Skeletal muscle is highly involved in macronutrient metabolism. To maintain proper energy metabolism and physiology, skeletal muscle must adapt to nutrient supply. Thus, diet macronutrient composition is an important modulator of skeletal muscle metabolism. Evidence from rodent and human models show high-fat diets contribute to impaired insulin signaling, as well as decreased fatty acid and glucose oxidation. Utilizing proteomic analysis of metabolic proteins in humans may lead to the mechanism behind skeletal muscle adaption to macronutrient composition, potentially providing the groundwork for characterizing the etiology of high-fat feeding induced metabolic disease. The objective of this study was to compare the substrate oxidation patterns and the levels of metabolic proteins in the fasted skeletal muscle of lean, healthy males that either increased fatty acid oxidation in response to the high-fat diet, termed responders, or males that decreased fatty acid oxidation, termed non-responders. We employed a controlled feeding study design, where the participants served as their own controls. Following a 2-week control diet (30% fat, 55% carbohydrate and 15% protein), participants came to the lab fasted overnight and a muscle biopsy was taken from their vastus lateralis muscle. Participants were then placed on a 5-day high-fat diet (50% fat [45% saturated fat], 35% carbohydrate, and 15% protein). Following this diet, participants again came to the lab fasted overnight and another muscle biopsy was taken from their vastus lateralis muscle. Both the control and the high-fat diets were isocaloric to habitual diets. Muscle from the biopsies were utilized for substrate metabolism measures and mass spectrometry. We did not observe any significant differences in glucose oxidation between responders and non-responders, prior to or following the high-fat diet. Our proteomic analysis identified 81 proteins and protein subunits involved in substrate metabolism but only 6 were differentially regulated by the high-fat diet. Independent of the high-fat diet, compared to non-responders, responders contained an overall higher content of protein subunits belonging to Complex I and ATP synthase. The findings from this study suggest that adaption to high-fat feeding is individual specific and proteomic changes alone cannot explain high-fat feeding induced metabolic changes. / Ph. D. / Skeletal muscle is highly involved in macronutrient metabolism, which consist of the breakdown and utilization of glucose and fatty acids, thus making the foods we ingest a major modulator of skeletal muscle metabolism. Over the last few decades, Americans have increased their ingestion of foods high in saturated fats, which has coincided with the increased prevalence of obesity and type 2 diabetes. Further, evidence suggests these metabolic diseases are associated with the skeletal muscle’s inability to switch between the utilization of glucose and fatty acid in response to nutrient supply. Analyzing metabolic protein content in humans may lead to the mechanism behind skeletal muscle adaption to macronutrient composition, potentially leading to the cause behind the development of high-fat feeding induced metabolic disease. The objective of our controlled feeding study was to compare the macronutrient metabolism and the content of metabolic proteins in the fasted skeletal muscle of healthy males that either increased fatty acid utilization in response to a high-fat diet, termed responders, or males that decreased fatty acid utilization, termed non-responders. Following a 2-week control diet (30% fat, 55% carbohydrate and 15% protein), participants came to the lab fasted overnight and a biopsy was taken from their thigh muscle called the vastus lateralis. Participants then began a 5-day high-fat diet (50% fat [45% saturated fat], 35% carbohydrate, and 15% protein). Following this diet, participants came to the lab fasted overnight and another biopsy was taken from their vastus lateralis muscle. Both the control and the high-fat diets were isocaloric to habitual diets. The muscle samples were used to analyze macronutrient metabolism and identify metabolic protein content. We did not observe differences in glucose utilization between responders and non-responders, prior to or following the high-fat diet. We identified 81 metabolic proteins and protein subunits but only 6 were differentially regulated by the high-fat diet. Independent of diet, responders contained higher levels of subunits from 2 proteins involved in cell energy production, Complex I and ATP synthase. Our findings suggest that adaption to high-fat feeding is individual specific and protein content changes alone cannot explain high-fat feeding induced metabolic changes.

Yes / Hair follicles (HFs) are immersed within dermal white adipose tissue (dWAT), yet human adipocyte-HF communication remains unexplored. Therefore, we investigated how perifollicular adipocytes affect the physiology of organ-cultured human anagen scalp HFs. Quantitative (immuno-)histomorphometry, microCT and transmission electron microscopy showed that the number and size of perifollicular adipocytes declined during anagen-catagen transition, whilst fluorescence lifetime imaging revealed increased lipid oxidation in adipocytes surrounding the bulge/sub-bulge region. Ex vivo, dWAT significantly stimulated hair matrix keratinocyte proliferation and HF pigmentation. Both dWAT pericytes and PREF1/DLK1+ adipocyte progenitors secreted hepatocyte growth factor (HGF) during human HF-dWAT co-culture, for which the c-Met receptor is expressed in the hair matrix and dermal papilla. These effects were abrogated by an HGF-neutralising antibody, and reproduced using recombinant HGF. Laser capture microdissection-based microarray analysis of the hair matrix showed that dWAT-derived HGF up-regulated KRT27, KRT73, KRT75, KRT84, KRT86 and TCHH. Mechanistically, HGF stimulated Wnt/β-catenin activity in the HM by inhibiting SFRP1 in the dermal papilla, up-regulating matrix AXIN2, LEF1, WNT6 and WNT10B expression. Our study demonstrates that dWAT regulates human hair growth and pigmentation via HGF secretion, and thus identifies important, molecular and cellular targets for therapeutic intervention in disorders of human hair growth and pigmentation.

