Remote delivery of a weight management intervention for adults with intellectual disabilities: Results from a randomized non-inferiority trial.

BACKGROUND: Remote delivery of multi-component weight management interventions results in clinically meaningful weight loss in adults without intellectual disabilities (ID), but the effectiveness of remotely delivered weight management interventions in adults with ID has not previously been evaluated. OBJECTIVE: To determine if a weight management intervention delivered remotely could achieve weight loss (kg) at 6 months that is non-inferior to in-person visits in adults with ID and overweight or obesity (BMI ≥25 kg/m2). METHODS: Participants were randomized to a 24-mo. trial (6 mos weight loss,12 mos weight maintenance, 6 mos. no-contact follow up) to compare weight loss achieved with the same multicomponent intervention delivered to individual participants in their home either remotely (RD) or during face-to-face home visits (FTF). RESULTS: One hundred twenty adults with ID (∼32 years of age, 53 % females) were randomized to the RD (n = 60) or the FTF arm (n = 60). Six-month weight loss in the RD arm (-4.9 ± 7.8 kg) was superior to 6-month weight loss achieved in the FTF arm (-2.1 ± 6.7 kg, p = 0.047). However, this may be partially attributed to the COVID-19 pandemic, since weight loss in the FTF arm was greater in participants who completed the intervention entirely pre-COVID (n = 33,-3.2 %) compared to post-COVID (n = 22, -0.61 %). Weight loss across did not differ significantly between intervention arms at 18 (p = 0.33) or 24 months (p = 0.34). CONCLUSION: Our results suggest that remote delivery is a viable option for achieving clinically relevant weight loss and maintenance in adults with ID. NCT REGISTRATION: NCT03291509.

Intrapersonal, interpersonal and environmental correlates of moderate to vigorous physical activity and sedentary time in adolescents with intellectual and developmental disabilities.

BACKGROUND: Although correlates of physical activity (PA) have been extensively examined in both children and adolescents who are typically developing, little is known about correlates of moderate to vigorous physical activity (MVPA) and sedentary time in adolescents with intellectual and developmental disabilities (IDD). Therefore, we examined intrapersonal, interpersonal and environmental factors and their association with device-based MVPA and sedentary time in adolescents with IDD. METHODS: MVPA and sedentary time was assessed using a hip-worn ActiGraph model wGT3x-BT tri-axial accelerometer across a 7-day period in adolescents with IDD and one of their parents. Pearson and point-biserial correlations were calculated to inspect the associations of PA (MVPA, sedentary time) with intrapersonal factors (demographic characteristic, BMI, waist circumference, motor ability, muscle strength, grip strength, cardiovascular fitness and self-efficacy for PA), interpersonal factors (parent demographics, parent BMI, parent MVPA and sedentary time, family social support for PA, parent barriers and support for PA, parent's beliefs/attitudes towards PA and number of siblings), and environmental factors (meteorologic season and COVID-19). Ordinary least squares regression was used to estimate the unique contributions of key factors to PA after controlling for participants' age, sex, race, waist circumference and total wear time. RESULTS: Ninety-two adolescents (15.5 ± 3.0 years old, 21.7% non-White, 6.5% Hispanic, 56.5% female) provided valid accelerometer data. Average sedentary time was 494.6 ± 136.4 min/day and average MVPA was 19.8 ± 24.2 min/day. Age (r = 0.27, P = 0.01), diagnosis of congenital heart disease (r = -0.26, P = 0.01) and parent sedentary time (r = 0.30, P = 0.01) were correlated with sedentary time. BMI (r = -0.24, P = 0.03), waist circumference (r = -0.28, P = 0.01), identifying as White (r = -0.23, P = 0.03) and parent MVPA (r = 0.56, P < 0.001) were correlated with MVPA. After adjusting for the adolescent's age, sex, race, waist circumference, and total wear time, the association between parent and adolescent MVPA remained significant (b = 0.55, P < 0.01, partial η2  = 0.11). CONCLUSION: The results of this study provide evidence that race, waist circumference and parental MVPA may influence the amount of MVPA in adolescents with IDD. The limited available information and the potential health benefits of increased MVPA highlight the need to evaluate the effectiveness of multi-component interventions targeting both intrapersonal and interpersonal levels to promote increased PA in adolescents with IDD.

