Depot Fat Research Articles

The Influence of Rapeseed Oil on Digestibility, Energy Metabolism and Tissue Fatty Acid Composition in Pigs

Abstract The influence of rapeseed oil on digestibility, energy metabolism and tissue composition in growing pigs was determined. Rapeseed oil (0, 4, 8 and 16%) was added to a soyabean meal and barley basal diet. Essential amino acids relative to net energy (NE) were kept constant by adjusting with crystalline amino acids. Rapeseed oil has a high content of the unsaturated fatty acids 18:1n-9, 18:2n-6 and 18:3n-3, and is rich in natural tocopherols, which act as antioxidants. The apparent protein digestibility was enhanced with increasing levels of rapeseed oil. Improving the ratio of essential to non-essential amino acids decreased nitrogen execretion in faeces and urine by 21% and 26%, respectively. The amount of digestible fat increased from 29 to 218 g day−1 from the control diet to the diet with 16% rapeseed oil, resulting in a fat retention of 195 to 213 g day−1. This demonstrates the ability of pig for de novo synthesis of fatty acids. The digestibility of the rapeseed oil was high (92.7), and the metabolizable energy (ME) content of rapeseed oil was 38.28 MJ ME kg−1. The net energy value of the rapeseed oil corresponded to 3.66 kg air dry barley. Higher intakes of unsaturated fatty acids in rapeseed oil were reflected in the body tissue composition of both depot fat and intramuscular fat of the pigs. The fatty acid composition of these tissues became more unsaturated with respect to 18:2n-6 and 18:3n-3 as well as 20:5n-3 and 22:5n-3. Arachidonic acid (20:4n-6) increased slightly in leaf fat but tended to decrease in M. longissimus dorsi and M. biceps femoris, where docosahexaenoic acid (22:6n-3) in leaf fat was unaffected by dietary rapeseed oil level. In the analysed muscles 22:6n-3 tended to decrease with increasing dietary rapeseed oil level.

Unusual fatty acids in the depot fat of the Canadian beaver ( Castor canadensis)

Unusual fatty acids in the adipose tissue of the Canadian beaver were analysed by argentation thin-layer chromatography, gas-liquid chromatography and gas chromatography-mass spectrometry of several adducts and spectroscopic measurements. The total proportion of trans-octadecenoic fatty acids and the distribution of double bonds in these acids resembled those of ruminant fats. Because trans-11-18:1 was the main trans-18:1 isomer of beaver fat and a conjugated diene cis-9, trans-11-18:2 was also detected, it can be deduced that linoleic acid ( cis-9, cis-12-18:2) is biohydrogenated in the beaver. The idea that microbial processes intervene before normal absorption and fatty acid metabolism of the beaver is also supported by the larger amounts of anteiso odd-chain fatty acids with respect to the corresponding iso acids in the beaver depots. In addition, the distribution of double bonds in the cis-octadecenoic acids was wide, as it is in the depot fats of ruminants.

Levels and congener pattern of polychlorinated biphenyls in kittiwakes ( Rissa tridactyla), in relation to mobilization of body-lipids associated with reproduction

Three groups of female kittiwakes ( Rissa tridactyla) were collected in a North-Norwegian colony: (i) before breeding; (ii) immediately after egg-laying; and (iii) late in the chick-rearing period. Concentrations of 21 selected individual polychlorinated biphenyls (PCBs) were determined in liver, brain and fat tissues by capillary gaschromatography (GC-ECD). This was done in order to investigate how the mobilization of lipids associated with breeding influences concentrations and compositions of PCBs in these tissues. The results indicate an average decrease in body mass from pre-breeding to late chick-rearing of almost 20%. During this period, the mean concentration of PCBs in brain tissue approximately quadruples. This increase can be attributed to the redistribution of PCBs from utilized depot fat to metabolizing organs. A strong negative correlation was found between body mass and lipid weight PCB-concentrations in all three tissues. The relative amounts of different PCB-congeners were quite similar in different tissues, and showed only minor changes during the breeding period.

Effects of fill volume of diets on digestive tract kinetics and fattening pattern of growing Holstein-Friesian bull calves.

