Contents - Previous - Next

This is the old United Nations University website. Visit the new site at

Nutritional quality of wheat protein in adults

The revised estimate of the lysine requirement in adults, 30 mg/kg/day, has implications for the nutritional quality of wheat proteins. Thus, it is worth considering this important plant protein source as a basis for evaluating the validity of the foregoing analysis of the lysine needs of healthy adults [55]. The lysine content of wheat products is summarized in table 6, together with the lysine content of a number of FAO/WHO amino acid scoring patterns. In addition, the usual concentration of lysine in most animal proteins and legumes [57] and that for the MIT requirement pattern are given for comparison in table 6. Therefore, if an amino acid score ([amino acid content in the food protein/amino acid content in the reference amino acid requirement pattern! x 100) is calculated for wheat flour, it would be greater than 100 when the 1985 FAO/WHO/UNU [9] amino acid requirement pattern for the adult is used as the reference pattern (table 7). This means that the nutritional value of wheat would be equal to that of high-quality animal protein foods, such as milk, egg, or meat [9]. On the other hand, for scoring purposes, the FAO/WHO/UNU [9] pre-school amino acid pattern (or the FAD/WHO pattern [24]) predicts a relative nutritional quality of 41%, and with the MIT pattern the score predicts a slightly higher value of 48%. In each case, lysine is determined to be the most limiting amino acid. These latter and lower estimates of the nutritional quality of wheat proteins in adults are consistent with the results of nitrogen balance experiments in healthy adults carried out at MIT approximately twenty years ago [58].

TABLE 6. Lysine content of wheat flour in comparison with other foods or amino acid requirement patterns

Food or requirement pattern Lysine content (mg/g protein)
Whole wheat flour [56] 24
Wheat flour (70% 80% extraction rate) [56] 20
Wheat bran [56] 16
Animal proteins [57] 85 ± 9
Legumes [57] 65 ± 7
1985 FAO/WHO/UNU pattern adults
schoolchildren pre-school children
1991 FAD/WHO pattern 58
MIT pattern 50

TABLE: 7. Lysine content of whole wheat flour in relation to an estimate of protein quality

Amino acid pattern Amino acid score
1985 FAO/WHO/UNU for adults [9] >100 (L)a
1991 FAD/WHO [24] 41 (L)
1989 Young et al. (MIT pattern) [4] 48 (L)
1985 FAO/WHO/UNU pre-school child [9] 41 (L)

a. L = lysine first limiting amino acid, not corrected for digestibility.

The nitrogen balance response to graded intakes of test dietary protein in healthy adults, expressed as relative protein value (RPV= [N balance slope with wheat/N balance slope with reference protein] x 100), was 54 for whole wheat protein, using beef protein as a reference. Expressed as relative nitrogen requirement (RNR = 1/[amount of wheat protein to achieve nitrogen balance in 97.5% of population amount of beef protein] x 100), the response was about 56 (table 8). The MIT amino acid requirement pattern predicted a value of 48. Hence, it is clear that there is very good agreement between these experimentally derived (nitrogen balance) and predicted (from amino acid score) estimates of the nutritional quality of whole wheat proteins. In contrast, use of the 1985 FAO/WHO/UNU adult amino acid pattern gives an invalid estimate of the nutritional value of wheat protein, in that this pattern makes wheat proteins nutritionally equivalent to beef proteins. Notwithstanding the problems that are faced in attempts to aggregate nitrogen balance data across separate studies carried out in different laboratories or within the same laboratory on different occasions [59], our observations support the conclusion that the 1985 FAO/WHO/UNU lysine requirement value of 12 mg/kg/day for the adult should be discarded. Further, they provide additional justification for the tentative working value of 30 mg/kg/day proposed above (or 50 mg lysine per gram of protein), and they strengthen our recommendation that this figure be used until additional data become available that may make any further change in the recommendation both necessary and desirable.

