Biomedical subjects

Carla K Miller

Publications and source records attributed to Carla K Miller.

11 recordsLinked to original sources

PubMed2006

The effect of three snack bars on glycemic response in healthy adults.

Many consumers prefer convenient, portable, and preportioned snack foods. Foods with a lower glycemic response are associated with reduced risk for chronic disease. The glycemic index and glycemic load of three nationally available snack bars were determined. Ten subjects, with mean age (+/-standard deviation) of 29+/-7 years and mean body mass index (+/-standard deviation) of 25.3+/-3.2, were tested on four occasions on nonconsecutive days. After an overnight fast, subjects consumed 50 g of available carbohydrate as a glucose beverage or as a portion of one of three bars: SmartZone nutrition bar (The Hershey Co, Hershey, PA), ZonePerfect nutrition bar (Abbott Laboratories, Abbott Park, IL), or SlimFast meal bar (SlimFast Foods Co, West Palm Beach, FL). Blood glucose was tested at 0, 15, 30, 45, 60, 90, and 120 minutes after consumption. Incremental area under the glucose response curve was calculated for each test bar and compared with that of the glucose beverage to determine glycemic index. The glycemic index (+/-standard error of the mean) for SmartZone was 10.9+/-3.9 and was significantly less (P<0.05) than that of ZonePerfect (43.7+/-7.3) or SlimFast (63.8+/-13.0). The glycemic loads (+/-standard error of the mean) for the SmartZone (2.0+/-0.7) and ZonePerfect (8.3+/-1.4) bars were significantly less (P<0.05) than the glycemic load of the SlimFast bar (21.1+/-4.3). Although the long-term impact of snack foods with a lower glycemic load requires further research, the SmartZone and ZonePerfect bars provide a lower glycemic response for consumers.

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PubMed2006

Comparative strategies for using cluster analysis to assess dietary patterns.

OBJECTIVES: To characterize dietary patterns using two different cluster analysis strategies. DESIGN: In this cross-sectional study, diet information was assessed by five 24-hour recalls collected over 10 months. All foods were classified into 24 food subgroups. Demographic, health, and anthropometric data were collected via home visit. SUBJECTS: One hundred seventy-nine community-dwelling adults, aged 66 to 87 years, in rural Pennsylvania. STATISTICAL ANALYSIS: Cluster analysis was performed. RESULTS: The methods differed in the food subgroups that clustered together. Both methods produced clusters that had significant differences in overall diet quality as assessed by Healthy Eating Index (HEI) scores. The clusters with higher HEI scores contained significantly higher amounts of most micronutrients. Both methods consistently clustered subgroups with high energy contribution (eg, fats and oils and dairy desserts) with a lower HEI score. Clusters resulting from the percent energy method were less likely to differentiate fruit and vegetable subgroups. The higher diet quality dietary pattern derived from the number of servings method resulted in more favorable weight status. CONCLUSIONS: Cluster analysis of food subgroups using two different methods on the same data yielded similarities and dissimilarities in dietary patterns. Dietary patterns characterized by the number of servings method of analysis provided stronger association with weight status and was more sensitive to fruit and vegetable intake with regard to a more healthful dietary pattern within this sample. Public health recommendations should evaluate the methodology used to derive dietary patterns.

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PubMed2005

Tanita foot-to-foot bioelectrical impedance analysis system validated in older adults.

Simple, accurate, and noninvasive methods for assessing body composition are needed in many clinical, community, and research settings. The foot-to-foot bioelectrical impedance analysis (BIA) system may be one method of addressing those needs. The objective of this study was to determine the validity of a foot-to-foot BIA system for body-composition assessment of older adults. Subjects 55 years of age or older without functional limitations or cognitive impairments (N=50) were measured using both the Tanita foot-to-foot system (Tanita Corporation of America, Inc, Arlington Heights, IL) and traditional hand-to-foot BIA. The correlation for percent body fat measurements between the Tanita and traditional BIA was r=0.84 (P<.001). Percent body fat estimates from both BIA measures were significantly correlated with waist circumference, body mass index, and age (all P<.01). The Tanita BIA system provides a valid measure of percent body fat in older adults, and could be a convenient and practical approach for assessment in public health settings.

