High Unsaturated Fat Research Articles

The Nutritional Quality of Commercially Bred Yellow Mealworm (Tenebrio molitor) Compared to European Union Nutrition Claims.

Due to its potential as a sustainable protein source, the industrial relevance of Tenebrio molitor, known as yellow mealworm, is set to increase substantially. Given the novelty of its application in the food industry, knowledge is lacking regarding the nutritional quality of commercially farmed mealworms. This study investigated the nutritional composition of larvae from four different rearing facilities in Belgium and specifically investigated whether their nutritional profiles adhered to defined European nutrition claims (Regulation (EC) No. 1924/2006). In particular, the European nutrition claims "high in protein", "high unsaturated fat", "high in fibre" and "rich in P, Mg, K, Zn and Mn" were applicable for all mealworm samples on a dry matter basis. On a fresh matter basis, yellow mealworms were found to be "high in protein", "high unsaturated fat" and "low in sugar".

Almond flour and its potential in diabetes management: A short review

Diabetes is caused by higher glucose in the bloodstream and is considered one of the major health problems in Indonesia. Wheat flour-based meals are unsuitable for people with diabetes due to their high glycaemic index (GI), which may rapidly increase blood glucose levels. The low-GI characteristic of almonds (Prunus dulcis) makes it very potential to replace the wheat flour used in foods. Almonds have a high fiber, unsaturated fat, magnesium, and vitamin E content but low in carbohydrates. Almond consumption also enhances satiety and lowers postprandial glycemia, hence making it suitable alternative flour for people with diabetes. This review aims to provide scientific information regarding the processing technique, nutritional content, bioactive compounds, antioxidant activity, and the diabetes-related health benefits of almond flour. This information is important for supporting almond flour’s potential in diabetes management through food controlling approach.

An improved pistachio detection approach using YOLO-v8 Deep Learning Models

Pistachios are an agricultural product widely used in the food industry. It is very important that pistachios are presented to the consumer in good quality on time. At the same time, whether the shells of pistachios are open or closed is an important criterion from a commercial industrial point of view. Pistachios with their shells open have a high unsaturated fat content, a high maturity level and an expensive market value. In this study, the open or closed status of pistachios was determined by using Artificial Intelligence-based deep learning models. For pistachio detection, 423 image data belonging to the Pesteh dataset were classified using models of the Yolov8 algorithm, which detects objects using convolutional neural networks. The data set is divided into 80% training, 10% validation and 10% testing. The performances of the models were evaluated with precision, recall, F1 and mAP score metrics. The highest test mAP value of the Yolov8 algorithm, which was run with image data consisting of pistachios, was obtained with the Yolov8-m model with 94.8%. The Yolov8-m model achieved a very successful result with 49.6 MB weight size, 11.0 ms inference time value and 0.33 hours training time value. In addition, the model's fast classification performance and small file size facilitate its applicability in the industrial field. The results show that the classification and detection of open and closed shell pistachios has been successfully carried out with Yolo models.

Do markers of adiposity and glycaemia mediate the association between low carbohydrate diet and cardiovascular risk factors: findings from the UK National Diet and Nutrition Survey (NDNS) 2008–2016

ObjectivesTo examine the associations between low carbohydrate diet (LCD) and conventional cardiovascular risk factors and investigate whether these associations are mediated by body mass index (BMI), waist circumference (WC) and...

Dietary fat differentially modulates the response of bone marrow-derived macrophages to TLR4 and NOD2 agonists.

Consumption of diets high in fat has been linked to the development of obesity and related metabolic complications. Such associations originate from the enhanced, chronic, low-grade inflammation mediated by macrophages in response to translocated bacteria, bacterial products, or dietary constituents such as fatty acids (FAs). Nucleotide-binding Oligomerization Domain 2 (NOD2) senses muramyl dipeptide (MDP), a component of bacterial peptidoglycan. The inability to sense peptidoglycan through NOD2 has been demonstrated to lead to dysbiosis, increased bacterial translocation, inflammation and metabolic dysfunction. Currently, it is unknown how consumption of HFDs with different FA compositions might influence NOD2-dependent responses. In this study, we subjected WT mice to a control diet or to HFDs comprised of various ratios of unsaturated to saturated fats and determined the macrophage response to TLR4 and NOD2 agonists. A HFD with equal ratios of saturated and unsaturated fats enhanced subsequent responsiveness of macrophages to LPS but not to MDP. However, a high-unsaturated fat diet (HUFD) or a high-saturated fat diet (HSFD) both decreased the responsiveness to NOD2 agonists compared to that observed in control diet (CD) fed mice. These data suggest that dietary fatty acid composition can influence the subsequent macrophage responsiveness to bacterial products.

