Gestational diabetes mellitus (GDM) is the most common medical complication of pregnancy and a severe threat to pregnant people and offspring health. The molecular origins of GDM, and in particular the placental responses, are not fully known. The present study aimed to perform a comprehensive characterisation of the lipid species in placentas from pregnancies complicated with GDM using high-resolution MS lipidomics, with a particular focus on sphingolipids and acylcarnitines in a semi-targeted approach. The results indicated that despite no major disruption in lipid metabolism, placentas from GDM pregnancies showed significant alterations in sphingolipids, mostly lower abundance of total ceramides. Additionally, very long-chain ceramides and sphingomyelins with twenty-four carbons were lower, and glucosylceramides with sixteen carbons were higher in placentas from GDM pregnancies. Semi-targeted lipidomics revealed the strong impact of GDM on the placental acylcarnitine profile, particularly lower contents of medium and long-chain fatty-acyl carnitine species. The lower contents of sphingolipids may affect the secretory function of the placenta, and lower contents of long-chain fatty acylcarnitines is suggestive of mitochondrial dysfunction. These alterations in placental lipid metabolism may have consequences for fetal growth and development.

The Mediterranean (MED) diet was associated with a reduced risk of chronic disease, but the epidemiological studies reported inconsistent findings related to the MED diet and non-alcoholic fatty liver disease (NAFLD) risk. This age and the gender-matched case-control study were conducted among 247 adult patients. The MED diet score was obtained based on the Trichopoulou model. Multivariate logistic regression was used to examine the association between the MED diet and NAFLD risk. NAFLD prevalence in people with low, moderate and high adherence to the MED diet was 33, 13⋅1 and 4⋅6 %, respectively. The increasing intake of the MED diet was significantly related to the increment intake of nuts and fruits, vegetables, monounsaturated fatty acid/polyunsaturated fatty acid ratio, legumes, cereals and fish. However, total energy consumption, low-fat dairy and meats intake were reduced (P for all < 0⋅05). Following control for age, the person in the highest of the MED diet tertile compared with the lowest, the odds of NAFLD decreased (OR: 0⋅40, 95 % CI: 0⋅17–0⋅95). This relation became a little stronger after further adjusting for sex, diabetes, physical activity and supplement intake (OR: 0⋅36, 95 % CI: 0⋅15–0⋅89). However, this association disappeared after adjusting for body mass index, waist and hip circumference (OR: 0⋅70, 95 % CI: 0⋅25–1⋅97). High adherence to the MED diet was associated with a 64 % reduction in NAFLD odds before some anthropometric variable adjustments. However, further prospective studies are required, particularly in BMI-stratified models.

The effect of fatty acids was studied on the developmental direction of Strongyloides ratti first-stage larvae (L1). The proportion of third-stage infective larvae increased markedly when L1 were cultured in faeces with added fatty acids such as palmitic (C16), stearic (C18), oleic (C18:1) and linoleic (C18:2) acids. Unsaturated fatty acids were more effective than saturated ones. Moreover, the proportion of infective larvae increased with quantity of linoleic acid but the triacylglycerols of any fatty acid had no effect. These results suggest that these free fatty acids cause physiological changes that determine the developmental course of L1 of S. ratti in nature.

The mechanisms and regulation of storage lipid formation in seeds are reviewed. Seed storage lipids are ultimately derived from simple carbon compounds, such as sucrose, which are imported into seeds from source tissues, such as leaves or pods. The partitioning of this important carbon towards storage lipid, carbohydrate or protein is regulated by a complex interaction between genetically-determined endogenous factors and external environmental influences. Storage lipids are synthesized from fatty acids, derived from acetyl-CoA, and glycerol 3-phosphate. Fatty acid biosynthesis and probably acetyl-CoA formation, occurs within the plastids to produce oleoyl-CoA. Further elaboration of oleoyl-CoA to produce polyunsaturates, hydroxylates or very long chain acyl-CoAs occurs on the endoplasmic reticulum, as does the esterification of acyl-CoAs to glycerol-3-phosphate to produce the final triacylglycerol storage oil. The temporal and hormonal regulation of storage lipid accumulation in seeds is discussed.