TABLE 8. Biological assessment of the nutritional quality of whole wheat proteins in young adultsa

Measure of quality Experimental
Predicted from amino acid values
1985 FAO/WHO/UNU [9] MIT pattern [4]
Relative protein value 54 >100 48
Relative nitrogen requirement 56 >100 48

a. Expressed in comparison with beef protein as reference protein [58].

Worldwide applicability of estimates of indispensable amino acid requirements

If it can be accepted that the tentative new amino acid requirement values given in table 2 represent a better approximation of the minimal physiological needs for well-nourished, healthy subjects studied largely in North America, it is legitimate to ask whether the amino acid requirements of individuals in developing regions, particularly where protein and/or dietary lysine are likely to be more limiting, are similar to or different from those given above. Although the current international FAD/WHO/UNU [9] amino acid requirement values, based largely on studies conducted in young adult American subjects, are recommended for application worldwide, our reassessment of the requirements for indispensable amino acids emphasizes the need to consider this nutritional-metabolic issue more critically than hitherto.

Unfortunately, there have not been any relevant 13C-tracer studies in subjects outside North America that directly explore this important practical issue. Hence, the Global Cereal Fortification Initiative (GCFI) of Ajinomoto Co., Inc., and Kyowa Hakko Kogyo Co., Ltd., Japan, is now sponsoring a multicentre study designed to confirm our new estimate of the lysine requirements of healthy adults (table 2) and its applicability in other populations. The results to be obtained from these studies within one or two years are expected to give a reasonable indication of the approximate minimum lysine needs of healthy Indian and Thai young adults, whose usual lysine intake levels are likely to be below those of the US subjects that we studied at MIT. This is an exciting and important development with profound implications for international nutritional and metabolic investigation and the value of studies on nutritional requirements in humans.

Furthermore, there are few relevant data that can be used to predict whether the indispensable amino acid needs, and the lysine requirements in particular, are similar or different among these various population groups. Studies of obligatory nitrogen losses in US [60-62], Chinese (Taiwan Province) [63], Indian [64], Nigerian [65, 66], and Japanese [67] men reveal that they are remarkably uniform [68]. This implies similar OAALs and similar dietary requirements for indispensable amino acids [5]. This would be so unless there were evidence that the efficiency of specific amino acid retention differed among apparently similar subjects in the population groups. According to FAO/WHO/UNU [9], nitrogen balance studies have not revealed any striking differences in estimates of total protein requirements, in relation to body cell mass, in studies of well-nourished subjects in different countries. Earlier studies suggesting that Nigerian men of low income are adapted to low-protein diets and utilize dietary protein more efficiently [65, 69] than, for example, US students [61] are not appropriate to answer this question. Indeed, they are probably flawed because the nitrogen balance results in the subjects studied indicated that they were depleted and that they were undergoing a body protein repletion response to the good diet given during the course of the experiments. Later studies in young Nigerian adult males [70] indicate that at maintenance nitrogen intakes, the efficiency of dietary protein utilization is essentially the same as that for caucasian and Asian subjects.

In summary, it seems rather unlikely that there would be any major differences in the minimal physiological requirements for lysine among groups of normal healthy adults of different genetic, nutritional, and environmental background. The ongoing GCFI-sponsored multicentre studies should provide evidence to support or refute this view. Thus, the GCFI study is potentially of great practical and international significance, and it is the authors' hope that there soon will be a broader appreciation for this fact by national and multinational authorities concerned with improving the nutritional well-being of underprivileged populations worldwide.

