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There are many different uses for one set of numbers.
They can be misused and often . . . they are expected to provide more or different information than they were ever designed to give" (14). Most recommendations:

a. are for nutrients as eaten after food processing and cooking;
b. are for healthy people; they do not allow for illnesses or major stresses in life;
c. may be affected by a variety of drugs;
d. are more than enough for most people and are therefore too high themselves as criteria for inadequate food intake;
e. do not have to be eaten every single day; a low intake one day can be balanced by eating more than the recommendation the next day;
f. do not say that you cannot eat more of the nutrient than the recommended amount, but do not indicate at what higher level toxic effects might arise;
g. assume a certain nutritive quality, biological value, or availability in the body (which is usually stated some where in the text of the report); for example, a re commendation for protein may assume that the mean net protein utilization is 70 per cent, or for iron, that part of it is coming from meat or fish;
h. assume that enough of other major nutrients and energy are consumed;
i. are for standard body size (e.g., weight) and range of usual exercise (usually stated somewhere in the report);
j. are for oral intake of the usual foods of the country- not for intravenous nutrition;
k. do not cover minor vitamins and trace elements; they assume that if the intake of the main nutrients is adequate and the diet is mixed, the minor nutrients will take care of themselves;
l. cannot fully allow for adaptation that can occur to high or low intake of some nutrients, e.g., energy, iron, and calcium;
m. only tell us about some 15 per cent of the energy intake- protein plus essential fatty acids- and not how the rest of the dietary energy should be distributed between different carbohydrates and fats (and alcohol);
n. do not allow for interactions among nutrients.

HOW RDIs ARE WORKED OUT

The WHO/FAO/IUNS book Food and Nutrition Terminology ( 15) indicates that "recommended dietary allowances" include a high margin of safety to cover individual variation and are usually related to the food supplies and dietary practices of the country in which they are formulated.

For any nutrient in a particular population group:

1. The average requirement is the lowest of the dietary standards. This is sufficient to maintain nutrient balance (or health) in 50 per cent of the group. Percentiles should be used, because the frequency distribution of individual requirements may not be parametric. This average requirement is insufficient for approximately half the population. This is the figure that is used for estimating energy needs of a group, but for other nutrients it could be used only for assessing diets, not for planning.

2. The group requirement is higher: it is the amount of a nutrient that meets the needs of nearly all individuals, say 97 per cent under physiological conditions. Where the distribution of individual requirements is approximately Gaussian, this value is the average requirement plus two standard deviations. It corresponds, therefore, to the safe level used by the FAD/WHO committee for protein requirements (16). The data on the distribution of nutrient requirements are extremely limited except for energy, protein, iron, and calcium.

3. Recommended intakes usually exceed the physiological requirements of nearly all the group for several reasons: (a) to allow for some extreme individuals or when the number of measurements of individual requirements is small; (b) because there are often differences of opinion as to the criteria that should be used to establish requirements (17)- vitamin C is a good example; (c) to allow for some of the common minor stresses of everyday life, e.g., smoking or oral contraceptives; (d) to allow for inefficient utilization by the body of some nutrients as consumed, e.g., iron; and (e) to make the intake consistent with what the particular population is accustomed to eating in its dietary traditions.

There are several approaches to estimating the requirements for a nutrient. Preliminary information comes from observations on the range of intakes by apparently healthy people and in some new instances from experimental deficiency in animals. The four principal direct types of information are:

a. At how low an intake of a nutrient does deficiency disease start to occur in the community?
b. How little of the nutrient will cure clinical signs of deficiency (spontaneous disease or experimentally induced in volunteers)?
c. What is the lowest intake of the nutrient that maintains metabolic balance over a long period? d. What is the minimum intake needed for tissue saturation or to give normal function tests for the nutrient?

Approaches a, b, and c are the classical methods. Here there have been difficulties because of multiple deficiencies in patients with deficiency disease, because depletion diets given to volunteers may not have been accurately analysed, because of adaptation to low intakes, and because of the well-known uncertainties in balance work, as in faecal marking and skin losses.

Newer methods are contributing to our knowledge, but there is a time lag between their use for basic research or for diagnosis and in work on human requirements. Radioisotope studies have been used to study the kinetics of vitamin C distribution (17); red cell transketolase activity is starting to be used to estimate thiamin requirements ( 18); and glutathione reductase is used for riboflavin (17). In estimating protein requirements, Scrimshaw has suggested that total body potassium and serum enzymes be added to the classical nitrogen balance method (19).