The Impact of Junk Food Eating Habits on Body Weight

Fast food is food that can be prepared and served very quickly. Junk food refers to fast food that contains refined sugar, white flour, trans fat, salt, high unsaturated fat and lots of food additives such as monosodium glutamate (MSG) and tartrazine, and lacks protein, vitamins and fiber. This study used qualitative research methods. The data collection technique was carried out by means of a literature study. The data that has been collected is then analyzed through three stages, namely data reduction, data presentation and drawing conclusions. The results showed that junk food such as burgers, french fries, pizza, grilled or fried chicken and chips generally contain a lot of saturated fat. Consumption of junk food has several impacts on health. Since the 21st century, obesity has been called a global pandemic because it spreads from youth to adults due to fast food eating has been proven. The affordability, taste, accessibility and variety of junk food in the market are key factors contributing to the impact it has on health.

Relationship between a Low-Carbohydrate, High-Fat Diet and Risk of Metabolic Syndrome in Korean Women.

Prevalence of metabolic syndrome with aging is higher in women than in men, and it increases after menopause. Interventions to reduce the risk of metabolic syndrome in women are important. A low-carbohydrate, high-fat diet is effective in weight loss and improvement cardiovascular risk factors including abdominal circumference, blood pressure, and blood lipid profile. We aimed to determine the relationship between a low-carbohydrate, high-fat diet and the risk of metabolic syndrome in Korean women. This cross-sectional study was conducted using secondary data from the 2014-2018 Korean National Health and Nutrition Examination Survey. Overall, 8,222 women aged >19 yr were included. The effect of a low-carbohydrate, high-fat diet on the risk of metabolic syndrome was analyzed by multiple logistic regression analysis using a complex sampling procedure. The diet significantly reduced the likelihood of metabolic syndrome development (P=0.044). In addition, regardless of the fat type, the diet significantly reduced the likelihood of low high-density lipoprotein cholesterolemia (low-carbohydrate, high-total fat, P=0.013; low-carbohydrate, high-unsaturated fat, P=0.006; low-carbohydrate, high-saturated fat, P=0.006). A low-carbohydrate, high-fat diet is an important intervention that can reduce the risk of metabolic syndrome, and the reduced consumption of carbohydrates can decrease the risk of low high-density lipoprotein cholesterolemia regardless of fat type. Therefore, it is necessary to actively explore the potential of this diet, targeting Asians, including Koreans.

Impact of High Fat Diet and Bolus Feeding on Chyle Accumulation in a Mouse Model of Generalized Lymphatic Anomaly.

Background: Generalized lymphatic anomalies (GLA) are complex vessel malformations that can impair lymphatic function. Potential GLA complications include lipid-rich lymph in the thoracic space or peritoneal cavity, respectively chylothorax and chylous ascites. To reduce the potential for chyle accumulation, GLA patients limit dietary fats. We hypothesized that dietary fatty acid composition impacts the potential for lymphatic dysfunction and chyle accumulation in GLA. Methods and Results: Adipose-specific overexpression of lymphatic growth factors has demonstrated lethal chylothorax in mice. Here, we utilized mice with inducible adipocyte overexpression of vascular endothelial growth factor-D (VD mice) to mimic lymphatic proliferation in GLA and assessed the incidence of chyle accumulation on a mixed high fat diet (HFD), high saturated fat diet (HSFD), or high unsaturated fat diet (HUSFD). Lipid transport was assessed by uptake rates of bolus oral triglyceride load and mesenteric fat analysis. Lymphatic expansion and inflammation were determined by whole mount immunofluorescence and gene expression. Body composition was assessed by MRI. HSFD 2-month wildtype groups resulted in an increase in TNF-α, IL-6, and IL-10 expression compared with chow-fed controls. The chyle accumulation incidence was highest in HFD-fed mice compared with either HSFD or HUSFD. Strikingly, increased mortality was observed irrespective of which high fat diet was consumed after administration of a bolus lipid load. Conclusion: Chronic HFD increases risk of chyle accumulation, however increased mortality was driven particularly by a bolus lipid load in VD mice. These findings suggest that although chronic HFD increases chyle accumulation risk, a single large meal feeding may increase risk of lethal chylothorax instances for GLA patients.