Changes in physical activity across a 6-month weight loss intervention in adolescents with intellectual and developmental disabilities.

BACKGROUND: Adolescents and young adults with intellectual and developmental disabilities (IDD) have high rates of obesity and low levels of physical activity. This analysis examined changes in light, moderate-to-vigorous physical activity (MVPA) and sedentary time, and the association between changes in MVPA and weight loss in adolescents and young adults with IDD and overweight and obesity participating in a 6-month multi-component weight loss intervention. METHODS: Adolescents and young adults with IDD and overweight or obesity (body mass index ≥ 85 percentile, n = 110, age ~16 years, 52.7% female) and a parent were randomised to one of three intervention groups: face-to-face delivery/conventional reduced energy diet (n = 36), remote delivery (RD)/conventional reduced energy diet (n = 39), or RD/reduced energy enhanced stop light diet (eSLD) (n = 35.) Participants were asked to engage in 60 min/day of MVPA on 5 or more days/wk. Participants and a parent attended twice monthly education/behavioural counselling sessions with a health educator to assist participants in complying with dietary and MVPA recommendations. Education/counselling in the RD arms was delivered remotely using video conferencing, and self-monitoring of MVPA and daily steps was completed using a wireless activity tracker. Education/counselling in the face-to-face arm was delivered during home-visits and self-monitoring of MVPA and daily steps was completed by self-report using paper tracking forms designed for individuals with IDD. MVPA, light activity, and sedentary time were assessed over 7 days at baseline and 6 months using a portable accelerometer (ActiGraph wGT3x-BT). RESULTS: Mixed modelling analysis completed using participants with valid accelerometer data (i.e. ≥4-10 h days) at baseline (n = 68) and 6 months (n = 30) revealed no significant changes in light, moderate- MVPA, or sedentary time across the 6-month intervention (all P > 0.05). Participants obtained 15.2 ± 21.5 min/day of MVPA at baseline and 19.7 ± 19.7 min/day at 6 months (P = 0.119). Mixed modelling indicated no significant effects of group (P = 0.79), time (P = 0.10), or group-by-time interaction (P = 0.21) on changes in MVPA from baseline to 6 months. Correlational analysis conducted on participants with valid accelerometer data at both baseline and 6 months (n = 24) revealed no significant associations between baseline sedentary time (r = 0.10, P = 0.40) and baseline MVPA (r = -0.22, P = 0.30) and change in MVPA across the 6-month intervention. Additionally, attendance at education/counselling sessions (r = 0.26, P = 0.22) and frequency of self-monitoring of MVPA were not significantly associated with change in MVPA from baseline to 6 months (r = 0.26, P = 0.44). Baseline MVPA (r = 0.02, P = 0.92) and change in MVPA from baseline to 6 months (r = 0.13, P = 0.30) were not associated with changes in body weight across the 6-month intervention. CONCLUSION: We observed a non-significant increase in MVPA (30%), which was not associated with the magnitude of weight loss in a sample of adolescents and young adults with IDD who participated in a 6-month multi-component weight loss intervention. Additional strategies to increase MVPA in adolescents and young adults with IDD participating in weight loss interventions need to be developed and evaluated.

Exploring the effectiveness of an 18-month weight management intervention in adults with Down syndrome using propensity score matching.