SOME REASONS FOR DIFFERENCES BETWEEN RECOMMENDATIONS

There are specific uncertainties for most of the nutrients which require judgement, and these are one reason why there are differences in the RDls in different countries and established by different committees. For vitamin D it is uncertainty about exposure to sunlight. For calcium it is the possibility of eventual adaptation to low intakes. European adults are usually in negative balance at intakes below 800 mg/day, while many Africans and Asians maintain healthy bones on only 50 mg/day. For folate the problem is the multiple forms in foods and incomplete information about their relative availability. For iron the frequency of distribution of losses in women are skewed to the right (20, p. 251), and committees differ as to the feasibility of covering women with the highest 5 per cent of menstrual losses by advising very high iron intakes for everyone. For niacin there is incomplete information on its availability to humans in different foods and on the contribution of tryptophan in different states of protein metabolism and hormonal conditions. For vitamin C the big question is the value of achieving tissue saturation. The United States now recommends 60 mg/day for men (17) to maintain adequate reserves as well as to prevent scurvy, while FAO/WHO, the United Kingdom, Canada, and 12 other countries concentrate on the latter criterion and recommend only 30 mg/day.

Another reason for differences between the final recommendations is bureaucratic rather than scientific. The available data on requirements plus safety factors have to be extrapolated or interpolated among varying numbers of age, sex, and activity subgroups. After infancy has passed, every country seems to divide up the ages of children in a different way (21). While West Germany (FRG) uses only 15 age/sex groups (22), Japan has 58, and other countries have intermediate numbers of subgroups.

WHAT DO THEIR AUTHORS INTEND THE RDls TO BE USED FOR?

The current US RDA report states:

RDAs are recommendations for the average daily amounts of nutrients that population groups should consume over a period of time. RDAs should not be confused with requirements for a specific individual. Differences in the nutrient requirements of individuals are ordinarily unknown. [171

The FAO/WHO Handbook says:

The figures for recommended intakes may be compared with actual consumption figures determined by food consumption surveys. Such comparisons, though always useful, cannot in themselves justify statements that undernutrition, malnutrition, or overnutrition is present in a community or group, as such conclusions must always be supported by clinical or biochemical evidence. The recommended intakes are not an adequate yardstick for assessing health because . . . each figure represents an average requirement augmented by a factor that takes into account inter-individual variability. [4]

The current (1978) British recommendations report states that, since the publication of the previous (1969) report, more difficulties have been encountered about the use of figures than about their validity. Although the figures were intended to apply to groups of people, they have been used mistakenly as recommendations for individuals.... Experience has shown that the distribution of nutrient intakes in a group of healthy people is such that many individuals eat less than the amounts put forward in the 1969 recommendations without any recognizable signs of deficiency A more practical definition of the recommended amount of a nutrient is as follows: The average amount of the nutrient which should be provided per head in a group of people if the needs of practically all members of the group are to be met. [23]

There is not much clear guidance to the dietitian who needs to assess the dietary history of individuals. The British report, for example, says:

Recommended amounts have a limited use in the evaluation of the results of surveys of the amounts of food eaten by individuals.... Since the distribution of requirements for nutrients is not known, it is not possible to estimate the probability that an individual is undernourished by comparing his or her intake with the recommended amount. Nevertheless, it would still be true to say that, on present knowledge, the greater the proportion of people with intakes below those recommended, the greater the possibility that some individuals may be undernourished with respect to the nutrient . . . in question. [ibid.]

The US report puts it a little more helpfully:

Even if a specific individual habitually consumes less than the recommended amounts of some nutrients, his diet is not necessarily inadequate for those nutrients. However, since the requirements of each individual are not known, it is clear that the more habitual intake falls below the RDA and the longer the low intake continues, the greater is the risk of deficiency. [17]

TWO OR MORE LEVELS?

Hegsted in 1975 argued that the two major uses of dietary standards- the evaluation of food consumption records and the planning of diets and food supplies- cannot be adequately fulfilled by a single set of standards;. . . the needs for these two purposes should be clearly recognized, and . . . standards and instructions for their use for each purpose should be developed.

