K. 1996. Life liberty and the pursuit of vegetables. New Scientist. 13 January, 1996
[vi] Mutch, P.B. 1988. Food guides for the vegetarian. Am.J.Clin.Nutr. 48:913-9
[vii] Michigan Department of Public Health. 1980. Basic Nutrition Facts. SLansing, M.I.: MD PH (MDPH publication) H-808.
[viii] Nieman, D.C. 1988. Vegetarian dietary practices and endurance performance. Am.J.Clin.Nutr. 48: 754-61.
[ix] Johnston, P.K. 1988. Counseling the pregnant vegetarians. Am.J.Clin.Nutr. 48:901-5.
[x] Smith, M.V. 1988. Development of a quick reference guide to accommodate vegetariansim in diet therapy for multiple disease conditions. Am.J.Clin.Nutr. 48: 906-9.
[xi] Jacobs, C. and Dwyer, J.T. 1988. Vegetarian children appropriate and inappropriate diets. Am.J.Clin.Nutr. 48:811-8.
by Professor Walter J. Veith Phd.