Conclusions and implications for nutrition policies and food programmes

Despite the economic, social, and human dimensions of protein-energy malnutrition in large areas of the developing world, current knowledge about the quantitative needs both for dietary energy and for the indispensable amino acids that are supplied by our food protein remains inadequate. In 1973 a group of senior investigators in the United Kingdom asked the rhetorical question "How much food does a man require?" [71]. Since that time, there has been a considerable amount of research on this topic. This follow-on effort has been facilitated by the development in a number of countries, including the United States, of whole-body calorimeters and by the application of the doubly labelled water technique, which permits a non-invasive, quantitative measure of energy expenditure in free-living individuals [72-75]. Hence, the energy requirements of individuals of all ages, from infants [76, 77] to the elderly [78], are now being refined and the database is being expanded. With reference to the requirements for indispensable amino acids, equivalent advances in technique have been slower to occur, and therefore their application has also been less extensive to date, in comparison with the explosion of studies involving use of the doubly labelled water method. However, it is encouraging to note that the application of amino acid kinetics and, by extension, the 13C-tracer balance method represents one of the most important developments in recent years with respect to the study of human amino acid requirements [28].

Based on these tracer-derived data, it is our view that the new, tentative requirements for indispensable amino acids represent the best available approximations of the needs for these nutrients in adults. Hence, we recommend that they be used as a rational basis for the formulation of amino acid mixtures, or of protein sources, intended for meeting the nutritional support of individuals in institutional settings; the determination of the composition of enteral products is a case in point. Furthermore, these newly proposed values for the amino acid requirements of adults serve, in our view, as a credible benchmark for assessing the quantitative impact of disease and trauma on amino acid requirements. They should aid, therefore, in the design of parenteral nutritional formulations and, hopefully, lead to improvements in their efficacy for supporting the nutritional and metabolic needs of patients in a catabolic state.

Finally, as pointed out above, the revised requirements for adults are similar to those of young children when expressed in relation to the need for dietary protein. On this basis, considerations of dietary protein quality become important in reference to adult human protein as well as in relation to the nutritional well-being of the younger age groups. This challenges the current dogma, as reflected by FAO/WHO/UNU [9], that indigestibility appears to be the most important factor determining the capacity of the protein sources in a usual mixed diet to meet the protein needs of adults. However, as has been stated by Berg and Singer [79] in their assessment of the historical background behind the now dominant use of recombinant DNA technology in biology, changes in human thought and technological developments lead to new issues that challenge traditional ideas. We presume that the 13C-tracer techniques used by our group and others represent another, perhaps small, advance in nutritional investigation. We recommended that the adult amino acid requirement values, referred to as the MIT Amino Acid Requirement Pattern, now be used to establish the quantitative profile of the amino acid component of an adequate diet. The new amino acid requirement pattern should be of greater value in identifying the nature and extent of the limiting indispensable amino acid(s) in national and regional diets. This pattern should be of particular assistance to those responsible for developing sound food and nutrition policies and programmes. The pattern should also be useful for evaluating the economic, social, and cultural merits of dietary protein complementation, food protein supplementation, and specific amino acid fortification, such as lysine fortification of wheat flour, as alternative or perhaps simultaneous approaches for improving the nutritional value of diets based predominantly on cereals.


The authors' studies were supported by NIH grants DK 15856, DK 42101, and RR 88, and by SHCC grant 15847.


