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Biomedical subjects

Susan I Barr

Publications and source records attributed to Susan I Barr.

At least 19 recordsLinked to original sources
PubMed2006

Regulation of appetite in lean and obese adolescents after exercise: role of acylated and desacyl ghrelin.

CONTEXT: Increased physical activity is an integral part of weight loss programs in adolescents. We hypothesized that exercise could affect appetite-regulating hormones and the subjective desire to eat, which could partly explain the poor success rate of the existing interventions. OBJECTIVE: The objective of this study was to investigate prospectively the effects of exercise on acylated ghrelin (AG) and desacyl ghrelin (DG) concentrations and on appetite. SETTING: The setting for this study was a tertiary care center. PARTICIPANTS: Normal-weight [NW; body mass index (mean +/- se), 20.7 +/- 0.5 kg/m2] and overweight (OW; body mass index, 32.4 +/- 1.7) male adolescents (n = 17/group, age 15.3 +/- 0.2 yr) were studied. INTERVENTION: Those studied participated in 5 consecutive days of aerobic exercise (1 h/d). MAIN OUTCOME: Changes in AG and DG concentrations and in appetite during a test meal were studied. RESULTS: Exercise did not significantly affect insulin sensitivity or body weight. Fasting total (AG and DG) ghrelin concentrations were lower in OW (600 +/- 33 pg/ml) compared with NW (764 +/- 33 pg/ml, P < 0.05) boys and were not affected by exercise. In contrast, there was a differential effect of exercise on both AG and DG (P <or= 0.019). AG significantly increased after exercise, and this increase was greater in NW compared with OW adolescents (P < 0.05). Higher AG concentrations were correlated with an increase in markers of appetite (P < 0.05). CONCLUSION: Exercise differentially affects AG and DG in NW and OW male adolescents. Our data suggest that total ghrelin does not adequately reflect AG and DG concentrations and that the influence of exercise-induced hormonal changes should be considered to ensure success in weight management.

Acylation↗
PubMed2006

Provision of small, frequent meals does not improve energy intake of elderly residents with dysphagia who live in an extended-care facility.

Malnutrition and dehydration are potential consequences of dysphagia, a common swallowing disorder among elderly individuals. Providing smaller, more frequent meals has been suggested (but not demonstrated) to improve energy intake among this group. Accordingly, this study was designed to assess whether the same energy content in five vs three daily meals would improve energy intake. Thirty-seven residents of an extended-care facility, aged older than 65 years, previously evaluated for dysphagia, and receiving a texture-modified diet, agreed to participate in a crossover study with random assignment to three or five meals during an initial 4-day study period, followed by the opposite meal pattern in a second period. Six were excluded from analysis, as their medical condition deteriorated before or during the study. Food and fluids consumed by participants during each study period were weighed before and after each meal. Average energy intakes were similar between the three- and five-meal patterns (1,325+/-207 kcal/day vs 1,342+/-177 kcal/day, respectively; P=0.565); fluid intake was higher with five meals (698+/-156 mL/day) vs three (612+/-176 mL/day; P=0.003). Because offering five daily feedings did not improve energy intakes when compared with three, dietitians caring for this vulnerable group might need to consider other nutrition intervention strategies.

Aged↗
PubMed2006

Recommended Dietary Allowances should be used to set Daily Values for nutrition labeling.

Guiding principles were recently suggested for revising the Daily Values (DVs) used for nutrition labels on foods and dietary supplements. These principles incorporate the new Dietary Reference Intakes, which are nutrient standards issued between 1997 and 2005 by the Institute of Medicine. Most of the principles are likely to lead to a more accurate basis for the DVs. However, the recommendation to use the Estimated Average Requirement (EAR) rather than the Recommended Dietary Allowance (RDA) should be reconsidered. Traditional public health messages to American and Canadian consumers have focused on nutrient intake levels with a high probability of being adequate. The RDA, with a 98% probability of adequacy, is designed to be the target nutrient intake for individuals; in contrast, the EAR has only a 50% probability of adequacy. Three considerations should lead to a preference for using the RDA rather than the EAR for the DVs: 1) consumers are likely to expect that a product (or a diet) with 100% of the DV has a high probability of nutrient adequacy; 2) use of the RDA for the DV will be consistent with other types of dietary guidance, such as the Dietary Guidelines for Americans 2005 and US food guides; and 3) use of the RDA as a standard for nutrient intake, rather than the EAR, has a potential benefit (a higher prevalence of adequate intakes) that exceeds potential risk (a higher prevalence of excessive intakes).