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PubMed2004

Food habits are related to glycemic control among people with type 2 diabetes mellitus.

OBJECTIVE: To investigate the food habits of people with type 2 diabetes and to identify those habits related to glycemic control. DESIGN: The purposive sampling plan targeted people (40 to 65 years old) living in two urban communities in the Southeastern United States with type 2 diabetes for >1 year (60% women, 50% African Americans and low-income individuals). In-depth interviews were used to identify food habits. Glycated hemoglobin (HbA(1c)) was measured to assess glycemic control. SUBJECTS: The final sample contained 89 participants (62% women, 48% African American, and 43% below 200% of the poverty level). STATISTICAL ANALYSES PERFORMED: Analysis of variance, principal component/factor analysis, cluster analysis, and multiple regression were used to relate food habits to glycemic control. RESULTS: A four-factor solution derived from 15 food habits explained 51.5% of the total variance in HbA(1c) values. High factor scores for three factors (Basic Eating Practices, Meal Planning, and Carbohydrate/Vegetable Strategies) and low factor scores for a fourth factor (Challenges of Dining Out) were related to lower HbA(1c) values. Based on similar patterns across the 15 food habits, participants were clustered into four groupings. The clusters differing on HbA(1c) (mean+/-standard deviation) were Healthful Eating Lifestyle (6.25+/-0.25), Disciplined Eating Approach (7.31+/-0.35), Limited Dietary Focus (8.28+/-0.33), and Poor Dietary Management (9.05+/-0.24). These groupings reflected different food habit factor profiles. CONCLUSIONS: Knowledge of the specific food habits of people with diabetes can offer a way to structure a meaningful dialog with clients about dietary self-management and guide the collaborative development of relevant dietary goals.

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PubMed2004

More favorable dietary patterns are associated with lower glycemic load in older adults.

OBJECTIVE: Glycemic load represents the total glycemic effect of the diet and may reduce the risk for chronic disease by affecting the risk for obesity and by altering metabolic endpoints. The food choices associated with lower-glycemic-load diets have received little investigation. Therefore, the purpose of this research was to examine the food patterns associated with lower-glycemic-load diets to establish targeted intervention messages. SUBJECTS/SETTING: A random sample (n=179; 81 male and 98 female subjects) of older adults > or =65 years of age in the Geisinger Rural Aging study, a nutritional risk screening study. METHODS: Standardized methodology was used to calculate the glycemic load from data obtained in five 24-hour recalls. Statistical analysis t tests compared dietary patterns between male and female subjects from two eating pattern clusters identified in previous cluster analysis based on food group intake. RESULTS: The mean (+/-standard deviation) glycemic load for the entire sample was 115.6 (+/-39.9). Two clusters were identified, and male and female subjects in one cluster had a lower glycemic load (113.7+/-44.2 and 94.0+/-27.5, respectively) than male and female subjects in the second cluster (139.9+/-38.8 and 110.7+/-35.9, respectively) ( P <.01). Participants in the lower-glycemic-load cluster consumed more carbohydrate from cereal, fruits, vegetables, and milk, whereas those in the higher-glycemic-load cluster consumed more breads and desserts. CONCLUSIONS: Promoting appropriate portions of nutrient-dense carbohydrate foods, particularly whole grain, fruits, vegetables, and dairy foods, may offer reasonable guidance for lowering the glycemic load of the diet among older adults. A lower-glycemic-load diet may reduce the risk for obesity and many chronic diseases.

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PubMed2004

Profiles of people with type 2 diabetes mellitus: the extremes of glycemic control.

