Fat Preference Research Articles

Degree of Saturation and Free Fatty Acid Content of Fats Determine Dietary Preferences in Laying Hens.

Simple SummaryUnderstanding fat sensing in chickens has the potential to improve least cost feed formulation relevant to poultry feeds. Acid oils (soybean acid oil and palm fatty acid distillate) are economical and sustainable feedstuffs with similar fatty acid composition to crude oils (soybean oil and palm oil) but richer in free fatty acids. However, potential issues relevant to the palatability of these oils have been raised. Four experimental diets were offered in a series of double-choice tests to study the effect of free fatty acid content and the unsaturated:saturated ratio on dietary preferences in hens. Hens showed a feed preference for palm oil added diets over soybean oil diets, with palm oil and palm fatty acid distillate being equally preferred. However, the hens demonstrated a preference for soybean oil when offered in choice with soybean acid oil. In conclusion, free fatty acid content and saturation degree affected feed preferences in hens. The use of oils with greater preference values may give rise to greater feed palatability, enhancing feed intake at critical stages.Behavioural and genetic evidence shows that the taste system is intimately related to the sensing of nutrients with consequences for poultry nutrition practices. A better understanding of how chickens may sense fat could provide the background for selecting feedstuffs used in poultry feeds. Acid oils have the potential to be economical and sustainable feedstuffs. These fat by-products from the edible oil refining industry possess a similar fatty acid composition to the crude oils but are richer in free fatty acids (FFA). An experiment was conducted to study the effect of FFA content and the unsaturated:saturated ratio (U:S) on dietary preferences in hens. Four fat sources were added to a basal diet at an inclusion rate of 6%, determining the experimental diets: soybean oil (SO; high U:S, 5% FFA); soybean acid oil (SA; high U:S, 50% FFA); palm oil (PO; low U:S, 5% FFA); and palm fatty acid distillate (PFAD; low U:S, 50% FFA). The experimental diets were offered in a series of double-choice tests to forty-eight Lohmann Brown laying hens housed individually in cages. Each hen was offered the ten potential binary combinations of the four diets including each diet compared to itself (referred to as four control double-choices). Feed intake was measured for two hours twice a day after one hour of fasting. Consumption was analysed as a standard preference index (% of test diet intake in comparison with the total intake). Preference values were compared to the random choice value of 50% using the Student’s t-test. None of the four control comparisons differ significantly from 50% (p > 0.05), indicating that the changes in preference values observed in the other binary comparisons were related to the dietary changes associated to fat ingredients. Hens showed a feed preference for palm oil added diets over soybean oil diets (p < 0.05), with PO and PFAD being equally preferred (p < 0.05). However, in this trial the hens demonstrated a preference for SO (low %FFA) when offered in choice with SA (high %FFA) (p < 0.05). These results suggest that the degree of saturation plays an important role in dietary fat preferences: hens prefer predominantly saturated oils even when these are rich in FFA. Furthermore, when presented with a choice between predominantly unsaturated oils, hens prefer feed with a low %FFA. In conclusion, %FFA and the U:S ratio affected feed preferences in hens. The use of oils with greater preference values may give rise to greater feed palatability, enhancing feed intake at critical stages.

Greater self-reported preference for fat taste and lower fat restraint are associated with more frequent intake of high-fat food

The determinants of the intake of high-fat products are not well recognized, but fat preference may be one of them. The aim of this study was thus to determine whether intake of different types of high-fat food is associated with fat preference in people with normal and increased body weight.Participants aged 20–40 years [n = 421] were enrolled in Poznań, Poland in 2016–2018. Fat preference was measured using the Fat Preference Questionnaire. Self-reported preference for fat taste (TASTE) and fat restraint (DIFF) scores were calculated. The frequency of consuming high-fat food was measured with an application for mobile devices using ecological momentary assessment.TASTE was positively associated with calorie intake and total frequency of eating high-fat food in both the normal weight and the overweight/obese groups. Overweight and obese people had lower DIFF (p < 0.001) than normal weight people. DIFF was negatively associated with total calorie intake and total intake of high-fat food, but only in normal weight people (β = −0.16, p < 0.01 and β = −0.26, p < 0.001, respectively). DIFF was negatively associated with the frequency of eating sweet (β = −0.33, p < 0.000) and meat high-fat food (β = −0.25, p < 0.001) in the normal weight group.The frequency of consumption of high-fat food and calorie intake are positively associated with self-reported preference for fat taste. In normal weight subjects fat restraint is negatively associated with calorie intake and total frequency of high-fat food intake, as well as with intake of different types of fatty food. Fat preference measures are thus associated with high-fat food intake, but these associations differ by body weight status.

