THE EFFECT OF THE INGESTION OF A LARGE AMOUNT OF FAT AND OF A BALANCED MEAL ON THE BLOOD LIPIDS OF NORMAL MAN*

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1 THE EFFECT OF THE INGESTION OF A LARGE AMOUNT OF FAT AND OF A BALANCED MEAL ON THE BLOOD LIPIDS OF NORMAL MAN* BY EVELYN B. MAN AND EDWIN F. GILDEA (From the Laboratory of Physiological Chemistry and the Biochemical Laboratory of the Department of Psychiatry, Yale University, New Haven) (Received for publication, August 4, 1932) The observed effects of a single fat meal on the level of the blood lipids in normal man are inconsistent. There is much uncertainty as to the normal range of blood lipids in the postabsorptive state, because data have been collected by the use of avarietyofmethods, each of which has a large experimental error. As most authors do not state the limits of error for their particular techniques, it is often impossible to compare their data with those of other studies on the same problem. A detailed description of the technique used in this study for the measurement of the serum fatty acids has been presented in a previous paper (Man and Gildea (193233)). It is fundamentally a modification of Stoddard and Drury s volumetric method, and was found lo have a limit of error of ~5 per cent. The lipid phosphorus was determined by a modification of the method of Fiske and Subbarow (1925). Range of Serum Lipids of Normal Subjects under Postabsorptive Conditions Table I presents the range of serum lipid values of normal healthy individuals. These subjects were from 21 to 40 years of age, and were members of the staff or students of the university. The blood was drawn about 9.00 a.m. Each person had eaten nothing since the previous evening meal, had indulged in no * Some of the data in this paper are taken from the dissertation presented by E. B. Man in partial fulfilment of the requirement for the degree of Doctor of Philosophy, Yale University,

2 62 Alimentary Lipemia in Normal Man exercise except walking around the building, and was not emotionally disturbed by the procedure. A comparison of these normal values for serum fatty acids with the determinations of other investigators is inconclusive. Stoddard and Drury (1929) published no data on the serum lipids of Feb. 16, , , , , , Mar. 15, , , , Dec. 15, , TABLE I Serum Lipids of Normal Subjects in Postabsorptive State Date Subject SC&X 1?ootal f&j I wids from I ;iter + 18 I N?r cent ot phpspho 1 iwtifd&stty Average... Minimum... Maximum... c. w. R. B. V. L. M. E. F. G. H. D. E. M. H. H. E. C. E. B. G. M. C. M. H. M. F. M. F. I Normal values for total fatty acids according et al. (1930) Average... Minimum... Maximum... M. F. I M. m.eq. n&.e* to Page m.eq NOW phospholipid ii%: n.eq fasting normal subjects. Stewart, Gaddie, and Dunlop (1931) seem to have made their analyses on whole blood and, therefore, t,heir determinations are not comparable with those on serum. The data of Patterson (1927), Stewart and White (1925), and Nicholls and Perlzweig (1928) were obtained by use of t.he Stewart

3 E. B. Man and E. F. Gildea 63 and White method which, as has been pointed out previously by Man and Gildea (1932), is unreliable and gives higher values than any of the other methods. The determinations made by modifications of the Bang oxidative method show wide variations because the oxidationreduction quotients used in the calculation of values vary considerably with each worker. Failure in some cases to state the quotient used in calculation limits the acceptability of data. Bloor (1928) presented no figures on fatty acids in the plasma from human blood. Blix (1926), Staub (1931), and Stenberg (1929) worked with whole blood. Rony and Ching (1930) worked with dog blood. Page et al. (1930) gave minimum, maximum, and average values for fatty acids in the plasma of normal subjects. These are presented at the bottom of Table I as mg. and milliequivalents of fatty acids. The latter figures have been calculated from the data on the assumption that palmitic and oleic acids are present in equal quantities in blood plasma. This assumption is based on the data which Bloor (1928) used for his calculations. Page stated that he followed Bloor s method. Many values for normal serum lipids have been made by nephelometric procedures. Of these, the Bloor, Pelkan, and Allen (1922) modification seems to have been used most frequently. In Bloor s original article he compared the values of plasma fatty acids determined by Kumagawa and Suto and by his nephelometric procedures, but none of these comparisons were made on plasma. An average of the normal values for plasma fatty acids obtained by Bloor (1916) by Hiller, Linder, Lundsgaard, and Van Slyke (1924), and by McClure and Huntsinger (1928), with the nephelometric method is approximately 330 mg. per cent of fatty acid or 12.0 milliequivalents of fatty acid, which agrees closely with the average obtained by Page and by us. If one could accept the values of many other workers with the nephelometric or Stewart and White methods, the range of normal would be between 7.0 milliequivalents (190 mg. per cent) and 3 milliequivalents (1000 mg. per cent). A similar variation was found in the normal group in this laboratory during the period that t,he method of Stewart and White was used.