BACKGROUND: Down syndrome (DS) is one of the most common birth defects in the USA associated with high levels of overweight and obesity. Unique characteristics of adults with DS that may contribute to the high levels of obesity are high rates of hypothyroidism, poor muscle tone, altered gait and lower resting metabolic rate. Due to these factors, it is unknown if the same weight management interventions that are effective in adults with intellectual or developmental disability (IDD) without DS are as effective in those with DS. Therefore, the purpose of this secondary analysis was to compare changes in weight, diet and physical activity between participants with DS-related and non-DS-related IDD participating in an 18-month weight management trial. METHODS: We used propensity score methods to adjust baseline variables of overweight/obese adults with and without DS participating in an 18-month effectiveness trial with 6 months weight loss and 12 months weight maintenance. Participants followed one of two reduced calorie diet plans, obtained 150 min of moderate-vigorous intensity physical activity (MVPA) per week, and logged dietary intake daily. A health educator held monthly at-home visits with participants and a caregiver to give feedback on intervention compliance. RESULTS: Out of the 124 participants that met the criteria for inclusion, 21 were diagnosed with DS and 103 with non-DS-related IDD. Twenty out of 21 participants with DS were successfully matched. Clinically significant weight loss was seen at 18 months in participants with DS (-5.2%) and non-DS-related IDD (-6.8%), with no difference between groups (P = 0.53). Significant reductions in energy intake were seen across the 18-month intervention in both DS and non-DS-related IDD groups with between-group differences at 12 months only (1119 vs. 1492 kcal/day, respectively; P = 0.003). Although MVPA did not increase in either group across the intervention, those with non-DS-related IDD had higher levels of MVPA compared with those with DS across 18 months. CONCLUSION: Participants with DS lost a clinically significant amount of weight across the 18-month intervention. Compared with those with non-DS-related IDD, those with DS lost similar amounts of weight, had similar decreases in energy intake and participated in less MVPA across the 18-month intervention. Although individuals with DS have physiological factors that may contribute to obesity, weight management interventions designed for individuals with IDD may be equally effective in this population.

Individual and family-based approaches to increase physical activity in adolescents with intellectual and developmental disabilities: Rationale and design for an 18 month randomized trial.

Adolescents with intellectual and developmental disabilities (IDD) are less physically active and have lower cardiovascular fitness compared with their typically developing peers. This population faces additional barriers to participation in moderate-to-vigorous physical activity (MVPA) such as reliance on parents, lack of peer-support, and lack of inclusive physical activity opportunities. Previous interventions to increase MVPA in adolescents with IDD have met with limited success, at least in part due to requiring parents to transport their adolescent to an exercise facility. We recently developed a remote system to deliver MVPA to groups of adolescents with IDD in their homes via video conferencing on a tablet computer. This approach eliminates the need for transportation and provides social interaction and support from both a health coach and other participants. We will conduct a 18-mo. trial (6 mos. active, 6 mos. maintenance, 6 mos. no-contact follow-up) to compare changes in objectively assessed MVPA in 114 adolescents with IDD randomized to a single level intervention delivered only to the adolescent (AO) or a multi-level intervention delivered to both the adolescent and a parent (A + P). Our primary aim is to compare increases in MVPA (min/d) between the AO and A + P groups from 0 to 6 mos. Secondarily we will compare changes in MVPA, sedentary time, cardiovascular fitness, muscular strength, motor ability, quality of life, and the percentage of adolescents achieving the US recommendation of 60 min. MVPA/d across 18 mos. We will also explore the influence of process variables/participant characteristics on changes in MVPA across 18 mos. NCT registration: NCT03684512.

The feasibility of using pedometers for self-report of steps and accelerometers for measuring physical activity in adults with intellectual and developmental disabilities across an 18-month intervention.

BACKGROUND: Improving physical activity in adults with intellectual and developmental disabilities (IDDs) is recommended to improve weight loss and general health. However, in order to determine the success of physical activity interventions, identification of feasible methods for assessment of physical activities is necessary. The purpose of this study is to assess the feasibility of adults with IDD to track daily steps and wear an accelerometer. METHODS: Overweight/obese adults with mild to moderate IDD followed a diet and physical activity program for 18 months. All participants were asked to wear a pedometer and track steps daily by using a pedometer and to provide accelerometer data for 7 days at baseline, 6, 12 and 18 months. Adherence to the pedometer protocol and plausibility of the number of recorded steps were assessed, and these measures along with average wear time of the accelerometer were recorded. RESULTS: Data were collected from 149 participants (36.5 ± 12.2 years of age, 57% female). Participants recorded a step value on 81.5% of days across the 18-month study, with 40.9% of written days classified as plausible. When wearing the accelerometer, 26.8% of participants met the recommended 4-day/10-h wear time criterion at baseline, and 22.6, 24.8 and 18.8% met the criterion at 6, 12 and 18 months, respectively. CONCLUSIONS: Adults with IDD will adhere reasonably well to wearing a pedometer long term, but may be unable to record the step data accurately. Furthermore, adults with IDD have poor compliance with accelerometer protocols, and future studies should determine if a shorter wear time protocol would produce valid data in this population.

