The relationship between resting metabolic rate and quality of life is moderated by age and body composition in women: a cross-sectional study.

BACKGROUND: Health-related quality of life (HRQOL) is related to body composition, which is also related to resting metabolic rate (RMR). RMR can be increased by exercise and diet interventions that are not dependent on changes in body composition, so a link between RMR and HRQOL may provide interventions that directly improve HRQOL in women. METHODS: One hundred twenty women (median age 63.5 [IQR: 53.0-71.0] years) completed one-time measurement of body composition (multi-frequency bioelectrical impedance), RMR (handheld calorimetry), and HRQOL (RAND-36). Physical (PCS) and mental (MCS) composite scores were calculated for the RAND-36. Pearson correlations were used to identify relationships between RMR, body composition, and HRQOL. Variables at the p < .01 level were entered into multiple regression models. RESULTS: Median body mass index was 26.1 [IQR: 23.2-30.9] kg/m2 and median lean mass index was 16.1 [IQR: 14.6-17.3] kg/m2. Body composition consisted of fat mass (median 27.2 [IQR: 20.3-34.7] kg) and lean mass (median 42.7 [IQR: 38.2-46.9] kg). Median RMR was 1165.0 [IQR: 1022.5-1380.0] kcal/day. Median HRQOL scores were PCS (84.0 [IQR: 74.0-93.0]) and MCS (85.0 [IQR: 74.3-90.0]). RMR was not directly related to PCS, but was directly and negatively related to MCS (p = .002). RMR was significantly and positively related to body composition (lean mass: p < .001; fat mass: p < .001), body mass index (p = .005), and lean mass index (p < .001); but only fat mass (PCS: p < .001; MCS: p < .001) and body mass index (PCS: p < .001; MCS: p < .001) were related to HRQOL, although the relationship was negative. In addition, age was found to be significantly negatively related to RMR (p < .001) and PCS (p = .003). Regression models confirmed the moderating influence of age and body composition on the relationship between RMR and HRQOL. RMR, age, fat mass, and body mass index explained 24% (p < .001) of variance in PCS; and RMR, fat mass, and body mass index explained 15% (p < .001) of variance in MCS. CONCLUSION: In women, the relationship between RMR and HRQOL is moderated by age and body composition. Understanding these pathways will allow clinicians and researchers to direct interventions more effectively.

Training interns in nutrition and dietetics: a cross-sectional study of the barriers and motivators to being a Registered Dietitian Nutritionist preceptor.

BACKGROUND: As is common across the health professions, training of Registered Dietitian Nutritionists (RDNs) requires experiential learning for interns/students to gain skills and demonstrate entry-level competency. Preceptors are essential to the experiential learning component of health care professional training, providing supervision and mentoring as students and interns gain the skills required for entry-level practice competency. Over the past 27 years, 47-73% of applicants to dietetic internships have received a placement. Practitioners willing to volunteer as preceptors are needed to generate more internship or experiential learning opportunities for the profession to continue to meet workforce demands. METHODS: The objective of this national-level online cross-sectional survey was to identify perceptions and attitudes associated with the preceptor role and incentives that might encourage precepting by current RDNs. A random sample of RDN and Nutrition and Dietetic Technicians, Registered (NDTR) professionals from the Commission on Dietetic Registration credentialed practitioner database were eligible to participate in the online survey. The main outcome measures included perceptions, attitudes, and preferred incentives to precept compared by preceptor experience categories (current, former, never precepted). Comparisons of perceptions, attitudes, and preferred incentives were made between preceptor experience categories using Chi-square and ANOVA. RESULTS: Of 2464 invitations, 308 participants had complete variables for analysis. Top incentives were the opportunity to earn continuing education units (65.9%) and having expenses paid to attend a national conference (49.5%). Significantly more (P < 0.001) "former" and "never" preceptors reported the ability to choose when to take an intern, training on how to teach and communicate with interns, and access to an "on-call" specialist as incentives compared to "current" preceptors. Significantly more (P < 0.01) "never" preceptors reported training on internship expectations and the ability to provide input on intern selection process as incentives compared to "current" or "former" preceptors. CONCLUSIONS: Incentives to serve as a preceptor differ based on "current", "former", or "never" precepted status. Promoting and strategizing solutions to the current imbalance between the greater number of dietetic internship applicants compared to preceptors should be targeted based on preceptor status to retain current preceptors, encourage former preceptors to return and recruit professionals who have never served.