Asian plantain (Plantago asiatica) essential oil (PAEO) contains multiple bioactive compounds, but its potential effects on lipid metabolism have not been examined. PAEO was found to be mostly composed of oxygenated monoterpenes, with linalool as the major component (82·5 %, w/w), measured using GC–MS. Incubation of 0–200 μg PAEO/ml with HepG2 cells for 24 h resulted in no significant toxicity. Incubation with 0·2 mg PAEO/ml altered the expression of LDL receptor (+83 %; P < 0·05) and 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase ( − 37 %; P < 0·05), as assessed using RT-PCR. LDL oxidation was markedly inhibited by PAEO treatment due to the prevalence of linalool compounds in PAEO. Oral administration of PAEO for 3 weeks in C57BL/6 mice significantly reduced plasma total cholesterol and TAG concentrations by 29 and 46 %, respectively. The mRNA (+58 %; P < 0·05), but not protein, levels of the LDL receptor were significantly higher, whereas both mRNA and protein levels of HMG-CoA reductase were significantly lower ( − 46 and − 11 %, respectively; P < 0·05) in the liver of PAEO-fed than of control mice. The mRNA levels of CYP7A1 were marginally reduced in HepG2 cells, but not in mouse liver after PAEO treatment. Thus, PAEO may have hypocholesterolaemic effects by altering the expression of HMG-CoA reductase. Reduced TAG and oxidised LDL may provide additional cardiovascular protective benefits.

The aim of the present article is to evaluate critically the various methods employed in studies designed to quantify precisely skeletal muscle substrate utilization during exercise. In general, the pattern of substrate utilization during exercise can be described well from O2 uptake measurements and the respiratory exchange ratio. However, if the aim is to quantify limb or muscle metabolism, invasive measurements have to be carried out, such as the determination of blood flow, arterio-venous (a-v) difference measurements for O2 and relevant substrates, and biopsies of the active muscle. As many substrates and metabolites may be both taken up and released by muscle at rest and during exercise, isotopes can be used to determine uptake and/or release and also fractional uptake can be accounted for. Furthermore, the use of isotopes opens up further possibilities for the estimation of oxidation rates of various substrates. There are several methodological concerns to be aware of when studying the metabolic response to exercise in human subjects. These concerns include: (1) the muscle mass involved in the exercise is largely unknown (bicycle or treadmill). Moreover, whether the muscle sample obtained from a limb muscle and the substrate and metabolite concentrations are representative can be a problem; (2) the placement of the venous catheter can be critical, and it should be secured so that the blood sample represents blood from the active muscle with a minimum of contamination from other muscles and tissues; (3) the use of net limb glycerol release to estimate lipolysis is probably not valid (triacylglycerol utilization by muscle), since glycerol can be metabolized in skeletal muscle; (4) the precision of blood-borne substrate concentrations during exercise measured by a-v difference is hampered since they become very small due to the high blood flow. Recommendations are given in order to obtain more quantitative and conclusive data in studies investigating the regulatory mechanisms for substrate choice by muscle.

Recent studies have shown that dietary oxidised fats influence the lipid metabolism in rats by activation of PPARα. In this study, we investigated whether a mildly oxidised fat causes activation of PPARα in pigs which are non-proliferators like man. Eighteen pigs were assigned to two groups and received either a diet containing 90 g/kg of a fresh fat or the same diet with 90 g/kg of an oxidised fat prepared by heating for 24 h at 180°C in a deep fryer. Pigs fed the oxidised fat had a higher peroxisome count, a higher activity of catalase and a higher mRNA concentration of mitochondrial 3-hydroxy-3-methylglutaryl-CoA synthase in the liver and a higher concentration of 3-hydroxybutyrate in plasma than pigs fed the fresh fat (P < 0·05). Hepatic mRNA concentrations of acyl-CoA oxidase and carnitine palmitoyltransferase-1 tended to be increased in pigs fed the oxidised fat compared to pigs fed the fresh fat (P < 0·10). Pigs fed the oxidised fat, moreover, had higher mRNA concentrations of sterol regulatory element-binding protein (SREBP)-1 and its target genes acetyl-CoA carboxylase and stearoyl-CoA desaturase in the liver and higher mRNA concentrations of SREBP-2 and its target genes 3-hydroxy-3-methylglutary-CoA reductase and LDL receptor in liver and small intestine. In conclusion, this study shows that even a mildly oxidised fat causes activation of PPARα in the liver of pigs. Up-regulation of SREBP and its target genes in liver and small intestine suggests that the oxidised fat could stimulate synthesis of cholesterol and TAG in these tissues.

