The comparison of a technology-based system and an in-person behavioral weight loss intervention.

The purpose of this study was to compare a technology-based system, an in-person behavioral weight loss intervention, and a combination of both over a 6-month period in overweight adults. Fifty-one subjects (age: 44.2 ± 8.7 years, BMI: 33.7 ± 3.6 kg/m(2)) participated in a 6-month behavioral weight loss program and were randomized to one of three groups: standard behavioral weight loss (SBWL), SBWL plus technology-based system (SBWL+TECH), or technology-based system only (TECH). All groups reduced caloric intake and progressively increased moderate intensity physical activity. SBWL and SBWL+TECH attended weekly meetings. SBWL+TECH also received a TECH that included an energy monitoring armband and website to monitor energy intake and expenditure. TECH used the technology system and received monthly telephone calls. Body weight and physical activity were assessed at 0 and 6 months. Retention at 6 months was significantly different (P = 0.005) between groups (SBWL: 53%, SBWL+TECH: 100%, and TECH: 77%). Intent-to-treat (ITT) analysis revealed significant weight losses at 6 months in SBWL+TECH (-8.8 ± 5.0 kg, -8.7 ± 4.7%), SBWL (-3.7 ± 5.7 kg, -4.1 ± 6.3%), and TECH (-5.8 ± 6.6 kg, -6.3 ± 7.1%) (P < 0.001). Self-report physical activity increased significantly in SBWL (473.9 ± 800.7 kcal/week), SBWL+TECH (713.9 ± 1,278.8 kcal/week), and TECH (1,066.2 ± 1,371 kcal/week) (P < 0.001), with no differences between groups (P = 0.25). The TECH used in conjunction with monthly telephone calls, produced similar, if not greater weight losses and changes in physical activity than the standard in-person behavioral program at 6 months. The use of this technology may provide an effective short-term clinical alternative to standard in-person behavioral weight loss interventions, with the longer term effects warranting investigation.

The Influence of Body Mass Index on Self-report and Performance-based Measures of Physical Function in Adult Women.

PURPOSE: Little is known about limitations in physical function across BMI categories in middle aged women using both self-report and performance-based measures. Furthermore, the impact of BMI on the measurement of function has not been explored. The purpose of this study was to assess physical function in adult women across BMI categories using self-report and performance-based measures and determine the influence of BMI on the relationship between the measures. METHODS: Fifty sedentary females (10 in each BMI category: normal weight, overweight, obese class I, II, and III) aged 51.2 ± 5.4 years participated. Assessments included demographics, past medical history, physical activity level, BMI, and self-report (Late Life Function and Disability Instrument) and performance-based measures of physical function (6-Minute Walk Test, timed chair rise, gait speed). Physical function was compared between BMI categories using analysis of variance. The influence of BMI on the relationship of self-report and performance-based measures was analyzed using linear regression. RESULTS: Compared to those that were normal weight or overweight, individuals with obesity scored lower on the self-report measure of physical function (LLFDI) for capability in participating in life tasks and ability to perform discrete functional activities. On the performance-based measures, the individuals with obesity had slower gait speed compared to the normal and overweight weight groups. For the 6-Minute Walk Test and timed chair stands, individuals with obesity had poorer performance compared to those who were normal weight. Linear regression analyses revealed that BMI attenuated the relationship between the self-report and performance-based measures by approximately 50%. CONCLUSIONS: While those with severe obesity were most impaired, adult women with less severe obesity also demonstrated significant decrements in physical function.

The effect of physical activity on 18-month weight change in overweight adults.

Few studies have been conducted that have examined the long-term effect of different doses of physical activity (PA) on weight change in overweight adults without a prescribed reduction in energy intake. This study examined the effect of different prescribed doses of PA on weight change, body composition, fitness, and PA in overweight adults. Two hundred seventy-eight overweight adults (BMI: 25.0-29.9 kg/m²; age: 18-55 years) with no contraindications to PA were randomized to one of three intervention groups for a period of 18 months. MOD-PA was prescribed 150 min/week and HIGH-PA 300 min/week of PA. Self-help group (SELF) was provided a self-help intervention to increase PA. There was no recommendation to reduce energy intake. MOD-PA and HIGH-PA were delivered in a combination of in-person and telephone contacts across 18 months. 18-month percent weight change was -0.7 ± 4.6% in SELF, -0.9 ± 4.7% in MOD-PA, and -1.2 ± 5.6% in HIGH-PA. Subjects were retrospectively grouped as remaining within ±3% of baseline weight (WT-STABLE), losing >3% of baseline weight (WT-LOSS), or gaining >3% of baseline weight (WT-GAIN) for secondary analyses. 18-month weight change was 0.0 ± 1.3% for WT-STABLE, +5.4 ± 2.6% for WT-GAIN, and -7.4 ± 3.6% for WT-LOSS. 18-month change in PA was 78.2 ± 162.6 min/week for WT-STABLE, 74.7 ± 274.3 for WT-GAIN, and 161.9 ± 252.6 min/week for WT-LOSS. The weight change observed in WT-LOSS was a result of higher PA combined with improved scores on the Eating Behavior Inventory (EBI), reflecting the adoption of eating behaviors to facilitate weight loss. Strategies to facilitate the maintenance of these behaviors are needed to optimize weight control.