Influence of a diet rich in linoleic acid on mRNA levels for enzymes of branched chain amino acids metabolism in rat's adipose tissue: a pilot study.

White adipose tissue plays an important role in the catabolism of branched chain amino acids (BCAAs). Two initial regulatory steps in BCAAs catabolism are catalyzed by branched chain aminotransferase (BCAT) and branched chain α-keto acid dehydrogenase complex (BCKDH complex), respectively. It has been demonstrated that synthetic ligands for PPARγ receptors increased mRNA levels for enzymes involved in BCAAs catabolism. We hypothesized that feeding rats with diet rich in linoleic acid (LA), a natural PPARγ agonist modifies mRNA levels for enzymes catalyzing BCAAs degradation in adipose tissue. The current pilot study was aimed at the investigation of the effect of diet rich in LA on mRNA levels for BCATm, branched chain α-keto acid dehydrogenase (E1 component of the BCKDH), and mRNA levels for the regulatory enzymes of BCKDH complex, a specific kinase (BDK) and a specific phosphatase (PPM1K) in epididymal white adipose tissue (eWAT). Wistar male rats were fed with high unsaturated fat diet containing mainly linoleic acid (study group) or with the high saturated fat diet (control group). The relative mRNA levels were quantified by reverse transcription-PCR. We have found that in rats fed diet rich in LA mRNA level for BCATm decreased, while mRNA amount for BDK increased. There was no difference between mRNA levels for BCKDH E1 and PPM1K. It is conceivable that changes in mRNA levels for enzymes involved in BCAAs metabolism in eWAT may lead to modification of BCAAs catabolic rate. Further studies are required to fully elucidate this issue.

Potential of Analog Meat from Rubber Seeds through Tissue Culture as a Solution for Unsaturated Fatty Acid Rich Meat: A Literature Review

Non-communicable diseases (NCD) in Indonesia is a chronic disease caused by many factors, such as genetical, physiological, environmental, behavioral and lifestile. According to Basic Health Research survey (RISKESDAS) in 2013 and 2018, the prevalence of NCD showed increasing number within the last 5 years. The cause of this phenomena was proofed due half of Indonesians people had been consuming high fat or cholesterol or fried food, 1 – 6 timer per week. This mini narrative review study aims to exploring and discovering the potency of meat analog (in-vitro meat) and tissue culture of rubber seed as a solution for high unsaturated fat meat diet. Literature study related to NCD was found in National Library of Medicine (PubMed). We found that rubber seed contains 9 out of 10 essential amino acid and some unsaturated fatty acids in which when combined with tempeh made by pillar nut (Vina unguiculata) will potentially become an analog meat (in vitro meat) by tissue culture. This idea should be implemented with experimental study hence clinical potency of aforementioned meat analog will be well known.

Impact of Dietary Fatty Acids on Chylous Effusion in a Mouse Model of Generalized Lymphatic Anomaly

Introduction Generalized lymphatic anomalies (GLA) are complicated vessel malformations that can result in impaired lymphatic function. Potential GLA complications include lipid-rich lymph in the thoracic cavity or abdomen, respectively chylothorax and chylous ascites. To reduce the potential for chylous accumulation, GLA patients limit dietary fats. We hypothesized that dietary fatty acid composition impacts the potential for lymphatic dysfunction and chylous effusion in GLA. Methods Adipose-specific overexpression of lymphatic growth factors has demonstrated lethal chylothorax in mice. Here we utilized mice with inducible adipose overexpression of VEGF-D (Adipo-VD) to mimic GLA and tested the chylothorax incidence with a mixed high fat diet (HFD), high saturated (HSFD), or high unsaturated (HUSFD) fat diet. Lipid transport was assessed by oral triglyceride uptake and mesenteric fat analysis. Lymphatic expansion and inflammation were determined by whole mount immunofluorescence and gene expression. Body composition was assessed with by MRI. Results Oral gavage of a triglyceride bolus increased chylous effusion in all groups. HSFD resulted in a significant increase in TNF-α, IL-6, and IL-10 expression compared to HFD and HUSFD groups. HFD fed mice demonstrated a significant increase is body fat compared to HUSFD fed mice. Interestingly, the chylous effusion incidence was highest in HFD fed mice compared to either HSFD and HUSFD. Conclusion HFD results in increased chylous effusion driven particularly by a bolus lipid load in Adipo-VD mice. These findings suggest that dietary fatty acid composition, and in particularly large meal feeding, may result in increased chylothorax risk for GLA patients.