Standards for evaluating food records must be based on estimates of nutrient needs.... Given appropriate standards, methods and statistical procedures, dietary surveys may be used to assign a "degree of risk" in the same manner as biochemical, clinical, and anthropometric procedures.

In contrast, the planning of diets requires consideration of factors other than estimates of nutrient needs. The general objective should be to plan diets acceptable for groups of mixed age and sex since this is the way most people eat. Food supplies, food habits, the aims of nutrition education . . . are relevant. Standards based on nutrient density may be the most useful for this purpose. [24]

At the round-table on dietary recommendations during the Second European Nutrition Conference, in 1977, Wretlind proposed three levels of dietary standards: minimal, acceptable, and desirable, all expressed in nutrient density with the lower two for evaluation of dietary records (25).

At the same conference, there was an unofficial suggestion from a small British group for a two-level system:

Diagnostic figures would be the physiological minimum requirement with some allowance for inter-individual variation that can be used for diagnosing low intakes. Such figures are derived from the sum of nutrient losses in balance experiments, under controlled conditions. Prescriptive figures would be intended in the first place for dietitians and caterers and also for the housewife and for nutrition education and beyond this for guidance in agricultural and economic planning. Unlike the diagnostic figures, these could be expressed as foods, though convertible to nutrients. The method of deriving these recommendations, which should be consistent with a nation's food traditions and resources, involves a different kind of judgement from that used to estimate the diagnostic figure.... Nutrient density (or concentration) could well be used to express the recommendations here but when energy requirements are high an increased consumption of cheaper foods with lower nutrient density would be acceptable and practical. [26]

The 1973 FAD/WHO "safe level" of protein of 0.57 g/kg/ day worked out to 7 per cent of available energy from protein. This figure may be revised on the basis of the recommendations of the 1981 FAO/WHO/UNU meeting mentioned earlier. Most people eat 11 or 12 per cent of their energy as protein. Not to do so would increase the risk of iron, calcium, or zinc deficiency.

The round-table concluded that individual countries might come to accept a single set of (lower) diagnostic figures. These could be similar to the FAD/WHO recommendations, which are lower than those for most affluent countries.

But there are likely to be more differences between countries in the (upper) recommended figures for meal planning. These cannot be quickly standardised because they are involved with traditional food and eating patterns. It seems to us neither desirable nor likely that these will become uniform in the foreseeable future.... Where a country's recommended intake for protein is generous- say 65 9 for an adult - this cannot be used as a criterion for assessing if a diet is inadequate; a low standard has to be found such as the FAD/WHO value of 37 9. [21]

The Scandinavian nutritionists considered Wretlind's system and have developed it into a two-tier system (27). Norway and Sweden will now make this system official. There is one table of recommendations for planning diets (e.g., the vitamin C figure is 60 mg/day for adults) and a separate table of standards for evaluating the intake of nutrients, and here the vitamin C figure for adults is 10 mg/day.

In Australia it has been suggested that three figures should be provided for the national recommendations that are being worked out by the National Health and Medical Research Council Working Party on Recommended Dietary Intake for some newer nutrients:

a. A lower diagnostic level, to be used by health professionals in assessing the adequacy of records of people's food intake. For vitamin C this figure might be 15 or 20 mg/day in adults.
b. The recommended dietary intake, a figure (or range) for consumers- for the general public- as well as for dietitians and home economists. This is a prescriptive figure, what people are advised to eat as a rule. For vitamin C this might be 75 mg/day.
c. An upper level, above which risk of adverse effects from high intake starts. Some such figures are already appearing in modern RDI reports, e.g., the 1980 US RDA report says that vitamin A toxicity is seen in adults with intakes over 15,000 retinol equivalents (15 times the R DA) for long periods, and regular ingestion of more than 7,500 RE (7.5 times the RDA) is not prudent. For many nutrients an upper level, where toxicity starts, has not yet been agreed upon; for vitamin C there would be dispute over whether it should be 1 up to 10 g per day or even more. One interim possibility for some nutrients might be to indicate the maximum amount that people would be likely to obtain from combinations of foods.

With the public's enthusiastic consumption of vitamin tablets, it is becoming necessary for government bodies and health professionals to have standard upper levels for all the nutrients. If the upper level for vitamin C were set high enough to satisfy the "health food" lobby, it could encourage people to take amounts that might eventually be shown to have some side effect that we do not know about.