  1. Young VR. McCollum Award Lecture: Kinetics of human amino acid metabolism: nutritional implications and some lessons. Am J Clin Nutr 1987;46:709-25.
  2. Young VR. Nutrient interactions with reference to amino acid and protein metabolism in non-ruminants; particular emphasis on protein-energy relations in man. Z Ernahrungswiss 1991;30:239-67.
  3. Young VR, Marchini JS. Mechanisms and nutritional significance of metabolic responses to altered intakes of protein and amino acids, with reference to nutritional adaptation in humans. Am J Clin Nutr 1990;51: 270-89.
  4. Young VR, Bier DM, Pellett PL. A theoretical basis for increasing current estimates of the amino acid requirements in adult man, with experimental support. Am J Clin Nutr 1989;50:80-92.
  5. Young VR, El-Khoury AK. Can amino acid requirements for nutritional maintenance in adult humans be approximated from the amino acid composition of body mixed proteins? Proc Natl Acad Sci USA 1995:92:300-4.
  6. Young VR, Pellett PL. Current concepts concerning indispensable amino acid needs in adults and their implications for international nutrition planning. Food Nutr Bull 1990;12:289-300.
  7. Hoshiai K. World balance of dietary essential amino acids relative to the 1989 FAD/WHO protein scoring pattern. Food Nutr Bull 1995;16:166-77.
  8. Young VR. Protein and amino acid requirements in humans: metabolic basis and current recommendations. Scand J Nutr 1992;36:47-56.
  9. FAO/WHO/UNU. Energy and protein requirements. Report of a joint FAO/WHO/UNU expert consultation. Technical report series no. 724. Geneva: World Health Organization, 1985.
  10. Williams HH, Harper AK, Hegsted DM, Arroyave G. Holt LE, Jr. Nitrogen and amino acid requirements. In: Food and Nutrition Board, National Research Council. Improvement of protein nutriture. Washington: National Academy of Sciences, 1974:23-63.
  11. FAD/WHO. Energy and protein requirements. Report of a joint FAD/WHO ad hoc expert committee. Technical report series no. 522. Geneva: World Health Organization, 1973.
  12. Dewey KG, Beaton G. Fjeld C, Lonnerdal B. Reeds P. Protein requirements of infants and children. Eur J Clin Nutr 1996;50:S119-50.
  13. Young VR, Cortiella J. Protein and amino acid requirements in healthy 6 to 12 month old infants. In: Heird WC, ed. Nutritional needs of the six to twelve month old infant. New York: Carnation Nutrition Education Series, Carnation Co, Glendale/Raven Press,1991:149-74.
  14. Pineda O. Torun B. Viteri FE, Arroyave G. Protein quality in relation to estimates of essential amino acid requirements. In: Bodwell CE, Adkins JS, Hopkins DT, eds. Protein quality in humans: assessment and in vitro estimation. Westport, Conn, USA: AVI Publishing, 1981:29-42.
  15. Torun B. Pineda O. Viteri FE, Arroyave G. Use of amino acid composition data to predict protein nutritive value for children with specific reference to new estimates of their essential amino acid requirements. In: Bodwell CE, Adkins JS, Hopkins DT, eds. Protein quality in humans: assessment and in vitro estimation. Westport, Conn, USA: AVI Publishing, 1981: 374-93.
  16. Fomon SJ, Nelson SE. Size and growth. In: Fomon SJ, ed. Nutrition of normal infants. St. Louis, Mo, USA: Mosby, 1993:36-84.
  17. Nakagawa I, Takahashi T. Suzuki T. Kobayashi K. Amino acid requirements of children: minimal needs of tryptophan, arginine and histidine based on nitrogen balance method. J Nutr 1963;80:305-10.
  18. Rose WC. The amino acid requirements of adult man. Nutr Abstr Rev 1957;27:631-67.
  19. Irwin MI, Hegsted DM. A conspectus of research on amino acid requirements of man. J Nutr 1971;101:53966.