Brain site-specific regulation of hedonic intake by orexin and DYN peptides: role of the PVN and obesity

ABSTRACT The orexin peptides promote hedonic intake and other reward behaviors through different brain sites. The opioid dynorphin peptides are co-released with orexin peptides but block their effects on reward in the ventral tegmental area (VTA). We previously showed that in the paraventricular hypothalamic nucleus (PVN), dynorphin and not orexin peptides enhance hedonic intake, suggesting they have brain-site-specific effects. Obesity alters the expression of orexin and dynorphin receptors, but whether their expression across different brain sites is important to hedonic intake is unclear. We hypothesized that hedonic intake is regulated by orexin and dynorphin peptides in PVN and that hedonic intake in obesity correlates with expression of their receptors. Here we show that in mice, injection of DYN-A1–13 (an opioid dynorphin peptide) in the PVN enhanced hedonic intake, whereas in the VTA, injection of OXA (orexin-A, an orexin peptide) enhanced hedonic intake. In PVN, OXA blunted the increase in hedonic intake caused by DYN-A1–13. In PVN, injection of norBNI (opioid receptor antagonist) reduced hedonic intake but a subsequent OXA injection failed to increase hedonic intake, suggesting that OXA activity in PVN is not influenced by endogenous opioid activity. In the PVN, DYN-A1–13 increased the intake of the less-preferred food in a two-food choice task. In obese mice fed a cafeteria diet, orexin 1 receptor mRNA across brain sites involved in hedonic intake correlated with fat preference but not caloric intake. Together, these data support that orexin and dynorphin peptides regulate hedonic intake in an opposing manner with brain-site-specific effects.

Diet-Induced Obesity Alters the Circadian Expression of Clock Genes in Mouse Gustatory Papillae.

Diet-induced obesity (DIO) is associated with a defect of the orosensory detection of dietary lipids in rodents. This dysfunction is not anecdotic since it might worsen the negative effects of obesity by promoting the overconsumption of energy-dense foods. Previous studies have highlighted a progressive devaluation of reward value of lipid stimuli due to a desensitization of dopaminergic brain areas in DIO mice. Paradoxically, the putative deleterious impact of obesity on peripheral fat detection by the gustatory papillae remains poorly documented. Using a whole transcriptomic investigation of the circumvallate papillae (CVP), an analysis of CVP genes involved in fat taste transduction and signaling along the day, and two bottle choice tests, we have found that (i) CVP, known to house the most taste buds in the oral cavity, displays a genic circadian rhythm, (ii) DIO reduces the oscillation of key genes involved both in the circadian clock and lipid detection/signaling, and (iii) the gene invalidation of the clock gene Rev-Erbα does not significantly affect fat preference despite an oily solution intake slightly lower than littermate controls. Taken together these data bring the first demonstration that the gustatory function is under control of a peripheral clock in mammals, as already reported in fly and suggest that a disturbance of this rhythmicity might contribute to the lower fatty taste acuity found in obese mice.

CD36 and GPR120 Methylation Associates with Orosensory Detection Thresholds for Fat and Bitter in Algerian Young Obese Children.

Background: The spontaneous preference for dietary fat is regulated by two lingual lipid sensors (CD36 and GPR120) in humans and rodents. Our objective was to investigate whether obesity in children is associated with methylation of lipid sensor genes, and whether this alteration was implicated in altered gustatory perception of fat and bitter and increased preference of palatable foods. Methods: School children were recruited and classified according to their body mass index (BMI) z-score into two groups: obese and lean children. The detection of orosensory perception for oleic acid and 6-n-propylthiouracil was assessed by using a 3-alternative forced-choice test. After blood DNA extraction, methylation patterns were investigated by methylation-specific PCR. The children were also subjected to a food habit questionnaire. Results: Obese children showed higher lipid and bitter detection thresholds than lean children. Besides, more obese children presented higher methylation level of the CpG sites than lean participants. Interestingly, CD36 and GPR120 gene methylation was associated with high lipid detection thresholds in obese participants. The obese participants preferred highly palatable fat-rich food items, associated with CD36 and GPR120 gene methylation. Conclusion: Epigenetic changes in CD36 and GPR120 genes might contribute to low orosensory perception of fat and bitter taste, and might be, consequently, critically involved in obesity in children

