Kathleen Woolf

Inhibiting food reward: delay discounting, food reward sensitivity, and palatable food intake in overweight and obese women

Overeating is believed to result when the appetitive motivation to consume palatable food exceeds an individuals capacity for inhibitory control of eating. This hypothesis was supported in recent studies involving predominantly normal weight women, but has not been tested in obese populations. The current study tested the interaction between food reward sensitivity and inhibitory control in predicting palatable food intake among energy‐replete overweight and obese women (N = 62). Sensitivity to palatable food reward was measured with the Power of Food Scale. Inhibitory control was assessed with a computerized choice task that captures the tendency to discount large delayed rewards relative to smaller immediate rewards. Participants completed an eating in the absence of hunger protocol in which homeostatic energy needs were eliminated with a bland preload of plain oatmeal, followed by a bogus laboratory taste test of palatable and bland snacks. The interaction between food reward sensitivity and inhibitory control was a significant predictor of palatable food intake in regression analyses controlling for BMI and the amount of preload consumed. Probing this interaction indicated that higher food reward sensitivity predicted greater palatable food intake at low levels of inhibitory control, but was not associated with intake at high levels of inhibitory control. As expected, no associations were found in a similar regression analysis predicting intake of bland foods. Findings support a neurobehavioral model of eating behavior in which sensitivity to palatable food reward drives overeating only when accompanied by insufficient inhibitory control. Strengthening inhibitory control could enhance weight management programs.

Physical Activity Is Associated with Risk Factors for Chronic Disease across Adult Women's Life Cycle

OBJECTIVE The purpose of this study was to examine the association of age (young, midlife, and older) and activity level (active and sedentary), determined by a pedometer, with risk factors of chronic disease, including body composition, dietary intake, serum lipids, insulin, leptin, C-reactive protein (CRP), plasma glucose, and resting metabolic rate (RMR) in women across the adult life cycle. METHODS Young (aged 20 to 30 years) (n=49), midlife (aged 40 to 50 years) (n=62), and older (aged 60 years and older) (n=47) women were recruited for this cross-sectional study. For 7 days, participants completed weighed food records and wore a pedometer. Based on the average number of steps per day, the women were further classified as active (>/=7,500 steps per day) or sedentary (<7,500 steps per day). Height, weight, and waist circumference were determined for each participant. Fasting blood samples were taken to assess serum lipid, CRP, insulin, leptin, thyroid stimulating hormone, and plasma glucose levels. RMR and body composition (via dual-energy x-ray absorptiometry) were assessed. RESULTS Young and midlife women had lower concentrations compared to older women for serum cholesterol (P<0.01), low-density lipoprotein cholesterol (P<0.01), triglycerides (P<0.01), leptin (P<0.01), and plasma glucose (P<0.01); midlife women had lower serum insulin concentrations vs young and older groups (P=0.01); young women had smaller waist circumference compared to midlife and older groups (P<0.01); percent body fat (P<0.01) and percent fat-free mass (P<0.01) differed between all ages. Lower values were found in active vs sedentary women for serum insulin (P=0.02), serum leptin (P<0.01), waist circumference (P<0.01) and percent body fat (P<0.01). A higher percent fat-free mass (P<0.01) was also found in active compared to sedentary women. No differences were found between activity groups for serum cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglycerides, CRP, plasma glucose levels, or RMR. RMR was higher in young and midlife vs the older women (P<0.01). Significant inverse correlations were found between activity (steps per day) and body mass index, insulin level, CRP concentration, leptin level, waist circumference, and body fat. Significant positive correlations were found between age and body mass index, total serum cholesterol level, low-density lipoprotein cholesterol level, serum triglyceride level, leptin level, plasma glucose level, CRP concentration, waist circumference, and body fat. Young and midlife women reported consuming more relative energy (kilocalories per kilogram body weight) and protein (grams per kilogram body weight) than older women (P<0.01). The midlife women reported consuming more dietary cholesterol compared to the young and older women (P<0.01). Active women reported a higher relative energy (kilocalories per kilogram body weight) and protein (grams per kilogram body weight) intake vs the sedentary women (P<0.01). Active women also reported a higher intake of dietary carbohydrates (grams per day, P<0.01; percent of energy, P=0.04). CONCLUSIONS Overall, these results indicate that younger age and greater physical activity, despite age, are associated with fewer risk factors for chronic disease, such as cardiovascular disease, type 2 diabetes, and obesity.