  20. Meguid MM, Matthews DE, Bier DM, Meredith CN, Soeldner JE, Young VR. Leucine kinetics at graded leucine intakes in young men. Am J Clin Nutr 1986;43: 770-80.
  21. Young VR, Gucalp C, Rand WM, Matthews DE, Bier DM. Leucine kinetics during three weeks at submaintenance-to-maintenance intakes of leucine in man: adaptation and accommodation. Hum Nutr Clin Nutr 1987; 41 C:1 -18.
  22. Marchini JS, Cortiella J, Hiramatsu T, Chapman TE, Young VR. Requirements for indispensable amino acids in adult humans: longer term amino acid kinetic study with support for the adequacy of the Massachusetts Institute of Technology amino acid requirement pattern. Am J Clin Nutr 1993;58:670-83.
  23. Young VR, Yu Y-M, Krempf M. Protein and amino acid turnover using the stable isotopes 15N, 13C and 2H as probes. In: Whitehead RG, Prentice A, eds. New techniques in nutritional research. San Diego, Calif, USA: Academic Press, 1991:17-72.
  24. FAD/WHO. Protein quality evaluation. Report of a joint FAD/WHO expert consultation. Paper no. 51. Rome: FAO, 1991.
  25. Carpenter KJ. Protein requirements of adults from an evolutionary perspective. Am J Clin Nutr 1992;55: 913-7.
  26. Millward DJ, Rivers JPW. The nutritional role of indispensable amino acids and the metabolic basis for their requirements. Eur J Clin Nutr 1988;42:367-93.
  27. Young VR. Amino acid requirements: the case for a major revision in current recommendations. J Nutr 1994;124:1517S-23S.
  28. Waterlow JC. Whole-body protein turnover in humans—past, present and future. Annu Rev Nutr 1995;15:57-92.
  29. Fuller ME, Garlick PJ. Human amino acid requirements: Can the controversy be resolved? Annu Rev Nutr 1994;14:217-41.
  30. El-Khoury AK, Fukagawa NK, Sanchez M, Tsay RH, Gleason RE, Chapman TE, Young VR. Validation of the tracer-balance concept with reference to leucine: 24-h intravenous tracer studies with L-[13C]leucine and [15N,15N]urea. Am J Clin Nutr 1994;59:1000-11.
  31. El-Khoury AK, Fukagawa NK, Sánchez M, Tsay RH, Gleason RE, Chapman TE, Young VR. The 24-h pattern and rate of leucine oxidation, with particular reference to tracer estimates of leucine requirements in healthy adults. Am J Clin Nutr 1994;59:1012-20.
  32. El-Khoury AK, Sánchez M, Fukagawa NK, Gleason RE, Tsay RH, Young VR. The 24-h kinetics of leucine oxidation in healthy adults receiving a generous leucine intake via three discrete meals. Am J Clin Nutr 1995; 62:579-90.
  33. Waterlow JC. The requirements of adult man for indispensable amino acids. Eur J Clin Nutr 1996;50:S151-79.
  34. Sánchez M, El-Khoury AK, Castillo L, Chapman TE, Young VR. Phenylalanine and tyrosine kinetics in young men throughout a continuous 24-h period, at a low phenylalanine intake. Am J Clin Nutr 1995;61:555-70.
  35. Sánchez M, El-Khoury AK, Castillo L, Chapman TE, Basile A, Beaumier L, Young VR. Twenty-four hour intravenous and oral tracer studies with L[13C]phenylalanine and L-[3-32H2]tyrosine at a tyrosine-free, generous phenylalanine intake in adults. Am J Clin Nutr 1996;63:532-45.
  36. Rose WC, Borman A, Coon MJ, Lambert GF. The amino acid requirements of man. X. The lysine requirement. J Biol Chem 1955;214:579-87.
  37. Meredith CN. Lysine requirements of young men: whole body protein and amino acid metabolism at various levels of lysine intake. Doctoral thesis, Massachusetts Institute of Technology, Cambridge, Mass, USA, 1982.
  38. Meredith C, Bier DM, Meguid MM, Matthews DE, Wen Z. Young VR. Whole body amino acid turnover with 13C tracers: a new approach for estimation of human amino acid requirements. In: Wesdorp RIC, Soeters PD, eds. Clinical nutrition 81. Edinburgh: Churchill Livingston, 1982:42-59.