SOME OTHER POSSIBLE TRENDS

It is believed by many that one person may need ten or more times as much of one nutrient as another person (28). Nutritionists tend to dismiss this idea, but our information about the range of individual requirements hardly entitles us to do so. There might also be national differences in nutrient requirements. They have hardly been looked for yet. There are, after all, national differences in lactose tolerance and liability to diabetes.

For proteins, Scrimshaw has encouraged nutritional scientists in some ten different countries to conduct nitrogen-balance studies at three intake levels with a standardized technique. Some preliminary results were presented at the Third Asian Nutrition Congress, in Jakarta in November 1980 (29-33).

Perhaps the best chance of collecting data on individual requirements for other nutrients is by similar international collaboration. These experiments are tedious and not very interesting or rewarding, but if scientists in ten different countries were to carry out six each, we would have much more idea of the range of requirements for, for example, pyridoxine in the elderly.

Dietary goals or guidelines have been published officially in the United States, Scandinavia, Australia, and Canada (34) and proposed by leading nutritionists in other countries (35). These are making up for the silence of most RDI reports on the desirable range of consumption of the main sources of energy- types and amounts of fats and carbohydrates and alcohol. Future recommendations may include these and perhaps give figures for dietary fibre. Already the 1980 US RDA report has a short chapter on desirable proportions of carbohydrates and fat, and the new Scandinavian recommendations give suggested ranges. The American report also discusses dietary fibre, but does not recommend a figure.

We are in a new era of interest in vitamins and minerals.

People are searching for an optimum level that will give "high level wellness" (36) or longevity, or reduce the risk of degenerative disease. It is not enough to see vitamin A as merely the chemical that prevents xerophthalmia. It looks as if a good intake of vitamin A (or of ß-carotene) confers some protection against the development of several epithelial cancers (37). It will be increasingly difficult for committees to recommend that people eat only enough vitamin A to prevent xerophthalmia or sufficient ascorbic acid to prevent scurvy. Even if generous intakes of ascorbic acid do not increase resistance to upper respiratory viral infections, it looks as if they may reduce the risk of gastric cancer (38) and solar cataract (39) and play a role in affective disorders (40). Many women are taking pyridoxine to neutralize the side effects of oral contraceptives, or for its reputed effect on premenstrual tension; there are suggestions that it may protect against atherosclerosis. These proposed newer roles for several nutrients are another reason for separating the prescriptive levels of intake from the lower levels used to diagnose risk of deficiency disease.

In developing countries it is coming to be realized that "the level of intake of essential nutrients judged to be adequate to meet the known nutritional needs of practically all healthy persons" (17) is insufficient for some individuals, especially young children, most of the time. They have recurrent infections that increase protein and other needs and cause metabolic losses while decreasing appetite. In between there may be catch-up growth if sufficient food is available. The United Nations University held a meeting on this problem in Costa Rica in 1977 and subsequently produced a report (41). There is less food available in Third World countries, but practical recommendations for protein intake of preschool children should perhaps be higher there than in hygienic, prosperous countries.

Walker and Walker think that we need a measure of reorientation of nutritional research endeavor. It is not so much that we have misgivings over the relevance of RDA to Third World populations, but rather that we are concerned over the lack of knowledge concerning the effects of the nutritional situations which will inevitably prevail in the not so distant future. Because of increases in population and because obviously there are limits to increases in food production, the huge bulk of the world's inhabitants will ultimately be compelled to consume a largely vegetarian diet. Surely, rather than aiming to produce faster growing or taller children, or seeking to learn more of what more can be added with advantage to the already luxus diets of most Western populations, we should be concentrating on studying the converse. Namely knowledge must be acquired of the relatively low levels of nutrient intakes, for young and old, which are consistent with satisfactory accomplishments of physiological processes and of performances of everyday tasks.... In recent surveys on segments of populations in Great Britain it transpired that appreciable numbers of people had intakes less than the recommendations without signs of malnutrition. It is precisely this type of situation in both developed and developing populations on which exact knowledge is required. [42]

Lastly, the RDls cannot be applied unmodified to sick people in hospital. In total parenteral nutrition many minor nutrients must be provided (10, p. 156)- such as pantothenic acid, vitamin K, chromium, and manganese- that are taken for granted when food is taken by mouth. But even with oral feeding the need for many nutrients is altered, usually upwards. With stress, trauma, surgery, and drugs the requirement for vitamin C may be near 250 mg/ day (ibid., p. 134); zinc requirements are increased for wound healing; more thiamin is needed when much of the energy intake is dextrose/water or glucose polymer, and people indoors cannot synthesize vitamin D in their skin.