Effects of Habitual Physical Activity on the Resting Metabolic Rates and Body Compositions of Women Aged 35 to 50 Years

OBJECTIVE To examine the effect habitual physical activity has on resting metabolic rate (RMR) and body composition (fat-free mass[FFM], fat mass, and percent body fat) in active compared to sedentary adult women. DESIGN RMR was measured (by indirect calorimetry) twice after a 12-hour fast at the same point of the menstrual cycle and 48 hours after exercise. FFM, fat mass and percent body fat were measured using whole body air displacement plethysmography. Energy intake and expenditure were determined using 7-day weighed-food records and activity logs. SUBJECTS Healthy, weight-stable premenopausal women aged 35 to 50 years classified as either active (approximately 9 hours per week of physical activity for 10 or more years) (n= 18) or sedentary (approximately 1 hour per week of physical activity) (n= 14). STATISTICAL ANALYSES Analysis of covariance was used to investigate differences in mean RMR (kcal/day) between the groups adjusted for FFM, and independent t tests were used to determine differences in demographic, energy expenditure, and diet variables. RESULTS Percent body fat and fat mass were lower (P<.0005) and RMR (adjusted for FFM) was significantly higher in the active women (P=.045) compared with sedentary controls. In the active and sedentary groups respectively, mean adjusted RMR was 1,510 kcal/day and 1,443 kcal/day, body fat was 18.9% and 28.8%, and fat mass was 11.1 kg and 18.8 kg. Groups were similar in body mass, FFM, body mass index, and age. Mean energy balance appeared to be more negative in the active group (P=.0059) due to significantly higher mean self-reported energy expenditures (P=.0001) and similar mean self-reported energy intakes (P=.52) compared with sedentary controls. These data indicate that active women who participate in habitual physical activity can maintain lower body fat and a higher RMR than sedentary controls with similar body mass, FFM, and body mass index. APPLICATIONS/CONCLUSIONS This research supports and emphasizes the benefits of habitual physical activity in maintaining RMR and lower body fat levels in middle-aged women.

Effect of Caffeine as an Ergogenic Aid During Anaerobic Exercise Performance in Caffeine Naïve Collegiate Football Players

Woolf, K, Wendy, KB, and Carlson, AG. Effect of Caffeine as an Ergogenic Aid During Anaerobic Exercise Performance in Caffeine Naïve Collegiate Football Players. J Strength Cond Res 23(5): 1363-1369, 2009-Research suggests that caffeine may improve performance in aerobic exercise; the evidence for anaerobic performance is mixed. This study examined the effect of caffeine (5 mg/kg body weight [BW]) vs. placebo on performance-based anaerobic exercise tests used during the National Football League (NFL) Combine. Collegiate football athletes (n = 17; 20 ± 2 yr; body mass index 29.4 ± 3.6 kg/m2) completed 2 study visits, 1 week apart. Participants were low caffeine users with a reported average intake of 16 ± 20 mg/day. On the day of testing, participants ingested a caffeinated (5 mg/kg BW caffeine + 0.125 g/kg BW carbohydrate) or placebo (0.125 g/kg BW carbohydrate) beverage, ate a light meal, and completed 3 exercise tests (40-yard dash, 20-yard shuttle, and a bench press) 60 minutes later. Borgs rating of perceived exertion (RPE) was recorded after each exercise test. Heart rate (HR) and blood pressure (BP) were monitored (pre-exercise and postexercise). Data were analyzed using paired t-tests, Wilcoxon signed rank test, and repeated measures analysis of variance. No significant differences were found between treatments for the exercise tests (40-yard dash: 5.01 ± 0.25 vs. 5.03 ± 0.26 s, p = 0.43; 20-yard shuttle: 4.64 ± 0.19 vs. 4.66 ± 0.24 s, p = 0.51; bench press: 17 ± 8 vs. 17 ± 8 reps, p = 0.51; caffeine vs. placebo, respectively). However, 59% of the participants improved in performance with the caffeine during the bench press and the 40-yard dash. No differences were found between treatments for RPE, HR, and BP. Caffeine did not improve performance for anaerobic exercise tests used at the NFL Combine in caffeine naïve male football athletes.

