Dietary Intake Control Research Articles

Appetite control by the tongue-gut axis and evaluation of the role of CD36/SR-B2

Understanding the mechanisms governing food intake is a public health issue given the dramatic rise of obesity over the world. The overconsumption of tasty energy-dense foods rich in lipids is considered to be one of the nutritional causes of this epidemic. Over the last decade, the identification of fatty acid receptors in strategic places in the body (i.e. oro-intestinal tract and brain) has provided a major progress in the deciphering of regulatory networks involved in the control of dietary intake. Among these lipid sensors, CD36/SR-B2 appears to play a significant role since this membrane protein, known to bind long-chain fatty acid with a high affinity, was specifically found both in enterocytes and in a subset of taste bud cells and entero-endocrine cells. After a short overview on CD36/SR-B2 structure, function and regulation, this mini-review proposes to analyze the key findings about the role of CD36/SR-B2 along of the tongue-gut axis in relation to appetite control. In addition, we discuss whether obesogenic diets might impair lipid sensing mediated by CD36/SR-B2 along this axis.

Diet and personality: Associations in a population-based sample

Background Large portions of the population of the United States of America fail to follow dietary recommendations. Psychological factors may contribute to non-adherence. Objective Establish the associations between heritable personality styles, attitudes towards food, and habitual eating behavior. Design Variables were assessed by questionnaire in a population-based sample of 629 subjects. Associations were established using correlation and regression analysis, taking gender, demographic, lifestyle and other factors into account. Results Differences in personality style were reflected in diet. For example, hostility and anxiety-proneness was associated with greater likelihood to continue eating when satiated, while sociability and low impulsivity correlated with greater monitoring and control of dietary intake and body weight. Immaturity, aloofness, self-consciousness and self-gratification were associated with greater susceptibility to hunger and lack of persistence with increased snack and alcohol consumption. These associations differed for the sexes and were stronger for attitudes towards food than actual eating behavior. Taking other factors into account reduced the number of significant associations between diet and personality, particularly for habitual eating behavior. Conclusions Associations exist between personality and diet. However, the strength of these associations is influenced by demographic, lifestyle and other factors. These findings have implications for future studies and efforts aimed at changing unhealthy dietary habits.

Adaptation and maladaptation of the heart in diabetes: Part II: potential mechanisms.

The prevailing concept of the heart’s response to changes in its environment is a complex network of inter-connecting signal transduction cascades.1 In such a scheme, the focus is on communication of various cell surface receptors, heterotrimeric G-proteins, protein kinases, and transcription factors.2–4⇓⇓ Diabetes is a disorder of metabolic dysregulation. At first glance it appears that metabolism and the metabolic consequences of diabetes do not fit into this signal-response coupling scheme. Two questions arise. First, is metabolism simply an “effect” rather than a “cause” of adaptation? Second, is metabolism only a by-product of signal transduction-induced adaptation, allowing equilibrium (and therefore maintenance of function) in the presence of the other adaptational responses? An alternative is to take a new, less restricted view of metabolism. Beyond its stereotypical function as a provider of ATP, alterations in metabolic flux within the cell create essential signals for the adaptation of the heart to situations such as diabetes. This concept is novel for the heart, but has already been considered in the liver. Like the phosphorylation events occurring in signal transduction cascades, changes in metabolic flux are extremely rapid. For example, translocation of GLUT4 to the cell surface in response to insulin occurs within a second.5 We have previously found that increases or decreases in workload also change metabolic fluxes in seconds.6,7⇓ Therefore, changes in metabolites are rapid enough to allow them to act as signaling molecules. Many of these acute changes in metabolic flux are brought about by the same signal transduction cascades believed to be involved in the adaptation of the heart to changes in its environment. Phosphatidylinositol 3-kinase, Ca2+, and protein kinase C, all of which play a role in cardiac adaptation, regulate metabolism in the heart.8,9⇓ Metabolic signals therefore provide a …