Food Labeling↗
PubMed2006

High cognitive dietary restraint is associated with increased cortisol excretion in postmenopausal women.

BACKGROUND: Cognitive dietary restraint (perceived ongoing effort to limit dietary intake to manage body weight) is common in women at all life stages. In young women, high dietary restraint has been associated with both increased excretion of cortisol (a stress hormone) and reduced bone mass. Whether this occurs in older women is unknown and is reported here for the first time. METHODS: Postmenopausal women (49-75 years old) with high (n = 41) or low (n = 37) dietary restraint were compared to examine differences in urinary cortisol excretion, body composition assessed by dual-energy x-ray absorptiometry (bone mineral density, % body fat), dietary intake, anthropometrics, current exercise, and perceived stress. RESULTS: Women with high or low dietary restraint did not differ in age, body mass index, waist-to-hip ratio, energy intake, perceived stress, current exercise, or measures of body composition. However, urinary cortisol excretion was higher in the high restraint group (248.2 +/- 61.7 nmol/d vs 204.3 +/- 66.1 nmol/d; p =.01). Multiple regression analysis indicated that restraint group (high or low) independently predicted 7.6% of the variance in cortisol excretion. CONCLUSIONS: Postmenopausal women with high dietary restraint excrete more cortisol than do those with low restraint, suggesting that dietary restraint may be a source of stress. Although this was not associated with negative health effects in this sample, further investigation is warranted.

Aged↗
PubMed2006

Introduction to dietary reference intakes.

Dietary Reference Intakes (DRIs) are nutrient reference standards used for planning and assessing the diets of apparently healthy Canadians and Americans. The development of DRIs reflects a joint initiative by the United States and Canada to update, expand on, and replace the former Recommended Nutrient Intakes for Canadians and Recommended Dietary Allowances for Americans. DRIs include the Estimated Average Requirement (EAR), Recommended Dietary Allowance (RDA), Adequate Intake (AI), and Tolerable Upper Intake Level (UL). The EAR is the average daily intake level that meets the requirement of 50% of healthy individuals in a life stage and gender group, whereas the RDA is set at a level that will meet the requirements of almost all (97%-98%) individuals in that life stage and gender group. An AI is a recommended intake level that is thought to meet the needs of almost all healthy individuals, and is set when there are insufficient data to establish an EAR (and therefore an RDA). The UL represents a threshold above which adverse effects of excessive intake may increase. In addition to these DRIs, macro nutrients have an Acceptable Macro nutrient Distribution Range (AMDR) and, for energy, an Estimated Energy Requirement (EER) is described.

Humans↗
PubMed2006

Applications of Dietary Reference Intakes in dietary assessment and planning.

Dietary Reference Intakes (DRIs) are used for assessing and planning diets of individuals and groups. Assessing individual intakes is complicated by the fact that neither the individual's usual nutrient intake nor their individual requirement is known. However, the degree of confidence that intakes are adequate or excessive can be estimated. Assessing diets of groups requires information on the group's usual nutrient intake distribution, which can be obtained by statistically adjusting 1 d intake distributions to remove within-person variability. For most nutrients with an Estimated Average Requirement (EAR), the group prevalence of inadequate intakes can be approximated by the percent whose usual intakes are less than the EAR. However, the prevalence of inadequacy cannot be determined for nutrients with an Adequate Intake (AI). The goals of planning are a low risk (for individuals) or low prevalence (for groups) of inadequate or excessive nutrient intakes. For individuals, these goals are met by planning intakes that meet the Recommended Dietary Allowance (RDA) or AI, are below the Tolerable Upper Intake Level (UL), and fall within the Acceptable Macronutrient Distribution Ranges (AMDRs). For groups, planning involves estimating a "target" usual intake distribution with an acceptably low prevalence less than the EAR and greater than the UL, planning menus to achieve the target distribution, and assessing the results.