Caregivers' effect on weight management in adults with intellectual and developmental disabilities.

INTRODUCTION: Caregivers of adults with IDD often play a large role in the ability of adults with IDD to lose weight. OBJECTIVE: The purpose of this study was to determine to examine the effects of the caregivers' perceived burdens and self-efficacy and their relationship to an individual (family member or paid staff) on weight changes across a weight management intervention for adults with IDD. METHODS: Overweight/obese adults with mild to moderate IDD, along with assigned caregivers who served as their study partner, were randomized to an 18-month weight management intervention. The living environment and caregiver relationship were assessed at baseline. Caregivers completed questionnaires regarding perceived hassles, uplifts, and self-efficacy in helping the participant follow a weight management intervention. RESULTS: 147 adults with IDD (∼57% women and ∼16% minorities) were included in data analysis. After 18 months, there were no differences in weight loss between participants who had a family member as their study partner and those who had a paid assistant as their study partner (-5.5 ± 5.2% vs. -5.6± 5.3% p = 0.16). However, paid assistants reported more hassles with following the diet intervention at 6 months (p < 0.05). Participants who had a paid assistant as their study partner were more likely to have multiple study partners during the study, which was correlated with smaller weight loss. CONCLUSION: While caregivers are important for weight management of adults with IDD, the caregiver's relationship to the participant does not affect weight change in an intervention.

Weight management for adolescents with intellectual and developmental disabilities: Rationale and design for an 18month randomized trial.

Adolescents with intellectual and developmental disabilities (IDD) are an underserved group in need of weight management. However, information regarding effective weight management for this group is limited, and is based primarily on results from small, non-powered, non-randomized trials that were not conducted in accordance with current weight management guidelines. Additionally, the comparative effectiveness of emerging dietary approaches, such as portion-controlled meals (PCMs) or program delivery strategies such as video chat using tablet computers have not been evaluated. Therefore, we will conduct an 18month trial to compare weight loss (6months) and maintenance (7-18months) in 123 overweight/obese adolescents with mild to moderate IDD, and a parent, randomized to a weight management intervention delivered remotely using FaceTime™ on an iPad using either a conventional meal plan diet (RD/CD) or a Stop Light diet enhanced with PCMs (RD/eSLD), or conventional diet delivered during face-to-face home visits (FTF/CD). This design will provide an adequately powered comparison of both diet (CD vs. eSLD) and delivery strategy (FTF vs. RD). Exploratory analyses will examine the influence of behavioral session attendance, compliance with recommendations for diet (energy intake), physical activity (min/day), self-monitoring of diet and physical activity, medications, and parental variables including diet quality, physical activity, baseline weight, weight change, and beliefs and attitudes regarding diet and physical activity on both weight loss and maintenance. We will also complete a cost and contingent valuation analysis to compare costs between RD and FTF delivery.

A virtual reality intervention (Second Life) to improve weight maintenance: Rationale and design for an 18-month randomized trial.

Despite the plethora of weight loss programs available in the US, the prevalence of overweight and obesity (BMI≥25kg/m(2)) among US adults continues to rise at least, in part, due to the high probability of weight regain following weight loss. Thus, the development and evaluation of novel interventions designed to improve weight maintenance are clearly needed. Virtual reality environments offer a promising platform for delivering weight maintenance interventions as they provide rapid feedback, learner experimentation, real-time personalized task selection and exploration. Utilizing virtual reality during weight maintenance allows individuals to engage in repeated experiential learning, practice skills, and participate in real-life scenarios without real-life repercussions, which may diminish weight regain. We will conduct an 18-month effectiveness trial (6 months weight loss, 12 months weight maintenance) in 202 overweight/obese adults (BMI 25-44.9kg/m(2)). Participants who achieve ≥5% weight loss following a 6month weight loss intervention delivered by phone conference call will be randomized to weight maintenance interventions delivered by conference call or conducted in a virtual environment (Second Life®). The primary aim of the study is to compare weight change during maintenance between the phone conference call and virtual groups. Secondarily, potential mediators of weight change including energy and macronutrient intake, physical activity, consumption of fruits and vegetables, self-efficacy for both physical activity and diet, and attendance and completion of experiential learning assignments will also be assessed.

Portion-controlled meals provide increases in diet quality during weight loss and maintenance.