Irish endocrine society: 23rd annual meeting

C CLARKE, CG BRENNAN, K RODGERS, RM DWYER, PPA SMYTH ENDOCRINE LABORATORY, DEPARTMENT OF MEDICINE AND THERAPEUTICS, UNIVERSITY COLLEGE DUBLIN, IRELAND he demonstration in extrathyroidal human tissues of the sodium iodide symporter (NIS) has raised the possibility that 1311, commonly used as a systemic therapeutic ablative agent in hyperthyroidism and thyroid cancer, might be applied in the treatment of tumours in other NISexpressing tissues such as human breast cancer. Thyroidal transport of 1311 is known to be proportional to circulating stable I and the aim of this study was to determine how stable I (KI) would effect such transport in human breast cancer cell lines MDA-MB-231, MCF-7 and in FRTL-5 thyroid cells. All cells were incubated with KI (01 00mM) for 72 hours after which 1Th I was added . Incubation and uptake of 'l by cells was counted every four hours. Timed efflux of '^I was measured every five minutes. KI in the incubation medium blocked 1251 uptake in a dose-dependent manner in the E receptor positive MCF7 cell line. The effect was less marked in the E receptor negative MDA-MB-231 with significant uptake being maintained even at an I concentration of 50mM. A similar blockade was seen in the FRTL-5 cells with maximum uptake blockade of 25mM I. The rate of efflux of 15I was similar in both MCF-7 and MDA-MB-231 cell lines with a tin of 35 and 40 minutes respectively. In contrast, efflux from the FRTL-5 cells was faster (tire=15 mins). As the human breast has a much lower avidity for I than the thyroid, control of dietary intake would assume even greater importance in radioactive iodine treatment of breast tumours or their metastases.

The Cafeteria Diet—An Inappropriate Tool for Studies of Thermogenesis

Diet-induced thermogenesis (DIT) is defined as a regulatory, facultative component of energy expenditure, stimulated by overeating, which helps maintain energy balance. DIT may play a central role in the regulation of energy expenditure and in the etiology of certain types of obesity. Most experiments testing the existence or the mechanisms of DIT have used the cafeteria diet for the purposes of stimulating hyperphagia, a requisite for studies of DIT. Yet such a diet is inappropriate for studies of thermogenesis because its use prevents researchers from obtaining an experimental outcome that can be clearly interpreted. The primary limitation of the cafeteria diet is that its nutritional composition is uncontrolled. The diet is self-selected from a variety of supermarket foods that tend to be high in fat and/or carbohydrate and low in protein, vitamins and minerals. Hence, the diets consumed by the animals are likely to be deficient in protein, vitamins or minerals. There is evidence that 1) dietary deficiency of protein, vitamins and minerals can increase thermogenesis and 2) in protein-adequate diets, the balance of fat and carbohydrate in the diet can also influence thermogenesis with high carbohydrate diets increasing thermogenesis more than isoenergetic high fat diets. Hence, an observed increase in thermogenesis in cafeteria fed animals might be interpreted incorrectly to be the result of increased energy consumption when it is attributable to dietary imbalance or deficiency. Because the diet is self-selected, it is possible for each animal to choose a diet that varies in nutritional composition from that selected by every other animal, so control of dietary intake is compromised. Palatable diets of controlled macro- and micronutrient composition are capable of stimulating hyperphagia on the order of 50 to 60%. Thus, the use of the cafeteria diet is both unnecessary and inappropriate.