4 64 Alimentary Lipemia in Normal Man E$ect on Serum Fatty Acids and Phospholipids of Ingestion of Large Amounts of Fat The majority of studies have been made with the nephelometric technique. Hiller, Linder, Lundsgaard, and Van Slyke (1924) in a review of the literature found only a few determinations on normal human subjects, and with the exception of those of Bang, these had been made with the ultramicroscopic technique. Bang (1918, pp. 104, 111) estimated the neutral fat of the blood in man and found only moderate rises, or none at all, after a meal of 100 gm. of butter, 250 cc. of cream, 100 gm. of meat, and 10 gm. of bread. Hiller, Linder, Lundsgaard, and Van Slyke reported only slight rises in plasma fatty acids after a meal of butter containing 1 gm. of fat per kilo of body weight. One out of six subjects showed a decrease. The average rise was 21.9 per cent. This is in marked contrast to the results obtained on dogs by all observers but the amount of fat fed to the normal subjects was much less per kilo of body weight than that fed to animals. Since 1924 a number of studies have been made on the effect of a single fat meal on the blood fat in man. Many of these have been performed with the nephelometric technique with variable results. McClure and Huntsinger found the most marked rise in plasma fatty acids after the introduction of oleic acid by tube into the duodenum, but they also found a rise after a meal of carbohydrate and a little protein. A review of the recent observations of workers using the oxidative techniques of Bang (1918, p. 86) and Bloor (1928) or the method of Stewart and White (1925) indicates t.hat little attention has been paid to the amount of fat fed in relation to the size of the subject. The effects described range from a decrease of 96 mg. per cent of fatty acid to a rise of 400 mg. per cent or 100 per cent above the fasting level (Blix, 1926; Nicholls and Perlzweig, 1928; Page et al., 1930). These results tend to confirm the work of Hiller. Therefore, it appears that a fat meal usually produces some increase in the level of serum fatty acids, but that frequently there may be no change whatsoever, and in some cases even a decrease may occur. After a fat meal the blood fatty acids usually begin to rise at 2 hours, reach a maximum between 3 and 5 hours, and return to normal at 7 and 8 hours. ExperimentIt seemed probable that more uniform results

5 E. B. Man and E. F. Gildea 65 TBBLE Lipemias of Normal Subjects Following Ingestion of Gm. of Fat per Kilo of Body Weight II 1951 Nov Dec Subject Time Phospho Patty acid Jonphoslipfififstt3 ram titer pholipid ttty acids m.eq. m.ep. m.q. E. F. G I V. L. M E. B. M.t I R. R. S.t L. H. C.t E. B. G G. B. C.t I * NaOH was used in saponification. t These subjects disliked the meal and experienced much discomfort in eating the whole amount.

6 66 Alimentary Lipemia in Normal Man Date Subject Time 1951 Dec L. J. T. L. B. W. TABLE IIConcluded 6 4 I I 6 I Bverage, per cent... Maximum,... Minimum, I... i. n.ep ; ; patty acid ram titer Tn.eq. onphoslholipid tty acida m.ep could be obtained if the amount of fat fed were proportional to the weight of each subject, and if some attempt were made to make the meals palatable. For these reasons we adopted a meal consisting of unsalted butter, 40 per cent cream, 2 to 3 slices of toast., 1 cup of coffee and no (or at the most 1 teaspoon of) sugar. Many of the subjects enjoyed eating this meal when it was made up as milk toast, but several did not like milk toast and ate the butter on the toast and drank the cream; the latter group did not find the meal palatable. Each subject received between 3.5 and 4 gm. of fat per kilo of body weight. These subjects were taken from among the group which had previously been used as normals for the studies of the postabsorptive state. They had had no food since the previous evening. Blood was taken before the fat meal, which was eaten between 8.30 and 9.30 a.m. Subsequent samples of blood were withdrawn 2, 4, and 6 hours later. The results are recorded in Table II. Every subject showed a marked rise in serum fatty acids, the average being 62 per cent, the maximum 133 per cent, and the minimum 34 per cent above the fasting level. There was a marked difference among the various individuals in their ability to ingest and to digest with comfort. these large amounts of fat. Four subjects, noted in Table II, disliked the