A reduced cholesterol butteroil was emulsified into skim milk, buttermilk, or buttermilk/butter-derived aqueous phase using different homogenization pressures and heat treatments to produce a 20% milk fat cream with a reduced cholesterol content. Transmission electron microscopic examination of reformulated cream emulsions showed an oil-in-water emulsion typical of milk lipid globules found in natural homogenized cream. Heat treatment (pasteurized and unpasteurized) and homogenization pressure (1500/500 PSI and 2000/500 PSI) had no effect on cream composition except for the significant effect of homogenization pressure on cholesterol content and the amount of phospholipid associated with the lipid globules. The formulations using buttermilk or buttermilk and butter-derived aqueous phase were the most similar in the amount of protein and phospholipid associated with the lipid globules when compared to a natural homogenized cream. The viscosity. interfacial area of lipid globules. creaming stability, and feathering stability of the three formulations and a control at the two homogenization pressures were measured over a two week storage period at 7°C. The apparent viscosity and interfacial area of the different creams varied significantly with formulation but not with homogenization pressure or length of storage time (p ≤ 0.05). Creaming stability was significantly affected by formulation, homogenization pressure, and length of storage tinle (p S ≤.05). Feathering appeared to be unaffected by any of the treatment factors. The reformulated cream using buttermilk and butter-derived aqueous phase was the closest in comparison to a natural homogenized cream in chelllical composition and physical properties. The ability to emulsify the reduced cholesterol butteroil into a stable cream emulsion may allow for the use of reduced cholesterol butteroil in fluid dairy products, ice cream, and cheese. Development of any full-fat product with a reduced cholesterol content will require a reformulation step until a method for cholesterol removal directly from fluid milk or cream is developed. / Master of Science

The objective of this study is to determine if fat as an energy source, and fiber in a pasture supplement will be beneficial when compared to a concentrate high in sugar and starch. In the first experiment, 12 pregnant and lactating mares were used in three different glycemic response tests to determine the effect of feeds on pregnant mares. The mares were fed a pelleted concentrate (PC) three months before foaling; after foaling they were divided into two groups and fed a feed high in sugar and starch (SS), or a feed high in fat and fiber (FF). The second experiment, used the same 12 mares (R mares) and 10 barren mares (B mares) in three different tests to determine the effects of the feeds, season and reproductive stage. A series of blood samples was collected via a jugular catheter from 0 to 390 min after consuming a meal. Glucose and insulin baseline and peak values, increments and areas under curves (AUC) were compared by ANOVA. For the first experiment, responses to PC did not differ between the two groups. Peak plasma glucose and insulin concentrations were higher in SS group than in FF during both early and late lactation. Glucose and insulin AUCs were higher in SS than in FF during both early and late lactation. In the second experiment, peak glucose increments had differences for the main effects feed, pregnancy and season, and interactions feed by pregnancy and feed by season. The glucose AUC values showed similar differences for the main effects and the interaction feed by pregnancy. Peak insulin increments had a difference for feed and pregnancy, but not the interactions. Insulin AUCs also revealed a difference between feed and pregnancy, and also for season, and the interaction feed by pregnancy. These results indicate that metabolic fluctuations are moderated by the replacement of sugar and starch with fat and fiber. This replacement may reduce the risk of certain digestive and metabolic disorders. / Master of Science

Performance of three carbohydrate-based fat replacers (pectin, gum, and oat fiber) in a southern-style baking powder biscuit was evaluated at substituted levels of 33%, 66%, and 100%. Objectives and sensory tests were conducted on all samples. Results were compared to the control for the determination of significant differences at (p<0.05). Overall objective test results suggested that there was an increase in the degree of expansion as the level of fat replacement increased. Significantly (p<0.05) softer crusts and crumbs were observed with the fat replaced variations. All fat-substituted biscuits had significantly (p<0.05) higher moisture contents. Upon 24 and 48 hours of storage, staling was observed in all variations with the 100% variations having the most staling. There was a significant (p<0.05) caloric reduction as the level of fat replacement increased. However, this was an over-estimation of the calories provided upon human utilization. Also, the Land and b values of the crust color significantly (p<0.05) decreased with fat sUbstitution. The QDA results indicated that the panelists observed the degree of browning, cell size, dryness, and tenderness significantly (p<0.05) decreased whereas, perceived cohesiveness significantly (p<0.05) increased as the level of fat replacement increased. Bitterness also increased as the fat replacement level increased. The general population with an Appalachian influence "moderately liked" the control and oat-based 33% and 66% variations which were selected on the basis of the QDA results. Overall, the fat substituted variations with the most desirable characteristics were the pectin and oat-based 33% biscuits. The 100% variations would be the most beneficial in caloric reduction, however, their attributes would not be representative of an "ideal" Southern-style baking powder biscuit. / Master of Science

