Web-based guide to health: relationship of theoretical variables to change in physical activity, nutrition and weight at 16-months.

BACKGROUND: Evaluation of online health interventions should investigate the function of theoretical mechanisms of behavior change in this new milieu. OBJECTIVES: To expand our understanding of how Web-based interventions influence behavior, we examined how changes at 6 months in participants' psychosocial characteristics contributed to improvements at 16 months in nutrition, physical activity (PA), and weight management as a result of the online, social cognitive theory (SCT)-based Guide to Health intervention (WB-GTH). METHODS: We conducted recruitment, enrollment, and assessments online with 272 of 655 (41.5%) participants enrolling in WB-GTH who also completed 6- and 16-month follow-up assessments. Participants' mean age was 43.68 years, 86% were female, 92% were white, mean education was 17.45 years, median income was US $85,000, 84% were overweight or obese, and 73% were inactive. Participants received one of two equally effective versions of WB-GTH. Structural equation analysis of theoretical models evaluated whether psychosocial constructs targeted by WB-GTH contributed to observed health behavior changes. RESULTS: The longitudinal model provided good fit to the data (root mean square error of approximation <.05). Participants' weight loss at 16 months was predicted by improvements in their PA (beta(total) = -.34, P = .01), consumption of fruits and vegetables (F&V) (beta(total) = -.20, P = .03) and calorie intake (beta(total) = .15, P = .04). Improvements at 6 months in PA self-efficacy (beta(total) = -.10, P = .03), PA self-regulation (beta(total) = -.15, P = .01), nutrition social support (beta(total) = -.08, P = .03), and nutrition outcome expectations (beta(total) = .08, P = .03) also contributed to weight loss. WB-GTH users with increased social support (beta(total) = .26, P = .04), self-efficacy (beta(total) = .30, P = .01), and self-regulation (beta(total) = .45, P = .004) also exhibited improved PA levels. Decreased fat and sugar consumption followed improved social support (beta(total) = -.10, P = .02), outcome expectations (beta(total) = .15, P = .007), and self-regulation (beta(total) = -.14, P = .008). Decreased calorie intake followed increased social support (beta(total) = -.30, P < .001). Increased F&V intake followed improved self-efficacy (beta(total) = .20, P = .01), outcome expectations (beta(total) = -.29, P = .002), and self-regulation (beta(total) = .27, P = .009). Theorized indirect effects within SCT variables were also supported. CONCLUSIONS: The WB-GTH influenced behavior and weight loss in a manner largely consistent with SCT. Improving social support, self-efficacy, outcome expectations, and self-regulation, in varying combinations, led to healthier diet and exercise habits and concomitant weight loss. High initial levels of self-efficacy may be characteristic of Web-health users interested in online interventions and may alter the function of SCT in these programs. Researchers may find that, although increased self-efficacy enhances program outcomes, participants whose self-efficacy is tempered by online interventions may still benefit. TRIAL REGISTRATION: Clinicaltrials.gov NCT00128570; http://clinicaltrials.gov/ct2/show/NCT00128570 (Archived by WebCite at http://www.webcitation.org/5vgcygBII).

Resist diabetes: A randomized clinical trial for resistance training maintenance in adults with prediabetes.