BACKGROUND: Behavioural weight-loss interventions utilising portion-controlled meals (PCMs) produce significant decreases in weight. However, their impact on diet quality during weight maintenance is unknown. The present study aimed to assess the influence of a weight management intervention employing PCMs and increased physical activity on diet quality during weight loss and weight maintenance. METHODS: One hundred and ninety-seven overweight and obese adults [67% women; mean (SD) BMI = 34.0 (4.6) kg m(-2); age = 46.1 (8.9) years] completed an 18-month trial. The weight-loss phase (0-6 months) consisted of energy restriction, which was achieved using PCMs plus fruits and vegetables and increased physical activity. During weight maintenance (6-18 months), participants consumed a diet designed to maintain weight loss. Body weight and dietary intake were assessed at baseline, and at 6, 12 and 18 months. The Healthy Eating Index-2010 (HEI) was calculated using data obtained from 3-day food records. RESULTS: Mean (SD) body weight was 14.3% (6.6%) and 8.7% (8.0%) below baseline at 6 and 18 months, respectively. The mean (SD) HEI-2010 score after weight loss [66.6 (9.4)] was significantly higher than baseline [46.4 (8.9)] and remained significantly higher than baseline at 18 months [57.7 (10.6)] (both P < 0.001). CONCLUSIONS: A weight management intervention using PCMs resulted in both clinically significant weight loss and increased diet quality scores, demonstrating that the use of PCMs during weight loss allows for meaningful changes in diet quality during weight maintenance.

Does increased prescribed exercise alter non-exercise physical activity/energy expenditure in healthy adults? A systematic review.

Prescribed physical activity/exercise training may reduce non-exercise physical activity resulting in no change in total daily energy expenditure and no or minimal exercise-induced weight loss. This systematic review evaluated cross-sectional, short-term (2-14 d), randomized and non-randomized trials which reported on the effect of prescribed physical activity/exercise on non-exercise physical activity/energy expenditure in healthy adults. PubMed and Embase were searched (from January 1990 to March 2013) for articles that presented data on the change in non-exercise physical activity/energy expenditure in response to prescribed physical activity/exercise training. Thirty-one articles were included in this review. One-hundred per cent of cross-sectional studies (n = 4), 90% of short-term studies (n = 10), 50% of non-randomized trials (n = 10) and 100% of randomized trials (n = 7) reported no reductions in non-exercise physical activity/energy expenditure in response to prescribed physical activity/exercise training. We found minimal evidence to support the hypothesis that prescribed physical activity/exercise training results in decreased non-exercise physical activity/energy expenditure in healthy adults. However, this literature is limited by the lack of adequately powered trials designed specifically to evaluate this hypothesis which have included assessments of both the energy expenditure of prescribed exercise and non-exercise energy expenditure using state-of-the-art techniques, i.e. indirect calorimetry and doubly labelled water, respectively.

Weight management for individuals with intellectual and developmental disabilities: rationale and design for an 18 month randomized trial.

Weight management for individuals with intellectual and developmental disabilities (IDD) has received limited attention. Studies on weight management in this population have been conducted over short time frames, in small samples with inadequate statistical power, infrequently used a randomized design, and have not evaluated the use of emerging effective dietary strategies such as pre-packaged meals (PMs). Low energy/fat PMs may be useful in individuals with IDD as they simplify meal planning, limit undesirable food choices, teach appropriate portion sizes, are convenient and easy to prepare, and when combined with fruits and vegetables provide a high volume, low energy dense meal. A randomized effectiveness trial will be conducted in 150 overweight/obese adults with mild to moderate IDD, and their study partners to compare weight loss (6 months) and weight maintenance (12 months) between 2 weight management approaches: 1. A Stop Light Diet enhanced with reduced energy/fat PMs (eSLD); and 2. A recommended care reduced energy/fat meal plan diet (RC). The primary aim is to compare weight loss (0-6 months) and weight maintenance (7-18 months) between the eSLD and RC diets. Secondarily, changes in chronic disease risk factors between the eSLD and RC diets including blood pressure, glucose, insulin, LDL-cholesterol, and HDL-cholesterol will be compared during both weight loss and weight maintenance. Finally, potential mediators of weight loss including energy intake, physical activity, data recording, adherence to the diet, study partner self-efficacy and daily stress related to dietary change will be explored.

