MacDougall D E, Jones P J, Vogt J, Phang P T, Kitts D D
Division of Human Nutrition, University of British Columbia, Vancouver, Canada.
Eur J Clin Invest. 1996 Sep;26(9):755-62. doi: 10.1046/j.1365-2362.1996.1980545.x.
To assess the influence of dietary fat composition on the contribution of dietary myristic and palmitic acid to total fat oxidation and energy production, eight healthy men consumed diets containing 40% of total energy as fat, largely as either butter, tallow or corn oil, for 11 days. On days 8 and 11 of each diet, [1-13C]-myristic or [1-13C]-palmitic acid (20 mg kg-1 body weight) was ingested mixed with the test breakfast meal. Respiratory gas exchange was measured before, and for 9h after, consumption of the meal. Breath 13CO2 enrichments were determined hourly by isotope ratio mass spectrometry. Cumulative 9-h percentage oxidation of dietary myristic acid exceeded that of palmitic acid (P < 0.01), but neither was influenced by fat treatment [n = 8, 7.1% (1.0) (SEM), 8.6% (0.9) and 8.9% (0.6) of dietary myristic acid and 3.3% (0.7), 3.0% (0.9), and 2.5% (0.6) of dietary palmitic acid from butter, tallow and corn oil meals respectively]. Net dietary myristic acid oxidation was greater (P < 0.05) after consumption of the meal high in butter than after consumption of other fats. Net dietary palmitic acid oxidation was similar after consumption of all test meals. Precedent fat treatment had no measurable effect on net fat or carbohydrate oxidation or energy expenditure. The overall contribution of dietary myristic or palmitic acid to total fat oxidation did not exceed 1% over 9 h for any dietary fat. These results suggest that, although dietary fatty acid content is the principal determinant of net dietary fatty acid oxidation, dietary fat sources with moderate differences in fat composition do not measurably alter total energy or substrate utilization after a meal.
为评估膳食脂肪组成对膳食肉豆蔻酸和棕榈酸在总脂肪氧化及能量产生中贡献的影响，8名健康男性连续11天食用脂肪供能占总能量40%的膳食，这些膳食主要以黄油、牛脂或玉米油形式提供。在每种膳食的第8天和第11天，将[1-¹³C] - 肉豆蔻酸或[1-¹³C] - 棕榈酸（20毫克/千克体重）与测试早餐混合摄入。在进餐前及进餐后9小时测量呼吸气体交换。每小时通过同位素比率质谱法测定呼出气体中¹³CO₂的富集度。膳食肉豆蔻酸的累积9小时氧化百分比超过棕榈酸（P < 0.01），但二者均不受脂肪处理的影响[每组n = 8，来自黄油餐、牛脂餐和玉米油餐的膳食肉豆蔻酸分别为7.1%（1.0）（标准误）、8.6%（0.9）和8.9%（0.6），膳食棕榈酸分别为3.3%（0.7）、3.0%（0.9）和2.5%（0.6）]。食用富含黄油的膳食后，膳食肉豆蔻酸的净氧化量更大（P < 0.05），而食用其他脂肪后膳食肉豆蔻酸的净氧化量相似。之前的脂肪处理对净脂肪或碳水化合物氧化及能量消耗没有可测量的影响。对于任何膳食脂肪，膳食肉豆蔻酸或棕榈酸对总脂肪氧化的总体贡献在9小时内均未超过1%。这些结果表明，尽管膳食脂肪酸含量是膳食脂肪酸净氧化的主要决定因素，但脂肪组成存在适度差异的膳食脂肪来源在进餐后不会显著改变总能量或底物利用情况。
