Meal replacements in the treatment of adolescent obesity: a randomized controlled trial.

Use of meal replacements (MRs) in lifestyle modification programs (LMPs) for obese adults significantly increases weight loss, compared with prescription of an isocaloric conventional diet (CD). This 12-month randomized trial examined 113 obese adolescents (mean ± s.d. age of 15.0 ± 1.3 years and BMI of 37.1 ± 5.1 kg/m2) who were assigned to a LMP, combined with meal plans of 1300-1500 kcal/day of CD (self-selected foods) or MR (three SlimFast shakes, one prepackaged meal, five vegetable/fruit servings). After month 4 (phase 1), participants originally treated with MR were unmasked to their phase 2 (months 5-12) random assignment: continued use of MR (i.e., MR+MR) or transitioned to CD (i.e., MR+CD). Participants initially treated with CD in phase 1, continued with CD (i.e., CD). All three groups were treated for an additional 8 months (phase 2). Regression models were used to evaluate percentage change in BMI from baseline to month 4 (phase 1), months 5-12 (phase 2), and baseline to month 12. At month 4, participants assigned to MR (N = 65) achieved a mean (±s.e.) 6.3 ± 0.6% reduction in BMI, compared to a significantly (P = 0.01) smaller 3.8 ± 0.8% for CD participants (N = 37). In phase 2, BMI increased significantly (P < 0.001) in all three conditions, resulting in no significant (P = 0.39) differences between groups in percentage change in BMI at month 12. Across groups, mean reduction in BMI from baseline to month 12 was 3.4 ± 0.7% (P < 0.01). Use of MR significantly improved short-term weight loss, compared with CD, but its continued use did not improve maintenance of lost weight.

Effect of a low-carbohydrate diet versus a low-fat, calorie-restricted diet on adipokine levels in obese, diabetic participants.

The effect of dietary macronutrient composition on adipokine concentrations remains unclear. Greater reductions in leptin have been reported in participants who followed low-carbohydrate versus low-fat diets, although these studies did not adjust for the important effects of weight loss on adipokines. We investigated the effect of macronutrient composition on adipokine levels in 144 obese, diabetic participants who were randomly assigned to a low- carbohydrate (< 30 g/day) or low-fat diet (≤ 30% of calories from fat with a deficit of 500 kcal/day). Weight, adipokines, and dietary intake were assessed at baseline and 6 months. Complete data were available for 79 participants. At month 6, weight, leptin, adiponectin, and tumor necrosis factor-α concentrations did not differ significantly between groups (P > 0.05 for all variables). However, significant changes in leptin and adiponectin occurred over time (P < 0.001 and P < 0.012, respectively). Modest weight loss, rather than macronutrient composition, likely accounted for the favorable changes observed in leptin and adiponectin over time.

Changes in symptoms of depression with weight loss: results of a randomized trial.

Recent studies of rimonabant have re-awakened interest in the possible adverse psychiatric effects of weight loss, as well as of weight loss medications. This study examined changes in symptoms of depression in 194 obese participants (age = 43.7 +/- 10.2 years; BMI = 37.6 +/- 4.1 kg/m(2)) in a 1-year randomized trial of lifestyle modification and medication. Participants were assigned to (i) sibutramine alone; (ii) lifestyle modification alone; (iii) sibutramine plus lifestyle modification (i.e., combined therapy); or (iv) sibutramine plus brief therapy. Participants completed the Beck Depression Inventory-II (BDI-II) at baseline and weeks 6, 10, 18, 26, 40, and 52. At 1 year, participants in combined therapy lost the most weight and those in sibutramine alone the least (12.1 +/- 8.8% vs. 5.5 +/- 6.5%; P < 0.01). Mean BDI-II scores across all participants declined from 8.1 +/- 6.9 to 6.2 +/- 7.7 at 1 year (P < 0.001), with no significant differences among groups. Despite this favorable change, 13.9% of participants (across the four groups) reported potentially discernible increases (>or= 5 points on the BDI-II) in symptoms of depression at week 52. They lost significantly less weight than participants in the rest of the sample (5.4 +/- 7.8% vs. 9.0 +/- 7.8%, respectively; P < 0.03). The baseline prevalence of suicidal ideation was 3.6%. Seven new cases of suicidal ideation were observed during the year, with three in lifestyle modification alone. Further research is needed to identify characteristics of obese patients at risk of negative mood changes (and suicidal ideation) in response to behavioral and pharmacologic therapies.

Metabolic syndrome and health-related quality of life in obese individuals seeking weight reduction.