Effect of menstrual cycle on resting metabolism: A systematic review and meta-analysis.

BACKGROUND: The need to control for the potential influence of menstrual cycle phase on resting metabolism (RMR) places a burden on research participants who must self-report onset of menstruation and researchers who must schedule metabolic testing accordingly. PURPOSE: To systematically review and analyze existing research to determine the effect of menstrual cycle on RMR. METHODS: We searched PubMed, CINAHL, MEDLINE, SPORTDiscus, and Scopus databases using the search terms "menstrual cycle and metabolic rate" and "menstrual cycle and energy expenditure." Eligibility criteria were English language, single-group repeated measures design, and RMR as either a primary or secondary outcome. Risk of bias was assessed based on study sample, measurement, and control of confounders. Differences between the follicular and luteal phases of the menstrual cycle were analyzed using the standardized mean difference in effect size. RESULTS: Thirty English-language studies published between 1930 and December 2019 were included in the systematic review, and 26 studies involving 318 women were included in the meta-analysis. Overall, there was a small but significant effect favoring increased RMR in the luteal phase (ES = 0.33; 95% CI = 0.17, 0.49, p < 0.001). DISCUSSION: Limitations include risk of bias regarding measurement of both menstrual cycle and RMR. Sample sizes were small and studies did not report control of potential confounders. Sub-group analysis demonstrated that in more recent studies published since 2000, the effect of menstrual phase was reduced and not statistically significant (ES = 0.23; 95% CI = -0.00, 0.47; p = 0.055). Until larger and better designed studies are available, based on our current findings, researchers should be aware of the potential confounding influence of the menstrual cycle and control for it by testing consistently in one phase of the cycle when measuring RMR in pre-menopausal women.

Dietitians vary by counseling status in bean promotion with type 2 diabetes clients: A pilot study.

Beans are noted for their beneficial effects on blood glucose for persons with type 2 diabetes mellitus (T2DM). However, little is known about dietitian attitudes and perceptions, self-efficacy, or counseling practices about beans in T2DM management. Through an online survey, the attitudes and perceptions dietitians have toward the role of beans in managing T2DM were examined. The practice intentions for advising T2DM clients about beans, perceived self-efficacy for counseling on general nutrition topics and specifically on beans, were evaluated. While the target population was dietitians, all persons on the Arizona Dietetic Association and the Arizona School Nutrition Association listservs received a direct email invitation for an online survey on foods and chronic disease. There was no mention of beans or pulses to reduce bias toward bean advocates. Of the 302 dietitian respondents, over 66% counseled clients with T2DM. Fewer clinical counseling dietitians recommended beans to control blood glucose (p = .041) or to increase fiber (p < .05), and more of them promoted beans as being the same as other carbohydrates (p = .002). Higher mean self-efficacy scores for general nutrition counseling were observed for T2DM counseling RDs (p < .001). Counseling dietitians in nonclinical settings had the highest bean self-efficacy score (p < .001). Findings suggest clinical counseling dietitians are aware of bean health benefits, but do not consistently suggest beans to improve nutrition for those with T2DM in contrast to dietitians who counsel in other settings.

Arizona Registered Dietitians Show Gaps in Knowledge of Bean Health Benefits.

Registered Dietitians (RDs) promote nutrition practices and policies and can influence food consumption patterns to include nutrient dense foods such as beans. Although many evidence-based health benefits of bean consumption (e.g., cholesterol reduction, glycemic control) have been demonstrated, there is limited research on the knowledge, attitudes, and perceptions of RDs regarding the inclusion of beans in a healthy diet. To fill this existing research gap, this cross-sectional survey explored the perceptions, knowledge, and attitudes of 296 RDs in Arizona, USA, toward beans. The RDs largely held positive attitudes toward the healthfulness of beans and were aware of many health benefits. Some gaps in awareness were evident, including effect on cancer risk, intestinal health benefits, folate content, and application with celiac disease patients. RDs with greater personal bean consumption had significantly higher bean health benefit knowledge. Twenty-nine percent of the RDs did not know the meaning of 'legume', and over two-thirds could not define the term 'pulse'. It is essential that RDs have up-to-date, evidence-based information regarding bean benefits to provide appropriate education to patients, clients, and the public.

