THE ABSORBABILITY OF NATURAL AND MODIFIED FATS^a

Abstract

IZTZ with the technical assistance of JOHN J. McMULLEN AND LUCIUS V. THOMAS Qitartermaste~ Food and Container InstittLte for the iZr?iieti Forces Chicago, IllinoisMost natural fats have been shown to be readily digested, but in the case of naturally-occurring fats of high melting point and of fats hardened by hydrogenation, the coefficient of digestibility may be reduced. Two major theories have been propounded to explain differences in digestibility :(1) that digestibility is inversely proportional to and dependent upon melting point (3, 9 ) ; or (2) that digestibility is limited by the amount of saturated fatty acids of carbon chains 18 or longer (8, 10). Other recent findings deserve coiisideration : Cheng, Morehouse, and Deuel ( 2 ) reported that monostearin was more digestible than either the triglyceride or the free fatty acid and Mattson, Baur, and Beck (12), that long-chain saturated fatty acids were better utilized as cliacetin fat than as triglyceride. These results indicate that not only is the chain length of the fatty acids imporant but also their association within the glyceride structure.To provide basic information for the development of fats which will meet the Armed Forces' stability requirement of 160" F. these various factors were explored. Preliminary studies of lipid materials formed by interrsterification with hexahydric alcohols were also conducted. METHODS AND MATERIALSDiets varying only in source of f a t were fed to adult male albino rats, 5 to 7 per group, for 15 days and feces collected on the last 5 days f o r digestibility measurement. I n each test a reference cottonseed-oil diet and a fat-free diet were fed. The amount of food offered was constant for all groups in each test and sufficient to permit small weight gains with the reference diet; i n most cases consumption was complete.The diets were composed of 80 parts of a diet base, as shown in Table 1, and 20 parts of test fat. Fats were dissolved in warm ethanol and mixed with the diet base; the diets were then placed on shallow trays and held at room temperature until the alcohol evaporated. This procedure was followed to insure intimate mixing of f a t with other diet components. The fat-free diet was treated in the same manner with 80 parts of base added to 30.7 parts of sucrose to yield a diet iso-nitrogenous when equal calories were fed.Fat content of the diet and of the feces was detcrmined by a modified Association of Official Agricultural Chemists (1) procedure as follows:To approximately 2 g. of wet feces was added 5 ml. of concentrated hydrochloric acid and digestion carried out at low boiling temperature, with

Medium‐Chain Triglycerides Increase Energy Expenditure and Decrease Adiposity in Overweight Men

“…Fat absorption was 99.6% with FctO consumption, which is similar to that observed in an animal trial comparing the digestibility of different types of fat (36). Also, earlier studies of the absorbability of fats in rats showed that coconut oil, which is rich in MCT, is 99.7% absorbed (37). With OL consumption, fat absorption was measured to be 99.7%, which is greater than the 97.4% absorption rate reported by Jones et al (38) for oleic acid.…”

The utilization of dietary fats by ruminants:I. The digestibility of some commercially available fats

“…In the case of non-ruminant animals it has been established that the extent to which a fat is absorbed is influenced by the proportions and chain length of the saturated fatty acids (Calloway et al 1956), the degree of unsaturation of the fat (Young & Garrett, 1963) and the arrangement of the fatty acids within the glyceride molecules (Renner & Hill, 1961;Mattson & Volpenheim, 1962;Davis, 1965). These observations have contributed to the current situation in which it is normal practice to include fats in rations designed for various classes of poultry, and to a lesser extent pigs.…”

“…studies; (6)Bayley (1963); (c)Benner & Hill (1961); (d)Lewis & Payne (1966); (e)Young (1961); (/)Hoagland & Snider (1943); {g)Fedde, Waibel & Burger (1960); (ft)Peterson & Vik-Mo (1968); (i)Calloway et al (1956); (j)March & Biely (1957).…”

Medium- versus long-chain triglycerides for 27 days increases fat oxidation and energy expenditure without resulting in changes in body composition in overweight women

“…Earlier studies of the absorbability of fats in rats showed that coconut oil is 99.7% absorbed compared to 98% for lard. 32 If we consider that RMR accounts for approximately 8 h daily and that the remaining time is spent in the post-meal period, then the average difference in EE with MCT consumption compared to LCT, as measured by indirect calorimetry, can be extrapolated to be 40.2 kcal on day 2 and 50.2 kcal on day 27. This would translate into a 0.14 -0.18 kg weight loss over a 27 day period.…”