Brenda M. Davy

Weight Gain Prevention: Identifying Theory-Based Targets for Health Behavior Change in Young Adults

Young adults attending college are more vulnerable to weight gain than the general population. We sought to identify health behavior change targets related to weight management in college students. Based on the Social Cognitive Theory model for health behavior change, we investigated the health-related lifestyle behaviors and physiological characteristics of this population. Forty-three college students (18.3+/-0.1 years) completed a series of quantitative assessments (eg, body weight and composition, cardiorespiratory fitness, and diet and activity habits) and structured qualitative assessments (ie, structured interview or focus group). Participants were predominantly normal weight (mean body mass index 22.2+/-0.4) and fit (maximal oxygen consumption 50.5+/-1.5 mL/kg/minute). However, healthful eating and physical activity were not considered high priorities, despite having ample free time, high exercise self-efficacy, positive outcome expectations for exercise, and a desire to exercise more. Participants reported that regularly engaging in exercise was difficult. This may have been due to poor planning/time management, satisfaction with body image, lack of accountability, and feelings of laziness. Dietary patterns generally met recommendations but were low in fruits, vegetables, and whole grains. Social support for exercise and healthful dietary habits were important factors associated with health behaviors. Students reported a decline in exercise and dietary habits relative to high school, which may have contributed to college weight gain. Our results suggest that this population may not have adequate self-regulatory skills, such as planning and self-monitoring, to maintain healthful behaviors in the college environment. Food and nutrition professionals working with young adults attending college may use these findings to guide the behavioral therapy component of their weight management medical nutrition therapy goals and outcomes.

Dietary biomarkers: advances, limitations and future directions

The subjective nature of self-reported dietary intake assessment methods presents numerous challenges to obtaining accurate dietary intake and nutritional status. This limitation can be overcome by the use of dietary biomarkers, which are able to objectively assess dietary consumption (or exposure) without the bias of self-reported dietary intake errors. The need for dietary biomarkers was addressed by the Institute of Medicine, who recognized the lack of nutritional biomarkers as a knowledge gap requiring future research. The purpose of this article is to review existing literature on currently available dietary biomarkers, including novel biomarkers of specific foods and dietary components, and assess the validity, reliability and sensitivity of the markers. This review revealed several biomarkers in need of additional validation research; research is also needed to produce sensitive, specific, cost-effective and noninvasive dietary biomarkers. The emerging field of metabolomics may help to advance the development of food/nutrient biomarkers, yet advances in food metabolome databases are needed. The availability of biomarkers that estimate intake of specific foods and dietary components could greatly enhance nutritional research targeting compliance to national recommendations as well as direct associations with disease outcomes. More research is necessary to refine existing biomarkers by accounting for confounding factors, to establish new indicators of specific food intake, and to develop techniques that are cost-effective, noninvasive, rapid and accurate measures of nutritional status.

Water Consumption Increases Weight Loss During a Hypocaloric Diet Intervention in Middle‐aged and Older Adults

Water consumption acutely reduces meal energy intake (EI) among middle‐aged and older adults. Our objectives were to determine if premeal water consumption facilitates weight loss among overweight/obese middle‐aged and older adults, and to determine if the ability of premeal water consumption to reduce meal EI is sustained after a 12‐week period of increased water consumption. Adults (n = 48; 55–75 years, BMI 25–40 kg/m2) were assigned to one of two groups: (i) hypocaloric diet + 500 ml water prior to each daily meal (water group), or (ii) hypocaloric diet alone (nonwater group). At baseline and week 12, each participant underwent two ad libitum test meals: (i) no preload (NP), and (ii) 500 ml water preload (WP). Meal EI was assessed at each test meal and body weight was assessed weekly for 12 weeks. Weight loss was ∼2 kg greater in the water group than in the nonwater group, and the water group (β = −0.87, P < 0.001) showed a 44% greater decline in weight over the 12 weeks than the nonwater group (β = −0.60, P < 0.001). Test meal EI was lower in the WP than NP condition at baseline, but not at week 12 (baseline: WP 498 ± 25 kcal, NP 541 ± 27 kcal, P = 0.009; 12‐week: WP 480 ± 25 kcal, NP 506 ± 25 kcal, P = 0.069). Thus, when combined with a hypocaloric diet, consuming 500 ml water prior to each main meal leads to greater weight loss than a hypocaloric diet alone in middle‐aged and older adults. This may be due in part to an acute reduction in meal EI following water ingestion.