OBJECTIVE: To determine whether a social cognitive theory (SCT)-based intervention improves resistance training (RT) maintenance and strength, and reduces prediabetes prevalence. RESEARCH DESIGN AND METHODS: Sedentary, overweight/obese (BMI: 25-39.9 kg/m2) adults aged 50-69 (N = 170) with prediabetes participated in the 15-month trial. Participants completed a supervised 3-month RT (2×/wk) phase and were randomly assigned (N = 159) to one of two 6-month maintenance conditions: SCT or standard care. Participants continued RT at a self-selected facility. The final 6-month period involved no contact. Assessments occurred at baseline and months 3, 9, and 15. The SCT faded-contact intervention consisted of nine tailored transition (i.e., supervised training to training alone) and nine follow-up sessions. Standard care involved six generic follow-up sessions. Primary outcomes were prevalence of normoglycemia and muscular strength. RESULTS: The retention rate was 76%. Four serious adverse events were reported. After 3 months of RT, 34% of participants were no longer prediabetic. This prevalence of normoglycemia was maintained through month 15 (30%), with no group difference. There was an 18% increase in the odds of being normoglycemic for each % increase in fat-free mass. Increases in muscular strength were evident at month 3 and maintained through month 15 (P<0.001), which represented improvements of 21% and 14% for chest and leg press, respectively. Results did not demonstrate a greater reduction in prediabetes prevalence in the SCT condition. CONCLUSIONS: Resistance training is an effective, maintainable strategy for reducing prediabetes prevalence and increasing muscular strength. Future research which promotes RT initiation and maintenance in clinical and community settings is warranted. TRIAL REGISTRATION: ClinicalTrials.gov NCT01112709.

Theory-based approach for maintaining resistance training in older adults with prediabetes: adherence, barriers, self-regulation strategies, treatment fidelity, costs.

Effectively preventing and treating chronic diseases through health behavior changes often require intensive theory- and evidence-based intervention including long-term maintenance components. We assessed the efficacy of theory-based maintenance approaches varying by dose for persistently performing resistance training (RT) with the hypothesis that a higher-dose social cognitive theory (SCT) approach would produce greater RT adherence than lower-dose Standard. The Resist-Diabetes study first established 2×/week resistance training (RT) in a 3-month supervised intervention in older (50-69 years, N = 170), overweight to obese (BMI 25-39.9 kg/m(2)) previously inactive adults who fit prediabetes criteria (fasting glucose concentration = 95-125 mg/dl; oral glucose tolerance test 2-h glucose concentration = 140-199 mg/dl or both). After the supervised phase, participants (N = 159) were then randomly assigned to one of two conditions for transition (3 weeks) and then RT alone in community settings for extended contact, maintenance (6 months), and then no contact (6 months). SCT featured continued tailored, interactive personal, and web-based check-ups focused on RT, self-regulation, and a barrier/strategies approach. Standard involved low-dose, generic personal, and web-based check-ups within the same theoretical approach. SCT and Standard both resulted in similar RT, 2×/week adherence during maintenance (74.4 %) and no-contact phases (53.1 %). Cost analysis indicated the Standard intervention for transition and maintenance was inexpensive ($160). Standard can be translated into practice with the potential for continuous contact and persistence in RT beyond the typical program maintenance phase.

Using response variation to develop more effective, personalized behavioral medicine?: evidence from the Resist Diabetes study.

Health behavior interventions have achieved some notable outcomes through generally higher dose interventions with intensive initial phases and long-term, faded contact maintenance phases with attention to mean changes and adherence rates. Interventions may be improved by shifting attention to the very large response variation that is typical for such protocols as exercise with non-, low, moderate, and high responders and even those who show adverse responses. Data from the Resist Diabetes study, which included adults (N = 159, ages 50-69 years) with prediabetes who were overweight or obese (BMI 25-39.9 kg/m(2)) and previously inactive, are presented. The data show a typical pattern of wide variation for changes on a 2-h oral glucose tolerance test (OGTT), defined by blood glucose concentration measured after 2 h following ingestion of 75 g of glucose, lean body mass, fat mass, strength, and blood pressure to the same resistance training protocol within a highly supervised phase and where adherence was high. A personalized behavioral medicine approach could focus on such individual patterns of response variation to tailor and alter additional intervention components, the staging of maintenance interventions, and then determining how to most effectively, and systematically, translate this adaptive intervention approach into practice to potentially achieve more optimal clinical outcomes.

Developing a new treatment paradigm for disease prevention and healthy aging.