BACKGROUND: No previous research has examined the association between metabolic syndrome (MetSyn) and health-related quality of life (HRQoL) using standard criteria for defining MetSyn. We hypothesized that MetSyn would be associated with lower HRQoL on measures of physical and mental health. METHODS AND PROCEDURES: Participants were 361 individuals in two randomized weight loss trials. MetSyn was defined by the National Cholesterol Education Panel criteria. The Medical Outcomes Study, Short Form-36 (SF-36) was used to assess HRQoL. Differences in HRQoL and in clinical and psychosocial characteristics were compared among participants with and without MetSyn. Multiple regression was used to determine predictors of HRQoL. RESULTS: MetSyn was associated with lower scores on the physical function and general health subscales of the SF-36 and on the physical component summary (PCS) score. This association remained after controlling for age or depression but was eliminated by controlling for BMI. MetSyn was not associated with lower mental quality of life, a higher depression score, tobacco or alcohol use, or a higher rate of psychosocial stressors. DISCUSSION: Individuals with MetSyn reported lower HRQoL. This appeared to be an effect of increased weight, rather than a unique effect of MetSyn. Larger studies are needed to assess whether MetSyn may have an independent effect on HRQoL.

The relationship between relative weight and school attendance among elementary schoolchildren.

OBJECTIVE: To determine the relationship between relative weight and school attendance among elementary schoolchildren. RESEARCH METHODS AND PROCEDURES: A total of 1069 fourth to sixth graders from nine elementary schools in the inner city of Philadelphia, PA, were part of an ongoing randomized control trial to assess prevention strategies for obesity. The mean rate of students eligible for free/reduced meals was 82.9 +/- 11.5%. Weight was measured in the second semester of the academic year. Absentee data for the entire academic year were recorded by homeroom teachers. Participants were classified into relative weight categories described by the Institute of Medicine: underweight, normal-weight, overweight, and obese. RESULTS: ANOVA showed that overweight children were absent significantly more than normal-weight children (12.2 +/- 11.7 days vs.10.1 +/- 10.5 days) (p < 0.05). Linear regression showed that the obese category remained a significant contributor to the number of days absent even after adjusting for age, race/ethnicity, and gender. DISCUSSION: These data suggest that in addition to the medical and psychosocial consequences of being overweight, heavier children have greater risk for school absenteeism than their normal-weight peers. As the rate of childhood obesity increases, parallel increases in school absenteeism should be expected.

Randomized trial of lifestyle modification and pharmacotherapy for obesity.

BACKGROUND: Weight-loss medications are recommended as an adjunct to a comprehensive program of diet, exercise, and behavior therapy but are typically prescribed with minimal or no lifestyle modification. This practice is likely to limit therapeutic benefits. METHODS: In this one-year trial, we randomly assigned 224 obese adults to receive 15 mg of sibutramine per day alone, delivered by a primary care provider in eight visits of 10 to 15 minutes each; lifestyle-modification counseling alone, delivered in 30 group sessions; sibutramine plus 30 group sessions of lifestyle-modification counseling (i.e., combined therapy); or sibutramine plus brief lifestyle-modification counseling delivered by a primary care provider in eight visits of 10 to 15 minutes each. All subjects were prescribed a diet of 1200 to 1500 kcal per day and the same exercise regimen. RESULTS: At one year, subjects who received combined therapy lost a mean (+/-SD) of 12.1+/-9.8 kg, whereas those receiving sibutramine alone lost 5.0+/-7.4 kg, those treated by lifestyle modification alone lost 6.7+/-7.9 kg, and those receiving sibutramine plus brief therapy lost 7.5+/-8.0 kg (P<0.001). Those in the combined-therapy group who frequently recorded their food intake lost more weight than those who did so infrequently (18.1+/-9.8 kg vs. 7.7+/-7.5 kg, P=0.04). CONCLUSIONS: The combination of medication and group lifestyle modification resulted in more weight loss than either medication or lifestyle modification alone. The results underscore the importance of prescribing weight-loss medications in combination with, rather than in lieu of, lifestyle modification.

A randomized controlled trial of a commercial internet weight loss program.

OBJECTIVE: To assess, in a 1-year randomized controlled trial, the efficacy of eDiets.com (a commercial Internet weight loss program) in improving weight, cardiovascular health, and quality of life. RESEARCH METHODS AND PROCEDURES: Participants were 47 women with a mean age of 43.7 +/- 10.2 (SD) years and a mean BMI of 33.5 +/- 3.1 kg/m2. They were randomly assigned to either: 1) eDiets.com, a commercial Internet-based program available to the public; or 2) a weight loss manual (i.e., LEARN Program for Weight Control 2000). At baseline, participants in both groups met briefly with a psychologist who instructed them to follow the components of their program as closely as possible. Additional brief visits were provided at weeks 8, 16, 26, and 52 to review their progress. Change in weight was the main outcome measure. RESULTS: At week 16, participants in eDiets.com lost 0.9 +/- 3.2% of initial weight compared with 3.6 +/- 4.0% for women assigned to the weight loss manual. At week 52, losses increased to 1.1 +/- 4.0% and 4.0 +/- 5.1%, respectively. Results of a last-observation-carried-forward analysis found that women in the manual group lost significantly (p < 0.05) more weight (at both times) than those treated by eDiets.com. (Results, however, of baseline-carried-forward and completers analyses did not reach statistical significance.) There were no significant differences between groups in changes in cardiovascular risk factors or quality of life. DISCUSSION: This study provides consumers with important information about the probable benefits they can expect from participating in a popular Internet-based weight loss program.

