「スポーツ食堂」に関する調査研究－ 「スポーツ食堂」の条件と管理栄養士の役割 －

　スポーツ選手における栄養補給の重要性の理解とともに「スポーツ食堂」「アスリート食堂」の名称で営業する食堂が出現しているが、現段階で定義や規定などは存在しない。本研究では「スポーツ食堂」の特徴を明らかにし、その条件、管理栄養士の役割などを論考することを目的に、日本のトップ選手向けに設置されている食堂と、学生スポーツ選手が利用する学生食堂の運営状況やメニュー等について質問紙により調査した。トップ選手向け食堂には、管理栄養士、さらには公認スポーツ栄養士が常駐していたのに対して、学生食堂には一部の食堂にのみ管理栄養士の配置があった。トップ選手向け食堂では、スポーツ栄養学を背景とした基本の「スポーツ食」の提供の他に、選手のコンディションやニーズに配慮した食事の提供が行われていた。学生食堂と異なり、スポーツ栄養情報の発信や栄養教育も多彩に行われトップ選手向け食堂は教育の場としても機能していた。高い価格が設定されていたが、トップ選手へは各競技団体などから食費支援があり、自己負担ではなかった。学生食堂では、安価での定食型の食事提供が中心で、スポーツ栄養への配慮が不足し、管理栄養士の配置のない食堂では栄養教育はほとんど実践されていなかった。学生食堂は、様々な制約があり給食会社による単独経営は難しく、管理栄養士を配置して良好な食事を安価で提供し、栄養教育のサービスを提供するには、食堂運営に大学の関与が必須である。管理栄養士を配置した学生食堂には、大学や保護者などからの補助金や、学生への食費補助などが行われていた。　以上のことから、「スポーツ食堂」の条件を4点にまとめた。1．スポーツ栄養学を背景とした「スポーツ食」の提供、2．種目、身体づくり、シーズン期分けなどに対応した食事提供、3．栄養情報発信、栄養教育の実践、4．管理栄養士の配置、である。管理栄養士が中心となってスポーツ選手に適した食事計画を立案、食事提供し、選手への栄養教育を実践することが重要である。これらの条件を学生食堂で整えるには、大学による学生食堂運営への関与が必要不可欠であると考える

雌ラットにおいて生殖腺の状態とエストロゲン環境が視床下部オキシトシン遺伝子発現および血清オキシトシンレベルに及ぼす影響

Oxytocin (OT) and its receptor (OTR) play various roles in the central and peripheral regulation of appetite and body weight. Previously, we have shown that the administration of OT markedly decreased appetite and body weight gain in ovariectomized (OVX) obese rats. In addition, recent studies have shown that the endogenous OT system is also affected by endogenous or exogenous estrogen. In this study, we showed that ovariectomy decreased rats' hypothalamic OT/OTR mRNA and serum OT levels, but did not affect their visceral fat OTR mRNA levels. The chronic administration of estradiol (E2) abrogated these ovariectomy-induced changes; i.e., it increased the rats' hypothalamic OT/OTR mRNA and serum OT levels, and may be associated with reductions in food intake and body weight gain. In addition, acute E2 administration increased the rats' hypothalamic OTR mRNA and serum OT levels, but did not affect their hypothalamic OT mRNA levels. Taken together, these results suggest that endogenous OT and/or OTR expression might be positively regulated by E2 and that the suppressive effects of E2 on appetite and body weight gain might be mediated, at least in part, by the OT system. Thus, we consider that OT might be a target hormone to pursue subsequent interventions of menopause for menopause-induced metabolic disorders

A novel PCOS rat model and an evaluation of its reproductive, metabolic, and behavioral phenotypes

Background: Although animal models of PCOS have been used in many studies, none of them can reproduce both the reproductive and metabolic phenotypes of PCOS. In addition, behavioral parameters have not been evaluated in PCOS animal models. Purpose: We tried to produce an improved rat model of PCOS, and the reproductive, metabolic, and behavioral phenotypes of the model rats were evaluated. Methods: Female rats were implanted with silicon tubes containing oil-dissolved dihydrotestosterone (Oil-DHT) as a new PCOS model. Their phenotypes were compared with those of conventional PCOS model rats (DHT), into which tubes containing crystalline DHT were implanted, and non-DHT-treated rats (control). Results: Both the Oil-DHT and DHT rats showed greater body weight gain, food intake, and fat depot weight than the control rats. Furthermore, these groups showed fewer estrous stages and increased numbers of cystic follicles. The DHT rats exhibited lower ovarian and uterine weights than the control rats, whereas no such changes were observed in the Oil-DHT rats. The Oil-DHT and DHT rats showed less locomotor activity in the light phase than the control rats. Conclusions: Our proposed PCOS model reproduced both the reproductive and metabolic phenotypes of PCOS and may have potential for PCOS research