An increasingly prevalent pattern of risk factors has emerged in middle-aged and older adults that includes the presence of type 2 diabetes or prediabetes, overweight or obese weight status with central obesity and very high body fat, low cardiorespiratory fitness (CRF), low strength, and a low lean-body-mass-to-body-fat ratio. Traditionally, these problems have been approached with a low-fat and low-calorie diet and with lower to moderate intensity activity such as walking. While the treatment has some clear benefits, this approach may no longer be optimal because it does not reflect more recent findings from nutrition and exercise sciences. Specifically, these fields have gained a greater understanding of the metabolic and functional importance of focusing on reducing body fat and central obesity while maintaining or even increasing lean body mass, a quality weight loss, and how to efficiently and effectively increase CRF and strength. Evidence is presented for shifting the treatment paradigm for disease prevention and healthy aging to include the DASH nutrition pattern but with additional protein, higher intensity, brief aerobic training, effort-based, brief resistance training, and structured physical activity. Recent interventions based on social cognitive theory for initiating and then maintaining health behavior changes show the feasibility and efficacy of the approach we are advocating especially within a multiple health behavior change format and the potential for translating the new treatment paradigm into practice.

Dietary intake modification in response to a participation in a resistance training program for sedentary older adults with prediabetes: findings from the Resist Diabetes study.

Engagement in one type of health behavior change may exert a "spillover" effect resulting in other behavior changes. Few studies have examined dietary intake following prolonged training, and none have evaluated spontaneous dietary changes beyond alterations in energy or macronutrient intake following initiation of strength/resistance training (RT). The purpose of this observational investigation was to determine if spontaneous dietary intake modifications occur in response to initiation of an RT program, among older adults. Previously sedentary adults with prediabetes (n=134, age=59±1 years) were enrolled in a supervised 12-week RT program. Participants were not given dietary advice or encouraged to change eating behaviors. Three non-consecutive 24-hour dietary recalls were collected at baseline and after 12 weeks of RT. Reductions in intake of energy (1914±40 kcal vs. 1834±427 kcal, p=0.010), carbohydrate (211.6±4.9 g vs. 201.7±5.2 g, p=0.015), total sugar (87.4±2.7 g vs. 81.5±3.1 g, p=0.030), glycemic load (113.4±3.0 vs. 108.1±3.2, p=0.031), fruits and vegetables (4.6±0.2 servings vs. 4.1±0.2 servings, p=0.018), and sweets and desserts (1.1±0.07 servings vs. 0.89±0.07 servings, p=0.023) were detected over time. No changes in other dietary intake variables were observed. Mode of exercise and disease state may be important factors in determining whether dietary modifications occur with exercise initiation, among previously sedentary adults. Successful initiation of RT may represent an opportunity for health care professionals to promote beneficial changes in dietary habits, among older adults with prediabetes.

Guide to Health: A Randomized Controlled Trial of the Effects of a Completely WEB-Based Intervention on Physical Activity, Fruit and Vegetable Consumption, and Body Weight.

BACKGROUND: Theory-based, efficacious, long-term, completely Internet-based interventions are needed to induce favorable shifts in health behaviors and prevent weight gain. PURPOSE: To assess nutrition, physical activity, and, secondarily, body weight outcomes in the tailored, social cognitive theory Guide to Health (WB-GTH) program with all recruitment, assessment, and intervention performed on the Internet. METHODS: The focus of the efficacy study was engaged participants who completed 3 or more program modules plus baseline, 6-months post and, 16-months follow-up assessments (n = 247). To be eligible, participants needed to be between 18-63 years of age, with a BMI between 23-39, sedentary to low-active but otherwise healthy. Participant had a mean age of 45.5 years (10.3), 86.2% were female, with 8.5% from minority groups, with a mean 17.5 (3.0) years of education, and had a median annual household income of about $85k. Nevertheless, about 83% were overweight or obese and about 75% were sedentary (i.e., <5000 steps/day) or had low levels of activity (i.e., 5,000 - 7499 steps/day). Participants were randomized to the WB-GTH-Basic intervention or WB-GTH-Enhanced intervention. Content, overall target behaviors, program goals and strategies were the same in the two interventions with the difference that Basic included a generic feedback and planning approach and Enhanced included a highly tailored planning and feedback approach. Participants reported at assessments pedometer step counts to assess physical activity, bodyweight from a scale provided, and fruit and vegetable (F&V) servings were assessed from food frequency questionnaires completed online. RESULTS: Participants in both Basic and Enhanced at follow-up increased physical activity by about 1400 steps/day, lost about 3% of bodyweight, and increased F&V by about 1.5 serving/day. There was evidence that the least physically active, those who were obese, and those with poorest nutrition made greater long-term improvements. CONCLUSIONS: Given similar outcomes for Basic and Enhanced, a relatively simple entirely Internet-based program can help people improve health behaviors and prevent weight gain.