Diet↗
PubMed2005

Diets and selected lifestyle practices of self-defined adult vegetarians from a population-based sample suggest they are more 'health conscious'

BACKGROUND: Few population-based studies of vegetarians have been published. Thus we compared self-reported vegetarians to non-vegetarians in a representative sample of British Columbia (BC) adults, weighted to reflect the BC population. METHODS: Questionnaires, 24-hr recalls and anthropometric measures were completed during in-person interviews with 1817 community-dwelling residents, 19-84 years, recruited using a population-based health registry. Vegetarian status was self-defined. ANOVA with age as a covariate was used to analyze continuous variables, and chi-square was used for categorical variables. Supplement intakes were compared using the Mann-Whitney test. RESULTS: Approximately 6% (n = 106) stated that they were vegetarian, and most did not adhere rigidly to a flesh-free diet. Vegetarians were more likely female (71% vs. 49%), single, of low-income status, and tended to be younger. Female vegetarians had lower BMI than non-vegetarians (23.1 +/- 0.7 (mean +/- SE) vs. 25.7 +/- 0.2 kg/m2), and also had lower waist circumference (75.0 +/- 1.5 vs. 79.8 +/- 0.5 cm). Male vegetarians and non-vegetarians had similar BMI (25.9 +/- 0.8 vs. 26.7 +/- 0.2 kg/m2) and waist circumference (92.5 +/- 2.3 vs. 91.7 +/- 0.4 cm). Female vegetarians were more physically active (69% vs. 42% active >/=4/wk) while male vegetarians were more likely to use nutritive supplements (71% vs. 51%). Energy intakes were similar, but vegetarians reported higher % energy as carbohydrate (56% vs. 50%), and lower % protein (men only; 13% vs. 17%) or % fat (women only; 27% vs. 33%). Vegetarians had higher fiber, magnesium and potassium intakes. For several other nutrients, differences by vegetarian status differed by gender. The prevalence of inadequate magnesium intake (% below Estimated Average Requirement) was lower in vegetarians than non-vegetarians (15% vs. 34%). Female vegetarians also had a lower prevalence of inadequate thiamin, folate, vitamin B6 and C intakes. Vegetarians were more likely than non-vegetarians to consider various health conditions and food/nutrition concerns when choosing foods. CONCLUSION: In this population-based study, evidence was obtained to indicate that vegetarians appear more 'health conscious' than non-vegetarians, although specific differences were not always consistent by gender. Additional population-based studies are required to determine if the observed gender differences exist in other populations.

Journal Article↗
PubMed2005

Canadian dietitians' approaches to counseling adult clients seeking weight-management advice.

This study describes Canadian dietitians' approaches to counseling adults seeking weight-management advice. Fifteen focus groups were conducted at seven sites across Canada. The participants, most of whom worked in clinical or private practice, discussed their approach to specific weight-management counseling scenarios, including women clients with and without associated risk factors (impaired glucose tolerance, hypertension, family history of cardiovascular disease) and long histories of dieting. Results indicate that participants used a lifestyle approach for weight-management counseling, where the main goal was improved client health through healthful eating and increased physical activity. In contrast to clients' perceived weight loss goals, participants rarely included weight loss as a goal for clients with no additional chronic disease risk factors. For clients with risk factors, some participants advocated moderate weight loss, while others aimed for health at any size. Participants also discussed the importance of clients' psychological well-being, particularly in relation to feelings about food and body image. Individualized approaches to setting goals, gathering information, and giving advice/educating were identified as key counseling strategies. Further research to evaluate the effectiveness of dietitians' weight-management approaches and additional counseling training for dietitians will enhance practitioners' skills and confidence in this area.