Physical activity and physical function in individuals post-bariatric surgery.

BACKGROUND: A better understanding of the physical activity behavior of individuals who undergo bariatric surgery will enable the development of effective post-surgical exercise guidelines and interventions to enhance weight loss outcomes. This study characterized the physical activity profile and physical function of 40 subjects 2-5 years post-bariatric surgery and examined the association between physical activity, physical function, and weight loss after surgery. METHODS: Moderate-to-vigorous intensity physical activity (MVPA) was assessed with the BodyMedia SenseWear® Pro (SWPro) armband, and physical function (PF) was measured using the physical function subscale of the 36-Item Short Form Health Survey instrument (SF-36(PF)). Height and weight were measured. RESULTS: Percent of excess weight loss (%EWL) was associated with MVPA (r = 0.44, p = 0.01) and PF (r = 0.38, p = 0.02); MVPA was not associated with PF (r = 0.24, p = 0.14). Regression analysis demonstrated that MVPA was associated with %EWL (ß = 0.38, t = 2.43, p = 0.02). Subjects who participated in ≥150 min/week of MVPA had a greater %EWL (68.2 ± 19, p = 0.01) than those who participated in <150 min/week (52.5 ± 17.4). CONCLUSIONS: Results suggest that subjects are capable of performing most mobility activities. However, the lack of an association between PF and MVPA suggests that a higher level of PF does not necessarily correspond to a higher level of MVPA participation. Thus, the barriers to adoption of a more physically active lifestyle may not be fully explained by the subjects' physical limitations. Further understanding of this relationship is needed for the development of post-surgical weight loss guidelines and interventions.

Effects of diet and physical activity interventions on weight loss and cardiometabolic risk factors in severely obese adults: a randomized trial.

CONTEXT: The prevalence of severe obesity is increasing markedly, as is prevalence of comorbid conditions such as hypertension and type 2 diabetes mellitus; however, apart from bariatric surgery and pharmacotherapy, few clinical trials have evaluated the treatment of severe obesity. OBJECTIVE: To determine the efficacy of a weight loss and physical activity intervention on the adverse health risks of severe obesity. DESIGN, SETTING, AND PARTICIPANTS: Single-blind randomized trial conducted from February 2007 through April 2010 at the University of Pittsburgh. Participants were 130 (37% African American) severely obese (class II or III) adult participants without diabetes recruited from the community. INTERVENTIONS: One-year intensive lifestyle intervention consisting of diet and physical activity. One group (initial physical activity) was randomized to diet and physical activity for the entire 12 months; the other group (delayed physical activity) had the identical dietary intervention but with physical activity delayed for 6 months. MAIN OUTCOME MEASURES: Changes in weight. Secondary outcomes were additional components comprising cardiometabolic risk, including waist circumference, abdominal adipose tissue, and hepatic fat content. RESULTS: Of 130 participants randomized, 101 (78%) completed the 12-month follow-up assessments. Although both intervention groups lost a significant amount of weight at 6 months, the initial-activity group lost significantly more weight in the first 6 months compared with the delayed-activity group (10.9 kg [95% confidence interval {CI}, 9.1-12.7] vs 8.2 kg [95% CI, 6.4-9.9], P = .02 for group × time interaction). Weight loss at 12 months, however, was similar in the 2 groups (12.1 kg [95% CI, 10.0-14.2] vs 9.9 kg [95% CI, 8.0-11.7], P = .25 for group × time interaction). Waist circumference, visceral abdominal fat, hepatic fat content, blood pressure, and insulin resistance were all reduced in both groups. The addition of physical activity promoted greater reductions in waist circumference and hepatic fat content. CONCLUSION: Among patients with severe obesity, a lifestyle intervention involving diet combined with initial or delayed initiation of physical activity resulted in clinically significant weight loss and favorable changes in cardiometabolic risk factors. TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT00712127.

Influence of marriage and parenthood on physical activity: a 2-year prospective analysis.