Soybean in pre-ruminant nutrition: A review

Soybean,Glycine max, is a highly nutritious seed. It contains high quality protein and unsaturated fat. Despite the high nutritive value of soybeans, its use has been limited by a number of anti- nutritional .factors which are capable of causing adverse nutritional and physiological responses in animals. Several processing methods such as heat treatment, use of chemicals such as acids, alkali and alcohols or a combination of these have been developed and used to reduce or completely eliminate these anti-nutritional factors and hence improve its utilization. This review addresses the nutritive value of soybean, anti-nutritional factors, effect of processing on the nutritive value of the seed and the utilization of soybean in milk replacers for pre-ruminants. Well processed soybean can provide high quality proteins that can be used to replace milk proteins in milk replacers for pre ruminants. Studies on utilization of milk replacers by pre-ruminants are scanty in Nigeria. More effort needs to be devoted to research in this area.

A vessel-inside-vessel microwave-assisted digestion method based on SO3 generation in situ for the mineral determination of fatty samples

Vessel-inside-vessel microwave-assisted acid digestion was developed for the analysis of samples with high-unsaturated fat content. For the first time, thermal decomposition of (NH4)2S2O8 solutions was evidenced for SO3 generation in situ and gas-phase modification in pressurized digestion flasks. NMR analysis demonstrated the oxidative effect of SO3 on olefin double bonds despite incomplete mineralization of oil samples. In this context, (NH4)2S2O8 decomposition was used in association with HNO3 solutions for sample digestion and mineral determination in edible oils (safflower, coconut, flaxseed, and chia). For all oils, dissolved organic carbon (DOC) contents lower than 5% m m-1 were obtained under optimum conditions: 210 °C with an irradiation time of 40 min, 7.0 mol L-1 HNO3 and 2.0 mol L-1 (NH4)2S2O8 in 0.9 mol L-1 H2SO4. Thus, a DOC reduction of about 70% was reached compared to digestions using only HNO3 at the same conditions. Additionally, a time reduction of up to three-fold was achieved compared to typically demanding edible oil digestions. The proposed method allowed the determination of As, Cd, Cr, Mn, Ni, and Pb in edible vegetable oil samples by ICP-MS. Accuracy was evaluated against the reference method, and no significant difference was observed (p = 0.05), with wide linear ranges and good linearity (r ≥ 0.999) and LOD ranging from 0.48 (As) to 2.41 (Cd) μg L-1.

Effects of maltodextrin on the physical properties of canola oil-based ice creams

Recent trend in production of healthy food products has stimulated ice cream manufacturers to minimize the saturated fat content by replacing it with high-unsaturated fat or oil such as canola oil, yet maintaining the physical properties of the end product. Addition of maltodextrin (MD) into the formulation may assist in obtaining the desirable physical properties. Therefore, the objective of this study was to develop hard ice creams containing different ratios of canola oil and MD. Four ice cream formulations were prepared by weight: MD-0 (5% oil, 0% MD), MD-1 (4% oil, 1% MD), MD-2 (3% oil, 2% MD), and MD-3 (2% oil, 3% MD). Both MD-2 and MD-1 exhibited the highest (45.05±4.28%) and the lowest (32.49±1.20%) overrun, respectively, yet there was no significant difference (p > 0.05) between all ice creams in terms of hardness (3.20-4.79 kg). Additionally, there was no significant difference (p > 0.05) between MD-0, MD-1, and MD-2 in their melting rates which were significantly slower (p < 0.05) than those of MD-3. In overall, decreasing the amount of oil (i.e. increasing amount of MD) resulted in significant (p < 0.05) increase in overrun, yet had no significant (p > 0.05) effect on the ice cream's hardness and melting rate except for MD-3 for the latter. The ice cream that exhibited the most desirable physical properties was MD-2 (overrun, 45.05±4.28%; hardness, 3.73±0.75 kg; slowest melting rate). This finding highlighted the potential of MD in providing desirable texture to the ice creams to certain extent. Future studies are recommended in maintaining the ice cream's flavour and physical properties upon storage, and in determining its sensory acceptability among consumers.

