Effects of fat content on fat hedonics: cognition or taste?

Understanding and perhaps overriding preferences for fat is important, given the relationship between higher dietary fat consumption and poorer health. We have examined the roles of potential mechanisms for differences in fat preference: actual fat content and expected fat content. The subjects were women (n=192, ages=50-69) recruited to a study of low-fat dietary change. Subjects were randomized to one of the four cells: participants received either a high- or low-fat milkshake at baseline, and half of each group was told that their milkshake was low in fat and the other half high in fat. Women who received a high-fat milkshake consumed more grams than women who received a low-fat milkshake. Women who expected low-fat shakes reported liking them more than those who expected high-fat milkshakes. These data indicate that both physiology and cognition play a role in determining consumption of high- and low-fat foods.     

Selective effects of vagal deafferentation and celiac-superior mesenteric ganglionectomy on the reinforcing and satiating action of intestinal nutrients

The role of vagal afferents and splanchnic fibers in nutrient-induced flavor conditioning and feeding suppression was determined. Male rats were fitted with intraduodenal (ID) catheters and given subdiaphragmatic vagal deafferentation (SDA), celiac-superior mesenteric ganglionectomy (CGX), combined (COM) treatments, or sham surgery. In separate conditioning trials, they were trained to drink (30 min/day) flavored saccharin solutions paired with concurrent ID infusions of 8% maltodextrin or water and 3.55% corn oil or water. Experiment 1 revealed that SDA and sham rats showed equal preferences for the nutrient-paired flavors over the water-paired flavors. In contrast, SDA rats, unlike sham rats, failed to suppress their intake of a palatable fluid when infused intraduodenally with maltodextrin or corn oil. Experiment 2 revealed that CGX, COM and sham rats all developed preferences for the maltodextrin-paired flavor, although CGX alone or COM attenuated the conditioned preference. CGX and COM treatments also attenuated or blocked the feeding inhibitory actions of ID nutrient infusions. These findings along with prior data indicate that gut vagal afferents and splanchnic nerves are not essential for flavor-nutrient preference conditioning, whereas both vagal afferents and splanchnic nerves are implicated in carbohydrate- and fat-induced satiation.     

The adipogenic potential of various extracellular matrices under the influence of an angiogenic growth factor combination in a mouse tissue engineering chamber

The extracellular matrix (ECM) Matrigel™ has frequently and successfully been used to generate new adipose tissue experimentally, but is unsuitable for human application. This study sought to compare the adipogenic potential of a number of alternative, biologically derived or synthetic ECMs with potential for human application, with and without growth factors and a small fat autograft. Eight groups, with six severe combined immunodeficient (SCID) mice per group, were created with bilateral chambers (silicone tubes) implanted around the epigastric vascular pedicle, with one chamber/animal containing a 5 mg fat autograft. Two animal groups were created for each of four ECMs (Matrigel™, Myogel, Cymetra® and PuraMatrix™) which filled the bilateral chambers. One group/ECM had no growth factors added to chambers whilst the other group had growth factors (GFs) (vascular endothelial growth factor-A (VEGF-A) plus fibroblast growth factor-2 (FGF-2) plus platelet-derived growth factor-BB (PDGF-BB)) added to both chambers. At 6 weeks, chamber tissue was morphometrically assessed for percent and absolute adipose tissue volume. Overall, the triple GF regime significantly increased percent¹ and absolute^# adipose tissue volume (p < 0.0005^1#) compared to chambers without triple GF treatment. The fat autograft also significantly increased percent (p < 0.0005) and absolute (p < 0.011) adipose tissue volume. Cymetra® (human collagen) constructs yielded the largest total tissue and absolute adipose tissue volume. We found that the pro-angiogenic FGF-2, VEGF-A and PDGF-BB combination in ECMs of synthetic and biological origin produced an overall significantly increased adipose tissue volume at 6 weeks and may have clinical application, particularly with Cymetra.     

Estimation of postoperative fat absorption using the <Superscript>13</Superscript>C mixed-triglyceride breath test in children with choledochal cyst

No previous studies have focused on postoperative fat malabsorption in children with choledochal cyst (CC) who undergo cyst excision and Roux-en-Y (RY) hepatico–jejunostomy (HJ), a combination of procedures that can lead to the non-physiological mixture of food and bile juice. To examine the effect of RYHJ with cholecystectomy on the fat absorption ability of children with CC, we estimated postoperative fat-absorption ability using the carbon 13-labeled mixed triglyceride (¹³C-MTG) breath test. Twelve postoperative children with CC and 12 normal control children were administered ¹³C-MTG orally and asked to give breath samples at six time points: once before the ¹³C-MTG ingestion and at five 60-min intervals post-ingestion. Fecal chymotrypsin activity and fecal fat excretion were also measured. The delta value of breath ¹³CO₂ at 3, 4, and 5 h after administration and the 5-h cumulative breath ¹³CO₂ were significantly lower in the CC children than in the controls. There were no significant differences in the fecal chymotrypsin activity or fecal fat excretion of the two groups. Conclusion. Occult fat malabsorption occurs in patients with CC after RYHJ, even in the absence of clinical symptoms or abnormal laboratory data.     