APPENDIX 1. References for 41 Dietary Intake Tables

AFRICA. No references available,

ARGENTINA. Secretaria de Estado de Salud Pública, Ministerio de Bienestar Social: "Table de Recomendaciones Nutricionales pare la República Argentina (6° Congreso Argentino de Nutrición) " 1976.

AUSTRALIA. Nutrition Committee, National Health and Medical Research Council: "Dietary Allowances for Use in Australia," Australian Government Publishing Service, Canberra.1970,

BELGIUM. No reference available.
BOLIVIA. Proyecto de Mejoramiento Nutricional entre el Gobierno de Bolivia y la Agencia Internacional pare el Desarrollo de los Estados Unidos: "Recomendación Diaria de Calorias y Nutrientes pare la Población Boliviana." La Paz.1978.

BULGARIA. "Recommended Dietary Allowances."

CANADA. Bureau of Nutritional Sciences, Food Directorate, Health Protection Branch, Department of National Health and Welfare: "Dietary Standard for Canada," 3rd ed. (2nd rev ). Supply and Services, Ottawa. 1975.

CARIBBEAN. Committee on Recommended Dietary Allowances, Caribbean Food and Nutrition Institute: "Recommended Dietary Allowances for the Caribbean," Caribbean Food and Nutrition Institute. 1979.

CENTRAL AMERICA. Institute of Nutrition of Central America and Panama (INCAP): "Recomendaciones dietéticas diaries pare Centro América y Panamá." Publication E-709 1973.

CHILE. Juliana Kain, Berta Avila, Sergio Valiente, División de Políticas y Programas de Alimentación y Nutrición Dippan, Instituto de Nutrición y Tecnologia de los Alimentos, Universidad de Chile: "Food Availability Goals for Chile, 1985."

CHINA, PEOPLE'S REPUBLIC OF. "Chinese Dietary Allowance." 1981.

COLOMBIA. Franz Pardo and Maria Dolores Gómez, Instituto Colombiano de Bienestar Familiar, Subdirección de Nutrición, División de Investigaciones Nutricionales, Ministerio de Salud Pública: "Recomendación Diaria de Calorias y Nutrientes pare la Población Colombiana." Bogota. 1975.

CZECHOSLOVAKIA. "Recommended Dietary Allowances." 1981.

DENMARK. See Scandinavia.

FAO/WHO. Food and Agriculture Organization of the United Nations, and World Health Organization: "Requirements of Ascorbic Acid, Vitamin D, Vitamin B₁₂, Folate, and Iron- Report of a Joint FAD/WHO Expert Group." FAO Nutrition Meetings Report Series No. 47. WHO Technical Report Series No, 452. World Health Organization, Geneva. 1970.

FINLAND, O. Turpeinen: "Food Composition Tables." 1980.

FRANCE, Henri Dupin and members of the Commission: Apports Nutritionnels Conseillés du CNERNA: "Apports nutritionnels conseillés- pour la population française," Technique et Documentation, Paris,1981.

GERMAN DEMOCRATIC REPUBLIC. Zentralinstitut für Ernährung der Akademie der Wissenschaften der DDR und der Gesellschaft für Ernährung in der DDR; (i) "Durchschnittswerte des physiologischen Energie- und Nährstoffbedarfs für die Bevölkerung der Deutschen Demokratischen Republik." (ii) "Empfehlungen für die tägliche Energie-und Nährstoffaufnahme in der Ernährungspraxis der Bevölkerung der Deutschen Demokratischen Republik - mit Hinweisen für die Gemeinschaftverpflegung," 2nd ed. Potsdam-Rehbrücke. 1980.

GERMANY, FEDERAL REPUBLIC OF. Deutsche Gesellschaft für Ernährung: "Empfehlungen für die Nährstoffzufuhr- Empfehlungen der Deutschen Gesellschaft für Ernährung e,V.," 4th ed. Umschau Verlag, Frankfurt am Main. 1979.
GREECE. No reference available.