Great expectations: "I'm losing 25% of my weight no matter what you say".

This study investigated whether informing obese individuals that they would lose only modest amounts of weight would lead them to adopt more realistic weight loss expectations. At a screening interview, 53 obese women reported that they expected to lose the equivalent of 28% of their initial weight during 1 year of treatment with the medication sibutramine. Prior to beginning treatment, participants were informed, both verbally and in writing, that they could expect to lose 5% to 15% of initial weight, the loss typically induced by current behavioral and pharmacologic approaches. This information, however, had little impact on their weight loss expectations when assessed on subsequent occasions. Results are discussed in terms of the origins, clinical significance, and potential malleability of obese individuals' weight loss expectations.

Agreement between weekly vs. daily assessment of appetite.

Hunger, satiation, and other aspects of appetite are frequently measured using end-anchored line ratings. This study investigated whether a single assessment of appetite, which covered the prior week, would yield the same results obtained by assessing appetite 3 days during the week. Participants were 51 women and 9 men (age mean 44.1, SD 9.8 years; BMI mean 38.0, SD 5.2 kg/m(2)) in a study evaluating the effectiveness of four weight control programs, three of which used sibutramine (15 mg/d). On three separate days of one week, participants rated appetite for that day. During a subsequent clinic visit, participants completed the same ratings in reference to the past week. The three daily values were averaged. All correlations between weekly and averaged daily values were strongly positive (r=0.63-0.80) and statistically significant (all p<0.001). All mean daily and weekly ratings fell within 3.3-7.2 mm of each other. Thus, good agreement was observed between the average daily assessments and one weekly assessment. The weekly assessment of appetite in the clinic appears to have several benefits, including uniformity of test administration and decreased burden on participants.

What consumers want to know about commercial weight-loss programs: a pilot investigation.

OBJECTIVE: In 1999, the Partnership for Healthy Weight Management recommended that providers of commercial weight-loss programs (and products) voluntarily disclose information concerning the safety, costs, and central components of their programs, as well as the credentials of program staff. These guidelines were drafted without the benefit of data from consumers concerning the specific information they desired. The present study provides such data. RESEARCH METHODS AND PROCEDURES: Participants were 90 women with a mean age of 44.02 +/- 9.17 years and body mass index of 36.11 +/- 4.82 kg/m(2) who were participants in one of two randomized weight-control trials. Before treatment, respondents were asked to imagine that they were "looking for a weight-loss plan" and to rate how important each of 16 factors would be in helping them select a plan. Ratings were made using 5-point scales, anchored by "not at all important" and "extremely important," (scored 1 and 5, respectively). Participants also identified the five factors that they thought were the most important, as well as the single most important. RESULTS: The mean rating for the importance of safety (4.57 +/- 0.60) was significantly greater than that for each of the 15 other variables (all p values < 0.05). In addition, significantly more respondents (27.8%) selected safety as the single most important factor than any other variable (all p values < 0.05). Other factors that were consistently judged as very important included information about diet (4.38 +/- 0.68), behavior modification (4.32 +/- 0.76), cost (4.19 +/- 0.92), and maintenance of weight loss (4.15 +/- 0.91). Staff credentials (3.88 +/- 0.83) were among the lowest rated items. DISCUSSION: The results generally support the disclosure guidelines proposed by the Partnership for Health Weight Management. Consumers, however, seem to desire information about weight loss, in addition to that concerning safety, cost, and central program components.

Latent structure of eating disorder symptoms: a factor analytic and taxometric investigation.

OBJECTIVE: The latent structure of eating disorder symptoms, as defined by DSM-IV, was tested in a group of 341 women with and without an eating disorder diagnosis. METHOD: The study group consisted of 201 participants with a diagnosis of anorexia nervosa, bulimia nervosa, binge eating disorder, or eating disorder not otherwise specified; 24 comparison subjects who were obese but did not have an eating disorder diagnosis; and 116 normal-weight comparison subjects. The presence and severity of DSM-IV eating disorder symptoms was assessed with the semi-structured Interview for the Diagnosis of Eating Disorders-IV. The study group was randomly divided into two subgroups for factor analytic studies, and the data were subjected to exploratory and confirmatory factor analysis. Pilot taxometric analyses were used to examine whether the obtained factors represented true dimensions or latent discrete classes. RESULTS: In exploratory factor analyses with data from subgroup 1, three factors were found to account for 66% of the variance in eating disorder symptoms: binge eating, fear of fatness/compensatory behaviors, and drive for extreme thinness. Confirmatory factor analysis cross-validated this factor structure with data from subgroup 2. The eating disorder groups and comparison groups were found to differ on at least one of the three factors. The results of the taxometric analyses were inconsistent with a strictly dimensional model of eating disorders and suggested that some features may be dimensional whereas others may be taxonic (discrete). DISCUSSION: The eating disorders, as defined by DSM-IV, can be conceptualized as having three latent features. Taxometric tests found empirical support for conceptualizing bulimia nervosa and binge eating disorder as discrete syndromes.