Determination of fat preferences of adult dogs

This study was carried out to determine the preferences of dogs for some commonly used fat sources in dog food. Three different types of food were produced using 5% additional sunflower oil, poultry fat, or beef tallow. The food was extruded using a twin-screw extruder at approximately 25% moisture and temperatures in the range of 90 °C to 135 °C. The extrudates were dried for 30-45 min at temperatures of up to 148 °C in a belt dryer. Next, the heated fats were sprayed onto the extrudates. The foods were cooled, sampled, and packaged. A total of 30 neutered adult (between 1 and 3 years old) male dogs were used. The preference of the dogs for the 3 different fat sources was determined via a 2-pan preference test. Preference tests were conducted for 12 days in pairs, and the dogs consumed each food for 8 days. The dogs had the greatest preference for food containing the additional sunflower oil, with a preference rate of 56%. Beef tallow was the least preferred fat, with a preference rate of 44%. Dogs preferred food containing sunflower oil more than food containing animal fats. It was concluded that dogs showed a preference in proportion to the linoleic acid level in each food.

Leptin promotes the fat preference associated with low-temperature acclimation in mice.

Although fluctuations in energy metabolism are known to influence intake as well as nutrient selection, there are no definitive reports on how food preferences change with changes in habitat temperature. We investigated the effects of habitat temperature on appetite and food preference and elucidated the underlying mechanism by conducting a feeding experiment and a leptin administration test on mice reared at low temperatures. Our results showed that the increased food intake and HFD preference observed in the 10°C group were induced by decrease in plasma leptin concentration. Then, a leptin administration experiment was conducted to clarify the relationship between leptin and food preference with low-temperature acclimation. The control group reared in 10°C significantly preferred the HFD, but the leptin-administered group did not. These results show that the peripheral system appetite-regulating hormone leptin not only acts to suppress appetite but also might inhibit preference for lipids in low-temperature acclimation.

Growth Differentiation Factor 15 Is Linked to Reduced Preference for Fatty Foods in Adults with Overweight or Obesity

Abstract Objectives Growth differentiation factor 15 (GDF15) reduces food intake, dietary fat preference, and body weight in pre-clinical studies. Through recent human and in vitro studies, we have identified a role for GDF15 in the energy expenditure (exercise) side of the energy balance equation. Collectively, GDF15 has emerged as a novel candidate for the treatment of human obesity. However, whether GDF15 regulates food intake or food preference in humans remains to be elucidated. Herein, we hypothesized that fasting and exercise-induced GDF15 plasma concentrations would be related to habitual food intake and preference in adults with overweight/obesity. Methods Samples previously collected from eleven adults (age: 54 ± 3, BMI: 32.4 ± 1.6, kg/m2, six women, five men) were subjected to secondary analysis. Fasting plasma GDF15 was quantified by ELISA, while habitual diet was measured from 3-day dietary records. Dietary data was analyzed by the Dietary Analysis Core at Pennington Biomedical Research Center using FNDDS (USDA 2015–2016). A sub-cohort (n = 9) further completed a 7-day aerobic exercise training for 60 min/day at ∼85% HRmax, GDF15 assessment was repeated post-training. Results At baseline, GDF15 showed trends in reduced total energy intake (kcals, R = −0.40, P = 0.22), and was inversely associated with fatty foods (oils, g/day) (R = −0.62, P &amp;lt; 0.05), consistent with animal models. Exercise increased GDF15 in six adults (responders), but decreased in three adults (non-responders). Responders habitually consumed 52% less total fat (g/1000kcals, P = 0.01) and 59% less oils (g/1000kcals, P = 0.01) compared to non-responders. In agreement, exercise-induced changes in GDF15 negatively associated with baseline fat (kcal/g, R = −0.68, P &amp;lt; 0.05) and cheese (serving/kcal, R = −0.67, P &amp;lt; 0.05) intake. Conclusions This study provides preliminary evidence that GDF15 is linked to reduced fatty food preference in adults with overweight or obesity, suggesting a promising anti-obesity effect of GDF15 in humans. Larger human trials with repeated measurements are warranted to further elucidate the response. Funding Sources The study was supported by the National Institute of Health: UL1RR024989, U54GM104940, DK108089 (JPK) and T32AT004094 (JTM – trainee).