Adult↗
PubMed2005

Diagnosis, symptoms, and calcium intakes of individuals with self-reported lactose intolerance.

OBJECTIVE: To determine methods of diagnosis, symptoms, and calcium intake from food and supplements for individuals with self-reported lactose intolerance. METHODS/DESIGN: Cross-sectional survey using a mailed questionnaire. SUBJECTS/SETTING: A convenience sample of 189 adults with self-reported lactose intolerance living in the metropolitan area of Vancouver Canada responded to posters or advertisements, and 159 returned completed questionnaires. MEASURES OF OUTCOME: Methods of diagnosis, symptoms experienced and their severity were self-reported. Estimated calcium intake from food and supplements was assessed using a food frequency questionnaire. Data were analyzed using descriptive statistics, chi-square, Pearson correlation analysis, t-tests and Analysis of Variance. RESULTS: Participants were 47 +/- 15 years of age; 72% female and 28% male; 67% Caucasian; and 54% had self-diagnosed their lactose intolerance. Of the 42% diagnosed by a physician, only 10% had been diagnosed by valid tests. Mean estimated food calcium intake was 591 +/- 382 mg/d and did not differ between those who were self- or physician-diagnosed. Only 11.5% of participants met their age-appropriate Adequate Intake (AI) from food calcium sources alone. Calcium supplements were used by 65% and provided an average of 746 +/- 703 mg calcium/day to those who used them; mean intakes of this group met the AI. CONCLUSIONS: Calcium intake from food sources alone is inadequate to meet the AI in individuals with self-reported lactose intolerance. Physicians managing lactose intolerance need current information on how the AI can be met through appropriate food choices and possible supplementation.

Adult↗
PubMed2005

Challenges in using the dietary reference intakes to plan diets for groups.

A recent report describes a new paradigm for planning the dietary intakes of groups, the goals of which are to achieve low prevalences of both inadequate and excessive intakes. However, there are many challenges involved in properly implementing these methods, and pilot studies are urgently needed. For individuals, the target for nutrient intakes is usually the Recommended Dietary Allowance (RDA); for nutrients without an RDA, the Adequate Intake (AI) can be used. Intakes should be planned so they do not exceed the Tolerable Upper Intake Level (UL). Several applications illustrating how to use the DRIs for planning the diets of individuals have been published, so this review will focus primarily on the methods that are recommended for planning the diets of groups.

Adolescent↗
PubMed2005

Cognitive dietary restraint is associated with stress fractures in women runners.

High levels of cognitive dietary restraint (CDR) have been associated with subclinical menstrual cycle irregularities and increased cortisol levels, both of which can affect bone mineral density (BMD). Low BMD has been implicated in stress fracture risk. We assessed CDR in female runners (> or = 20 km/wk) with a recent stress fracture (SF) and with no stress fracture history (NSF). A sample of 79 runners (n = 38 SF, 29 +/- 5 y; n = 41 NSF, 29 +/- 6 y) completed a 3-d food record and questionnaire assessing physical activity, menstrual cycle history, and perceived stress. SF and NSF runners had similar body mass index (21.2 +/- 1.8 vs. 22.0 +/- 2.5 kg/m2), physical activity (35.7 +/- 13.5 vs. 33.4 +/- 1.34 km/wk), perceived stress, and dietary intakes. CDR, however, was higher in SF runners (11.0 +/- 5.4 vs. 8.4 +/- 4.3, P < 0.05). Subclinical menstrual cycle disturbances and increased cortisol levels that are associated with high CDR, might in turn contribute to lowered BMD and increased stress fracture risk.

Adult↗
PubMed2004

Nutrient intakes of infants and toddlers.