Young Holstein-Friesian bull calves were tested in three trials for their performance and digestive tract kinetic responses to diets differing in their fill volume (FV) in the digestive tract. In Trial 1, a high ME (11.7 MJ/kg of DM) diet was compared with three medium ME (10.5 MJ/kg of DM) diets, one of high FV and two of low FV. In Trial 2, two silages (wheat and sorghum), differing in FV, were compared with or without poultry litter inclusion. All the diets in this trial had the same ME content of 10.5 MJ/kg of DM. Rate of gain, DM and ME intake, and depot fat percentage at slaughter were recorded. In Trial 3, two diets (high and low FV) and the same ME content of 10.4 MJ/kg of DM were compared in a short-term trial for digestive tract kinetics using a single dose of Cr-NDF and Co-EDTA as particulate and solute markers, respectively. Calves in Trial 1 fed medium ME and low FV diets had higher (not significant) DMI than high ME calves but similar ADG, whereas medium ME and high FV calves had the lowest DMI (P < .1) and ADG (P < .05). Low FV and medium ME calves were leaner (P < .05) at slaughter than the high ME calves and fatter (not significant) than the high FV and medium ME calves. In Trial 2, reduction of FV by silage replacement increased DMI (P < .01) and ADG (P < .05). Incorporation of poultry litter into the diets resulted in effects in the same direction (not significant). Such a reduction caused increased (P < .01 for both silage end poultry litter effects) deposition of cod fat in the carcass. Mean retention time estimations in Trial 3 indicated increased (P = .055) particle retention time in the low FV calves, compared to the high FV calves. This increase was due to a longer (P = .1) stay of particles in the lower parts of the digestive tract, and not in the rumen. Lowering the FV of medium ME diets increased DMI of calves to support ADG equal to that of a high ME diet, but with a lower fat accumulation.

Response to dietary fat and cholesterol in young adult boars genetically selected for high or low plasma cholesterol.

Twenty-eight young adult boars (age 7 to 8 mo) genetically selected for four generations for high (HG) or low (LG) plasma cholesterol were studied to assess dietary and genetic effects and their interactions on cholesterol metabolism. Boars within a genetic group were paired according to their plasma cholesterol concentration at 8 wk of age and were fed for 15 wk (2.7 kg/d) one of two diets (16.5% fat and 1,156 mg of cholesterol/kg diet, HD; or 3.1% fat and 0 cholesterol diet, LD) in a 2 x 2 factorial arrangement. Plasma total cholesterol (P < .01) and HDL-cholesterol (P < .01) concentrations were higher in boars fed HS (P < .01) and in HG boars (P < .01). There was a trend toward a diet x genotype interaction for plasma HDL-cholesterol (P < .06). Plasma insulin concentration tended to be lower in boars fed HD (P < .09) or HG boars (P < .10). There was a diet x genotype interaction for plasma glucagon (P < .04) concentration and a trend toward an interaction for insulin (P < .07). After 15 wk, all boars were killed by electrocution and exsanguination and measurements were taken. Backfat thickness was greater (P < .01) and carcass length (P < .01) and weights of the four lean cuts (P < .02) were lower in LG than in HG boars. No microscopic atherosclerotic plaques were observed in aorta or coronary arteries. Cholesterol concentration in subcutaneous fat was lower (P < .04) in LG boars, suggesting that cholesterol content of depot fat can be reduced by genetic selection in swine.

The pathogenesis of fat embolism.

Fat embolism is a common autopsy finding in patients with or without a history of trauma. There are two basic mechanisms causing fat to embolize. Depot-derived fat embolism arises by disruption of depot fat, usually as a result of trauma, allowing direct entry into the bloodstream. Plasma-derived fat embolism is caused by agglutination of endogenous or infused exogenous fat such as Intralipid, with consequent embolism. Chylomicrons and Intralipid liposomes are known to undergo calcium-dependent agglutination by C-reactive protein (CRP), and this may play a role in vivo in this type of fat embolism.

Positional distribution of ω3 Fatty acids in marine lipid triacylglycerols by high‐resolution13C nuclear magnetic resonance spectroscopy

AbstractThe positional distribution [α(1,3)‐acyl and ß(2)‐acyl] of ω3 fatty acids [18:4(n‐3), 20:4(n‐3), 20:5(n‐3), 22:5(n‐3) and 22:6(n‐3)] in depot fat of Atlantic salmon (Salmo salar), harp seal oil and cod liver oil triacylglycerols has been examined by13C nuclear magnetic resonance (NMR) spectroscopy. The positional distribution data can be defined from the spectrum of the carbonyl (C1 carbon) and the methylene (C2 and glyceryl carbon) regions. In depot fat of Atlantic salmon and cod liver oil, docosahexaenoic acid (DHA) was concentrated in the ß‐position of the triacylglycerides with 72.6 and 74.4%, respectively. Only 3.2% of DHA and 4.6% of eicosapentaenoic acid (EPA) were esterified to the ß‐position of the triacylglycerides in harp seal oil. EPA is nearly randomly distributed in cod liver oil and muscle lipids of Atlantic salmon, with 37.8 and 39.7%, respectively, in the ß‐position. In general, the13C NMR‐derived data were in accordance with corresponding data reported in the literature obtained by conventional techniques.