Arterial Destiffening With Weight Loss in Overweight and Obese Middle-Aged and Older Adults

We tested the hypothesis that weight loss via a hypocaloric diet would reduce arterial stiffness in overweight and obese middle-aged and older adults. Thirty-six individuals were randomly assigned to a weight loss (n=25; age: 61.2±0.8 years; body mass index: 30.0±0.6 kg/m2) or a control (n=11; age: 66.1±1.9 years; body mass index: 31.8±1.4 kg/m2) group. Arterial stiffness was measured via carotid artery ultrasonography combined with applanation tonometry and carotid-femoral pulse wave velocity via applanation tonometry at baseline and after the 12-week intervention. Body weight, body fat, abdominal adiposity, blood pressure, &bgr;-stiffness index, and carotid-femoral pulse wave velocity were similar in the 2 groups at baseline (all P>0.05). Body weight (−7.1±0.7 versus −0.7±1.1 kg), body fat, and abdominal adiposity decreased in the weight loss group but not in the control group (all P<0.05). Brachial systolic and diastolic blood pressures declined (P<0.05) only in the weight loss group. Central systolic and pulse pressures did not change significantly in either group. &bgr;-Stiffness index (−1.24±0.22 versus 0.52±0.37 U) and carotid-femoral pulse wave velocity (−187±29 versus 15±42 cm/s) decreased in the weight loss group but not in the control group (all P<0.05). The reductions in carotid-femoral pulse wave velocity were correlated with reductions in total body and abdominal adiposity (r=0.357–0.602; all P<0.05). However, neither total body nor abdominal adiposity independently predicted reductions in arterial stiffness indices. In summary, our findings indicate that weight loss reduces arterial stiffness in overweight/obese middle-aged and older adults, and the magnitudes of these improvements are related to the loss of total and abdominal adiposity.

Beverage consumption and adult weight management: A review.

Total energy consumption among United States adults has increased in recent decades, and energy-containing beverages are a significant contributor to this increase. Because beverages are less satiating than solid foods, consumption of energy-containing beverages may increase energy intake and lead to weight gain; trends in food and beverage consumption coinciding with increases in overweight and obesity support this possibility. The purpose of this review is to present what is known about the effect of beverage consumption on short-term (i.e., meal) energy intake, as well as longer-term effects on body weight. Specific beverages addressed include water, other energy-free beverages (diet soft drinks, coffee and tea), and energy-containing beverages (soft drinks, juices and juice drinks, milk and soy beverages, alcohol). Existing evidence, albeit limited, suggests that encouraging water consumption, and substituting water and other energy-free beverages (diet soft drinks, coffee and tea) for energy-containing beverages may facilitate weight management. Energy-containing beverages acutely increase energy intake, however long-term effects on body weight are uncertain. While there may be health benefits for some beverage categories, additional energy provided by beverages should be compensated for by reduced consumption of other foods in the diet.

Health Literacy is associated with Healthy Eating Index Scores and Sugar-Sweetened Beverage Intake: Findings from the Rural Lower Mississippi Delta

BACKGROUND Although health literacy has been a public health priority area for more than a decade, the relationship between health literacy and dietary quality has not been thoroughly explored. OBJECTIVE To evaluate health literacy skills in relation to Healthy Eating Index (HEI) scores and sugar-sweetened beverage (SSB) consumption while accounting for demographic variables. DESIGN Cross-sectional survey. PARTICIPANTS/SETTING A community-based proportional sample of adults residing in the rural Lower Mississippi Delta. METHODS Instruments included a validated 158-item regional food frequency questionnaire and the Newest Vital Sign (scores range 0 to 6) to assess health literacy. STATISTICAL ANALYSES PERFORMED Descriptive statistics, analysis of variance, and multivariate linear regression. RESULTS Of 376 participants, the majority were African American (67.6%), without a college degree (71.5%), and household income level <

The beverage intake questionnaire: determining initial validity and reliability.

20,000/year (55.0%). Most participants (73.9%) scored in the two lowest health literacy categories. The multivariate linear regression model to predict total HEI scores was significant (R(2)=0.24; F=18.8; P<0.01), such that every 1-point increase in health literacy was associated with a 1.21-point increase in HEI scores, while controlling for all other variables. Other significant predictors of HEI scores included age, sex, and Supplemental Nutrition Assistance Program participation. Health literacy also significantly predicted SSB consumption (R(2)=0.15; F=6.3; P<0.01) while accounting for demographic variables. Every 1 point in health literacy scores was associated with 34 fewer kilocalories per day from SSBs. Age was the only significant covariate in the SSB model. CONCLUSIONS Although health literacy has been linked to numerous poor health outcomes, to our knowledge this is the first investigation to establish a relationship between health literacy and HEI scores and SSB consumption. Our study suggests that understanding the causes and consequences of limited health literacy is an important factor in promoting compliance to the Dietary Guidelines for Americans.