OBJECTIVES: To assess the nutrient adequacy of the diets of US infants and toddlers 4 to 24 months of age. DESIGN: Descriptive analysis of the usual nutrient intakes of infants and toddlers using 24-hour recall data from the 2002 Feeding Infants and Toddlers Study. SUBJECTS: A national random sample of 3,022 infants and toddlers, with 2 days of recall available for 703 sample members. Sample sizes by age were: infants 4 to 6 months (n=862), infants 7 to 11 months (n=1,162), and toddlers 12 to 24 months (n=998). STATISTICAL ANALYSES PERFORMED: Using the personal computer version of the Software for Intake Distribution Estimation, we estimated (where applicable) the percentage of infants and toddlers with usual intakes below the estimated average requirement, compared the means of usual nutrient intake distributions with adequate intake levels, and compared the 99th percentile of usual intake distributions with tolerable upper intake levels. RESULTS: For infants under 12 months of age, mean usual intakes exceeded the adequate intake for all nutrients. For toddlers 12 to 24 months of age, the estimated prevalence of inadequacy was low for most nutrients; however, 58% of toddlers had usual vitamin E intakes less than the estimated average requirement. Mean energy intake exceeded the estimated energy requirement by 10% for infants 4 to 6 months, 23% for infants 7 to 12 months, and 31% for toddlers 12 to 24 months of age. The discrepancy between mean energy intake and the estimated energy requirement for infants 4 to 6 months of age was larger for infants fed solids than for infants consuming only breast milk or formula. Fiber intakes of toddlers were below the adequate intake. APPLICATIONS: Studies should examine whether parents overreport foods consumed by infants and toddlers, and whether infants and toddlers are consuming more energy than required. Additional research is indicated to substantiate some of the new Dietary Reference Intakes for infants and children 1 to 3 years of age.

Breast Feeding↗
PubMed2004

Prevalence of picky eaters among infants and toddlers and their caregivers' decisions about offering a new food.

OBJECTIVES: To determine the prevalence of infants and toddlers who were considered picky eaters, the predictors of picky eater status and its association with energy and nutrient intakes, food group use, and the number of times that caregivers offered a new food before deciding their child disliked it. DESIGN: Cross-sectional survey of households with infants and toddlers (ages four to 24 months) was conducted. SUBJECTS/SETTING: National random sample of 3,022 infants and toddlers. METHODS: Data included caregiver's socioeconomic and demographic information, infants' and toddlers' food intake (24-hour recall), ethnicity, and caregivers' reports of specified times that new foods were offered before deciding the child disliked it. STATISTICAL ANALYSES: For picky and nonpicky eaters, t tests were used to determine significant mean differences in energy and nutrient intakes. Logistic regression was used to predict picky eater status, and chi(2) tests were used for differences in the specified number of times that new foods were offered. RESULTS: The percentage of children identified as picky eaters by their caregivers increased from 19% to 50% from four to 24 months. Picky eaters were reported at all ages for both sexes, all ethnicities, and all ranges of household incomes. On a day, both picky and nonpicky eaters met or exceeded current age-appropriate energy and dietary recommendations. Older children were more likely to be picky. Those in the higher weight-for-age percentiles were less likely to be picky. The highest number of times that caregivers offered a new food before deciding the child disliked it was three to five. APPLICATIONS/CONCLUSIONS: Dietetics professionals need to be aware that caregivers who perceive their child as a picky eater are evident across gender, ethnicity, and household incomes. When offering a new food, mothers need to provide many more repeated exposures (eg, eight to 15 times) to enhance acceptance of that food than they currently do.

Adolescent↗
PubMed2004

Women with high scores for cognitive dietary restraint choose foods lower in fat and energy.