Deer Preference for Juniper Forage and Volatile Oil Treated Foods

Cafeteria feeding trials were used to determine preferences by mule deer (Odocoileus hemionus) among alligator juniper (Juniperus deppeana), Utah juniper (J. osteosperma), and Rocky Mountain juniper (U. scopulorum) foliage and for pelleted feeds treated with their volatile oils. Deer exhibited a preference (P < 0.05) for alligator juniper, but did not differentiate between Utah and Rocky Mountain junipers. Preferences were inversely related to concentrations of volatile oil content of junipers. Terpene fraction of volatile oils also was related to preference, and deer selected against forages with higher concentrations of oxygenated monoterpenes. The forage species most preferred (alligator juniper) had the lowest absolute concentration of oxygenated monoterpenes. J. WILDL. MANAGE. 44(1):114-120 According to Goatcher and Church (1970), the sense of taste in higher animals functions in several processes, among which are: control of ingestive behavior, onset of specific appetites, and reinforcement in learning situations. Taste is important in nutrition. Theories on control of dietary intake have emerged from studies on energizing properties of sensory cues on behavior. One unifying concept is that taste, acting as a sensory cue, is involved in regulation of intake by linking relief of nutritional stress to some identifying sensory characteristics of food available. It is thought that the linking role may be both innate (acting in short term control) and learned (influencing long term regulation). The sense of taste has been thoroughly investigated in the laboratory rat, but other species, particularly wild ruminants, have received little study. Most investigators consider juniper a low-palatability, emergency browse for deer (Hill 1946, Smith and Hubbard 1954, Julander 1962). Yet Hill and Harris (1943) in South Dakota, and Lovaas (1958) in Montana, found varying degrees of use of common juniper (J. communis) and creeping juniper (J. horizontalis) by white-tailed deer (0. virginianus) and mule deer, respectively. Likewise, Anderson et al. (1965) found one-seed juniper (J. monosperma) and alligator juniper to be important yearlong mule deer foods in southeastern New Mexico. Junipers contain volatile oils that are inhibitory to deer rumen microorganisms (Schwartz et al. 1980). Inhibitory properties of these oils are proportional to their concentration and related to their chemical structure. When oils are fractionated into major components (monoterpene hydrocarbons, oxygenated monoterpenes, and sesquiterpenes), the oxygenated monoterpenes are the most inhibitory fraction. The role of these inhibitory properties of juniper oil as they relate to deer preference and selectivity of juniper is not understood. 1Data presented were collected by 2 Graduate Research Assistants at Colorado State University, W. G. Jobman and P. Smith. Financial support was provided by the USDA Forest Service. We also thank J. A. Bailey for graduate student guidance. 2 Present address: Alaska Department of Fish and Game, Moose Research Center, P.O. Box 3150, Soldotna, AK 99669. 3 Present address: U.S. Fish and Wildlife Service, Denver Wildlife Research Center, P.O. Box 2800, Kenai, AK 99611. 114 J. Wildl. Manage. 44(1):1980 This content downloaded from 157.55.39.104 on Mon, 20 Jun 2016 05:57:15 UTC All use subject to http://about.jstor.org/terms DEER PREFERENCE FOR JUNIPER Schwartz et al. 115 This is the 3rd phase of an investigation of the roles of volatile oils of Rocky Mountain, Utah, and alligator junipers in mule deer nutrition. The first 2 phases evaluated volatile oil content and composition of the 3 juniper species, and the role of these volatile oils and fractions on rumen microbial function (Schwartz et al. 1980). In this phase, we determined relative acceptance of 3 species of juniper and their volatile oil components using cafeteria feeding trials with mule deer. The following items were tested: (1) if deer preferred 1 of 3 species of juniper when equally available as raw forage; (2) if deer showed a selective response to ground and pelleted foliage of the 3 species of juniper in which differences in physical form were eliminated; (3) if deer differentiated among various levels of volatile oils normally encountered in natural vegetation; (4) if deer differentiated or showed preference among pelleted feeds dosed with equal concentrations of volatile oils from the 3 juniper species; and (5) if deer differentiated among 3 groups of pelleted feed dosed with equal concentrations of monoterpene hydrocarbons, oxygenated monoterpenes, and sesquiterpenes. We thank D. S. deCalesta for manu-