7 E. B. Man and E. F. Gildea 67 meal and experienced much discomfort in eating the whole amount. Afterwards, they were slightly nauseated off and on during the day and in the following 12 hours suffered from a mild diarrhea. One subject not included in Table II was nauseated by the meal and 6 hours later vomited what appeared to be most of the butter and cream. The other subjects did not mind eating the meal and three of them actually liked it; one man even insisted that he would have enjoyed a larger amount of fat. No correlation seems to exist between the level of lipemia reached and the ability to digest the meal with comfort. In six of the subjects the apex of the rise was reached in 4 hours and in three it came after 6 hours. The phospholipids were also determined as lipid phosphorus. The changes were not as great as those of the fatty acids, the average rise being 18 per cent, the maximum 28 per cent, and the minimum 5 per cent. Serum sugar rose slightly in only three subjects; in the others it tended to be slightly lower than it had been in the postabsorptive state. Thus it appears that a fat meal of 3.5 to 4 gm. per kilo of body weight does produce a consistent rise of at least 34 per cent in the serum fatty acids of normal adults. E$ect of Standard Balanced Meal on Serum Fatty Acids A standard balanced meal was fed to normal people similar to those used for the large fat meal. This meal is described below. 150 gm. grape fruit sections. 100 whole milk cream corn flakes bread butter... 2 eggs... Total... Breakfast Eaten by Normal Subjects Protein gm Fat gm. Carbohydrate Calories gm ! I

8 68 Alimentary Lipemia in Normal Man None of the people experienced any difficulty in eating this breakfast. Only two samples of blood were taken, the first in the postabsorptive state and the second 3 hours after ingestion of the meal. TABLE Alimentary Lipemias of Normal Subjects. Blood Taken before and 3 Hours after a Balanced Breakfast Containing 69 Gm. of Fat III Date Time Subject Feb Mar Feb Mar. 2 ( 2 14 I c. w. R. B. V. L. M. E. F. G. H. D. E. M. H. H. E. C. E. B. G. lipid fatty acids n.eq a.eq OM fatty mids from biter + 18,er cent of mph&id atty acids m.eq Xon,hosphoipid atty wida I.e* This meal amounted to between 0.5 and 1.0 gm. of fat per kilo * of body weight for each person. The weight of carbohydrate plus protein was slightly greater than the weight of the fat. Even this meal produced a rise in the serum fatty acids in all

9 E. B. Man and E. F. Gildea subjects but one, and in this person the meal was equivalent to only 0.5 gm. of fat per kilo. The maximum increase was f40per cent and the average +21 per cent (Table III). Thus, in this group the ingestion of other foods with fat did not prevent the rise in serum fatty acids as has been claimed by some workers (McClure and Huntsinger, 1928; Bang, 1918, pp. 104, 111). The phospholipids showed only a very slight increase, in most cases not beyond the limit of experimental error. SUMMARY The normal range of the serum fatty acids for man in the postabsorptive state is discussed and compared with values obtained with a modification of the Stoddard and Drury technique. The ingestion of 3.5 to 4 gm. of fat per kilo of body weight by nine normal men and women is shown to produce a marked rise in serum fatty acids and a moderate increase in the serum phospholipids. The ingestion of a balanced meal, containing at least 0.6 gm. of fat per kilo and with carbohydrate plus protein slightly exceeding the weight of the fat, is found to produce a rise in the serum fatty acids of normal men and women. BIBLIOGRAPHY Bang, I., &o&em. Z., 91,86, 104, 111 (1918). Blix, G., Skand. Arch. Physiol., 48, 267 (1926). Bloor, W. R., J. Biol. Chem., 26,577 (1916); 77,53 (1928). Bloor, W. R., Pelkan, K. F., and Allen, D. M., J. Biol. Chem., 62, 191 (1922). Fiske, C. H., and Subbarow, Y., J. Biol. Chem., 66,375 (1925). Hiller, A., Linder, G. C., Lundsgaard, C., and Van Slyke, D. D., J. Exp. Med., 39, 931 (1924). Man, E., and Gildea, E. F., J. Biol. Chem., 99,43 (193233). McClure, C. W., and Huntsinger, M. E., J. Biol. Chem., 76, 1 (1928). Nicholls, E. G., and Perlzweig, W. A., J. Clin. Inv., 6, 195 (1928). Page, I. H., Pasternack, L., and Burt, M. L., Biochem. Z., 223,445 (1930). Patterson, J. W. T., Biochem. J., 21,958 (1927). Rony, H. R., and Ching, T. T., Endocrinology, 14,355 (1930). Staub, H., Biochem. Z., 232,128 (1931). Stenberg, S., Acta med. &and., 71,558 (1929). Stewart, C. P., Gaddie, R., and Dunlop, D. M., Biochem. J., 26, 733 (1931). Stewart, C. P., and White, A. C., Biochem. J., 19,840 (1925). Stoddard, J. L., and Drury, P. E., J. Biol. Chem., 84,741(1929).

10 THE EFFECT OF THE INGESTION OF A LARGE AMOUNT OF FAT AND OF A BALANCED MEAL ON THE BLOOD LIPIDS OF NORMAL MAN Evelyn B. Man and Edwin F. Gildea J. Biol. Chem. 1932, 99:6169. Access the most updated version of this article at Alerts: When this article is cited When a correction for this article is posted Click here to choose from all of JBC's alerts This article cites 0 references, 0 of which can be accessed free at #reflist1