Both raw and retrograded starch decrease serum triacylglycerol concentration and fat accretion in the rat

Male Wistar rats were meal-fed on diets containing various amounts of resistant starch in the form of raw starch (either amylomaize starch, potato starch or modified high-amylose starch) or retrograded starch (prepared from each of the starches) for 6 weeks. Two diets containing normal maize starch were fed as diets poor in resistant starch. Energy absorption (energy consumption minus faecal energy loss), growth, weight of the epididymal fat pads, serum total cholesterol and triacylglycerol concentrations and a number of intestinal and faecal variables were determined. The resistant starches affected all the variables determined except the serum total cholesterol concentration. Relationships were found between energy absorption and both growth and the weight of the fat pads, and between the weight of the fat pads and both the serum triacylglycerol concentration and the serum total cholesterol concentration. No clear differences between the effects of the two types of resistant starch (raw starch v. retrograded starch) were found except that raw potato starch hardly stimulated H2 excretion and led to lower amounts of propionic and butyric acids in the caecal contents than the other starches. The results suggest that dietary resistant starch reduces energy absorption leading to less abdominal depot fat and lower serum triacylglycerol concentrations.

The optimal depot fat composition for hibernation by golden-mantled ground squirrels (Spermophilus lateralis).

Golden-mantled ground squirrels (Spermophilus lateralis) are herbivores that hibernate during winter. Although little is known about the nutritional/physiological constraints on hibernation, numerous studies have demonstrated that increasing the amount of linoleic acid (a polyunsaturated fatty acid) in the diet enhances hibernation. This is probably because high linoleic acid diets reduce the melting points of the depot fats produced for hibernation which makes them more metabolizable at low body temperatures. This suggests that a major limitation on hibernation may be obtaining enough linoleic acid in the diet for proper hibernation. In all previous studies, however, the amount of linoleic acid in the diets of free-ranging animals was either not considered, or the range of dietary linoleic acid contents in the experiments was less than that of natural diets. It is thus not known whether the amount of linoleic acid available to hibernators under natural conditions actually limits their torpor patterns. A series of laboratory feeding and hibernation experiments were conducted with S. lateralis and artificial diets with different linoleic acid contents that were either below or above the linoleic acid content of the natural diet. The results demonstrated that when dietary linoleic acid contents are either below or above natural levels, hibernation ability is greatly reduced. Hibernation ability was reduced when the squirrels were maintained on a high linoleic acid diet probably by the production of toxic lipid peroxides in brown adipose tissues. The results indicate that there is an optimal level of dietary linoleic acid for proper hibernation, and this is equal to that of the natural diet.(ABSTRACT TRUNCATED AT 250 WORDS)

Dietary effects on fat deposition and fatty acid profiles in muscle and fat depots of Friesian bull calves.

Dietary effects on fat deposition, cholesterol level, and fatty acid profiles of muscle and fat depots in Friesian bull calves were evaluated in two trials. In Trial 1 (eight pens of seven Friesian bull calves), three levels of ME (10.4, 10.9, 11.7 MJ/kg of DM; diets L, M and H, respectively) were offered to three groups of calves throughout the entire experimental period. Calves of the fourth group were fed diet M for the first 80 d and diet L thereafter (Treatment ML). Calves were 185 +/- 15 d of age and 215 +/- 18 kg BW at the start of the trial and were slaughtered when they reached a predetermined equal degree of fatness, in a BW range of 480 to 580 kg, and an age range of 417 to 548 d. In Trial 2, four groups of calves (eight pens of seven Friesian bull calves) had free access to diets of the same ME (11.7 MJ/kg of DM) but that differed in either CP content (11.3 vs 13.4%) or had poultry litter substituted for part of soybean meal at the equivalent CP. Calves were 18o +/- 13 d of age and 240 +/- 19 kg BW at the start of the trial and were slaughtered after 232 +/- 11 d, at 508 +/- 22 kg BW. In both trials, dressing percentages and carcass percentages of kidney, pelvic, and cod fat depots were recorded at slaughter, and samples of the 12th rib longissimus muscle with its subcutaneous fat were obtained for lipid analyses. Increasing the ME concentration shortened the growing period and tended to increase carcass depot fat percentage.(ABSTRACT TRUNCATED AT 250 WORDS)