CD36 gene polymorphism -31118 G>A (rs1761667) is associated with overweight and obesity but not with fat preferences in Mexican children.

CD36 glycoprotein is a candidate receptor involved in the gustatory detection of lipids and emerging evidence has suggested that genetic variations in CD36 may modulate the oral perception threshold to fatty acids. Here, we analyzed the association of -31118 G>A polymorphism in CD36 gene with nutritional status and preferences for fatty foods in Mexican children. Genotyping of SNP rs1761667 was performed in school-age children (n=63) in addition to sensory tests evaluating the preference and satisfaction score assigned to oil-based sauces of different fatty acid composition. The G allele was associated with high BMI z-score in children (OR=2.43, 95% (CI 1.02-5.99); p=0.02) but CD36 genotypes (AA, GA, and GG) did not show significant association with the preference and satisfaction scores assigned to oil-based sauces. The BMI z-score showed no association with the preference to oil-based sauces; however, children with normal weight gave higher satisfaction scores to sauces with a high content of unsaturated fatty acids than to sauces rich in saturated fatty acids (0.56±1.26 vs. 0.06±1.22; p=0.02). Therefore, the G allele of -31118 G>A SNP in CD36 gene is associated with overweight and obesity in Mexican children but do not appear to modulate the preferences and satisfaction scores to fat.

Novel GPR120 agonist TUG891 modulates fat taste perception and preference and activates tongue-brain-gut axis in mice

GPR120 is implicated as a lipid receptor in the oro-sensory detection of dietary fatty acids. However, the effects of GPR120 activation on dietary fat intake or obesity are not clearly understood. We investigated to determine whether the binding of TUG891, a novel GPR120 agonist, to lingual GPR120 modulates fat preference in mice. We explored the effects of TUG891 on obesity-related hormones and conducted behavioral choice tests on mice to better understand the physiologic relevance of the action of TUG891. In cultured mouse and human taste bud cells (TBCs), TUG891 induced a rapid increase in Ca2+ by acting on GPR120. A long-chain dietary fatty acid, linoleic acid (LA), also recruited Ca2+ via GPR120 in human and mouse TBCs. Both TUG891 and LA induced ERK1/2 phosphorylation and enhanced in vitro release of glucagon-like peptide-1 from cultured human and mouse TBCs. In situ application of TUG891 onto the tongue of anesthetized mice triggered the secretion of pancreatobiliary juice, probably via the tongue-brain-gut axis. Furthermore, lingual application of TUG891 altered circulating concentrations of cholecystokinin and adipokines, associated with decreased circulating LDL, in conscious mice. In behavioral tests, mice exhibited a spontaneous preference for solutions containing either TUG891 or LA instead of a control. However, addition of TUG891 to a solution containing LA significantly curtailed fatty acid preference. Our study demonstrates that TUG891 binds to lingual GPR120 receptors, activates the tongue-brain-gut axis, and modulates fat preference. These findings may support the development of new fat taste analogs that can change the approach to obesity prevention and treatment.

Bile acid receptor TGR5 is critically involved in preference for dietary lipids and obesity

We investigated the implication of Takeda G protein-coupled receptor 5 (TGR5) in fat preference and fat sensing in taste bud cells (TBC) in C57BL/6 wild-type (WT) and TGR5 knock out (TGR5−/−) male mice maintained for 20 weeks on a high-fat diet (HFD). We also assessed the implication of TGR5 single nucleotide polymorphism (SNP) in young obese humans. The high-fat diet (HFD)-fed TGR5−/− mice were more obese, marked with higher liver weight, lipidemia and steatosis than WT obese mice. The TGR5−/− obese mice exhibited high daily food/energy intake, fat mass and inflammatory status. WT obese mice lost the preference for dietary fat, but the TGR5−/− obese mice exhibited no loss towards the attraction for lipids. In lingual TBC, the fatty acid-triggered Ca2+ signaling was decreased in WT obese mice; however, it was increased in TBC from TGR5−/− obese mice. Fatty acid-induced in vitro release of GLP-1 was higher, but PYY concentrations were lower, in TBC from TGR5−/− obese mice than those in WT obese mice. We noticed an association between obesity and variations in TGR5 rs11554825 SNP. Finally, we can state that TGR5 modulates fat eating behavior and obesity.