HUNGARY. R. Tarján and K. Lindner: "Tápanyagtábiázat- Az országos élelmenzés és tápiálkozástudományi intézet munkásságe alapján ósszeállitotta." Medicina Könyvkiadó, Budapest. 1978.

ICELAND. See Scandinavia.

INDIA. (i) "Recommended Dietary Intakes of Nutrients." 1981. (ii) Indian Council of Medical Research, National Institute of Nutrition: Nutrition News, vol, 2, no. 3. Hyderabad.1981,

INDONESIA. "Recommended Dietary Allowance (RDA) for Good Health in Indonesia."

ITALY, Commissione "Ad Hoc" della Società Italiana di Nutrizione umana, Istituto Nazionale della Nutrizione, Ministero dell' Agricoltura e delle Foreste: "Livelli di assunzione reccomandati di nutrient) per gli italiani." Rome. 1978.

JAPAN, Ministry of Health and Welfare: "Recommended Dietary Allowances for Japanese." 1979.

KOREA, "Recommended Dietary Allowances (per Person per Day)," 3rd ed, 1980.

MALAYSIA. "Suggested Daily Dietary Intakes- Peninsular Malaysia," 1973.

MEXICO. Instituto Nacional de Nutrición, División de Nutrición: "Recommendaciones de Nutrimentos pare la Población Mexicana." Publication L-17. Mexico, 1970,

NETHERLANDS. Voorlichtingsbureau voor de Voeding: "Nederlandse Voedingsmiddelentabel Aanbevolen hoeveelheden energie en voedingsstoffen," 31st rev. ed. The Hague. 1978.

NIGERIA, No reference available.

NORWAY. See Scandinavia.

NEW ZEALAND. Nutrition Department, University of Otago: "Recommendations for Selected Nutrient Intakes of New Zealanders." 1981.

PHILIPPINES. Philippines National Science Development Board, Food and Nutrition Research Institute: "Recommended Dietary Allowances (RDA) of Specific Nutrients per Day for Filipinos." FNRI Publication No. 76. 1977.

POLAND. "Recommended Dietary Allowances." 1969.

PORTUGAL. "Tabela de Necessidades em Calorias e Nutrientes por Grupos de Idades e Sexos." 1978.

ROMANIA. No reference available.

SCANDINAVIA. "Nutrition Recommendations for the Nordic Countries." 1980.

SINGAPORE. "Recommended Daily Dietary Allowances for Moderately Active People in Singapore."

SOUTH AFRICA, REPUBLIC OF. No reference available.

SPAIN. Instituto de Nutrición, Consejo Superior de Investigaciones Científicas: "Ingestas Recomendadas de Energía y Nutrientes pare la Población Española." Madrid.1980.

SRI LANKA. No reference available,

SWEDEN. See Scandinavia.

SWITZERLAND. No reference available.

TAIWAN. No reference available.

THAILAND. Nutrition Division, Department of Public Health Promotion, Ministry of Health: "Recommended Daily Allowances in Thailand." Bangkok. 1970.

TURKEY. Institute of Nutrition and Food Sciences, Hacettepe University: "Recommended Dietary Allowances." Ankara. 1972.

WESTERN PACIFIC. WHO Regional Office for the Western Pacific: "The Health Aspects of Food and Nutrition: A Manual for Developing Countries in the Western Pacific Region of the World Health Organization," 3rd ed. Manila, 1979,

YUGOSLAVIA, No reference available.

APPENDIX 2. Variations in RDls According to Activity/Work Level

The following countries give RDls for the nutrients specified that vary depending on the level of activity or work.

All countries: energy, thiamin, riboflavin, niacin.

Bulgaria: protein, vitamin A, vitamin C, phosphorus, iron.

People's Republic of China: protein.
Czechoslovakia: protein, vitamin C; vitamin A, vitamin E, calcium, phosphorus, magnesium {very active only) iron, zinc (very active boys only).

France: protein (adults only),

German Democratic Republic: protein: vitamin E (heavy and very heavy work only for males, very heavy work only for females),

Hungary: protein; vitamin D (heavy work only).

Netherlands: protein.

Poland: protein; vitamin C (very heavy work only),

Portugal: protein.

United Kingdom: protein.
USSR: protein, fat, carbohydrate, vitamin B6, ascorbic acid,

REFERENCES

1. Report of the Committee on International Dietary Allowances of the international Union of Nutritional Sciences, Nutr. Abstr. Fov., 45: 89(1975).

