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2013-11-17, 18:29
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Differential oxidation of individual dietary fatty acids in humans.
Abstract:
Background: Dietary fatty acids that are more prone to oxidation than to storage may be less likely to lead to obesity.
Objective: The aim of this study was to determine the effect of chain length, degree of unsaturation, and stereoisomeric effects of unsaturation on the oxidation of individual fatty acids in normal-weight men.
Design: Fatty acid oxidation was examined in men consuming a weight-maintenance diet containing 40% of energy as fat. After consuming the diet for 1 wk, subjects were fed fatty acids labeled with 13C in the methyl or carboxyl position (10 mg/kg body wt). The fatty acids fed in random order were laurate, palmitate, stearate, oleate, elaidate (the trans isomer of oleate), linoleate, and linolenate blended in a hot liquid meal. Breath samples were collected for the next 9 h and the oxidation of each fatty acid was assessed by examining liberated 13CO2 in breath.
Results: Cumulative oxidation over the 9-h test ranged from a high of 41% of the dose for laurate to a low of 13% of the dose for stearate. Of the 18-carbon fatty acids, linolenate was the most highly oxidized and linoleate appeared to be somewhat conserved. 13C recovery in breath from the methyl-labeled fatty acids was ≈30% less than that from the carboxyl-labeled fatty acids.
Conclusions: In summary, lauric acid is highly oxidized, whereas the polyunsaturated and monounsaturated fatty acids are fairly well oxidized. Oxidation of the long-chain, saturated fatty acids decreases with increasing carbon number.
Am J Clin Nutr October 2000 vol. 72 no. 4 905-911
http://ajcn.nutrition.org/content/72/4/905.long
The influence of the type of dietary fat on postprandial fat oxidation rates: monounsaturated (olive oil) vs saturated fat (cream).
Abstract:
OBJECTIVE:
To compare postprandial whole-body fat oxidation rates in humans, following high-fat (43% of total energy) mixed breakfast meals, of fixed energy and macronutrient composition, rich in either monounsaturated fat (MUFA) from extra virgin olive oil or saturated fat (SFA) from cream.
DESIGN:
Paired comparison of resting metabolic rate (RMR), thermic effect of a meal and substrate oxidation rates following consumption of isocaloric breakfast meals, differing only in the type of fat, administered in random order 1-2 weeks apart.
SUBJECTS:
Fourteen male volunteers, body mass index (BMI) in the range 20-32 kg/m(2), aged 24-49 y and resident in Melbourne, Australia, were recruited by advertisement in the local media or by personal contact.
MEASUREMENTS:
Body size and composition was determined by anthropometry and dual energy X-ray absorptiometry (DEXA). Indirect calorimetry was used to measure RMR, thermic effect of a meal, post-meal total energy expenditure and substrate oxidation rate. Blood pressure and pulse rates were measured with an automated oscillometric system. Fasting and 2 h postprandial glucose and insulin concentrations and the fasting lipid profile were also determined.
RESULTS:
In the 5 h following the MUFA breakfast, there was a significantly greater postprandial fat oxidation rate (3.08+/-4.58 g/5 h, P=0.017), and lower postprandial carbohydrate oxidation rate (P=0.025), than after the SFA breakfast. Thermic effect of a meal was significantly higher (55 kJ/5 h, P=0.034) after the MUFA breakfast, in subjects with a high waist circumference (HWC > or = 99 cm) than those with a low waist circumference (LWC<99 cm). This difference was not detected following the SFA breakfast (P=0.910).
CONCLUSION:
If postprandial fat oxidation rates are higher after high MUFA, rather than SFA meals, then a simple change to the type of dietary fat consumed might have beneficial effects in curbing weight gain in men consuming a relatively high-fat diet. This may be particularly evident in men with a large waist circumference.
Int J Obes Relat Metab Disord. 2002 Jun;26(6):814-21.
http://www.ncbi.nlm.nih.gov/pubmed/12037652
Differential oxidation of individual dietary fatty acids in humans.