Toward a General Theory of Energy Management in Wintering Birds

Once a bird of a species that caches food becomes independent from its parents, it has four possible sources of energy and nutrients: (1) food it has not found, (2) food it has collected and placed in cache sites the locations of which it has forgotten, (3) food it has collected and placed in cache sites the locations of which it has remembered, (4) food it has collected, ingested and 'cached' internally as depot fat. Non-caching birds have only sources (1) and (4). In virtually all cases, a natural diet adequate in energy is also adequate in all specific nutrients (reviewed by Grubb 1989), so hereafter we will use the term energy to mean both energy and nutrients. Nonbreeding birds are assumed to manage the various forms of energy at their command in ways promoting survival until the next breeding season. Given the unitary nature of the selective force involved, namely increased survivorship, we should not expect management strategies for the various forms of energy to be independent. However, such an expectation tacitly underlies much theory and empirical study. Our intention here is first to review briefly the components of energy management that are currently drawing attention from researchers, then to focus on several promising lines of research for discovering the linkages necessary for a general theory. The bulk of our attention will be devoted to food-caching small passerines such as tits.

The degree of dietary fatty acid unsaturation affects torpor patterns and lipid composition of a hibernator.

Diets rich in unsaturated and polyunsaturated fatty acids have a positive effect on mammalian torpor, whereas diets rich in saturated fatty acids have a negative effect. To determine whether the number of double bonds in dietary fatty acids are responsible for these alterations in torpor patterns, we investigated the effect of adding to the normal diet 5% pure fatty acids of identical chain length (C18) but a different number of double bonds (0, 1, or 2) on the pattern of hibernation of the yellow-pine chipmunk, Eutamias amoenus. The response of torpor bouts to a lowering of air temperature and the mean duration of torpor bouts at an air temperature of 0.5 degree C (stearic acid C18:0, 4.5 +/- 0.8 days, oleic acid C18:1, 8.6 +/- 0.5 days; linoleic acid C18:2, 8.5 +/- 0.7 days) differed among animals that were maintained on the three experimental diets. The mean minimum body temperatures (C18:0, +2.3 +/- 0.3 degrees C; C18:1, +0.3 +/- 0.2 degree C; C18:2, -0.2 +/- 0.2 degrees C), which torpid individuals defended by an increase in metabolic rate, and the metabolic rate of torpid animals also differed among diet groups. Moreover, diet-induced differences were observed in the composition of total lipid fatty acids from depot fat and the phospholipid fatty acids of cardiac mitochondria. For depot fat 7 of 13 and for heart mitochondria 7 of 14 of the identified fatty acids differed significantly among the three diet groups. Significant differences among diet groups were also observed for the sum of saturated, unsaturated and polyunsaturated fatty acids.(ABSTRACT TRUNCATED AT 250 WORDS)

Lipoprotein lipase and hormone-sensitive lipase activity and mRNA in rat adipose tissue during pregnancy.

To investigate the factors controlling maternal depot fat accumulation during early pregnancy and net decrease during late pregnancy, the activity and mRNA expression of adipose tissue lipoprotein lipase (LPL) and hormone-sensitive lipase (HSL) were related to several other lipid metabolic parameters. Virgin control rats, pregnant rats (at days 12, 15, 19, and 21), and lactating rats (at days 5 and 10 postpartum) were studied. In adipose lumbar tissue of late pregnant rats, LPL activity decreased to about one-third that of the virgin control animals, with < 10% of initial LPL mRNA expressed as determined by Northern blots. HSL activity increased maximally 1.5-fold with a fourfold increase of HSL expression at days 12-15 of pregnancy and decreased to control levels after parturition. The HSL-to-LPL mRNA and activity ratios were enhanced from days 15 and 19 of pregnancy, respectively, and remained so even during lactation, mainly because of the marked lowering of the LPL values. This enhancement coincided with increments in plasma free fatty acids and glycerol levels indicating an increased depot fat breakdown. These results give no indication of an involvement of LPL and HSL gene expression changes in the accumulation of maternal depot during early pregnancy. In contrast, such changes could be responsible for the net breakdown of this fat depot during late gestation. Thus, during this physiological state, long-term (e.g., transcriptional) regulation of LPL and HSL gene expression could be an important mechanism for the control of adipose tissue mass breakdown during late gestation.