Glycemic Response to Black Beans and Chickpeas as Part of a Rice Meal: A Randomized Cross-Over Trial.

Legumes, such as black beans (Phaseolus vulgaris L.) and chickpeas (Cicer arietinum L.), have a low glycemic index, and may reduce the glycemic load of meals in which they are included. Although the low glycemic response of beans consumed alone has been documented, few studies have examined the glycemic response to traditional food combinations such as black beans and rice or chickpeas and rice. This randomized cross-over study examined the glycemic and insulinemic impact of 50 grams of available carbohydrate from three test meals: plain white rice (control), black beans with rice, and chickpeas with rice among healthy adult women (n = 12, 18-65 years). Treatments were consumed on different mornings, a minimum of 7 days apart. Blood samples were collected at time 0 (fasting), and at 30, 60, 90, and 120 min postprandial, and were subsequently analyzed for glucose and insulin concentrations. Glucose response based on the incremental area under the curve showed a significant difference by treatment (p = 0.027). Changes in blood glucose concentrations were significantly different for the black bean meal and the chickpea meal in comparison to rice alone at 60 min (p = 0.026 and p = 0.024), 90 min (p = 0.001 and p = 0.012) and 120 min post prandial (p = 0.024; black bean meal). Findings indicate that combinations of black beans and chickpeas with white rice improve glycemic response, providing evidence that has promising implications for dietary guidance to reduce postprandial glucose and related health risks through traditional food patterns.

Daily flaxseed consumption improves glycemic control in obese men and women with pre-diabetes: a randomized study.

The study hypothesis was that fasting glucose, insulin, fructosamine, C-reactive protein, and interleukin-6 decrease and adiponectin increases with daily flaxseed consumption in overweight or obese individuals with pre-diabetes. In this randomized, cross-over study overweight or obese men and postmenopausal women (n = 25) with pre-diabetes consumed 0, 13, or 26 g ground flaxseed for 12 weeks. Glucose, insulin, homeostatic model assessment (HOMA-IR), and normalized percent of α-linolenic fatty acid (ALA) were significantly different by treatment (multiple analysis of variance, P = .036, P = .013, P = .008, P = .024 respectively). Paired t tests showed glucose decreased on the 13 g intervention compared to the 0 g period [13 g = -2.10 ± 1.66 mg/L (mean ± SEM), 0 g = 9.22 ± 4.44 mg/L, P = .036]. Insulin decreased on the 13 g intervention but not the 26 g (P = .021) and 0 g (P = .013) periods (13 g = -2.12 ± 1.00 mU/L, 26 g = 0.67 ± 0.84 mU/L, 0 g = 1.20 ± 1.16 mU/L). HOMA-IR decreased on the 13 g period but not on the 26 g (P = .012) and 0 g (P = .008) periods (13 g = -0.71 ± 0.31, 26 g = 0.27 ± 0.24, 0 g = 0.51 ± 0.35). The α-linolenic fatty acid decrease for the 0 g period was different than the 13 g (P = .024) and 26 g (P = .000) periods (13 g = 0.20 ± 0.04, 26 g = 0.35 ± 0.07, 0 g = -0.01 ± 0.07). Fructosamine, high sensitivity C-reactive protein, adiponectin, and high-sensitivity interleukin-6 had no significant differences. Flaxseed intake decreased glucose and insulin and improved insulin sensitivity as part of a habitual diet in overweight or obese individuals with pre-diabetes.

Phaseolus beans: impact on glycaemic response and chronic disease risk in human subjects.