Comparison of the Effect of Calorie-Matched High Saturated Fat and High Unsaturated Fat Diets on Lysosomal Renal Injury in Non-Obese, Streptozotocin-Injected CD-1 Mice

Comparison of the Effect of Calorie-Matched High Saturated Fat and High Unsaturated Fat Diets on Lysosomal Renal Injury in Non-Obese, Streptozotocin-Injected CD-1 Mice

The role of the Mediterranean diet on weight loss and obesity-related diseases.

Pandemic obesity is a major public health problem because of its association with non-communicable diseases and all-cause mortality, which can be improved/delayed with weight loss. Thus, several scientific societies and governments have launched guidelines to reduce body weight and adiposity or, at least, to avoid weight gain. In spite of the abundant literature on the topic, there is still controversy on the relative roles of fat and carbohydrate in the diet on weight gain. Present recommendations to avoid weight gain and obesity are directed to reduce intake of total energy variably and of total fat to <30% of energy, in spite on the lack of evidence of protection against cardiovascular disease (CVD) and mortality. By contrast, both high and low carbohydrate diets are associated with CVD and all-cause mortality in prospective studies, with a safe intake level at ≈50% of energy. Many popular diets with widely different macronutrient composition, including the Mediterranean diet, have been used in obesity; when energy-restricted, all result in similar modest weight loss at 6months, but the effects are largely lost at 12months. The Mediterranean diet is a plant-based, high-fat, high-unsaturated fat dietary pattern that has been consistently associated with lower rates on non-communicable diseases and total mortality in prospective studies and with reduced CVD in the PREDIMED trial. For this merits above other diets, this dietary pattern might also be used advantageously for weight loss. The results of the PREDIMED and PREDIMED-Plus randomized controlled trials on adiposity variables in high-risk populations are discussed.

Nuts.

Nuts are fruits composed of two parts: an inedible hard shell and an edible seed. Nuts are known as an energy-dense and nutrient-rich food source. In general, nuts are recognized as a good source of fat, fiber, and protein. Nuts are extremely beneficial parts of any diet since their consumption may lower risk for some diseases, such as cardiovascular diseases and cancer. They are acknowledged for their low glycemic index owning to high unsaturated fat and protein content and relatively low carbohydrate content. They have been shown to increase cognitive function as well.

Physical and Morphological Characterization of Chitosan/Montmorillonite Films Incorporated with Ginger Essential Oil

Novel bionanocomposite films of chitosan/montmorillonite (CS/MMT) activated with ginger essential oil (GEO) were produced and characterized in terms of their physical and morphological properties. The homogenization process led to a good interaction between the chitosan and the nanoparticles, however the exfoliation was diminished when GEO was incorporated. Film glass transition temperature did not statistically change with the incorporation of either MMT or GEO, however the value was slightly reduced, representing a relaxation in the polymer chain which corroborated with the mechanical and barrier properties results. Pristine chitosan films showed excellent barrier properties to oxygen with a permeability of 0.184 × 10−16 mol/m·s·Pa being reduced to half (0.098 × 10−16 mol/m·s·Pa) when MMT was incorporated. Although the incorporation of GEO increased the permeability values to 0.325 × 10−16 mol/m·s·Pa when 2% of GEO was integrated, this increment was smaller with both MMT and GEO (0.285 × 10−16 mol/m·s·Pa). Bionanocomposites also increased the UV light barrier. Thus, the produced bioplastics demonstrated their ability to retard oxidative processes due to their good barrier properties, corroborating previous results that have shown their potential in the preservation of foods with high unsaturated fat content.