Obesity is associated with insulin resistance. Insulin resistance underlies a constellation of adverse metabolic and physiological changes (the insulin resistance syndrome) which is a strong risk factor for development of type 2 diabetes and CHD. The present article discusses how accumulation of triacylglycerol in adipocytes can lead to deterioration of the responsiveness of glucose metabolism in other tissues. Lipodystrophy, lack of adipose tissue, is also associated with insulin resistance. Any plausible explanation for the link between excess adipose tissue and insulin resistance needs to be able to account for this observation. Adipose tissue in obesity becomes refractory to suppression of fat mobilization by insulin, and also to the normal acute stimulatory effect of insulin on activation of lipoprotein lipase (involved in fat storage). The net effect is as though adipocytes are ‘full up’ and resisting further fat storage. Thus, in the postprandial period especially, there is an excess flux of circulating lipid metabolites that would normally have been ‘absorbed’ by adipose tissue. This situation leads to fat deposition in other tissues. Accumulation of triacylglycerol in skeletal muscles and in liver is associated with insulin resistance. In lipodystrophy there is insufficient adipose tissue to absorb the postprandial influx of fatty acids, so these fatty acids will again be directed to other tissues. This view of the link between adipose tissue and insulin resistance emphasises the important role of adipose tissue in ‘buffering’ the daily influx of dietary fat entering the circulation and preventing excessive exposure of other tissues to this influx.

Postprandial lipaemia (PL) is associated with the metabolic syndrome, CVD and endothelial dysfunction. Aerobic exercise has been shown to reduce PL. Although resistance exercise is recommended for the improvement of the quality of life, management of body weight and prevention of several disorders, its effect on PL has received little attention. The present study examined the effects of low-volume resistance exercise (LVRE) and high-volume resistance exercise (HVRE) on PL. Ten healthy young men performed three trials, each conducted over 2 d. On the afternoon of day 1, they either refrained from exercise (control), performed LVRE (two sets of eight exercises, twelve repetitions at twelve repetitions maximum (RM) in each set; energy expenditure 0·76 MJ), or performed HVRE (four sets of eight exercises, twelve repetitions at 12RM in each set; energy expenditure 1·40 MJ). On the morning of day 2 they consumed a meal containing 67 kJ/kg body weight, of which 65 % energy was from fat. Blood samples were obtained in the fasted state and for 6 h postprandially. The total area under the TAG curve (AUC; mmol/l × h) was lower (P < 0·05) in HVRE (8·76 (sd 3·20)) and LVRE (9·29 (sd 3·64)) compared with control (11·60 (sd 4·35)). The incremental AUC was lower in HVRE compared with control (3·07 (sd 2·53) v. 5·58 (sd 3·72)), but not different between LVRE (3·86 (sd 2·29)) and control. In conclusion, resistance exercise of 1·40 MJ (four sets – eight exercises – twelve RM) or 0·76 MJ (two sets – eight exercises – twelve RM) before a high-fat meal reduces the total postprandial lipaemic response.

The aim of the present study was to determine the influence of the dietary fatty acid profile on the lipoprotein composition in sea bream fed different vegetable oils. Six experimental diets were formulated combining fish oil with three vegetable oils (soybean, rapeseed, linseed) in order to obtain 60–80 % (w/w) fish-oil replacement. VLDL, LDL and HDL in plasma samples were obtained by sequential centrifugal flotation. The lipid class, protein content and fatty acid composition of each lipoprotein fraction were analysed. HDL was the predominant lipoprotein in sea bream plasma containing the highest proportion of protein (34 %) and phosphatidylcholine. LDL presented a high content of cholesterol, whereas triacylglycerol comprised a larger proportion of VLDL. The lipid class of the lipoprotein fractions was affected by the dietary vegetable oils. Thus, a high dietary inclusion of soyabean and linseed oil (80 %) increased the cholesterol in HDL and LDL in comparison to fish oil. Similarly, the triacylglycerol concentration of VLDL was increased in fish fed 80 % soyabean and linseed oils owing to the low n-3 highly unsaturated fatty acid content of these diets. Lipoprotein fatty acid composition easily responded to dietary fatty acid composition. VLDL was the fraction more affected by dietary fatty acid, followed by LDL and HDL. The n-3 highly unsaturated fatty acid content increased in the order VLDL less than LDL and less than HDL, regardless of dietary vegetable oils.