Effects of growth hormone treatment in adults with Prader-Willi syndrome.

OBJECTIVE: Since limited data exist on adults with Prader-Willi syndrome (PWS) and growth hormone (GH) treatment, we report our experience on the effects of treatment for one year on body composition, physical activity, strength and energy expenditure, diet, general chemistry and endocrine data with quality of life measures. DESIGN: We studied 11 adults with PWS (6F:5M; average age=32 yrs) over a 2 year period with GH treatment during the first year only. Electrolytes, IGF-I, glucose, thyroid, insulin, lipids, body composition, physical activity and strength, diet, energy expenditure and quality of life data were collected and analyzed statistically using linear modeling at baseline, at 12 months following GH therapy and at 24 months after treatment cessation for 12 months. RESULTS: Total lean muscle mass was significantly increased (p<0.05) during GH treatment along with moderate-vigorous physical activity and plasma IGF-I and HDL levels, but returned to near baseline after treatment. Percent body fat decreased during the 12 months of GH treatment but increased after treatment. CONCLUSIONS: Previously reported beneficial effects of GH treatment in children with PWS were found in our adults regarding body composition, physical activity and plasma HDL and IGF-I levels. Several beneficial effects diminished to near baseline after cessation of GH treatment for 12 months supporting the continuation of treatment in PWS into adulthood and possibly adults not previously treated during childhood.

Indirect and direct relations between aerobic fitness, physical activity, and academic achievement in elementary school students.

BACKGROUND: There is evidence to suggest that increasing physical activity (PA) improves academic achievement (AA) in children and that aerobic fitness is associated with both cognitive function and AA. However, it is not known how these variables are interrelated and analyses with adequate control for socioeconomic variables are needed. It was hypothesized that PA would not directly affect AA but would have an indirect effect on AA through its effect on aerobic fitness. The purpose of this study was to test this hypothesized mediation using path analysis. METHODS: Cross-sectional data including AA, aerobic fitness, and daily PA assessed through accelerometry were collected from a large sample (N = 687) of 2nd and 3rd grade students. Demographic data were assessed via parent self-report. RESULTS: A total of 401 students wore the accelerometer for at least 10 hours on 3 days or more and were included in the final path analysis to evaluate potential relations among PA (predictor), aerobic fitness (mediator), and WIAT-III subtest standard scores (outcomes; i.e., reading, spelling, and mathematics). Findings showed a direct effect of PA on aerobic fitness (b = 0.009, p < 0.001) and an indirect effect (mediation) of PA via fitness on math achievement (b = 0.003, p < 0.01) after controlling for student's grade, gender, body mass index, mother's education level, and household income, as well as intraclass correlations among classes and schools. Neither PA nor aerobic fitness were correlated with WIAT-III reading or spelling scores. CONCLUSIONS: Mediation analysis indicated that PA exerted an influence on math achievement through its effects on aerobic fitness but was not associated with reading or spelling achievement scores.

One set resistance training: effect on body composition in overweight young adults.

AIM: This study evaluate the impact of a 6-month, 1-set RT protocol on changes in weight and body composition in overweight young adults. METHODS: Sixty-three overweight young adults were randomized to RT or control; 55 participants (RT: N.=32; C: N.=23; BMI=27.3+2.9; age=20.7+2.7 yrs) competed the 6 month training protocol and all assessments. RT consisted of 1-set, 9 exercises, 3 times/wk., with a resistance of 3-6 repetition maximum (RM). Body composition was assessed using dual energy X-ray absorptiometry, and strength using 1RM. Participants were instructed to maintain their normal ad libitum diet and normal activities of daily living. RESULTS: Body weight and BMI increased significantly (P<0.05) in RT and C, however; the between group difference was not significant. RT induced a mean increase in fat-free mass of 1.5 kg in both males and females with significant between groups differences for change in fat-free mass noted in the total sample, and in both males and females. Between group differences for change in fat mass were not statistically significant in the total sample, or in either gender. Significant between group differences for change in % fat were noted in the total sample (RT=-0.3%, C=+5.8%, P<0.05) and in females (RT=-3.7%, C=+3.0%, P<0.01), but not in males (RT=3.4%, C=9.8%). Significant between group differences (P<0.001) were observed for change in chest (RT=45 %, C=3%) and leg press (RT=57 %, C=9%) maximal strength. CONCLUSION: A 6 month, 1-set RT program in overweight young adults increased fat-free mass and prevented increases in fat mass and % fat.

