Amy D. Otto

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.

Four-year weight losses in the Look AHEAD study: factors associated with long-term success.

This report provides a further analysis of the year 4 weight losses in the Look AHEAD (Action for Health in Diabetes) study and identifies factors associated with long‐term success. A total of 5,145 overweight/obese men and women with type 2 diabetes were randomly assigned to an intensive lifestyle intervention (ILI) or a usual care group, referred to as Diabetes Support and Education (DSE). ILI participants were provided approximately weekly group or individual treatment in year 1; continued but less frequent contact was provided in years 2–4. DSE participants received three group educational sessions in all years. As reported previously, at year 4, ILI participants lost an average of 4.7% of initial weight, compared with 1.1% for DSE (P < 0.0001). More ILI than DSE participants lost ≥5% (46% vs. 25%, P < 0.0001) and ≥10% (23% vs. 10%, P < 0.0001) of initial weight. Within the ILI, achievement of both the 5% and 10% categorical weight losses at year 4 was strongly related to meeting these goals at year 1. A total of 887 participants in ILI lost ≥10% at year 1, of whom 374 (42.2%) achieved this loss at year 4. Participants who maintained the loss, compared with those who did not, attended more treatment sessions and reported more favorable physical activity and food intake at year 4. These results provide critical evidence that a comprehensive lifestyle intervention can induce clinically significant weight loss (i.e., ≥5%) in overweight/obese participants with type 2 diabetes and maintain this loss in more than 45% of patients at 4 years.

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.

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.

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/m2) 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.

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.

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.

Cinnamon as a supplemental treatment for impaired glucose tolerance and type 2 diabetes.

Most recent estimates claim the prevalence of obesity in the United States to be 32.2% in adult men and 35.5% in adult women [1]. Fifty-seven million American adults 20 years of age or older have impaired glucose tolerance, suggesting that at least 57 million American adults have prediabetes [2]. Additionally, 23.6 million people, or 7.8%, of the population are believed to have diabetes [2]. These staggering numbers clearly suggest that multiple dietary strategies need to be implemented to help treat these diseases. One such strategy would be the use of cinnamon, rich in polyphenols, and thought to serve as an insulin sensitizer and an antioxidant. This is of interest because oxidative stress has been linked as a contributing factor in obesityrelated diseases such as type 2 diabetes and cardiovascular diseases [3]. Several in vitro, as well as in vivo, studies have shown cinnamon to have a positive effect on insulin pathways [4–8]. In humans, the effect of cinnamon on glucose control and lipid parameters in type 2 diabetic patients has yielded conflicting results [9–12]. The present study further investigates the use of cinnamon as a supplemental treatment in the area of obesity, diabetes, and cardiovascular disease.

Physical Activity and Obesity

There is an increasing prevalence of overweight and obesity in the United States and other developed countries. This can have significant public health implications because of the association of excess body weight with increased risk of chronic diseases. It has been suggested that the increasing prevalence of excess body weight (overweight and obesity) and related diseases also has a significant impact on health care costs. Physical activity can significantly affect weight control and can also have an independent effect on associated chronic disease risk factors. However, physical activity participation is less than optimal. Thus, it is important for health care professionals to understand the role of physical activity in weight loss, the prevention of weight gain, and the prevention of weight regain, and to understand how to provide accurate and meaningful information to their patients.