Despite the good growth performance of several fish species when dietary fish oil is partly replaced by vegetable oils, recent studies have reported several types of intestinal morphological alterations in cultured fish fed high contents of vegetable lipid sources. However, the physiological process implied in these morphological changes have not been clarified yet, since alterations in the physiological mechanisms involved in the different processes of lipid absorption could be responsible for such gut morphological features. The objective of the present study was to investigate the activities of reacylation pathways in fish, the glycerol-3-phosphate and the monoacylglycerol pathways, in order to clarify the intestinal triacylglycerol (TAG) and phospholipid biosynthesis to better understand the morphological alterations observed in the intestine of fish fed vegetable oils. Intestinal microsomes of sea bream fed different lipid sources (fish, soyabean and rapeseed oils) at three different inclusion levels were isolated and incubated with l-[14C(U)]glycerol-3-phosphate and [1-14C]palmitoyl CoA. The results showed that in this fish species the glycerol-3-phosphate pathway is mainly involved in phospholipid synthesis, whereas TAG synthesis is mainly mediated by the monoacylglycerol pathway. Feeding with rapeseed oil reduced the reacylation activity in both pathways, explaining the high accumulation of lipid droplets in the supranuclear portion of the intestinal epithelium, whereas soyabean oil enhanced phosphatidylcholine synthesis, being associated with the increase in VLDL found in previous studies.

Exercise prior to eating has repeatedly been shown to reduce postprandial lipaemia. The aim of the present study was to investigate whether this effect was manifest in the presence of two factors that independently mitigate postprandial lipaemia: eumenorrhoea and moderate fat intake. Eight healthy eumenorrhoeic rowers consumed a meal of moderate fat content (35% total energy, 0·66g/kg body mass) 14h after having either rowed at 55% of maximal aerobic power (81% of maximal heart rate) for 80min or rested. Both trials were performed during the luteal phase. Blood samples were drawn before the meal and for 8h postprandially for the measurement of individual fatty acids in the triacylglycerol and NEFA fractions, as well as of glucose, insulin and oestradiol. Plasma oestradiol concentrations were not significantly different in the two trials. The postprandial lipaemic response, expressed as either plasma triacylglycerol concentration or area under the triacylglycerol–time curve, was 35% lower (P<0·05) after exercise. The postprandial glycaemic and insulinaemic responses were also lower, indicating increased insulin sensitivity, whereas the NEFA response was higher, suggesting a lower entrapment of dietary fatty acids in adipose tissue after exercise. Finally, exercise increased the proportion of unsaturated:saturated NEFA during the postprandial period. In conclusion, aerobic exercise performed 14h before a moderate-fat meal reduced postprandial lipaemia in women in the luteal phase. This effect shows the potential of exercise to mitigate even moderate lipaemic responses in eumenorrhoeic women.

Studies in rodents show that inulin and oligofructose can reduce the plasma levels of cholesterol and triacylglycerols (TG). In addition, they can oppose TG accumulation in liver and have favourable effects on hepatic steatosis. The hypotriglyceridaemic effect is due to a reduction in hepatic re-esterification of fatty acids, but mainly in the expression and activity of liver lipogenesis, resulting in lower hepatic secretion rate of TG. This repression of lipogenesis is not observed in adipose tissue. The effect on liver lipogenesis can be explained by reduced insulin/glucose levels or by a selective exposure of the liver to increased amounts of propionic acid produced in the large intestine during fermentation of non-digestible carbohydrates. The decrease in plasma cholesterol could also be due to inhibition of cholesterol synthesis by propionic acid or to modifications in the bile acid metabolism. Studies in man yield more conflicting results with a decrease or no effects on plasma lipid levels, and, when a decrease is observed, more marked effects on TG than on cholesterol and more consistent action of inulin than of oligofructose. Besides the difference in the dose of inulin or oligofructose used, differences in metabolic status could play a role in this discrepancy between man and animals since reduction in plasma TG is observed in man mainly in a situation of increased liver lipogenesis (high-carbohydrate diet, obesity, hypertriglyceridaemia). The effects on plasma cholesterol appear also more marked in hyperlipidaemic subjects than in healthy controls, suggesting that inulin and oligofructose have beneficial effects in these types of subjects.