Consumption of Phaseolus vulgaris bean species such as pinto, black, navy or kidney may be beneficial in the prevention and treatment of chronic diseases. In particular, conditions that are promoted by increased glycaemic stress (hyperglycaemia and hyperinsulinaemia) including diabetes, CVD and cancer seem to be reduced in individuals who eat more of these beans. The present paper discusses the influence of P. vulgaris species on glycaemic response and the impact that relationship may have on the risk of developing diabetes, CVD and cancer.

Bean and rice meals reduce postprandial glycemic response in adults with type 2 diabetes: a cross-over study.

BACKGROUND: Around the world, beans and rice are commonly consumed together as a meal. With type 2 diabetes increasing, the effect of this traditional diet pattern on glycemic response has not been studied fully. METHODS: We evaluated the glycemic response of bean and rice traditional meals compared to rice alone in adults with type 2 diabetes. Seventeen men and women with type 2 diabetes controlled by metformin (n = 14) or diet/exercise (n = 3) aged 35-70 years participated in the randomized 4 × 4 crossover trial. The white long grain rice control, pinto beans/rice, black beans/rice, red kidney beans/rice test meals, matched for 50 grams of available carbohydrate, were consumed at breakfast after a 12 hour fast. Capillary blood glucose concentrations at baseline and at 30 minute intervals up to 180 minutes postprandial were collected. MANOVA for repeated measures established glucose differences between treatments. Paired t tests identified differences between bean types and the rice control following a significant MANOVA. RESULTS: Postprandial net glucose values were significantly lower for the three bean/rice treatments in contrast to the rice control at 90, 120 and 150 minutes. Incremental area under the curve values were significantly lower for the pinto and black bean/rice meals compared to rice alone, but not for kidney beans. CONCLUSIONS: Pinto, dark red kidney and black beans with rice attenuate the glycemic response compared to rice alone. Promotion of traditional foods may provide non-pharmaceutical management of type 2 diabetes and improve dietary adherence with cultural groups.

Perceptions of flatulence from bean consumption among adults in 3 feeding studies.

BACKGROUND: Many consumers avoid eating beans because they believe legume consumption will cause excessive intestinal gas or flatulence. An increasing body of research and the 2010 Dietary Guidelines for Americans supports the benefits of a plant-based diet, and legumes specifically, in the reduction of chronic disease risks. The purpose of the current research was to investigate the perception of increased flatulence and gastrointestinal discomfort among participants who consumed a ½ cup of beans daily for 8 or 12 weeks. METHODS: Participants in three studies to test the effects of beans on heart disease biomarkers completed the same weekly questionnaire to assess gastrointestinal discomfort issues such as increased flatulence, stool changes, and bloating. Studies 1 and 2 were randomized crossover trials. Participants consumed ½ cup of pinto beans, black-eyed peas, and canned carrots as control (n = 17) in Study 1 for three randomized 8-week phases. For Study 2, participants ate ½ cup baked beans or canned carrots as control (n = 29) for two randomized 8-week phases. Study 3 was a parallel arm trial with 40 subjects receiving ½ cup pinto beans and 40 consuming a control soup for 12 weeks. Changes in the frequency of perceived flatulence, stool characteristics, and bloating were the primary outcome measures. Chi-square distributions were examined for the presence or absence of symptoms and demographic characteristics to determine differences by gender, age, body mass index (BMI), and bean type. RESULTS: Less than 50% reported increased flatulence from eating pinto or baked beans during the first week of each trial, but only 19% had a flatulence increase with black-eyed peas. A small percentage (3-11%) reported increased flatulence across the three studies even on control diets without flatulence-producing components. CONCLUSIONS: People's concerns about excessive flatulence from eating beans may be exaggerated. Public health nutritionists should address the potential for gastrointestinal discomfort when increasing fiber intake from beans with clients. It is important to recognize there is individual variation in response to different bean types.

Dietary intakes, attitudes toward carbohydrates of postmenopausal women following low carbohydrate diets.