A Point-of-Purchase Intervention Featuring In-Person Supermarket Education Affects Healthful Food Purchases

OBJECTIVE This study tested the efficacy of a multicomponent supermarket point-of-purchase intervention featuring in-person nutrition education on the nutrient composition of food purchases. DESIGN The design was a randomized trial comparing the intervention with usual care (no treatment). SETTING AND PARTICIPANTS A supermarket in a socioeconomically diverse region of Phoenix, AZ. One hundred fifty-three adult shoppers were recruited onsite. INTERVENTION The intervention consisted of brief shopping education by a nutrition educator and an explanation and promotion of a supermarket point-of-purchase healthful shopping program that included posted shelf signs identifying healthful foods, sample shopping lists, tips, and signage. MAIN OUTCOME MEASURES Outcomes included purchases of total, saturated, and trans fat (grams/1,000 kcal), and fruits, vegetables, and dark-green/yellow vegetables (servings/1,000 kcal) derived through nutritional analysis of participant shopping baskets. ANALYSIS Analysis of covariance compared the intervention and control groups on food purchasing patterns while adjusting for household income. RESULTS The intervention resulted in greater purchasing of fruit and dark-green/yellow vegetables. No other group differences were observed. CONCLUSIONS AND IMPLICATIONS Long-term evaluations of supermarket interventions should be conducted to improve the evidence base and to determine the potential for influence on food choices associated with decreased chronic disease incidence.

Relationships of Self-Reported Dietary Factors and Perceived Acne Severity in a Cohort of New York Young Adults

BACKGROUND Recent observational and experimental evidence suggests that diet may contribute to acne prevalence. OBJECTIVES To examine the differences in select dietary factors (glycemic index [GI], total sugar, added sugar, fruit/fruit juice, fruit/vegetables, vegetables, saturated fat, trans fat, and number of milk and fish servings per day) between groups of self-reported acne severity. Secondary objectives were to investigate the differences in food-aggravated acne beliefs and acne-specific quality-of-life between groups of self-reported acne severity. DESIGN This study utilized a cross-sectional design. PARTICIPANTS/SETTING A total of 248 (115 male, 133 female) participants, age 18 to 25 years, completed questionnaires designed to measure self-reported acne severity, select dietary factors, food-aggravated acne beliefs, acne-specific quality-of-life, and anthropometric and demographic characteristics. The Block fat/sugar/fruit/vegetable food frequency questionnaire assessed usual dietary intake. Data were collected in New York City between January and May 2012. STATISTICAL ANALYSES PERFORMED One-way between groups analysis of variance examined differences in dietary factors, anthropometric characteristics, and acne-specific quality-of-life between groups of self-reported acne. χ² tests compared food-aggravated acne beliefs and demographic characteristics between groups of self-reported acne. RESULTS Compared with participants with no or mild acne, participants with moderate to severe acne reported greater dietary GI (P<0.001), added sugar (P<0.001), total sugar (P<0.001), number of milk servings per day (P<0.001), saturated fat (P<0.001), and trans-fatty acids (P<0.001), and fewer servings of fish per day (P=0.002). Among all participants, 58.1% perceived diet to aggravate or influence acne. CONCLUSIONS This study suggests that diet, particularly dietary GI, saturated fat, trans fat, milk, and fish may influence or aggravate acne development. Future research is necessary to elucidate the proposed mechanisms linking diet and acne and determine the impact of medical nutrition therapy on acne development.

Acne: The Role of Medical Nutrition Therapy

Acne is a common disease in Westernized nations, particularly among adolescents and young adults. Acne has substantial effects on quality of life, making treatment essential. Medical nutrition therapy as a potential treatment for acne is not new, although the literature examining diet and acne during the past 100 years is mixed. During the late 1800s and early 1900s, diet was commonly used as an adjunct treatment for acne. During the 1960s, however, the diet-acne connection fell out of favor. In recent years, dermatologists and registered dietitians have revisited the idea and become increasingly interested in the role of medical nutrition therapy in acne treatment. This article reviews the history and existing literature examining the association between diet and acne. Although the total number of studies conducted within the past 40 years is relatively small, the growing body of epidemiologic and experimental evidence suggests a relationship between diet and acne. Compared with other dietary factors, more research examines dietary glycemic load. The evidence is more convincing for high glycemic load diets, compared with other dietary factors. To date there are no randomized controlled trials investigating the relationship between frequent dairy or milk consumption and acne. Similarly, the number of research studies examining the relationship between dietary fat and/or n-3 fatty acids is sparse and the evidence is less robust. Taken together, several methodologic limitations need to be addressed, and additional research, preferably randomized controlled trials, is warranted before comprehensive evidence-based guidelines can be established. While dermatologists and registered dietitians continue to debate and research the potential relationship between diet and acne, the best dietary approach is to address each acne patient individually, carefully considering the possibility of dietary counseling.