  39. Kim KI, Elliott JI, Bayley HS. Oxidation of an indicator amino acid by young pigs receiving diets with varying levels of lysine or threonine and an assessment of amino acid requirements. Br J Nutr 1983;50:391-9.
  40. Kim KI, McMillan I, Bayley HS. Determination of amino acid requirements of young pigs using an indicator amino acid. Br J Nutr 1983;50:369-82.
  41. Zello GA, Pencharz PB, Ball RO. Dietary lysine requirement of young adult males determined by oxidation of L-[1-13C]phenylalanine. Am J Physiol 1993;264: E677-85.
  42. Zello GA, Pencharz PB, Ball RO. Phenylalanine flux, oxidation and conversion to tyrosine in humans studied with L-[1-13C]phenylalanine. Am J Physiol 1990; 259:E835-43.
  43. Duncan A, Pencharz PB, Ball RO. Lysine requirement of adult males using indicator amino acid oxidation. The effect of a lower protein intake. FASEB J 1995; 9(4):A865 (Abstract No. 5018).
  44. Munro HN. Free amino acid pools and their role in regulation. In: Munro HN, ed. Mammalian protein metabolism. Vol IV. New York: Academic Press, 1970:299-386.
  45. Young VR, Scrimshaw NS. Nutritional evaluation of proteins and protein requirements. In: Milner M, Scrimshaw NS, Wang DIC, eds. Protein resources and technology. Westport, Conn, USA: AVI Publishing, 1978:136-73.
  46. Jansen GR. Biochemical parameters and protein quality. In: Bodwell CE, Adkins JS, Hopkins DT, eds. Protein quality in humans: assessment and in vitro estimation. Westport, Conn, USA: AVI Publishing, 1981: 118-43.
  47. Eggum BO. The levels of blood amino acids and blood urea as indicators of protein quality. In: Porter JWG, Rolls BA, eds. Proteins in human nutrition. New York: Academic Press, 1973:317-27.
  48. Meredith CN, Wen Z-M, Bier DM, Matthews DE, Young VR. Lysine kinetics at graded lysine intakes in young men. Am J Clin Nutr 1986;43:787-94.
  49. Millward DJ, Price GM, Pacy PJH, Quevest RM, Halliday D. The nutritional sensitivity of diurnal cycling of body protein enables protein deposition to be measured in subjects at nitrogen equilibrium. Clin Nutr 1991 ;10:239-44
  50. Millward DJ, Pacy PJ. Postprandial protein utilization and protein quality assessment in man. Clin Sci 1995; 88:597-606.
  51. Price GM, Halliday D, Pacy PJ, Quevdo MR, Millward DJ. Nitrogen homeostasis in man: influence of protein intake on the amplitude of diurnal cycling of body nitrogen. Clin Sci 1994;86:910-2.
  52. Rand WM, Scrimshaw NS, Young VR. Conventional (long-term) nitrogen balance studies for protein quality evaluation in adults: rationale and limitations. In: Bodwell CE, Adkins JS, Hopkins DT, eds. Protein quality in humans: assessment and in vitro estimation. Westport, Corm, USA: AVI Publishing, 1981:61-94.
  53. Motil KJ, Matthews DE, Bier DM, Burke JF, Munro HN, Young VR. Whole-body leucine and lysine metabolism: response to dietary protein in young men. Am J Physiol 1981;240:E712-21.
  54. Reeds PJ. Amino acid needs and protein scoring patterns. Proc Nutr Soc 1990;49:489-97.
  55. Young VR, Pellett PL. Wheat proteins in relation to protein requirements and availability of amino acids. Am J Clin Nutr 1985;41:1077-90.
  56. Sikka KC, Johari RP, Duggan SK, Ahuja VP, Austin A. Comparative nutritive value and amino acid content of different extractions of wheat. Agric Food Chem 1975;23:24-6.
  57. Pellett PL, Young VR. Role of meat as a source of protein and essential amino acids in human protein nutrition. In: Pearson AM, Dutson TR, eds. Meat and health. Advances in meat research, vol 6. New York: Elsevier Science Publishing, 1990:329-70.