PURPOSE: Middle-aged women have the highest levels of obesity and comprise the largest group of dieters. Few investigators have examined how women apply weight-loss diet principles in an unsupervised setting. Dietary intakes and attitudes toward carbohydrates were examined in women who were self-reported low carbohydrate dieters (SRLCDs); these intakes and attitudes were compared with those of women who were following their normal diet (non-dieters [NDs]). METHODS: A convenience sample of 29 postmenopausal women aged 45 to 65 was recruited. Data were obtained by interview, questionnaire, and direct anthropometric measurement. Descriptive statistics, chi-square analysis, and analysis of variance were used to compare groups. RESULTS: Although total energy and protein intakes were similar, SRLCDs consumed significantly more fat and less carbohydrate (expressed as a percentage of total energy) and more cholesterol and less fibre than did NDs. Both groups had unfavourable attitudes toward carbohydrates. CONCLUSIONS: The SRLCDs ate more fat than recommended. Women who are considering following a low carbohydrate diet need to know the nutritional risks of unbalanced self-designed low carbohydrate diets. Negative attitudes toward carbohydrates were not confined to dieters. Nutrition education is necessary to help consumers understand basic nutrition principles and to be more skeptical of fad diets.

Pinto bean consumption reduces biomarkers for heart disease risk.

OBJECTIVE: To determine effects of daily intake of 1/2 cup pinto beans, black-eyed peas or carrots (placebo) on risk factors for coronary heart disease (CHD) and diabetes mellitus (DM) in free-living, mildly insulin resistant adults over an 8 week period. METHODS: Randomized, crossover 3x3 block design. Sixteen participants (7 men, 9 women) received each treatment for eight-weeks with two-week washouts. Fasting blood samples collected at beginning and end of periods were analyzed for total cholesterol (TC), low density lipoprotein cholesterol (LDL-C), high density lipoprotein cholesterol, triacylglycerols, high-sensitivity C-reactive protein, insulin, glucose, and hemoglobin A1c. RESULTS: A significant treatment-by-time effect impacted serum TC (p = 0.026) and LDL (p = 0.033) after eight weeks. Paired t-tests indicated that pinto beans were responsible for this effect (p = 0.003; p = 0.008). Mean change of serum TC for pinto bean, black-eyed pea and placebo were -19 +/- 5, 2.5 +/- 6, and 1 +/- 5 mg/dL, respectively (p = 0.011). Mean change of serum LDL-C for pinto bean, black-eyed pea and placebo were -14 +/- 4, 4 +/- 5, and 1 +/- 4 mg/dL, in that order (p = 0.013). Pinto beans differed significantly from placebo (p = 0.021). No significant differences were seen with other blood concentrations across the 3 treatment periods. CONCLUSIONS: Pinto bean intake should be encouraged to lower serum TC and LDL-C, thereby reducing risk for CHD.

Effects of an 8-week high-protein or high-carbohydrate diet in adults with hyperinsulinemia.

CONTEXT: Incidence of insulin resistance (IR) in Americans is steadily rising. IR may be ameliorated with < or = 5% loss in body weight. OBJECTIVE: To examine effects of 2 weight-loss diets on body weight and composition in overweight adults with IR. DESIGN: Participants randomly assigned to a high-protein, low-fat (HPLF) or a high-carbohydrate, low-fat (HCLF) diet for 8 weeks. SETTING: All meals prepared and weighed in the metabolic kitchen at Arizona State University. Lunch consumed on-site; all other meals packaged for home consumption. PATIENTS: Twenty overweight, healthy participants with elevated fasting serum insulin (> or = 15 microU/L) were recruited. INTERVENTIONS: Both diets were low-fat (27% kcal from fat; < 7% saturated, < or = 10% monounsaturated, and < or = 10% polyunsaturated) and energy-restricted (energy levels were 1200, 1500, 1700 or 2000 kcal); HPLF: 32% protein, 41% carbohydrate; HCLF: 59% carbohydrate, 14% protein. Energy levels were assigned on the basis of participant's resting metabolic rate. MAIN OUTCOME MEASURES: Body composition, etabolic indices, fasting plasma glucose, and insulin. RESULTS: No significant differences were found in the main outcome measures between the diets. Body weight (HPLF: -4.9 kg; HCLF: -4.0 kg) and total percent body fat (HPLF: -1.5%; HCLF: -0.4%) significantly reduced from baseline to week 8 (P = .005 and P = .035, respectively). CONCLUSION: Both diets promoted > or = 5% loss in body weight and significantly reduced percent body fat.