Effect of acute high-intensity interval cycling while viewing a virtual natural scene on mood and eating behavior in men: A randomized pilot trial

Summary Background and aim This study examined the effect of using virtual reality glasses during high-intensity interval exercise (HIIE) on mood and eating behaviour in men. Methods Twenty-three healthy young men (age 20.5 ± 1.2 years, BMI 22.1 ± 3.4 kg/m2, VO2peak 34.6 ± 6.5 ml/kg/min) participated in the study. Augmented green environment virtual reality while performing HIIE (VR) compared with HIIE (CON) at 90 %VO2peak were performed for 20 min. Mood was assessed using the Subjective Exercise Experiences Scale (SEES), which consists of three domains including positive well-being, psychological distress, and fatigue. Eating behaviour was assessed and included appetite sensations, food preferences, and food intake. Results Results showed that there was no significant differences between VR and CON on mood and eating behaviour. The interaction of preference (implicit wanting) for high fat food showed a tendency to increase from pre-post VR compared to CON (P = 0.052). A secondary analysis of tertiles of the three domains of SEES showed no interaction effect of VR vs CON on appetite sensations. However, there was a general group effects of psychological distress on desire to eat (P = 0.049). Conclusions In conclusion, VR-augmented HIIE did not have a differential effect on mood or eating behaviour compared to HIIE alone, except a potential negative impact on fat preference. Psychological distress may lead to greater desire to eat during VR-augmented HIIE.

Visible Fat Content of Hotpot Beef Acceptability by New Zealand Chinese, Japanese, and Korean Consumers

Hotpot meat is a popular way of meat consumption in some Asian countries. This study was carried out to investigate the effect of visible fat content on consumer acceptability of hotpot meat. Hotpot beef with six visible fat levels (11%–35%) was produced and digitally photographed, and the images were ranked by panels of New Zealand Chinese (110), Japanese (145), and Korean (118) consumers. For all the nationalities, a preference for visible fat was influenced by both gender and age. The Chinese preferred the visibly fattiest hotpot beef, whereas the Koreans preferred the leanest with the Japanese preferring the two fat extremes equally. For individuals in the age range of 19–30 years, both Chinese males and females preferred the higher fat meat (35%), while their Japanese and Korean counterparts preferred the second visibly leanest (14%). For those over 50 years, Chinese females preferred the lower fat meat compared to their male counterparts, whereas there was no gender difference at this age for the Japanese and Koreans preference for the visibly lean hotpot beef. This study indicates that there are subtle differences between nationalities in terms of their preference for the fat content of hotpot beef that may have implications in meat merchandising, product development, and health policies.

Strain differences in muscarinic cholinergic receptor antagonism of fat intake and acquisition and expression of fat-conditioned flavor preferences in male BALB/c, C57BL/6 and SWR mice

Murine strain differences occur for both intakes of and preferences for sugars and fats. Previous studies demonstrated that the muscarinic cholinergic receptor antagonist, scopolamine (SCOP) more potently reduced sucrose and saccharin intakes in inbred C57BL/6 and BALB/c than SWR mice, sucrose-conditioned flavor preferences (CFP) expression in BALB/c, but not C57BL/6 or SWR mice, and sucrose-CFP acquisition in BALB/c relative to SWR and C57BL/6 mice. Although fat intake and fat-CFP are observed in all three strains, strain-specific effects were previously observed following dopamine D1, opiate and NMDA receptor antagonism of sweet and fat intake and CFP. The present study investigated whether muscarinic receptor antagonism differentially affected fat (Intralipid) intake and preferences in these strains by examining whether SCOP altered fat (Intralipid) intake and fat-CFP expression and acquisition in BALB/c, C57BL/6 and SWR mice. SCOP (0.1–10 mg/kg) significantly reduced Intralipid (5%) intake in all three strains across 2 h. In fat-CFP expression experiments, food-restricted mice consumed one flavored (conditioned stimulus (CS)+, 5 sessions) Intralipid (5%) solution and a differently-flavored (CS−, 5 sessions) Intralipid (0.5%) solution. Two-bottle CS choice tests with the two flavors mixed in 0.5% Intralipid occurred following vehicle and two SCOP doses (1, 5 mg/kg). SCOP elicited small, but significant reductions in fat-CFP expression in BALB/c and C57BL/6, but not SWR mice. In fat-CFP acquisition experiments, separate groups of BALB/c, C57BL/6 and SWR mice were treated prior to the ten acquisition training sessions with vehicle or two SCOP (2.5, 5 mg/kg) doses followed by six two-bottle choice tests without injections. SCOP eliminated fat-CFP acquisition in all three strains. Thus, muscarinic receptor signaling mediates learning, and to a lesser degree maintenance of fat-CFP while maximally inhibiting fat intake in the three strains.