For people with diabetes, hemoglobin A1c (HbA1c) is a measure of blood glucose control and an indication of the risk of developing diabetes complications. However, a given HbA1c value does not provide information about the diabetes self-management practices or philosophies of individuals in poor (HbA1c > 8.0%) or excellent (HbA1c < 6.5%) control. To contrast the experiences and attitudes of people at the extremes of glycemic control, interviews were conducted among 44 individuals (40-65 years old) diagnosed with diabetes for over 1 year. The participants were identified based upon their HbA1c value from a larger sample of people with type 2 diabetes that included African Americans, women, and persons with low income. Narratives were analyzed using a case-based and conceptually clustered matrix approach. The life course concept (life histories and natural transitions in roles and responsibilities across the life span) and the explanatory model of illness (individuals' beliefs about the causes, consequences, and treatment of a disease) provided the framework for the interview guide and the analysis of the narratives. Two self-management philosophy groups emerged from participants with excellent control (Committed [n = 15] and Tentative [ n = 7]) and three groups were identified among the poorly controlled group (Hopeful [n = 8], Hassled [n = 6 ], and Overwhelmed [n = 8]). Perseverance, coping skills, and age at diagnosis were life course concepts that distinguished participants within these groups. From the explanatory model of illness, beliefs about the cause of the disease, physical changes, and accepting the consequence of the disease influenced differences in these self-management philosophies. The profiles of people at the extremes of glycemic control can help those treating people with diabetes or seeking to improve self-management interventions understand differences in self-management philosophies and concentrate on specific issues hindering self-care control.

Adult↗

PubMed2004

Knowledge of dietary supplement label information among female supplement users.

The use of dietary supplements is a popular form of health behavior, especially among women. Little research has been conducted to determine consumers' comprehension of supplement label information. Therefore, this research evaluated comprehension of supplement label information among women 25-45 years of age who consumed a dietary supplement > or =4 times per week. Participants (n=51) completed a written questionnaire about supplement practices, a 10-item knowledge test, and an individual interview about terms used on supplement labels. Participants answered 70% of the questions correctly on the knowledge test indicating adequate knowledge of dietary sources of nutrients. Knowledge of recommended dosages, dosing instructions, and instructions about inappropriate use of supplements for certain people also was adequate. However, misconceptions regarding the term "natural" on supplement labels, product claims, and testing for product safety existed among participants. Supplement users need additional education about supplement claims and testing for product safety and efficacy to make informed health care choices.

Adult↗

PubMed2004

Dietary patterns of rural older adults are associated with weight and nutritional status.

OBJECTIVES: To characterize dietary patterns of rural older adults and relate patterns to weight and nutritional status. DESIGN: Cross-sectional. SETTING: Rural Pennsylvania. PARTICIPANTS: One hundred seventy-nine community-dwelling adults aged 66 to 87 years. MEASUREMENTS: A home visit was conducted to collect demographic, health behavior, and anthropometric data and a blood sample. Five 24-hour dietary recall were administered. Cluster analysis classified participants into dietary patterns using food subgroup servings. Chi-square, analysis of covariance, and logistic regression were used to assess differences across clusters. RESULTS: A low-nutrient-dense cluster (n=107), with higher intake of breads, sweet breads/desserts, dairy desserts, processed meats, eggs, and fats/oils, and a high-nutrient-dense cluster (n=72) with higher intake of cereals, dark green/yellow vegetables, other vegetables, citrus/melons/berries, fruit juices, other fruits, milks, poultry, fish, and beans, were identified. Those in the high-nutrient-dense cluster had lower energy intake; higher energy-adjusted intake of fiber, iron, zinc, folate, and vitamins B(6), B(12), and D; higher Healthy Eating Index scores; higher plasma vitamin B(12) levels; and a lower waist circumference. Those with a low-nutrient-dense dietary pattern were twice as likely to be obese, twice as likely to have low plasma vitamin B(12) levels, and three to 17 times more likely to have low nutrient intake. CONCLUSION: This study provides support for recommending a high-nutrient-dense dietary pattern for older adults. Behavioral interventions encouraging diets characterized by high-nutrient-dense foods may improve weight and nutritional status of older adults.

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PubMed2003

Decision-making patterns for dietary supplement purchases among women aged 25 to 45 years.