Fatty acid composition of Verata goat kids fed either goat milk or commercial milk replacer

Fatty acid composition of perirenal fat of young Verata male and female kids fed with natural milk and with three concentrations of commercial milk replacer was studied. There was no effect associated with sex. In each gender the only statistical difference in fatty acid composition between the four feeding groups under study were pentadecanoic acid (C15:0), heptadecanoic acid (C17:0) and heptadecenoic acid (C17:1) which were higher in all cases in naturally fed kids ( P < 0.05). The origin of odd-numbered fatty acids in depot fats of goat kids is discussed considering the possible role of microbial rumen synthesis in goat kids or the direct incorporation from the milk (or milk replacer) fat. The relatively low stearic concentration in perirenal fat in all groups (around 15%) suggest low ruminal activity. Determination of C15:0, C17:0 and C17:1 in perirenal fat could help differentiate the feeding system of young kids and might be useful for identification purposes of goat kid carcasses.

Fat reserves and reproduction in the green turtle, Chelonia mydas

Measurements were made of the fat and water content of standard cores of fat lining the inner carapace of green turtles caught and butchered by indigenous fishermen in Daru, Papua New Guinea. The amount of depot fat, total lipid and neutral lipid per core varied with the sex, maturity and reproductive status of the turtle. The fat content of cores from prepubescent turtles did not vary with sex. In contrast, cores from adult female turtles had a significantly greater fat content than those from males. Cores from pubescent and vitellogenic females had the highest fat content. Neutral (storage) lipid was significantly higher in cores from vitellogenic females than in those from breeding, which suggests that sub-carapace depot fat is used to fuel the energetically expensive costs of migration and egg production. Cores from breeding females had a significantly higher fat content than those from males, which suggests that the energetic costs of vitellogensis and egg-laying are reflected in sub-carapace fat stores. The greater energetic cost to this fat store for breeding by females is also reflected in the significantly higher water content of the fat of females that had bred in the previous season compared with those in vitellogenesis. In contrast, there was no significant difference between the water content of cores from non-breeding and breeding males.

Dietary fats, selected body temperature and tissue fatty acid composition of agamid lizards (Amphibolurus nuchalis)

The composition of tissue and membrane fatty acids in ectothermic vertebrates is influenced by both temperature acclimation and diets. If such change in body lipid composition and thermal physiology were linked, a diet-induced change in body lipid composition should result in a change in thermal physiology. We therefore investigated whether the selected body temperature of the agamid lizardAmphibolurus nuchalis (body mass 20 g) is influenced by the lipid composition of dietary fatty acids and whether diet-induced changes in thermal physiology are correlated with changes in body lipid composition. The selected body temperature in two groups of lizards was indistinguishable before dietary treatments. The selected body temperature in lizards after 3 weeks on a diet rich in saturated fatty acids rose by 2.1 °C (photophase) and 3.3 °C (scotophase), whereas the body temperature of lizards on a diet rich in unsaturated fatty acids fell by 1.5 °C (photophase) and 2.0 °C (scotophase). Significant diet-induced differences were observed in the fatty acid composition of depot fat, liver and muscle. These observations suggest that dietary lipids may influence selection of body temperature in ectotherms via alterations of body lipid composition.

Fatty acids in the subcutaneous adipose tissue of intensively fed SA Mutton Merino and Dorper wethers

Recent ambiguity about the role of animal fat in causing coronary heart disease, coupled with the controversy regarding the effect of various levels of energy nutrition on ruminant depot fats, prompted an investigation into the influence of high-energy nutrition, breed and slaughter weight on the fatty acid profiles of ruminants. Two isonitrogenous and isomineral diets containing 11·76 MJ ME/kg DM and 10·18 MJ ME/kg DM were fed to Dorper and SA Mutton Merino wethers of ± 20 kg to 37 and 43 kg live weight. Subcutaneous fat samples and feed samples were collected for fatty acid analysis. Treatment significantly affected the subcutaneous fatty acid profiles of wethers, which includes C15:0, C16:0, C17:0, C17:1, C18:0, C18:1, C18:2 and C18:3. Treatment also influenced the concentration of saturated and unsaturated fatty acids in the subcutaneous adipose tissue as well as the concentration of trans-fatty acids. The results obtained suggest that dietary energy levels may significantly affect the fatty acids in the subcutaneous fat of wethers. Breed differences, after correcting for carcass fatness, occurred in C16:0.