Epidemiological surveys suggest that a higher intake of tea may be associated with a lower risk of CHD. There is accumulating evidence that postprandial lipaemia makes a substantial contribution to the incidence of CHD. Our aim was, therefore, to evaluate the effect of tea catechins (major ingredients in green tea) on postprandial lipid responses in human subjects after the consumption of test meals. In a randomized triple-crossover design, nine male subjects with mild or borderline hypertriacylglycerolaemia consumed 10 (control), 224 (moderate dose) and 674 mg (high dose) of the assigned tea catechins three times each along with a standardized light meal consisting of a piece of bread spread with 20 g butter. Plasma lipids were measured in the fasting state and 1, 2, 3, 4 and 6 h after consuming the light meal. Results showed that, compared with the control, moderate and high doses of tea catechins reduced the incremental area under the plasma triacylglycerol curves by 15·1 and 28·7 %, respectively. Next, the rapid elevation of remnant-like particle cholesterol was significantly inhibited by a high dose of tea catechins 2 h after consuming the light meal (P<0·01). In the range of tea catechin dosages, no significant differences were observed in the postprandial responses for plasma total cholesterol or NEFA at any time point. In conclusion, this trial demonstrated that tea catechins attenuated the postprandial increase in plasma triacylglycerol levels following a fat load. These results may provide evidence for one of the possible mechanisms involved in lowering the incidence of CVD, and may prove useful in further studies on the beneficial health effects of tea drinking.

To assess the effects of acute dietary saturated fat intake on glucose-induced insulin secretion rate (ISR), measured by the C-peptide deconvolution method, and on insulin clearance and sensitivity, five obese and five normal-weight women (controls) were studied after either a 100g oral butter load or a 100ml water load. At 120min after the oral load a hyperglycaemic clamp was performed over 180min. A dramatic increase of ISR occurred after butter compared with the water challenge in the controls (1305·6 (SE 124·1) v. 616·1 (SE 52·5) pmol/min; P<0·01) and to a lesser degree in the obese subjects (1975·0 (SE 44·1) v. 1417·5 (SE 56·0) pmol/min; P<0·05). Insulin sensitivity was impaired after butter (0·60×10−2 (SE 0·11×10−2) v. 2·26×10−2 (SE 0·32×10−2) ml/min per kgFFM per (pmol/l); P<0·01) in the controls but not in the obese group. Insulin clearance during the clamp was reduced after butter compared with after the water load only in the controls (0·89 (SE 0·22) v. 1·70 (SE 0·15) litres/min; P<0·01). The data are consistent with the hypothesis that acute excess lipid availability may lead to a compensatory elevation in glucose-induced insulin secretion as a result of the decline in insulin sensitivity and a reduced insulin clearance.

The majority of the studies that have found a lowering effect of exercise on postprandial lipaemia have employed exercise 12–18 h before a test meal of exaggerated fat content (over 60 % total energy). The aim of the present study was to investigate whether this effect is manifest when exercise is performed immediately before a test meal of moderate fat content. Eleven healthy young men cycled for 45 min at 62 % maximal heart rate or rested, and, immediately afterwards, consumed a meal of moderate fat content (35 % total energy, 0·65 g/kg body mass) in a random counterbalanced design. Blood samples were drawn before exercise, before the meal, and for 8 h postprandially. No significant differences were observed in plasma triacylglycerol concentrations and areas under the triacylglycerol concentration v. time curves between exercise and rest, although exercise reduced the postprandial lipaemic response by 17 %. Non-esterified fatty acids, glucose, and insulin did not differ significantly between the trials. In conclusion, moderate exercise performed immediately before a meal of a fat content typical to the Western diet had only a modest effect on postprandial lipaemia.