Lower Healthy Eating Index-2005 dietary quality scores in older women with rheumatoid arthritis v. healthy controls

OBJECTIVE To assess the dietary quality of older women with and without rheumatoid arthritis (RA) using the Healthy Eating Index-2005 (HEI-2005) to identify potential strategies to improve the nutritional status. DESIGN Cross-sectional. Diet was assessed using 7 d food records and analysed for nutrient composition (Food Processor v. 7.11). Diet quality was determined using the HEI-2005, a measure of compliance with 2005 US Dietary Guidelines. Individuals with RA completed a self-reported evaluation of arthritis (pain scale and disability index). Independent two-tailed t tests or Mann-Whitney tests compared the differences between groups and correlations were computed between HEI-2005 and measures of disease reactivity. SETTING Arizona, USA. SUBJECTS Older (> or = 55 years) women (n 108) with RA (n 52) and healthy controls (HC; n 56). RESULTS There were no differences between groups in age, weight, or BMI (kg/m2). HC participants had higher mean HEI-2005 scores for whole fruit (cups; P = 0.02), total fruit (cups; P = 0.05), whole grains (oz; P = 0.004), oil (g; P = 0.05) and total HEI score (P = 0.04) than the RA group. In the RA group, these same HEI components were inversely correlated with disability index (r = -0.20, P = 0.04). Participants with RA reported lower mean intakes of carbohydrate (g; P = 0.02), fibre (g; P = 0.01) and vitamin C (mg; P = 0.04). CONCLUSIONS This is the first study examining the dietary quality in older women with and without RA using the HEI-2005. Living with RA was associated with significantly lower dietary quality. Since even small changes in dietary quality can translate into better nutritional status, future interventions should focus on increasing dietary quality in this high-risk group.

Availability of Outpatient Clinical Nutrition Services for Patients With Cancer Undergoing Treatment at Comprehensive Cancer Centers.

PURPOSE The mission of US Comprehensive Cancer Centers (CCC) is to reduce cancer morbidity and mortality. The type of clinical nutrition services available to outpatients seeking treatment at CCCs is unknown. The purpose of this cross-sectional study was to determine the prevalence and types of outpatient clinical nutrition services available at CCCs. METHODS A list of the National Cancer Institute (NCI) -designated CCCs was compiled. A telephone survey that queried clinical nutrition services available to outpatients undergoing treatment was developed. The survey was conducted with clinical nutrition personnel during usual working hours between April and October 2012. RESULTS Of the 40 CCCs, 32 (80%) completed the survey. Thirty CCCs offered referral- or consult-based services with a clinical nutrition professional such as a registered dietitian (RD). Other services included nutrition classes (56%), nutrition pamphlets (94%), and counseling by non-nutrition health care providers (81%). Twenty-three of the centers monitored patients regularly, but less than half followed a clinical nutrition protocol such as those established by the Academy of Nutrition and Dietetics. Referral-based services were provided for cancers with a high prevalence of malnutrition, such as head and neck and GI, with most monitoring patients regularly but less than half using evidence-based protocols. CONCLUSION CCCs rely on referral-based clinical nutrition service, which are not consistently a part of multidisciplinary care. An in-depth comparison of clinical nutrition services among other approaches to cancer care, including a comparison of clinical outcomes among these different approaches, is needed.

Diet quality of individuals with rheumatoid arthritis using the Healthy Eating Index (HEI)-2010

Background: Rheumatoid arthritis (RA) afflicts approximately 1.5 million American adults and is a major cause of disability. As disease severity worsens, individuals with RA may experience functional decline that can impact dietary intake. Objective: The objective of this study is to assess the diet quality of individuals with RA using the Healthy Eating Index (HEI)-2010 and examine associations between diet quality and disease activity and functional status. Methods: This cross-sectional study assessed diet quality and disease activity and functional status in adults with RA. Participants completed seven-day weighed food records, which were scored using the HEI-2010. Participants had a fasting blood draw and completed the Multidimensional Health Assessment Questionnaire to determine disease activity and functional status. Results: The mean age of individuals with RA (N = 84) was 53 ± 14 years, and 86.9% were female. The mean HEI-2010 total score was 58.7 ± 15.9, with 7.1% of participants scoring “good”, 58.3% “fair”, and 34.5% “poor”. Most participants did not adhere to recommended intakes of total fruit, total vegetables, whole grains, fatty acids, refined grains, sodium, and empty calories. An unadjusted multiple linear regression model found duration of morning stiffness and C-reactive protein concentration to be significant variables to inversely predict HEI-2010 total score. Conclusions: The diet quality of many individuals with RA needs improvement and may be related to functional disability associated with RA. Healthcare providers should encourage individuals with RA to meet dietary guidelines and maintain a healthy diet. Moreover, healthcare providers should be aware of the potential impacts of functional disability on diet quality in individuals with RA.