Food preferences and intake in a population of Dutch individuals with self-reported smell loss: An online survey

Olfaction plays a major role in food intake regulation. Losing the sense of smell might therefore affect eating behavior. This study investigated food preferences and intake in individuals suffering from self-reported smell loss with an online survey. Members of the Dutch Anosmia Foundation (DAF) performed the Macronutrient and Taste Preference Ranking Task (n = 71) to measure preference for foods high in fat, carbohydrates or protein and low energy foods, and for sweet and savory tastes. To assess dietary intake, adherence to the Dutch Dietary Guidelines for consumption of vegetables, fruit, fiber, fish, saturated fat, trans fatty acids, salt and alcohol was measured (n = 105). Results of the DAF participants were compared to local cohort groups. Both the control and DAF participants showed the lowest preference for carbohydrate-rich foods and highest preference for low-energy foods. Participants suffering from congenital smell loss showed an aberrant pattern, with a higher preference for fat. The total adherence score to the Dutch Dietary Guidelines was similar for the control and DAF group, but adherence scores for fiber, trans fatty acids and alcohol were lower in DAF participants. Overall, no major significant differences in food preferences and intake were found for participants who lost their sense of smell during life. Participants suffering from congenital smell loss did show changes in food preferences, suggesting they are potentially more taste-oriented during eating. Together these results show the importance of tailored advice on dietary intake for this patient group.

Effects of moderate- and high-intensity acute aerobic exercise on food reward and appetite in individuals with methamphetamine dependence

PurposeDrug addiction is characterised by overvaluation of drug-related rewards and undervaluation of “natural”, non-drug-related rewards. Methamphetamine (MA) is the second largest illegally abused drug in the world. Studies have shown that acute aerobic exercise can reduce the incidence of MA-dependent individuals' craving for drug-related cues, but the impact of exercise on food reward in this population has yet to be established. The aim of this study was to determine the effects of moderate and high-intensity acute aerobic exercise on food reward and subjective feelings of appetite in MA-dependent populations. MethodsForty-four men, who met the DSM-V criteria for MA dependence, with BMI of 24.7 ± 3.1 kg/m2 and age of 31.9 ± 3.8 years, were randomly assigned to two exercise training groups: moderate- (n = 22; 65%~75% HRmax) or high- (n = 22; ≥ 85% HRmax) intensity. Each group performed a resting control or exercise session for 35 min, 1wk apart, in a counterbalanced order. Food reward (explicit liking, implicit wanting and relative preference) for high or low fat and sweet or savoury food images was assessed by the Leeds Food Preference Questionnaire and subjective feelings of appetite were measured by VAS. ResultsGreater relative preference (high: P = .018; moderate: P = .034) and implicit wanting (high: P = .018; moderate: P = .034) for high-fat savoury foods was noted following acute aerobic exercise compared to the control session. Exercise also increased subjective sensations of hunger (F (1,42) =8.28, P = .006). ConclusionsThe current study provides the first evidence that acute aerobic exercise can increase reward for high fat savoury foods and stimulate appetite in MA-dependent individuals. In the context of exercise as a therapeutic option for MA dependence, these changes suggest an improvement in responsiveness to natural, non-drug rewards.

Maternal coconut oil intake on lactation programs for endocannabinoid system dysfunction in adult offspring

Maternal exposure to coconut oil metabolically programs adult offspring for overweight, hyperphagia and hyperleptinemia. We studied the neuroendocrine mechanisms by which coconut oil supplementation during breastfeeding as well as continued exposure of this oil throughout life affect the feeding behavior of the progeny. At birth, pups were divided into two groups: Soybean oil (SO) and Coconut oil (CO). Dams received these oils by gavage (0.5 g/kg body mass/day) during lactation. Half of the CO group continued to receive CO in chow throughout life (CO + C). Adult CO and CO + C groups had overweight; the CO group had hyperphagia, higher visceral adiposity, and hyperleptinemia, while the CO + C group had hypophagia only. The CO group showed higher DAGLα (endocannabinoid synthesis) but no alteration of FAAH (endocannabinoid degradation) or CB1R. Leptin signaling and GLP1R were unchanged in the CO group, which did not explain its phenotype. Hyperphagia in these animals can be due to higher DAGLα, increasing the production of 2-AG, an orexigenic mediator. The CO + C group had higher preference for fat and lower hypothalamic GLP1R content. Continuous exposure to coconut oil prevented an increase in DAGLα. The CO + C group, although hypophagic, showed greater voracity when exposed to a hyperlipidemic diet, maybe due to lower GLP1R, since GLP1 inhibits short-term food intake.