Two species of euphausiids (Thysanoessa macrura Sars and Euphausia vallentini Stebbing) from the Southern Indian Ocean were analysed for their lipid content, fatty acid and fatty alcohol composition, in relation to developmental stage (T.m) and sex (E.v). Lipid composition showed wax esters and triacylglycerols as main neutral lipids for T. macrura and E. vallentini respectively. Allometric relationships between lipid class and total lipids indicated that changes in total lipids were size dependent and mainly related to wax esters in T. macrura and polar lipids (both phosphatidylcholine or PC and phosphatidylethanolamine or PE) in E. vallentini. No difference in lipid composition could be shown for male and female E. vallentini, while sampling location, developmental stage and sex were significantly influential in T. macrura. In this latter species wax esters displayed relatively similar fatty acid and alcohol composition in both juvenile and female stages, whereas a striking difference could be seen between females and juveniles in terms of polar lipids with a very low PE content in females. Male and female E. vallentini showed little differences in fatty acid structure with the exception of PC in females, which were low in 22:6n-3. The trophic status of these two species was established using multivariate discriminant analysis, which indicated for E. vallentini a degree of omnivory similar to E. superba, while these T. macrura appeared more omnivorous than individuals collected in other areas of the Southern Ocean. Clustering of polar lipid composition suggested a link between differences in PC fatty acid and the post-spawn stage of the female of E. vallentini collected. The same probably applies for the changes in PE recorded for T. macrura females.

The content and composition of phospholipids and triacylglycerols (TAGs) in Bufo arenarum oocytes in stages III and IV of their oogenesis were studied. The total amount of phospholipids in stage IV oocytes is 0.5-fold higher than in stage III oocytes. In both cases, the main phospholipids are phosphatidylcholine (PC) and phosphatidylethanolamine (PE). A striking observation concerns the high level of diphosphatidylglycerol (DPG) in stage III oocytes, which could be indicative of a relatively larger mitochondrial population with respect to other oogenetic stages. A net increase in sphingomyelin content was found during oogenesis. This fact could be related to the role of this phospholipid in the signal transductional pathways. In PC, palmitic (16:0), linoleic (18:2) and oleic (18:1) are the major fatty acids for both types of oocytes, while in PE the main acyl groups are 18:1, 16:0, arachidonic acid (20:4n6) and 18:2. PE is more unsaturated than PC and both phospholipids are more unsaturated in stage III oocytes than in stage IV oocytes. The amount of triacylglycerols is 0.3-fold higher in stage IV oocytes than in stage III oocytes. In both stages, the main fatty acids are 18:2, 18:1 and 16:0. During oogenesis, a significant increase in 18:1 and 18:3n3, and a decrease in 18:2 of TAG were found. The unsaturation index of TAGs from stage IV oocytes is higher than that from stage III oocytes. The TAG increase during oogenesis is consistent with the putative use of these lipids as a source of energy in embryo development.

The effects of dietary saturated fatty acids and polyunsaturated fatty acids (PUFA) of the n-3 and n-6 series on weight gain, body composition and substrate oxidation were investigated in broiler chickens. At 3 weeks of age three groups of chickens (n 30; ten birds per group) were fed the fat-enriched experimental diets for 5 weeks. These diets were isonitrogenous, isoenergetic and contained 208 g protein/kg and 80 g edible tallow, fish oil or sunflower oil/kg; the dietary fatty acid profiles were thus dominated by saturated fatty acids, n-3 PUFA or n-6 PUFA respectively. Resting RQ was measured in five birds from each treatment group during weeks 4 and 5 of the experiment. There were no significant differences between treatments in total feed intake or final body mass. Birds fed the PUFA diets had lower RQ and significantly reduced abdominal fat pad weights (P<0·01) compared with those fed tallow. The dietary lipid profile changes resulted in significantly greater partitioning of energy into lean tissue than into fat tissue (calculated as breast lean tissue weight:abdominal fat mass) in the PUFA groups compared with the saturated fat group (P<0·01; with no difference between the n-3 and n-6 PUFA groups). In addition, the PUFA-rich diets lowered plasma concentrations of serum triacylglycerols and cholesterol. The findings indicate that dietary fatty acid profile influences nutrient partitioning in broiler chickens.

The process by which dietary carbohydrate is transformed into fat in the human body is termed de novo lipogenesis. New methods for the measurement of this process in humans are available and have been used to investigate the role of the carbohydrate form (fed as a liquid or solid), the level of processing of carbohydrate in foods, and the role of lipogenesis in the control of liver triacylglycerol secretion. The present paper will discuss how research results are affected by both the physical state of the carbohydrate in the diet and by the metabolic state of individual research subjects. Of interest is the relationship between the glycemic index of a food (or indicators of a food's glycemic index) and that food's ability to stimulate lipogenesis in humans. Given the increasing prevalence of obesity worldwide, future scientific emphasis will expand methods to quantitate the lipogenic potential of specific foods and dietary patterns and investigate how the metabolic state of insulin resistance affects lipogenesis and/or contributes to obesity.