Androgen’s effects in female

The metabolic effects of androgens and their underlying mechanisms in females have been revealed by recent studies. An excess of androgens can have adverse effects on feeding behavior and metabolic functions and induce metabolic disorders / diseases, such as obesity, insulin resistance, and diabetes, in women and experimental animals of reproductive age. Interestingly, these effects of androgens are not observed in ovariectomized animals, indicating that their effects might be dependent on the estrogen milieu. Central and peripheral mechanisms, such as alterations in the activity of hypothalamic factors, reductions in energy expenditure, skeletal muscle insulin resistance, and β-cell dysfunction, might be related to these androgens’ effects

Biotin levels in blood and follicular fluid

It has been shown that biotin, a water-soluble vitamin (B7), plays roles in reproductive functions, such as oocyte maturation and embryo development, in experimental animals. On the other hand, little is known about the clinical effects of biotin on human reproduction. In this study, serum and follicular fluid biotin levels were measured in patients who underwent in vitro fertilization / intracytoplasmic sperm injection (IVF / ICSI), and their associations with reproductive outcomes were evaluated. As a result, biotin was detected in follicular fluid, as well as serum, and the biotin levels of follicular fluid were found to be positively correlated with those of serum. The biotin levels of serum were higher than those of follicular fluid, suggesting that biotin may be taken up into the follicular fluid from the blood. Although serum and follicular fluid biotin levels tended to be higher in pregnant patients than in non-pregnant patients, these data did not show the significant statistical difference. These findings indicate that biotin does not contribute to the maintenance of oocyte quality, and hence, it does not increase fertilization and pregnancy rates

Changes in Serum Oxytocin Levels under Physiological and Supraphysiological Gonadal Steroid Hormone Conditions in Women of Reproductive Age: A Preliminary Study

Oxytocin (OT) affects many behavioral, psychological, and physiological functions, including appetite and body weight regulation. Central and peripheral OT levels are markedly affected by gonadal steroids, especially estrogen, and the anorectic effects of estrogen are partially mediated by OT in rodents. In this study, the relationship between the estrogen milieu and serum OT levels was evaluated in women of reproductive age under physiological (n = 9) and supraphysiological estrogenic conditions (n = 7). Consequently, it was found that serum OT levels were increased in physiological (the ovulatory phase) and supraphysiological (on the day of the human chorionic gonadotropin trigger in an ovarian stimulation cycle) estrogenic conditions, and that serum OT levels were positively correlated with serum estradiol levels. On the other hand, serum OT levels were negatively correlated with serum progesterone levels, and there was no correlation between serum and follicular OT levels. These results suggest that OT levels may be positively and negatively regulated by estrogen and progesterone, respectively, in humans. However, the physiological roles of these actions of gonadal steroids on OT remain unclear

A novel PCOS rat model and an evaluation of its reproductive, metabolic, and behavioral phenotypes

Abstract Background Although animal models of PCOS have been used in many studies, none of them can reproduce both the reproductive and metabolic phenotypes of PCOS. In addition, behavioral parameters have not been evaluated in PCOS animal models. Purpose We tried to produce an improved rat model of PCOS, and the reproductive, metabolic, and behavioral phenotypes of the model rats were evaluated. Methods Female rats were implanted with silicon tubes containing oil‐dissolved dihydrotestosterone (Oil‐DHT) as a new PCOS model. Their phenotypes were compared with those of conventional PCOS model rats (DHT), into which tubes containing crystalline DHT were implanted, and non‐DHT‐treated rats (control). Results Both the Oil‐DHT and DHT rats showed greater body weight gain, food intake, and fat depot weight than the control rats. Furthermore, these groups showed fewer estrous stages and increased numbers of cystic follicles. The DHT rats exhibited lower ovarian and uterine weights than the control rats, whereas no such changes were observed in the Oil‐DHT rats. The Oil‐DHT and DHT rats showed less locomotor activity in the light phase than the control rats. Conclusions Our proposed PCOS model reproduced both the reproductive and metabolic phenotypes of PCOS and may have potential for PCOS research

Changes in Endogenous Oxytocin Levels and the Effects of Exogenous Oxytocin Administration on Body Weight Changes and Food Intake in Polycystic Ovary Syndrome Model Rats

Polycystic ovary syndrome (PCOS) is frequently seen in females of reproductive age and is associated with metabolic disorders that are exacerbated by obesity. Although body weight reduction programs via diet and lifestyle changes are recommended for modifying reproductive and metabolic phenotypes, the drop-out rate is high. Thus, an efficacious, safe, and continuable treatment method is needed. Recent studies have shown that oxytocin (OT) reduces body weight gain and food intake, and promotes lipolysis in some mammals, including humans (especially obese individuals), without any adverse effects. In the present study, we evaluated the changes in endogenous OT levels, and the effects of acute and chronic OT administration on body weight changes, food intake, and fat mass using novel dihydrotestosterone-induced PCOS model rats. We found that the serum OT level was lower in PCOS model rats than in control rats, whereas the hypothalamic OT mRNA expression level did not differ between them. Acute intraperitoneal administration of OT during the dark phase reduced the body weight gain and food intake in PCOS model rats, but these effects were not observed in control rats. In contrast, chronic administration of OT decreased the food intake in both the PCOS model rats and control rats. These findings indicate that OT may be a candidate medicine that is efficacious, safe, and continuable for treating obese PCOS patients