Guide to health: nutrition and physical activity outcomes of a group-randomized trial of an Internet-based intervention in churches.

BACKGROUND: Theory-based interventions accessible to large groups of people are needed to induce favorable shifts in health behaviors and body weight. PURPOSE: The aim was to assess nutrition; physical activity; and, secondarily, body weight in the tailored, social cognitive Guide to Health (GTH) Internet intervention delivered in churches. METHODS: Participants (N = 1,071; 33% male, 23% African American, 57% with body mass index > or = 25, 60% sedentary, Mdn age = 53 years) within 14 Baptist or United Methodist churches were randomized to the GTH intervention only (GTH-Only; 5 churches), with church-based supports (GTH-Plus; 5 churches), or to a waitlist (control; 4 churches). Verified pedometer step counts, measured body weight, fat, fiber, and fruit and vegetable (F&V) servings from food frequency and supermarket receipts were collected at pretest, posttest (7 months after pretest), and follow-up (16 months after pretest). RESULTS: Participants in GTH-Only increased F&V at post (approximately 1.50 servings) compared to control (approximately 0.50 servings; p = .005) and at follow-up (approximately 1.20 vs. approximately 0.50 servings; p m = .038) and increased fiber at post (approximately 3.00 g) compared to control (approximately 1.5 g; p = .006) and follow-up (approximately 3.00 g vs. approximately 2.00 g; p = .040). GTH-Plus participants compared to control increased steps at post (approximately 1,500 steps/day vs. approximately 400 steps/day; p = .050) and follow-up (approximately 1,000 steps/day vs. approximately - 50 steps/day; p = .010), increased F&V at post (approximately 1.5 servings; p = .007) and follow-up (approximately 1.3 servings; p = .014), increased fiber at post (approximately 3.00A g; p = .013), and follow-up (approximately 3.00; p = .050) and decreased weight at post (approximately - 0.30 kg vs. approximately + 0.60 kg; p = .030). CONCLUSIONS: Compared to control, both GTH treatments improved nutrition at posttest, but church supports improved physical activity and nutrition at posttest and follow-up, suggesting environmental supports may improve Internet-based interventions.

Long-term weight gain prevention: a theoretically based Internet approach.

BACKGROUND: A major focus of Healthy People 2010 is promoting weight management and physical activity because overweight, obesity, and a sedentary lifestyle are strongly associated with risk for heart disease and stroke, diabetes, cancers, and premature death. METHODS: Prevalence data and a focused review of weight management and physical activity studies point to the long-term weight gain prevention in normal weight (21-25 BMI), overweight (25-29 BMI), and even moderate obese (30-34 BMI) people as one alternative to prioritizing weight loss in health behavior interventions. This is because on a population basis annual weight gain is small (approximately 0.8 kg/year) and preventing weight gain appears to require only an energy shift of about 100 cal/day either through a modest increase in physical activity and/or consuming slightly less calories to maintain an energy balance. A more dynamic use of social cognitive theory (SCT) for developing programs to maintain health behavior changes is emerging with some evidence of long-term maintenance. The high use of the Internet provides a vehicle to reach different population segments with readily accessible, SCT-tailored long-term programs. Research studies using the Internet with tailored SCT interventions have shown changes in nutrition practices, physical activity, and weight loss for up to a year. CONCLUSIONS: One promising approach to weight gain prevention in population segments is the development and wide spread use of longer-term Internet programs using specific principles and procedures from SCT.