BACKGROUND: Physical activity (PA) tends to decrease from adolescence to young adulthood, and factors that have been proposed to contribute to this decrease are life transitions. The focus of this study is to examine life transitions, such as marriage and parenthood, and the impact they may have on the physical activity levels of young adults. METHODS: This 2-year prospective analysis assessed physical activity (hrs/wk) and sociodemographics in young adults (n = 638, 48% male, 15% nonwhite, 24 ± 1.1 years old) via questionnaire. PA data were normalized through log transformations and examined using ANCOVAs, controlling for appropriate covariates. RESULTS: ANCOVA results showed that becoming married did not significantly change PA compared with individuals who stayed single [F(1,338) = 0.38, P = .54, d = 0.06]. Conversely, PA was significantly lower [F(1,517) = 6.7, P = .01, d = 0.41] after having a child, compared with individuals who stayed childless. CONCLUSIONS: These results suggest that marriage does not impact PA in young adults, but having a child significantly decreases PA in parents, and may offer an optimal period of intervention.

Acute effect of walking on energy intake in overweight/obese women.

This study examined the acute effect of a bout of walking on hunger, energy intake, and appetite-regulating hormones [acylated ghrelin and glucagon-like peptide-1 (GLP-1)] in 19 overweight/obese women (BMI: 32.5 ± 4.3 kg/m²). Subjects underwent two experimental testing sessions in a counterbalanced order: exercise and rest. Subjects walked at a moderate-intensity for approximately 40 min or rested for a similar duration. Subjective feelings of hunger were assessed and blood was drawn at 5-time points (pre-, post-, 30-, 60-, 120-min post-testing). Ad libitum energy intake consumed 1-2h post-exercise/rest was assessed and similar between conditions (mean ± standard deviation; exercise: 551.5 ± 245.1 kcal [2.31 ± 1.0 MJ] vs. rest: 548.7 ± 286.9 kcal [2.29 ± 1.2 MJ]). However, when considering the energy cost of exercise, relative energy intake was significantly lower following exercise (197.8 ± 256.5 kcal [0.83 ± 1.1 MJ]) compared to rest (504.3 ± 290.1 kcal [2.11 ± 1.2 MJ]). GLP-1 was lower in the exercise vs. resting condition while acylated ghrelin and hunger were unaltered by exercise. None of these variables were associated with energy intake. In conclusion, hunger and energy intake were unaltered by a bout of walking suggesting that overweight/obese individuals do not acutely compensate for the energy cost of the exercise bout through increased caloric consumption. This allows for an energy deficit to persist post-exercise, having potentially favorable implications for weight control.

A prospective observational study of obesity, body composition, and insulin resistance in 18 women with bipolar disorder and 17 matched control subjects.

OBJECTIVE: Patients with bipolar disorder are at increased risk for diabetes and cardiovascular diseases, possibly because of more severe insulin resistance. The primary purpose of this study was to determine whether insulin resistance is characteristic of bipolar disorder. METHOD: The Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) was performed in 18 women with DSM-IV bipolar I disorder, and results were compared to those of 17 matched controls. Other risk factors were compared, including blood pressure, blood lipids, and abdominal obesity by computed tomography (CT). Additionally, substrate utilization was measured by indirect calorimetry, and free-living energy expenditure was estimated using wearable activity monitors. All data were collected between February 2006 and December 2007. RESULTS: Patients with bipolar disorder were no more insulin resistant than controls after accounting for generalized obesity (mean +/- SEM HOMA-IR = 2.7 +/- 0.7 vs. 2.5 +/- 0.7, for patients and controls, respectively; p = .79). Although blood lipid profiles were generally similar in patients and controls, obese patients had higher blood pressure than controls. Obese patients had more mean +/- SEM total abdominal fat (718.1 +/- 35.1 cm² vs. 607.4 +/- 33.6 cm²; p = .04), and tended (p = .06) to have more visceral abdominal fat. Patients oxidized 13% less fat during resting conditions, although their resting metabolic rate was similar to that of controls. CONCLUSION: Women with bipolar I disorder were no more insulin resistant than matched controls after accounting for their level of obesity. However, they were more hypertensive, had higher amounts of abdominal obesity, and had reduced rates of fat oxidation. Therefore, women with bipolar I disorder may be at a heightened risk for future weight gain and concomitant risk for diabetes and cardiovascular disease.

Lifestyle intervention strategies to prevent and control type 2 diabetes.

The intensive lifestyle intervention of the DPP (Diabetes Prevention Program) showed weight loss to be a dominant predictor of reduced diabetes incidence for those at high risk for the disease. The intensive lifestyle intervention of Look AHEAD (Action for Health in Diabetes) has also shown that weight loss is associated with improved diabetes control and cardiovascular risk factors and reduced medicine for those with the disease. DPP and Look AHEAD implemented the use of motivational incentives and campaigns to assist participants in their commitment to lifestyle change. Other studies have also used incentives as effective strategies to engage individuals in weight loss and in making positive physical activity and dietary changes. Special consideration should be given to implementing various incentive strategies to assist overweight and obese individuals with weight loss. Using these motivational incentive strategies can be an effective means to help individuals succeed with their weight loss efforts.