  58. Young VR, Fajardo L, Murray E, Rand WM, Scrimshaw NS. Protein requirements of man: comparative nitrogen balance response within the submaintenance-to-maintenance range of intakes of wheat and beef proteins. J Nutr 1975;105:534-42.
  59. Millward DJ, Jackson AA, Price G. Rivers JPW. Human amino acid and protein requirements: current dilemmas and uncertainties. Nutr Res Rev 1989;2:109-32.
  60. Young VR, Scrimshaw NS. Endogenous nitrogen metabolism and plasma amino acids in young adults given a "protein-free" diet. Br J Nutr 1968;22:9-20.
  61. Calloway DH, Margen S. Variation in endogenous nitrogen excretion and dietary nitrogen utilization as determinants of human protein requirements. J Nutr 1971;101 :205-16.
  62. Scrimshaw NS, Hussein MA, Murray E, Rand WM, Young VR. Protein requirements of man: variations in obligatory urinary and fecal nitrogen losses in young men. J Nutr 1972;102:1595-1604.
  63. Huang PC, Chong HE, Rand MW. Obligatory urinary and fecal nitrogen losses in young Chinese men. J Nutr 1972;102:1605-14.
  64. Gopalan C, Narasinga Rao BS. Effect of protein depletion on urinary nitrogen excretion in undernourished subjects. J Nutr 1966;90:213-8.
  65. Nicol BM, Phillips PG. Endogenous nitrogen excretion and utilization of dietary protein. Br J Nutr 1976;35: 181 -93.
  66. Atinmo T. Mbofung CMF, Hussain MA, Osotimehin BO. Human protein requirements: obligatory urinary and faecal nitrogen losses and the factorial estimation of protein needs of Nigerian male adults. Br J Nutr 1985;54:605-11.
  67. Inoue G. Fujita Y. Kishi K, Yamamoto S. Niiyama Y. Nutritive values of egg protein and wheat gluten in young men. Nutr Rep Int 1974;10:201-7.
  68. Bodwell CE, Schuster EM, Kyle E, Brooks B. Womack M, Steele P. Ahrens R. Obligatory urinary and fecal nitrogen losses in young women, older men, and young men and the factorial estimation of adult human protein requirements. Am J Clin Nutr 1979;32: 2450-9.
  69. Nicol BM, Phillips PG. The utilization of dietary protein by Nigerian men. Br J Nutr 1976;36:337-51.
  70. Atinmo T. Mbofung CMF, Eggum G. Osotimehin B. Nitrogen balance study in young Nigerian adult males using four levels of protein intake. Br J Nutr 1988;60: 451 -58.
  71. Durnin JVGA, Edholm OG, Miller DS, Waterlow JC. How much food does man require? Nature 1973;242: 418.
  72. Schoeller DA, Ravussin E, Schutz Y. Acheson KJ, Baertschi P. Jequier E. Energy expenditure by doubly labeled water: validation in humans and proposed calculation. Am J Physiol 1986;250:R823-30.
  73. Schoeller DA. Measurement of energy expenditure in free-living humans by using doubly labeled water. J Nutr 1988;118:1278-89.
  74. Prentice AM, ed. The doubly-labeled water method for measuring energy expenditure. Technical recommendations for use in humans. Vienna: International Atomic Energy Agency, 1990.
  75. Prentice AM, Spaaij CJK, Goldberg GR, Poppitt SD, van Raaij JMA, Totton M, Swann D, Black AK. Energy requirements of pregnant and lactating women. Eur J Clin Nutr 1996;50:S82-111.
  76. Roberts SB, Savage J. Coward WA, Chew B. Lucas A. Energy expenditure and intake in infants born to lean and overweight mothers. N Engl J Med 1988;318: 461 -6.
  77. Butte NF, Wong W. Garza C, Ferlic L, Smith EO, Klein PD. Energy expenditure and deposition of breast-fed and formula-fed infants during infancy. Pediatr Res 1990;28:63140.
  78. Roberts SB, Young VR, Fuss P. Fiatatore MA, Richard B. Rasumssen H. Wagner D, Joseph L, Holehouse E, Evans WJ. What are the dietary energy needs of elderly adults? Int J Obesity 1992;16:969-76.
  79. Berg P. Singer MF. The recombinant DNA controversy: twenty years later. Proc Natl Acad Sci USA, 1995;92:9011-3.

Contents - Previous - Next