Reproductive effort in Ad�lie penguins

We estimated reproductive effort (energy expenditures for reproduction, as opposed to maintenance) in Adelie penguins breeding at Palmer Station, Antarctica. Data on body composition changes and metabolic rate were obtained using isotopic methods. Adelie breeding behavior consists of an initial courtship stage (during which both sexes fast), incubation, the ‘guard’ stage (when chicks are 1 to 18–28 days old), and the ‘creche’ stage (from the end of guarding until chicks are 28–45 days old). Both males and females lost considerable mass during the initial stages of the reproductive season, but males fasted longer and lost more mass. Mass losses of both sexes consisted of 66% depot fat and 34% lean tissue. Mass and body composition remained constant once birds resumed feeding. The metabolic expenditure for the foraging necessary to accumulate the mass lost while fasting — one component of reproductive effort —was about 63 MJ in males and 39 MJ in females. Field metabolic rates (FMR) were low during courtship and while incubating, increasing more than 2-fold when birds resumed foraging. Although mean FMR increased between incubation and the creche stage, differences between stages were small and not significant. We used FMR data and an energy balance model to estimate the cost of feeding chicks. Results suggest a maintenance FMR of about 2.7 × basal metabolism (BMR), increasing to 3.4–3.6 × BMR during the creche stage. The reproductive effort (as metabolic expenditures) associated with feeding chicks is 31 MJ (males) to 36 MJ (females). Cumulative reproductive effort is 94 MJ in males and 75 MJ in females, or 5.3–6.2% of the annual energy budget. The reproductive effort devoted to chick care does not appear to be constrained by physiological or time limitations. Instead, selection to reduce the risk of predation may prevent the evolution of increased parental care.

Preparation of Naturally 13C-Rich Free Fatty Acids (FFA) from Corn Oil and their Application in Metabolic Studies of Lactating Cows

Abstract When the 13C/12C ratios in lactose and milk fat of normally fed healthy cows are compared to 13C/12C in feed a metabolic depletion of 13C in the milk constituents becomes obvious. Due to a carbon isotope effect in the decarboxylation step of pyruvate to Acetyl-Co-A resulting in a 13C depleted acetate, depot fat and milk fat are especially reduced in 13C relative to 12C. Under pathophysiological conditions after longer fasting periods or in ketosis, long chain fatty acids from depot fat are metabolized and their 13C depleted carbon atoms enter the citric acid cycle via Acetyl-Co-A. Then the intermediary products of this cycle become 13C depleted too and with a drain on the oxalacetate pool by gluconeogenesis 13C depleted carbon atoms are channeled into lactose. This hypothesis is apt to explain a 13C/12C decrease in lactose of ketotic cows relative to healthy controls. It is supported by the observation that 13C-rich fatty acids from corn oil dosed orally to a ketotic cow increase the 13C/12C rati...

Androgen Treatment of Abdominally Obese Men

Middle-aged men with abdominal obesity were treated in a double-blind study with moderate doses of transdermal preparations of testosterone (T), dihydrotestosterone (DHT), or placebo. This resulted in moderately elevated T concentrations and marked decreases in follicle stimulating and luteinizing hormones in the group treated with T, while the DHT group showed elevated DHT, markedly lower T values, and less diminution of gonadotropin concentrations. In the group treated with T visceral fat mass decreased (measured by computerized tomography) without significant changes in other depot fat regions. Lean body mass did not change. In the group treated with T, glucose disposal rate, measured with the euglycemic hyperinsulinemic clamp method, was markedly augmented. Plasma triglycerides, cholesterol, and fasting blood glucose concentrations as well as diastolic blood pressure decreased. There were no such changes in the DHT or placebo treatment groups. The men treated with T reported increased well-being and energy. In none of the groups did prostate volume, specific prostate antigen concentration, genito-urinary history, or urinary flow measurement change. It is suggested that supplementation of abdominal obese men with moderate doses of T might have several beneficial effects.