2. A Wretlind, A.S. Truswell, S. Hejda, B. Isaksson, W. Kübler, and F. Vivanco, "Round Table on Comparison of Dietary Recommendations in Different European Countries," in N. Zöllner, G. Wolfram, and Ch. Keller, eds., Second European Nutrition Conference (S. Karger, Basel, Munich, Paris, London, New York, and Sydney, 1977), pp. 209-279.

3. Select Committee on Nutrition and Human Needs, US Senate, "Dietary Goals for the United States," 2nd ed. (Stock No, 052-07004376-8, US Government Printing Office, Washington, D.C., 1977),

4. World Health Organization, Handbook on Human Nutritional Requirements (WHO, Geneva, 1974).

5. I. Leitch, "The Evolution of Dietary Standards," Nutr.. Abstr. Rev., 11:509 (1942).

6. A.S. Truswell, "Minimal Estimates of Needs and Recommended Intakes of Nutrients," in J. Yudkin, ea., Diet of Man: Needs and Wants, Rank Prize Foods Symposium, Bath, UK (Applied Science, London, 1978), pp. 5-24.

7. interdepartmental Committee on Nutrition for National Defense, Manual for Nutrition Surveys, 2nd ed. (National Institutes of Health, Bethesda, Md., USA; US Government Printing Office, Washington, D.C., 1963).

8. A.S. Truswell and 1. Darnton-Hill, "Food Habits of Adolescents," Nutr. Rev.,., 39: 73 11981).

9. M. Bennion, Clinical Nutrition, p. 17 [Harper & Row, New York and London, 1974).

10. S. Davidson, R. Passmore, J.F. Brock, and A.S. Truswell, Human Nutrition and Dietetics,, 7th ed. (Churchill Livingstone, Edinburgh and London, 1979).

11. Department of Education and Science, Welsh Office, Nutrition in Schools, report of the Working Party on the Nutritional Aspects of School Meals (H.M, Stationery Office, London, 1 975).

12. R.G. Hansen, B.W. Wyse, and A.W. Sorenson, Nutritional Quality Index of Foods (Avi Publishing Co., Westport, Conn. USA, 1979).

13. Council on Foods and Nutrition, "Improvement of the Nutritive Quality of Foods, General Policies," J.A.M.A., 225:1116 (1968).

14. R.M. Leverton, "The RDAs Are Not for Amateurs," J. Amor. Dietet. Assn., 66:9 11975).

15. World Health Organization/Food and Agriculture Organization/lnternational Union of Nutritional Sciences, Food and Nutrition Terminology: Definitions of Selected Terms and Expressions in Current Use (WHO, Geneva, 1973),

16. Energy and Protein Requirements, report of a Joint FAO/ WHO Ad Hoc Expert Committee, WHO Tech. Rep. Ser., no. 522 (WHO, Geneva, 1973),

17. Committee on Dietary Allowances, Food and Nutrition Board, (Rocommended Dietary Allowances, 9th rev. ed. (National Academy of Sciences, National Research Council, Washington, D.C., 1980).

18. B. Wood, A. Gijsbers, A. Goode, S. Davis, J. Mulholland, and K, Breen, "A Study of Partial Thiamin Restriction in Human Volunteers," Amor. J. Clin. Nutr., 33: 848 11980).

19. N.S. Scrimshaw, "Shattuck Lecture- Strengths and Weaknesses of the Committee Approach: An Analysis of Past and Present Recommended Dietary Allowances for Protein in Health and Disease," Now Eng. J. Med., 294: 136, 198 (1976).

20. T.H. Bothwell, R.W. Charlton, J.P. Cook, and C.A. Finch, Iron Metabolism in Man (Blackwell, Oxford, UK, 1979).

21. A. Wretlind, S. Hejda, B. Isakkson, W. Kübler, A.S. Truswell, and F. Vivanco, "Round Table on Comparison of Dietary Recommendations in Different European Countries: Conclusions," Nutr. Metab., 21: 244 (1977).

22. Deutsche Gesellschaft für Ernährung, Empfehlungen für die Nährstoffzufuhr. (Umschau Verlag, Frankfurt am Main, FRG, 1 975).