Soy isoflavone and ascorbic acid supplementation alone or in combination minimally affect plasma lipid peroxides in healthy postmenopausal women.

The objective of this study was to assess synergistic antioxidant properties of vitamin C and isoflavones. The design was a placebo-controlled crossover trial: 500 mg vitamin C, 5 mg/kg body weight isoflavones, 500 mg vitamin C plus 5 mg/kg body weight isoflavones, or placebo. Total lipid peroxides, plasma vitamin C, and blood pressure were measured. Eight of 10 healthy postmenopausal women completed the study. A multiple analysis of variance was performed and least-squares difference post-hoc test utilized to determine where differences occurred. Significance was defined as P <.05. There was a significant reduction in total lipid peroxides between baseline and isoflavone treatments (3.22+/-0.72 vs 2.47+/-0.82 nmol/mL, P <.05). Mean systolic blood pressure was higher during isoflavone intervention than placebo (117+/-14 vs 125+/-15 mm Hg, P= .042). Supplementation with vitamin C and isoflavones did not produce a synergistic antioxidant effect. A slight but significant increase in systolic blood pressure occurred with isoflavone supplementation. A larger study should be conducted to fully explore the potential interactions between these antioxidants.

Hypertensive crisis associated with high dose soy isoflavone supplementation in a post-menopausal woman: a case report [ISRCTN98074661].

BACKGROUND: Isoflavones are gaining popularity as alternatives to hormone replacement therapy. However, few guidelines exist to inform the public as to an appropriate dose. This case involves a postmenopausal woman who experienced a hypertensive crisis while consuming a high-dose isoflavone supplement as part of a research protocol. CASE PRESENTATION: The participant was part of a placebo-controlled crossover trial to investigate the potential synergism of the antioxidant activity of soy isoflavones and vitamin C. Upon entry into the study, this healthy, well-nourished, normotensive postmenopausal woman (51 years old), consumed the first of four randomly assigned treatments (500 mg vitamin C plus 5 mg/kg body weight soy isoflavones). During this treatment, the participant's systolic blood pressure spiked to a recorded 226/117 mmHg, necessitating medical intervention and discontinuation of study participation. Two plausible mechanisms for this hypertensive crisis are discussed. CONCLUSION: Due to the availability and increasing popularity of soy supplements, practitioners should be aware of the potential side effects associated with their use. Practitioners counseling clients who are consuming soy isoflavone supplements should advise them that elevated blood pressure may be a potential side-effect to consider and monitor.

Effect of flaxseed and wheat bran on serum hormones and lignan excretion in premenopausal women.

OBJECTIVE: To examine the effects of flaxseed consumption (a lignan-rich plant food) alone and in combination with wheat bran on serum hormones and urinary lignan excretion in premenopausal women. METHODS: Sixteen subjects were studied for four feeding treatments lasting two menstrual cycles each in a randomized, crossover design. During each treatment, subjects consumed their habitual diets supplemented with baked goods containing no flaxseed or wheat bran, 10 g of flaxseed, 28 g of wheat bran, or 10 g of flaxseed plus 28 g of wheat bran/day. Serum samples collected during the mid-luteal phase of the second menstrual cycle of each diet treatment were analyzed for serum hormones and sex hormone binding globulin. Urine samples collected during the same time period were analyzed for urinary lignan excretion. RESULTS: There were no changes in serum hormone concentrations or sex hormone binding globulin on any of the treatments. Urinary lignan excretion significantly increased on diet treatments that included flaxseed, but inclusion of wheat bran did not significantly alter lignan excretion. CONCLUSIONS: Urinary lignan excretion increased with flaxseed consumption, but serum hormones did not change in this group of premenopausal women. Consumption of wheat bran with flaxseed did not alter urinary lignan excretion associated with flaxseed consumption.