Abstract:
Background: Dietary fatty acids that are more prone to oxidation than to storage may be less likely to lead to obesity.
Objective: The aim of this study was to determine the effect of chain length, degree of unsaturation, and stereoisomeric effects of unsaturation on the oxidation of individual fatty acids in normal-weight men.
Design: Fatty acid oxidation was examined in men consuming a weight-maintenance diet containing 40% of energy as fat. After consuming the diet for 1 wk, subjects were fed fatty acids labeled with 13C in the methyl or carboxyl position (10 mg/kg body wt). The fatty acids fed in random order were laurate, palmitate, stearate, oleate, elaidate (the trans isomer of oleate), linoleate, and linolenate blended in a hot liquid meal. Breath samples were collected for the next 9 h and the oxidation of each fatty acid was assessed by examining liberated 13CO2 in breath.
Results: Cumulative oxidation over the 9-h test ranged from a high of 41% of the dose for laurate to a low of 13% of the dose for stearate. Of the 18-carbon fatty acids, linolenate was the most highly oxidized and linoleate appeared to be somewhat conserved. 13C recovery in breath from the methyl-labeled fatty acids was ≈30% less than that from the carboxyl-labeled fatty acids.
Conclusions: In summary, lauric acid is highly oxidized, whereas the polyunsaturated and monounsaturated fatty acids are fairly well oxidized. Oxidation of the long-chain, saturated fatty acids decreases with increasing carbon number.
Am J Clin Nutr October 2000 vol. 72 no. 4 905-911
http://ajcn.nutrition.org/content/72/4/905.long
The influence of the type of dietary fat on postprandial fat oxidation rates: monounsaturated (olive oil) vs saturated fat (cream).
Abstract:
OBJECTIVE:
To compare postprandial whole-body fat oxidation rates in humans, following high-fat (43% of total energy) mixed breakfast meals, of fixed energy and macronutrient composition, rich in either monounsaturated fat (MUFA) from extra virgin olive oil or saturated fat (SFA) from cream.
DESIGN:
Paired comparison of resting metabolic rate (RMR), thermic effect of a meal and substrate oxidation rates following consumption of isocaloric breakfast meals, differing only in the type of fat, administered in random order 1-2 weeks apart.
SUBJECTS:
Fourteen male volunteers, body mass index (BMI) in the range 20-32 kg/m(2), aged 24-49 y and resident in Melbourne, Australia, were recruited by advertisement in the local media or by personal contact.
MEASUREMENTS:
Body size and composition was determined by anthropometry and dual energy X-ray absorptiometry (DEXA). Indirect calorimetry was used to measure RMR, thermic effect of a meal, post-meal total energy expenditure and substrate oxidation rate. Blood pressure and pulse rates were measured with an automated oscillometric system. Fasting and 2 h postprandial glucose and insulin concentrations and the fasting lipid profile were also determined.
RESULTS:
In the 5 h following the MUFA breakfast, there was a significantly greater postprandial fat oxidation rate (3.08+/-4.58 g/5 h, P=0.017), and lower postprandial carbohydrate oxidation rate (P=0.025), than after the SFA breakfast. Thermic effect of a meal was significantly higher (55 kJ/5 h, P=0.034) after the MUFA breakfast, in subjects with a high waist circumference (HWC > or = 99 cm) than those with a low waist circumference (LWC<99 cm). This difference was not detected following the SFA breakfast (P=0.910).
CONCLUSION:
If postprandial fat oxidation rates are higher after high MUFA, rather than SFA meals, then a simple change to the type of dietary fat consumed might have beneficial effects in curbing weight gain in men consuming a relatively high-fat diet. This may be particularly evident in men with a large waist circumference.
Int J Obes Relat Metab Disord. 2002 Jun;26(6):814-21.
http://www.ncbi.nlm.nih.gov/pubmed/12037652