Total body bone mineral content and density during weight loss and maintenance on a low- or recommended-dairy weight-maintenance diet in obese men and women.

BACKGROUND: Diets high in either dairy or calcium during moderate weight reduction both prevent loss of bone mineral density (BMD) and suppress bone turnover. The purpose of this study was to determine whether recommended dairy and calcium intakes during weight maintenance favorably affect total body BMD (TBBMD) and bone mineral content (TBBMC) in obese adults. METHODS: Obese men (n=49) and women (n=64), aged 40.8+/-0.6 years, underwent 12 weeks of moderate energy restriction (approximately 1200 kcal/day) followed by 24 weeks on either a low or recommended dairy weight maintenance diet. The TBBMC and TBBMD values were measured using dual energy X-ray absorptiometry at baseline, 12, 24 and 36 weeks. Concentrations of calcium, intact parathyroid hormone (iPTH), 25OH and 1,25 (OH)(2) vitamin D in plasma were also measured. Data were analyzed using a two-factor repeated measures analysis of variance. RESULTS: After weight loss, women exhibited a small, but statistically significant, increase in TBBMC (1.17+/-0.57%), whereas TBBMD increased in the men (1.34+/-0.28%). The iPTH concentration decreased significantly in all subjects. Despite significantly greater intakes of calcium, vitamin D and protein compared with the recommended dairy diet, there were no treatment-related differences in outcome variables after 24 weeks of weight maintenance. The TBBMC remained unchanged in women during weight stabilization; both TBBMC and TBBMD decreased in men (-1.59+/-0.51% and -0.70+/-0.25%, respectively). CONCLUSIONS: In summary, results of this study do not provide convincing evidence that moderate weight loss through energy restriction and mild exercise reduces TBBMC in obese men and women. Similarly, a weight-maintenance diet providing the recommended daily servings of dairy does not seem to affect changes in BMC after weight loss.

Cardiorespiratory fitness and brain atrophy in early Alzheimer disease.

OBJECTIVE: To examine the correlation of cardiorespiratory fitness with brain atrophy and cognition in early-stage Alzheimer disease (AD). BACKGROUND: In normal aging physical fitness appears to mitigate functional and structural age-related brain changes. Whether this is observed in AD is not known. METHODS: Subjects without dementia (n = 64) and subjects with early-stage AD (n = 57) had MRI and standard clinical and psychometric evaluations. Peak oxygen consumption (VO(2)(peak)), the standard measure of cardiorespiratory fitness, was assessed during a graded treadmill test. Normalized whole brain volume, a brain atrophy estimate, was determined by MRI. Pearson correlation and linear regression were used to assess fitness in relation to brain volume and cognitive performance. RESULTS: Cardiorespiratory fitness (VO(2)(peak)) was modestly reduced in subjects with AD (34.7 [5.0] mL/kg/min) vs subjects without dementia (38.1 [6.3] mL/kg/min, p = 0.002). In early AD, VO(2)(peak) was associated with whole brain volume (beta = 0.35, p = 0.02) and white matter volume (beta = 0.35, p = 0.04) after controlling for age. Controlling for additional covariates of sex, dementia severity, physical activity, and physical frailty did not attenuate the relationships. VO(2)(peak) was associated with performance on delayed memory and digit symbol in early AD but not after controlling for age. In participants with no dementia, there was no relationship between fitness and brain atrophy. Fitness in participants with no dementia was associated with better global cognitive performance (r = 0.30, p = 0.02) and performance on Trailmaking A and B, Stroop, and delayed logical memory but not after controlling for age. CONCLUSIONS: Increased cardiorespiratory fitness is associated with reduced brain atrophy in Alzheimer disease (AD). Cardiorespiratory fitness may moderate AD-related brain atrophy or a common underlying AD-related process may impact both brain atrophy and cardiorespiratory fitness.

Weight maintenance, behaviors and barriers among previous participants of a university-based weight control program.