Women with high dietary restraint typically report restricting energy intake and using reduced-kilocalorie foods in an effort to achieve or maintain a certain body weight. However, previous studies of food choices associated with dietary restraint have been limited by the self-report of participants' food selections. We provided all foods consumed during a free-living 24-hour period to 62 normal-weight women with high (n=33) or low (n=29) dietary restraint, and observed choices from among similar foods varying in fat, fiber, and energy content. Women with high dietary restraint consumed less energy and chose reduced-kilocalorie and reduced-fat foods more frequently than unrestrained eaters. Group differences in choices of milk, cream cheese, mayonnaise, salad dressing, and soda were noted. Dietitians may consider frequent use of reduced-kilocalorie and reduced-fat foods a potential indicator of high dietary restraint, which may have health consequences. Accordingly, further exploration of clients' tendency to restrict dietary intake may be warranted.

Adult↗
PubMed2003

Cognitive dietary restraint is associated with eating behaviors, lifestyle practices, personality characteristics and menstrual irregularity in college women.

This study characterized associations of restraint with selected physical, lifestyle, personality and menstrual cycle characteristics in female university students. The survey instrument, distributed to 1350 women, included standardized questionnaires (Three-Factor Eating Questionnaire, Perceived Stress Scale and Rosenberg's Self-esteem Scale), and assessed weight and dieting history, exercise, lifestyle characteristics, menstrual cycle characteristics and whether participants were following vegetarian diets. Among the 596 respondents included in the analysis (44%), women with high (n=145), medium (n=262) or low (n=189) restraint had similar ages, heights and weights. Despite this, compared to women with low scores, those with high scores exercised more (4.6+/-5.3 vs. 3.2+/-3.5 h/wk), were more likely to be vegetarian (14.5 vs. 3.7%), have a history of eating disorders (13.7 vs. 1.2%), be currently trying to lose weight (80.3 vs. 15.3%), report irregular menstrual cycles (34.7 vs. 17.0%), and have scores reflecting lower self-esteem and higher perceived stress. Menstrual irregularity was an independent predictor of restraint score, and restraint score was the only variable to differentiate women with regular and irregular menstrual cycles. We conclude that women with high restraint may use a combination of behavioral strategies for weight control, and differ from women with low restraint scores in personality characteristics and weight history. Some of these behaviors or characteristics may influence menstrual function.

Adolescent↗
PubMed2003

Folate intakes and awareness of folate to prevent neural tube defects: a survey of women living in Vancouver, Canada.

OBJECTIVE: To estimate folate intake and knowledge in women of childbearing age, in relation to risk of neural tube defects. SUBJECTS/SETTING: One hundred forty-eight women (aged 18 to 45 years) in the Vancouver area of British Columbia, Canada. DESIGN: Using an interviewer-administered survey, we examined women for folate knowledge and the relation of folate knowledge to intake in a random sample. Contribution of folate from food, fortified grain products, and supplements was assessed by validated semiquantitative food frequency questionnaire. STATISTICAL ANALYSIS PERFORMED: Descriptive statistics, t tests, Chi;(2), Pearson correlation analysis. RESULTS: Mean daily folate intake from food, fortified foods, and supplementation was 812+/-710 Dietary Folate Equivalents (DFE)/day. Fortification of bread and grain products contributed 104+/-68 microg synthetic folic acid (SFA)/day (equal to 174+/-114 DFE), and supplements contributed 205+/-388 microg SFA/day. Although 86% of women met the Estimated Average Requirement (320 DFE/day) for folate, only 26% met the recommendation (400 microg SFA/day) for women capable of becoming pregnant. Most (95%) of the women had heard of folate, but only 25% knew that it could prevent birth defects. One-fourth of the women had good or very good knowledge of folate-rich foods. However, folate knowledge was not related to its intake. The most common sources of folate information were magazines/newspapers, doctors, and television/radio. Lack of awareness of the importance of folate was the most common reason given for choosing not to use folic acid supplements before pregnancy. However, 78% of the women indicated that, with knowledge of the benefits of folate, they would use supplemental folic acid daily to reduce the risk of birth defects. APPLICATIONS/CONCLUSIONS: Educational strategies are required to increase folate awareness among women and to promote the benefits of periconceptional folic acid supplementation. Targeting physicians to educate women on the importance of folate could be a potentially successful route. J

Adolescent↗