High Saturated and Unsaturated Fat Diets Yield Different Disease Phenotypes in Mice

Excessive consumption of unsaturated or saturated fatty acids have adverse effects on certain health parameters, namely increased risk of obesity, diabetes, and cardiovascular disease. Specifically, saturated fats are linked to increased cardiovascular risk while unsaturated fats are suggested to protect against cardiovascular disease. Our previous work suggested that various high fat diets have differential effects on cardiac hypertrophy and function. However, it was not clear whether a high saturated fat diet (HSFD) or high unsaturated fat diet (HUFD) could elicit different disease phenotypes. Therefore, the purpose of this study was to evaluate the effects of HSFD or HUFD on the development of obesity, diabetes, and cardiac lipotoxicity in mice. Male, C57BL/6J mice received normal chow (CON, n=12), HSFD (n=15) or HUFD (n=15) for 12 weeks. Body weight and food intake were measured weekly. After 12 weeks, the adipose tissue and heart were removed and weighed. Glucose, fatty acids, and cholesterol were analyzed in serum using biochemical assays. Cardiac triglycerides (TG) were measured in heart tissue extracts. Both HSFD and HUFD significantly increased body weight above CON. Interestingly, body weight increased by ~63% in the HUFD while the HSFD increased ~41% (P&lt;0.05). Adipose tissue mass was increased 5‐fold in both HFD groups and was ~10% greater in the HUFD. Surprisingly, caloric intake was higher in the HSFD (15.3±0.8) compared to HUFD (12.8±0.1) and CON (11.9±0.7). Serum cholesterol levels were elevated in both HSFD and HUFD. Blood glucose was significantly increased only in the HUFD while serum fatty acids were increased only in the HSFD. Cardiac hypertrophy, assessed by the heart weight to tibia length ratio, was increased in the HSFD but not HUFD group. Cardiac TGs were ~25% higher in HSFD but &lt;10% in HUFD compared to CON. These data show that excess consumption of saturated or unsaturated fats increased body weight and adiposity in mice. However, high consumption of unsaturated fatty acids resulted in a pronounced increase in body weight, body fat, and hyperglycemia, consistent with an obese and diabetic phenotype. Conversely, high consumption of saturated fatty acids caused elevated serum lipids, cardiac hypertrophy, and cardiac lipid accumulation, consistent with cardiac lipotoxicity. In conclusion, the fatty acid composition of diets may be critical in the development of disease phenotypes resulting from high fat feeding in mice.Support or Funding InformationThis work was supported by funding from the American Heart Association and Ursinus College.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

High-Fat Diet-Induced Obesity Model Does Not Promote Endothelial Dysfunction via Increasing Leptin/Akt/eNOS Signaling.

Experimental studies show that the unsaturated high-fat diet-induced obesity promotes vascular alterations characterized by improving the endothelial L-arginine/Nitric Oxide (NO) pathway. Leptin seems to be involved in this process, promoting vasodilation via increasing NO bioavailability. The aim of this study was to test the hypothesis that unsaturated high-fat diet-induced obesity does not generate endothelial dysfunction via increasing the vascular leptin/Akt/eNOS signaling. Thirty-day-old male Wistar rats were randomized into two groups: control (C) and obese (Ob). Group C was fed a standard diet, while group Ob was fed an unsaturated high-fat diet for 27 weeks. Adiposity, hormonal and biochemical parameters, and systolic blood pressure were observed. Concentration response curves were performed for leptin or acetylcholine in the presence or absence of Akt and NOS inhibitor. Our results showed that an unsaturated high-fat diet promoted a greater feed efficiency (FE), elevation of body weight and body fat (BF), and an adiposity index, characterizing a model of obesity. However, comorbidities frequently associated with experimental obesity were not visualized, such as glucose intolerance, dyslipidemia and hypertension. The evaluation of the endothelium-dependent relaxation with acetylcholine showed no differences between the C and Ob rats. After NOS inhibition, the response was completely abolished in the Ob group, but not in the C group. Furthermore, Akt inhibition completely blunted vascular relaxation in the C group, but not in the Ob group, which was more sensitive to leptin-induced vascular relaxation. L-NAME incubation abolished the relaxation in both groups at the same level. Although Akt inhibitor pre-incubation reduced the leptin response, group C was more sensitive to its effect. In conclusion, the high-unsaturated fat diet-induced obesity improved the vascular reactivity to leptin and does not generate endothelial dysfunction, possibly by the increase in the vascular sensitivity to leptin and increasing NO bioavailability. Moreover, our results suggest that the increase in NO production occurs through the increase in NOS activation by leptin and is partially mediated by the Akt pathway.