Translational Research: Bridging the Gap between Long-Term Weight Loss Maintenance Research and Practice

Consuming energy-containing beverages may lead to weight gain, yet research investigating this issue is limited. An easily administered beverage intake assessment tool could facilitate research on this topic. The purpose of this cross-sectional investigation was to determine the validity and reliability of a self-administered beverage intake questionnaire (BEVQ) that estimates mean daily intake of beverages consumed across 19 beverage categories. Participants (N=105; aged 39+/-2 years) underwent assessments of height, weight, body mass index, and dietary intake using 4-day food intake records from June 2008 to June 2009. The BEVQ was completed at two additional visits (BEVQ1, BEVQ2). Urine samples were collected to objectively determine total fluid intake and encourage accurate self-reporting. Validity was assessed by comparing BEVQ1 with food intake record results; reliability was assessed by comparing BEVQ1 and BEVQ2. Analyses included descriptive statistics, bivariate correlations, paired samples t tests, and independent samples t tests. Self-reported water and total beverage intake (in grams) were not different between the BEVQ1 and food intake records (mean difference 129+/-77 g [P=0.096] and 61+/-106 g [P=0.567], respectively). Total beverage and sugar-sweetened beverage energy intake were significantly different, although mean differences were small (63 and 44 kcal, respectively). Daily consumption (in grams) of water (r=0.53), total beverages (r=0.46), and sugar-sweetened beverages (r=0.49) determined by the BEVQ1 were correlated with reported intake determined by the food intake record, as was energy from total beverages (r=0.61) and sugar-sweetened beverages (r=0.59) (all P values <0.001). Reliability was demonstrated, with correlations (P<0.001) detected between BEVQ1 and BEVQ2 results. The BEVQ is a valid, reliable, and rapid self-administered dietary assessment tool.

Water Consumption Reduces Energy Intake at a Breakfast Meal in Obese Older Adults

The number of US adults classified as overweight or obese has dramatically increased in the past 25 years, resulting in a significant body of research addressing weight loss and weight loss maintenance. However, little is known about the potential of weight loss maintenance interventions to be translated into actual practice settings. Thus, the purpose of this article is to determine the translation potential of published weight loss maintenance intervention studies by determining the extent to which they report information across the reach, efficacy/effectiveness, adoption, implementation, and maintenance (RE-AIM) framework. A secondary purpose is to provide recommendations for research based on these findings. To identify relevant research articles, a literature search was conducted using four databases; 19 weight loss maintenance intervention studies were identified for inclusion. Each article was evaluated using the RE-AIM Coding Sheet for Publications to determine the extent to which dimensions related to internal and external validity were reported. Approximately half of the articles provided information addressing three RE-AIM dimensions, yet only a quarter provided information addressing adoption and maintenance. Significant gaps were identified in understanding external validity, and metrics that could facilitate the translation of these interventions from research to practice are presented. Based upon this review, it is unknown how effective weight loss maintenance interventions could be in real-world situations, such as clinical or community practice settings. Future studies should be planned to address how weight loss maintenance intervention programs will be adopted and maintained, with special attention to costs for participants and for program implementation.

Large Artery Stiffening With Weight Gain in Humans: Role of Visceral Fat Accumulation

Water consumed before a meal has been found to reduce energy intake among nonobese older adults. However, it is unknown whether this effect is evident among overweight and obese older adults, a population who would benefit from strategies to improve energy intake regulation. Our purpose was to determine whether premeal water consumption reduces meal energy intake in overweight and obese older adults. Twenty-four overweight and obese adults (body mass index=34.3+/-1.2), mean age 61.3+/-1.1 years, were given an ad libitum standardized breakfast meal on two randomly assigned occasions. Thirty minutes before the meal, subjects were given either a 500-mL water preload or no preload. Energy intake at each meal was covertly measured. Meal energy intake was significantly less in the water preload condition as compared with the no-preload condition (500+/-32 vs 574+/-38, respectively; P=0.004), representing an approximate 13% reduction in meal energy intake. The percentage reduction in meal energy intake following the water preload was not related to sex, age, body mass index, or habitual daily water consumption (all P>0.05). Given the high prevalence of overweight and obesity among older adults, future studies should determine whether premeal water consumption is an effective long-term weight control strategy for older adults.