The aim of this thesis was to investigate the effects of dietary fatty acids on body composition and ectopic fat in humans, with emphasis on the role of the omega-6 polyunsaturated fatty acid (PUFA) linoleic acid (18:2n-6) and the saturated fatty acid (SFA) palmitic acid (16:0). The overall hypothesis was that linoleic acid would be beneficial compared with palmitic acid during overfeeding, as previously indicated in animals. Papers I, II and IV were double-blinded, randomized interventions in which different dietary fats were provided to participants and Paper III was a cross-sectional study in a community-based cohort (PIVUS) in which serum fatty acid composition was assessed as a biomarker of dietary fat intake. In Paper I, overfeeding with sunflower oil (n-6 PUFA) for 7 weeks caused less accumulation of liver fat, visceral fat and total body fat (as assessed by MRI) compared with palm oil (SFA) in young and lean subjects despite similar weight gain among groups. Instead, sunflower oil caused a larger accumulation of lean tissue. In Paper II, plasma from Paper I was analyzed with NMR-based metabolomics, aiming to identify metabolites differentially affected by the two dietary treatments. Acetate decreased by PUFA and increased by SFA whereas lactate increased by PUFA and decreased by SFA. In Paper III, the proportion of linoleic acid in serum was inversely associated with contents of visceral-, subcutaneous- and total body adipose tissue whereas the proportion of palmitic acid was directly associated with visceral- and total body adipose tissue in 70-year old men and women. In Paper IV, overfeeding with sunflower oil for 8 weeks caused less accumulation of liver fat compared with palm oil also in overweight and obese subjects. SFA increased visceral fat in men only. Accumulation of lean tissue was similar between groups. In conclusion, SFA (palmitic acid) from palm oil promotes marked liver fat accumulation in both normal-weight and overweight/obese subjects during overeating, whereas n-6 PUFA (linoleic acid) from sunflower oil prevents such liver fat accumulation. Diverging effects of SFA and PUFA on visceral adipose tissue and lean tissue may only be applicable in some groups and/or circumstances. These results imply that negative effects associated with weight gain (e.g. fatty liver) may be partly counteracted by the type fat in the diet, overall supporting a beneficial role of diets higher in unsaturated fat compared with saturated fat for preventing liver fat accumulation.

Dietary guidelines recommend that Americans consume no more than 30 percent of energy intake from fat. The most recent national survey reported that U.S. women consume about 36 percent of energy from fat. Very little is presently known about the fat intake, or food sources of fat in the diets of college students, a subgroup of the population, with newly established eating habits. This study examined nutrient intake and sources of fat in the diets of 233 women and 60 men enrolled in six introductory nutrition courses from September 1987 through June 1988. Female students were further subdivided to determine whether the independent variables, living situation (on campus or off campus), or fat content of diet (fat intake less than or equal to 30 percent of energy consumed, or fat intake more than 30 percent of energy consumed) had an effect on nutrient intake or food sources of fat. Each student in the sample kept a two-day food intake record, and filled out a form reporting their sex, age, major, and living arrangement. Dietary intakes were analyzed for macronutrients, types of fat, cholesterol, vitamin B6, calcium, iron, and zinc. Mean intakes, nutrient density, proportion of students who did not meet 75 percent of the RDA, and energy distribution as percent intake of protein, fat, and carbohydrate were compared between sample subgroups. Foods were categorized into 27 food groups. Groupings, adapted from Popkin et. al. (15), were based on the Four Food Groups, which were further subdivided by fat content. Per capita consumption of each food group, proportion of users of each food category, and per user consumption of foods in each category were compared between sample subgroups. T-tests were used to compare mean nutrient and food group intakes, and chi-square analysis was used to compare proportion of individuals who met 75 percent of the RDA, and proportion of individuals that consumed foods from each food group. The college women in this sample exceeded dietary guidelines for fat consumption. They did, however, have a lower intake of fat than a national sample of women 19 to 34 years, living in the western U.S. in 1986, and a correspondingly lower intake of cholesterol. A large proportion of the college women consumed less than 75 percent of the RDA for vitamin B6, calcium, iron, and zinc. Meat is a major source for all of these nutrients except calcium. College women consumed less zinc than the national sample of women, and had a lower intake of meat. Women with a low fat intake, also, had a lower intake of zinc, and consumed less meat. The college men did not have a proportionately greater intake of fat than college women, although they did have a greater intake of cholesterol due to the greater consumption of foods of animal origin. / Graduation date: 1990