Women frequently consume dietary supplements but the criteria used to select supplements have received little investigation. This research identified the decision-making criteria used for dietary supplements among women aged 25 to 45 years who consumed a supplement at least four times per week. Participants (N=51) completed an in-store shopping interview that was audiotaped, transcribed, and analyzed qualitatively for the criteria used to make supplement selections. Qualitative analysis revealed 10 key criteria and the number of times each person used each criterion was quantified. Cluster analysis identified five homogeneous subgroups of participants based on the criteria used. These included brand shopper, bargain shopper, quality shopper, convenience shopper, and information gatherer. Supplement users vary in the criteria used to make point-of-purchase supplement selections. Dietetics professionals can classify supplement users according to the criteria used to tailor their nutrition counseling and better meet the educational needs of consumers.

Adult↗

PubMed2002

Nutrition education improves metabolic outcomes among older adults with diabetes mellitus: results from a randomized controlled trial.

BACKGROUND: Few diabetes education programs have been designed specifically for older adults. This study evaluated the impact of a nutrition intervention on the blood glucose and lipoprotein levels of adults > or =65 years of age without functional limitations but with type 2 diabetes for > or =1 year. METHODS: Ninety-eight people were randomized to the experimental or control group. A pretest-posttest control group design was used to evaluate the intervention. Ninety-two people (94%) completed the study. The 10-week intervention incorporated principles from information processing, learning theory, and Social Cognitive Theory to meet the needs of older adults. Analysis of covariance compared outcomes between groups. The paired t test compared results within groups. RESULTS: Participants exceeded the guidelines for optimal glycemic control at pretest. The experimental group had greater improvements in fasting plasma glucose (P = 0.05) and glycated hemoglobin (P < 0.01) than the control group. Significantly more participants in the experimental group than control group met the treatment goals for total cholesterol at posttest (P < 0.05). CONCLUSIONS: Older adults with diabetes need additional education to achieve metabolic control. Nutrition education can improve metabolic control among this cohort. Improved metabolic outcomes reduce the morbidity and mortality associated with diabetes.

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PubMed2002

Evaluation of a theory-based nutrition intervention for older adults with diabetes mellitus.

OBJECTIVE: To evaluate an intervention to improve food label knowledge and skills in diabetes management among older adults with diabetes mellitus. DESIGN: A randomized pretest-posttest control group design was used. SUBJECTS/SETTING: Participants (48 experimental, 50 control) were aged 65 years and older with type 2 diabetes for 1 year or longer; 93 participants (95%) completed the study, conducted in an outpatient setting. INTERVENTION: The intervention included 10 weekly group sessions led by a dietitian. Information processing, learning theory, and Social Cognitive Theory principles were used in program development and evaluation. MAIN OUTCOME MEASURES: Participants' knowledge, outcome expectations (expected results of behavior), self-efficacy, and decision-making skills were assessed. Instrument validity and reliability were established before program evaluation. STATISTICAL ANALYSES PERFORMED: Factor analysis identified underlying factor structures. Analysis of covariance with pretest score as covariate was used to compare groups at posttest. Paired t tests compared results within groups. RESULTS: Two factors were identified for outcome expectations (positive and negative) and for self-efficacy (promoters of and barriers to diabetes management). The experimental group had greater improvement in total knowledge scores (mean +/- standard error of the mean: 7.8+/-0.7) than the control group (0.2+/-0.7) (P < .0001), positive outcome expectations (0.59+/-0.15 vs 0.06+/-0.15, P = .01), promoters of diabetes management (0.83+/-0.12 vs -0.09+/-0.18, P < or = .001) and decision-making skills (5.1+/-0.5 vs 0.3+/-0.5, P < .0001) and greater reduction in barriers to diabetes management (1.1+/-0.16 vs 0.34+/-0.16, P < .01). No significant difference in negative outcome expectations occurred between groups at posttest. APPLICATIONS/CONCLUSIONS: Older adults with diabetes can benefit from nutrition education designed to improve knowledge and skills necessary for diabetes management.

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