Comparison of techniques for self-monitoring eating and exercise behaviors on weight loss in a correspondence-based intervention.

This study examined whether different methods of self-monitoring eating and exercise behaviors affect the process of self-monitoring and change in body weight in overweight adults. Forty-two subjects participated in a 16-week correspondence-based weight-loss intervention using a pretest-posttest randomized design. Dietary intake was prescribed at 1,200 to 1,500 kcal/day and <30% dietary fat. Physical activity was progressed to 200 minutes/week. Participants were randomly assigned to self-monitoring eating and physical activity behaviors using a traditional detailed method or transitioning to an abbreviated method. Transitioning to an abbreviated method returned significantly more diaries than using a traditional detailed method (P=0.04). Participants completing the study showed no significant difference in weight loss between the traditional detailed method (-7.5+/-5.3 kg) and the abbreviated method (-7.6+/-5.5 kg), with similar results for intention-to-treat analysis (detailed method -3.9+/-5.3 kg vs abbreviated method -4.3+/-5.8 kg). Weight loss was significantly associated with number of self-monitoring diaries completed (r=0.53, P<0.05). Findings suggest the self-monitoring process, rather than the detail of self-monitoring, is important for facilitating weight loss and change in eating and physical activity behaviors. Transitioning to a simplified approach to self-monitoring does not negatively affect short-term weight loss in overweight adults. These results may have implications for improving self-monitoring in overweight adults during periods of weight loss.

The efficacy of a technology-based system in a short-term behavioral weight loss intervention.

OBJECTIVE: The objective was to examine the efficacy of adding a technology-based program to an in-person, behavioral weight loss intervention. RESEARCH METHODS AND PROCEDURES: Fifty-seven subjects (BMI=33.1+/-2.8 kg/m2; age=41.3+/-8.7 years) participated in a 12-week intervention with random assignment to Standard In-Person Behavioral Weight Control Program (SBWP) or Intermittent or Continuous Technology-Based Program (INT-TECH, CON-TECH). SBWP subjects received seven individualized weight loss sessions encouraging dietary and exercise modifications. INT-TECH and CON-TECH subjects received all SBWP components; additionally, these groups used a SenseWear Pro Armband (BodyMedia, Inc.) to monitor energy expenditure and an Internet-based program to monitor eating behaviors. These features were used by INT-TECH subjects during weeks 1, 5, and 9 and CON-TECH subjects weekly throughout the intervention. RESULTS: Intent-to-treat analysis revealed weight loss of 4.1+/-2.8 kg, 3.4+/-3.4 kg, and 6.2+/-4.0 kg, for SBWP, INT-TECH, and CON-TECH groups, respectively (CON-TECH>INT-TECH, p

Treatment and prevention of obesity: what is the role of exercise?

The increasing prevalence of overweight and obesity highlight the need for improved intervention strategies to counteract this significant public health problem. To this end, it appears that increases in energy expenditure through exercise and other forms of physical activity may be an important component of effective interventions to enhance initial weight loss and the prevention of weight regain. However, to achieve these outcomes, adequate levels of exercise and physical activity appear to be necessary, with 60 to 90 min/d currently being recommended. While this appears to be a significant amount of activity, overweight and obese adults should be counseled to progressively increase to these levels of exercise and physical activity. Moreover, there is significant evidence that even if an overweight or obese adult is unable to achieve this level of activity, that significant health benefits can be realized by participating in at least 30 minutes of daily activity that is at least moderate in intensity. Therefore, it is important to have interventions that target these levels of physical activity to improve health-related outcomes and to facilitate long-term weight control.

Physical activity considerations for the treatment and prevention of obesity.

Overweight and obesity present significant public health concerns because of the link with numerous chronic health conditions. Excess body weight is a result of an imbalance between energy intake and energy expenditure. Physical activity is the most variable component of energy expenditure and therefore has been the target of behavioral interventions to modify body weight. It appears that physical activity is an important component on long-term weight control, and therefore adequate levels of activity should be prescribed to combat the obesity epidemic. Although there is evidence that 30 min of moderate-intensity physical activity may improve health outcomes, the amount of physical activity that may be necessary to control body weight may be >30 min/d. There is a growing body of scientific literature suggesting that at least 60 min of moderate-intensity physical activity may be necessary to maximize weight loss and prevent significant weight regain. Moreover, adequate levels of physical activity appear to be important for the prevention of weight gain and the development of obesity. Physical activity also appears to have an independent effect on health-related outcomes when compared with body weight, suggesting that adequate levels of activity may counteract the negative influence of body weight on health outcomes. Thus, it is important to target intervention strategies to facilitate the adoption and maintenance of an adequate amount of physical activity to control body weight.