Linear Fat Deposition in the Middle Layer of the Left Ventricular Myocardium: Computed Tomographic Findings

We report here a case of streaky fat deposition in the middle layer of the left ventricular myocardium, without any underlying etiology, and this was seen on computed tomography coronary angiography. This report suggests that left ventricular middle layer fat deposition should be investigated in order to determine its etiology, the pathogenesis and the prognosis.     

Swedish pre-school children eat too much junk food and sucrose

Aim: To analyze dietary intake in healthy 4‐year‐old children. Methods: Families from three Paediatric Health Care Centres in different socio‐economic areas in Göteborg completed 7‐day food records and questionnaires about socio‐economy. Results: One hundred thirty two/153 completed the study, 49% of parents were university educated. Eighteen percent of children were overweight/obese. Energy intake was high; 67% had sucrose intake exceeding Nordic Nutrition Recommendations (NNR) but 36% had n‐3 fatty acid intake <0.5 energy percent. Significant negative correlations were found between sucrose and fat and between BMI and fat intake. Junk food supplied 24% of energy. Ninety‐two percent had low vitamin D intake, 70% low iron and 21% low calcium intake. Gruel, which was consumed by 28%, had a positive impact on micronutrient intake. Child care and mother's origin seemed to influence dietary intake. Conclusion: In 4‐year olds from well‐educated urban families, 18% was overweight/obese. Total energy intake was above present NNR but lower than 20 years ago, when overweight was rare. Fat energy intake was negatively associated with BMI, and low n‐3 fatty acid intake was associated with higher body weight. In several aspects dietary intake was not optimal in the children.     

Hypothalamic neurons innervating fat tissue in the pig express leptin receptor immunoreactivity

While leptin receptors have been found in both the autonomic ganglion neurons and the hypothalamic nuclei, studies dealing with the projections from the central nervous system to the adipose tissue have been conducted mainly in laboratory animals. Therefore, the purpose of our study was to establish whether hypothalamic neurons are transsynaptically connected to adipose tissue depots in the pig, and if these neurons express leptin receptor immunoreactivity. Pseudorabies virus (PRV; Bartha's K strain) was introduced in perirenal or subcutaneous adipose tissue depots in domestic pigs. On day 9, animals were euthanized and hypothalami were collected and processed immunohistochemicaly with primary antisera against PRV and leptin receptor (OBR). PRV-labeled neurons were localized in paraventricular nucleus, supraoptic nucleus and arcuate nucleus following injections in both the perirenal and the subcutaneous adipose tissue depots. Ventromedial nucleus, dorsomedial nucleus and preoptic area-labeled neurons were observed after injection of the PRV into the perirenal adipose tissue, while in the lateral hypothalamic area-labeled neurons projected only to the subcutaneous adipose tissue. The majority of the PRV-labeled neurons simultaneously expressed OBR-immunoreactivity. Our results provide the morphological data on multisynaptic projections from hypothalamus to the fat tissue in the pig and demonstrate that these neurons, located in areas involved in reproductive processes and feeding behavior, may regulate fat tissue metabolism.     

Body composition measured by dual-energy X-ray absorptiometry half-body scans in obese children

Aim: To perform a methods comparison of a left or right half‐body scan versus whole‐body scan for measuring body composition in a sample of obese children. Methods: A group of obese children (n = 58; ≥95th BMI percentile; 8–18 years) were required to undergo a dual‐energy X‐ray absorptiometry (DXA) body composition measurement as part of an ongoing cohort study; 34 fit within the imaging field of the DXA scanner and were eligible for inclusion in the present analysis. Percent fat, total mass, fat mass, lean mass and bone mineral content (BMC) were estimated from half‐body scans and compared with the whole‐body results. Assessment was completed using GE enCORE 11.40 software. Results: In comparing left‐ and right‐side scans to whole‐body scans, there was significant correlation for all body composition variables (p ≤ 0.005, R² = 0.996–1.0). Bland Altman analyses also showed high levels of agreement between half‐body estimates and whole‐body measurements. Conclusion: This study supports using a half‐body scan methodology for percent fat, total mass, fat mass, lean mass, and BMC as a valid alternative to full‐body analysis in obese children and youth.