23. Department of Health and Social Security, Recommended Doily Amounts of Food Energy and Nutrients for Groups of People in the United Kingdom, report by the Committee on Medical Aspects of Food Policy, Report on Health and Social Subjects 15 (H.M, Stationery Office, London, 1979).

24. D.M. Hegsted "Dietary Standards," J. Amer. Dietet Assn., 66:13 (1975).

25. A. Wretlind, "Round Table on Comparison of Dietary Recommendations in Different European Countries: Introduction. General Aspects on Dietary Allowances," Nutr. Metab., 21: 210 (1977).

26. A.S. Truswell, "Round Table on Comparison of Dietary Recommendations in Different European Countries: The United Kingdom and Eire," Nutr. Metab., 21: 224 11977).

27. A. Bruce, "A Critical Evaluation of the RDA and Suggestions on How They Can Be Improved," Voeding, 41: 288 (1980).

28. R.J. Williams, Biochemical Individuality: The Basis for the Genetotrophic Concept {Science Edition, Wiley & Sons, New York, 1963).

29. N.S. Scrimshaw, "Nutrient Requirements for Asian Countries," Third Asian Nutrition Congress, Jakarta, 6-10 Oct. 1980, Abstracts, p. 59.

30. G. Inoue, K. Kishi, T. Komatsu, and I. Hagi, "Human Protein Requirements in Asian Countries," Third Asian Nutrition Congress, Jakarta, 6-10 Oct. 1980, Abstracts, p. 58.

31. K. Tontisirin, P.O. Sirichakawal, and A, Valyasevi, "Nutrient Requirements for ASEAN Countries: The Study of Protein Need with Thai Adult Males," Third Asian Nutrition Congress, Jakarta, 610 Oct. 1980, Abstracts, p. 60.

32. B.C. Roxas and C.l. Intengan, "Protein Requirement Studies in the Philippines," Third Asian Nutrition Congress, Jakarta, 6-10 Oct.1980, Abstracts, p.62.

33. Muhilal and Krisdinamurtirin, "Protein Requirements in Indonesia," Third Asian Nutrition Congress, Jakarta, 6-10 Oct, 1980, Abstracts,, p. 63,

34. "Dietary Advice to the Public: 1957-1980," special report, Nutr. Rev., 38:353 (1980).

35. R. Passmore, D.F. Hollingsworth, and J. Robertson, "Prescription for a Better British Diet," Brit Med. J., 1: 527 (1979).

36. D.B, Ardell, High Level Wellness: An Alternative to Doctors, Drugs and Disease (Rodale Press, Emmaus, Penn. USA, 1977).

37. R. Peto, R. Doll, J.D. Buckley, and M.B. Sporn, "Can Dietary Beta-Carotene Materially Reduce Human Cancer Rates?" Nature, 290:201 (1981).

38. J.V. Joossens and J. Geboers, "Nutrition and Gastric Cancer," Proceedings of the Nutrition Society (UK), 40: 37 (1981) .

39. F, Hollows and D. Moran, "Cataract- The Ultraviolet Risk Factor," Lancet, 2: 1249 (1981).

40. G.J. Naylor and A.H.W. Smith, "Vanadium: A Possible Aetiological Factor in Manic Depressive Illness," Psychol. Med., 11:249 (1981),

41, F. Viteri, R.G. Whitehead, and V.R. Young, eds., Protein-Energy Requirements under Conditions Prevailing in Devoloping Countries: Current Knowledge and Research Needs (The United Nations University, Tokyo, Japan, 1979).

42, A.R.P. Walker and B.F. Walker, "Recommended Dietary Allowances and Third World Populations," Amer. J. Clin. Nutr., 34:2319 (1981),

REVISIONS OF PAG GUIDELINES TO BE PUBLISHED

The next issue of the Food and Nutrition Bulletin will feature revisions of four PAG Guidelines - numbers 6, "Preclinical Testing of Novel Sources of Protein"; 7, "Human Testing of Supplementary Food Mixtures"; 12, "Production of Single-Cell Protein for Human Consumption"; and 15, "Nutritional and Safety Aspects of Novel Protein Sources for Animal Feeding"- and their re-issue as PAG/UNU Guidelines. The revisions are based on the work of a combined task force of the International Union of Nutritional Sciences, the International Union of Food Science and Technology, the International Union of Pure and Applied Chemistry, and the International Union of Microbiological Societies, convened by the United Nations University, and have been further reviewed by experts in many countries.

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