Objectives: To investigate the effects of medium-and long-chain triacylglycerol (MLCT) on blood triglyceride (TG) in Chinese hypertriglyceridemic subjects. Methods: A double-blind controlled clinical trial was carried out, in which 112 subjects with hypertriglyceridemia were randomly divided into two dietary oil groups: (1) long-chain triacylglycerol (LCT) and (2) MLCT. All subjects were requested to ingest fixed energy and to continue their normal activity levels, and to consume LCT or MLCT oil at 25-30 g daily during the study period. Anthropometric measurements of body weight, body mass index (BMI), body fat, body fat percentage, waist and hip circumference (WC and HC), areas of subcutaneous and visceral fat by computed tomography scanning and blood biochemical markers were measured at the beginning and end of the study. Results: There were 50 and 51 subjects left in LCT and MLCT groups, respectively. There were no significant differences in daily intake of energy, protein, fat and carbohydrate, as well as the daily physical activity between the two groups during the study. After 8 weeks, MLCT group showed a significant decrease in body weight, BMI, WC, HC, ratio of WC and HC, body fat, body fat percentage and subcutaneous fat when compared with the initial values. The decrease in body weight, BMI, WC, body fat and subcutaneous and visceral fat was significantly greater in MLCT group than that in the LCT group. Furthermore, the serum concentrations of TG in MLCT group were significantly lower than those in the LCT group. Conclusions: Consumption of MLCT may reduce body weight, body fat and blood TG in hypertriglyceridemic subjects under an appropriate dietary regime.

We found previously that the ingestion of margarine containing medium-chain triacylglycerols (MCT) resulted in a significant increase in postprandial thermogenesis when compared with long-chain triacylglycerols (LCT). Diets that included margarine containing MCT and LCT were compared for 12 weeks in 73 subjects to investigate the effects on body weight, body fat, areas of subcutaneous and visceral fat, serum total cholesterols, triglycerides, lipoproteins, plasma glucose, serum insulin, total ketone bodies, and the activities of aspartate aminotransferase, alanine aminotransferase, and γ-glutamyltranspeptidase. We conducted a double-blind, controlled study and used blended rapeseed oil and soybean oil (LCT) as a comparison. Two groups ingested 2,100-2,400 kcal/day of energy, 65-73 g/day of total fat, and 14 g/day of test margarine (5 g/day of MCT or LCT). The subjects on the MCT diet demonstrated significant decreases in body fat weight (-3.8 ± 2.4 kg vs -2.4 ± 1.7 kg; MCT vs LCT, mean ± SD), subcutaneous fat (-38.2 ± 29.9 cm 2 vs -22.6 ± 19.3 cm 2 ), and visceral fat (-12.2 ± 11.2 cm 2 vs -1.6 ± 12.8 cm 2 ) after 12 weeks. There were no clinical differences in measured blood parameters. We suggest that the postprandial increase in thermogenesis and control of postprandial triglyceride levels may explain these results. J Atheroscler Thromb, 2003; 10: 290-298.

Medium-chain fatty acids (MCFA) have attracted attention as part of a healthy diet, because they are absorbed and transported directly into the liver via the portal vein, metabolized rapidly by beta-oxidation, and increase diet-induced thermogenesis. Because medium-chain triacylglycerols (MCT) containing only MCFA has a few weak points as frying oils, we have developed medium- and long-chain triacylglycerols (MLCT). MLCT is produced by lipase-catalyzed enzymatic transesterification. Recently, long-term clinical trials have demonstrated that MLCT and MCT result in less body fat-deposition. MLCT oil (Trade name: Healthy Resseta) is safe and can be substitute for common edible vegetable oils. Healthy Resseta has been approved as FOSHU (Food for Specified Health Use), by the Ministry of Health, Labour and Welfare of Japan in December 2002 for use as a cooking oil with a suppressing effect on body fat accumulation. Healthy Resseta is widely sold in Japan.

SummaryThe purpose of this study was to investigate the effect of 5-10g of medium chain triacylglycerols (MCT) on diet-induced thermogenesis in healthy humans. The study compared diet-induced thermogenesis after ingestion of test foods containing MCT and long-chain triacylglycerols (LCT), using a double-blind, crossover design. Eight male and eight female subjects participated in study 1 and study 2, respectively. In both studies, the LCT was a blend of rapeseed oil and soybean oil. In study 1, the liquid meals contained 10g MCT (10M), a mixture of 5g MCT and 5g LCT (5M5L), and 10g LCT (10L). In study 2, the subjects were given a meal (sandwich and clear soup) with the mayonnaise or margarine containing 5g of MCT or LCT. Postprandial energy expenditure was measured by indirect calorimetry before and during the 6h after ingestion of the test meals. Diet-induced thermo genesis was significantly greater after 5M5L and 10M ingestion as compared to 10L inges tion. Ingestion of the mayonnaise or margarine containing 5g MCT caused significantly larger diet-induced thermogenesis as compared to that of LCT. These results suggest that, in healthy humans, the intake of 5-10g of MCT causes larger diet-induced thermogenesis than that of LCT, irrespective of the form of meal containing the MCT.

This study investigated the effects of a liquid meal containing medium-and long-chain triacylglycerols (MLCT) on diet-induced thermogenesis (DIT) and was conducted in double-blind crossover manner. Twenty subjects participated in this examination. The subjects consumed the liquid meal, which was made with 14g of canola oil (LCT, long-chain triacylglycerols) or MLCT containing about 12% medium-chain fatty acids (MCFA). Oxygen consumption and carbon dioxide production were measured by indirect calorimetry. Resting energy expenditure (REE) was determined based on there parameters, applying the equation of Weir. Increase in DIT after ingesting the liquid meal with MLCT during 6h was significantly greater than with LCT (P<0.05). The results suggest that the substitution of MLCT for cooking oil is useful to control body weigh and fat in subjects.