175. Targeting the Gut-Brain Axis to Regulate Preference and Striatal Response to Fat

High fat diet (HFD) leads to disrupted striatal dopamine function and alterations in fat preference. One mechanism by which this occurs is depletion of gut lipid messengers, including oleoylethanolamine (OEA), which when replenished rescues dopamine response and increases preference for low fat emulsions via the generation of vagal afferent signals (Tellez et al., 2013). Using a supplement containing the OEA precurser N-oleyl-phosphatidylethanolamine and epigallocatechin-3-gallate (NOPE+EGCG), we tested whether this effect translates to humans and whether supplementation improves outcomes on a behavioral weight loss trial.

Aerobic Exercise Improves Food Reward Systems in Obese Rats via Insulin Signaling Regulation of Dopamine Levels in the Nucleus Accumbens.

The dopaminergic pathway, comprising projections from the ventral tegmental area to the nucleus accumbens, constitutes the core of the brain reward system. Insufficient food reward caused by dopamine signaling dysfunction in the nucleus accumbens is an important contributor to obesity and may be associated with insulin signaling. Aerobic exercise has a positive effect on both preventing and treating obesity. In addition, physical exercise is important in striatal dopamine homeostasis and improves insulin sensitivity in the peripheral and central nervous system. Therefore, we hypothesized that aerobic exercise may increase dopamine levels in the nucleus accumbens through insulin signaling, thus improving food reward in obesity. In the present study, we used a rat model of obesity, induced by high fat diet. Obese rats exhibited lower basic dopamine concentration in the nucleus accumbens induced by eating or extracellular insulin, attenuated insulin signaling, and increased fat preference. Interestingly, an 8-week aerobic exercise regimen reversed these symptoms. In addition, we noted a significant increase in insulin Akt/GSK3-β signal transduction in the nucleus accumbens. These data demonstrate that aerobic exercise promotes dopamine levels in the nucleus accumbens through insulin signal transduction, which may constitute an important neurobiological mechanism of exercise against obesity.

Fat preference and fat intake in individuals with and without anorexia nervosa

Fat restriction is a characteristic eating behavior among individuals with anorexia nervosa (AN), and laboratory meal studies demonstrate restricted fat intake among low-weight patients. The Geiselman Food Preference Questionnaire-I© (FPQ) is a validated self-report measure that yields a fat preference score (FPS). Prior research reported that patients with AN had a significantly lower FPS than did healthy control (HC) participants. The goal of the current study was to compare self-reported fat preference (FPS) to fat intake (multi-item meal (MIM) study) in low-weight ANs and HCs. Specific aims were 1) to determine if the FPS differed between ANs and HCs; 2) to determine if fat and energy intakes differed between ANs and HCs; and 3) to determine if the FPS was associated with fat and energy intakes in ANs and HCs. Forty-four female AN inpatients and 48 female HCs completed the FPQ and participated in a MIM study. Compared to HCs, ANs consumed less energy (469.1 ± 397.7 vs. 856.4 ± 346.8 kcal, p < 0.001), less fat (16.4 ± 20.4 vs. 36.7 ± 18.9 g, p < 0.001), and a smaller percentage of calories from fat (22.9 ± 13.8 vs. 36.6 ± 8.0%, p < 0.001) at the MIM. Compared to HCs, ANs also had a lower FPS (79.7 ± 27.4 vs. 102.3 ± 18.9, p < 0.001). The FPS was significantly and positively correlated with caloric intake (r = 0.481, p < 0.01), total fat (r = 0.453, p < 0.01), and the percentage of calories from fat (r = 0.37, p < 0.05) in ANs as well as in HCs (kcal: r = 0.583, p < 0.001; fat: r = 0.621, p < 0.001; % fat kcal: r = 0.601, p < 0.001). The FPS is related to objective measures of energy and fat intake in patients with AN as well as in healthy individuals.