2 pp. / Of all the nutrients in the food supply, fat and cholesterol probably receive the most attention from health professionals and the public alike. The scientific evidence is clear that a high-fat diet relates to chronic health problems such as heart disease, some types of cancer, diabetes, and obesity. But both fat and cholesterol are natural components of the body that are vital to good health, and too little fat in your diet is just as unhealthy as too much. This article reviews dietary fats and provides guidelines for choosing foods to balance the type and amount of fat in your diet.

More than 30% of the population suffers from obesity, which increases the risk of death and secondary health problems. Body fat [white adipose tissue (WAT) and brown adipose tissue (BAT)] are innervated and regulated by the sympathetic nervous system (SNS). WAT stores energy, while BAT generates heat for thermoregulation. Fat also has sensory innervations, but the roles of sensory nerves are still being elucidated. Hence, understanding the neuroanatomy of the SNS innervations of fat and the neural regulation of fat metabolism will be valuable for advancing obesity treatment. Using trans-synaptic tract tracers with unique fluorescent proteins, we defined and compared the SNS innervations of visceral fat [mesenteric WAT (MWAT)] and subcutaneous fat [inguinal WAT (IWAT)] and of IWAT and interscapular BAT (IBAT) in Siberian hamsters. MWAT and IWAT have moderately shared SNS innervations within the hindbrain, but separate SNS innervations in rostral regions. In contrast, IWAT and IBAT have relatively separate SNS circuitries throughout the brain yet some overlap in SNS nuclei known to regulate thermogenesis. We tested for the presence of functional coordination between IWAT and IBAT defined by overlap in IWAT SNS and IBAT SNS innervations. When IBAT function was impaired by SNS denervation, IWAT SNS drive, thermogenic activity, and beige adipocyte recruitment increased in cold exposed hamsters likely through coordination with IWAT SNS pathways. Conversely, we found that only SNS drive to IWAT increased during acute food deprivation suggesting that populations of SNS neurons singly innervating each fat depot may contribute to differential SNS drive to fat. Lastly, we demonstrated that IWAT sensory nerves mediate the functional coordination between IWAT and IBAT and the regulation of SNS drive to fat. The absence of IWAT sensory feedback via sensory denervation differentially decreased SNS drive to IBAT and IWAT itself, but not to MWAT, retroperitoneal WAT, and epididymal WAT in cold exposed hamsters. Collectively, the studies in this dissertation provide neuroanatomical evidence of separate and shared SNS brain sites likely receiving sensory signaling and regulating SNS drive to fat, and direct evidence of the roles of SNS and sensory nerves innervating fat to energetic homeostasis and thermoregulation.

Thesis (MTech (Consumer Science: Food and Nutrition))--Cape Peninsula University of Technology, 2016. / Objective: To determine the association between the dietary fat knowledge and consumption of foods rich in fat among first-year students in self-catering residence at a university of technology, Cape Town, South Africa. Design: The two concepts – the dietary fat knowledge (represented by dietary fat food knowledge and dietary fat nutrition knowledge) and the consumption of foods rich in fat – were assessed separately. Two norm-referenced, valid and reliable knowledge tests and an intake screening questionnaire were used for the assessments (as subsidiary objectives), before the associations between the concepts were determined (main objective). The dietary fat food and nutrition knowledge as assessed was categorised in the range poor or below average, average and good or above average, and the consumption of foods rich in fat as high, quite high, the typical Western diet, approaching low or desirable. The Pearson‟s chi-square test was applied to these categorical findings to determine if associations (five percent significance) existed between the concepts. Results: The stratified sample included 225 first-year students. Nearly half (48.4%) of them achieved an average fat food knowledge score, while the majority (80.9%) achieved a poor fat nutrition knowledge score. More than half (52.5%) either followed a typical Western diet, a diet quite high in fat or high in fat. While no significant (p > 0.05) association was found between the students‟ dietary fat food knowledge and consumption of foods rich in fat, significant results were found in the association between the students‟ dietary fat nutrition knowledge and consumption of foods rich in fat (p < 0.05) and between their fat food knowledge and fat nutrition knowledge (p < 0.001). Conclusions: An inverse association was found between the students‟ dietary fat nutrition knowledge and fat consumption, a positive association between their dietary fat food knowledge and dietary fat nutrition knowledge, and no association between their dietary fat food knowledge and fat consumption.