OBJECTIVE: To examine weight loss maintenance among previous participants of a university-based behavioral weight management program and to compare behavioral strategies and perceived barriers between successful and unsuccessful maintainers. METHOD: Previous program participants (n=179) completed mailed surveys assessing current weight, weight control behaviors and perceived barriers to weight loss maintenance. RESULTS: At 14.1+/-10.8 months following completion of treatment, survey respondents were on average 12.6+/-12.6 kg, or 11.3+/-10.7%, below baseline weight; 76.5% of respondents had successfully maintained weight, defined as maintaining a weight loss of at least 5% below baseline. Compared to unsuccessful maintainers, successful maintainers reported practicing four dietary and three physical activity weight control strategies more often and experiencing five barriers to healthy eating and exercise less often. After accounting for time since treatment and maximum weight loss while in treatment, the strongest correlates of successful weight loss maintenance were frequent exercise and perceived difficulty of weight management. CONCLUSIONS: Clinically meaningful weight loss maintenance was achieved by the majority of participants. Findings support the literature indicating that physical activity is one of the strongest predictors of successful weight loss maintenance. Findings also suggest that strategies to reduce the level of perceived effort required for long-term weight control may improve maintenance outcomes.

Effects of long-term aerobic exercise on EPOC.

This study sought to determine the influence of 16 months of progressive aerobic exercise on excess postexercise oxygen consumption (EPOC) and the extent EPOC contributed to weight management. Twenty-five overweight/obese women and 16 overweight/obese men participated in a 16-month exercise program (moderate-intensity treadmill walking) that progressed across the first 26 weeks to 5 days.wk(-1), 45 min.session(-1), and 75% HRR. Three-hour EPOC was measured at baseline, 9 months, and 16 months by indirect calorimetry in response to an exercise session (treadmill walking), in which energy expenditure (EE) was estimated from the participant's previous 10 exercise sessions. For women, EPOC was 7.5 +/- 4.9, 9.6 +/- 7.6, and 6.5 +/- 6.5 L at baseline, 9 months, and 16 months, respectively (p > 0.05). For men, EPOC increased from baseline (11.8 +/- 6.8 L) to 9 months (13.5 +/- 8.6 L) (p < 0.05) with no further increase at 16 months (13.5 +/- 11.0 L). Change in EPOC was correlated with change in EE at 9 months (r = 0.65; p < 0.05) and 16 months (r = 0.58; p < 0.05) for men but not women. Progressive long-term exercise significantly influenced EPOC in overweight/obese men but not women. Change in volume of exercise likely explained the increase in energy expenditure during EPOC in men. EPOC contributed modestly to EE compared to the exercise itself.

Peripheral insulin and brain structure in early Alzheimer disease.

OBJECTIVE: Accumulating evidence suggests insulin and insulin signaling may be involved in the pathophysiology of Alzheimer disease (AD). The relationship between insulin-mediated glucoregulation and brain structure has not been assessed in individuals with AD. METHODS: Nondemented (Clinical Dementia Rating [CDR] 0, n = 31) and early stage AD (CDR 0.5 and 1, n = 31) participants aged 65 years and older had brain MRI to determine whole brain and hippocampal volume and 3-hour IV glucose tolerance tests to determine glucose and insulin area under the curve (AUC). Linear regression models were used to assess the relationship of insulin and glucose with brain volume, cognition, and dementia severity. RESULTS: In early AD, insulin and glucose AUCs were related to whole brain (insulin beta = 0.66, p < 0.001; glucose beta = 0.45, p < 0.01) and hippocampal volume (insulin beta = 0.42, p < 0.05; glucose beta = 0.46, p < 0.05). These relationships were independent of age, sex, body mass index, body fat, cardiorespiratory fitness, physical activity, cholesterol, and triglycerides. Insulin AUC, but not glucose, was associated with cognitive performance in early AD (beta = 0.40, p = 0.04). Insulin AUC was associated with dementia severity (Pearson r = -0.40, p = 0.03). Glucose and insulin were not related to brain volume or cognitive performance in nondemented individuals. CONCLUSIONS: Increased peripheral insulin is associated with reduced Alzheimer disease (AD)-related brain atrophy, cognitive dysfunction, and dementia severity, suggesting that insulin signaling may play a role in the pathophysiology of AD.