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.     

Effect of Internet Support on the Long‐Term Maintenance of Weight Loss

Objective: To investigate the efficacy of an Internet weight maintenance program. Research Methods and Procedures: Two hundred fifty‐five healthy overweight and obese adults (mean ± SD BMI, 31.8 ± 4.1 kg/m²) men (18%; mean ± SD age, 45.8 ± 8.9 yrs) participated in a 6‐month behavioral weight control program conducted over interactive television. Treatment was followed by a 12‐month weight maintenance program with three conditions: frequent in‐person support (F‐IPS), minimal in‐person support (M‐IPS) and internet support (IS). Main outcome measures included body weight, program adherence, and social influence components. Results: There were no significant differences among the groups in weight loss (mean ± SD) from baseline to 18 months (7.6 ± 7.3 kg vs. 5.5 ± 8.9 kg vs. 5.1 ± 6.5 kg, p = 0.23 for the IS, M‐IPS, and F‐IPS, respectively). Discussion: Participants assigned to an internet‐based weight maintenance program sustained comparable weight loss over 18 months compared with individuals who continued to meet face‐to‐face. Therefore, the internet appears to be a viable medium for promoting long‐term weight maintenance.     

The Impact of Calcium and Dairy Product Consumption on Weight Loss

Objective: Recent evidence suggests that diets high in calcium and dairy products are associated with lower body weight, particularly lower body fat levels. The purpose of this study was to compare weight and body fat loss on a calorie-restricted, low-dairy (CR) vs. high-dairy (CR+D) diet. Research Methods and Procedures: Fifty-four subjects (BMI 30 ± 2.5 kg/m², 45 ± 6.6 years, 4 men) were randomly assigned to calorie-restricted (−500 kcal/d) low-dairy calcium (n = 29; ∼1 serving dairy/d, 500 mg/d calcium) or high-dairy calcium (n = 25; 3 to 4 servings dairy/d, 1200 to 1400 mg/d calcium) diets for 12 months. Main outcome measures included change in weight (kilograms) and body fat (percentage). Results: There were no significant differences between groups at baseline. At 12 months, weight and body fat loss were not significantly different. Subjects in the CR vs. CR+D conditions lost 9.6 ± 6.5 vs. 10.8 ± 5.9 kg (p = 0.56) and 9.0 ± 3.8 vs. 10.1 ± 3.6 kg body fat (p = 0.37). Discussion: These findings suggest that a high-dairy calcium diet does not substantially improve weight loss beyond what can be achieved in a behavioral intervention.     

A Pilot Internet‐Based Behavioral Weight Loss Intervention with or without Commercially Available Portion‐Controlled Foods

Objective : To evaluate the short‐term impact of portion‐controlled food provision in combination with an Internet behavioral weight loss program on weight, blood cholesterol, and blood glucose levels. Design and Methods : Fifty participants, mean age 46 ± 10.7 years and mean body mass index 35.1 ± 3.8 kg/m², were randomized to one of two study groups, an Internet behavioral weight loss program (Internet‐alone; n = 25) or an Internet behavioral weight loss program plus a commercially available portion‐controlled diet (Internet + PCD; n = 25) for 12 weeks. Results : An intent‐to‐treat analysis found that the mean weight change in the Internet + PCD group was ?5.7 ± 5.6 kg and in the Internet‐alone group (n = 25) was ?4.1 ± 4.0 kg (P = 0.26). Participants in the Internet + PCD group achieved significantly greater improvements in blood glucose (?2.6 ± 5.7 vs. 1.4 ± 11.0 mg/dl; P = 0.05) and LDL cholesterol (?8.2 ± 18.0 vs. ?0.6 ± 21.0 mg/dl; P = 0.04), compared with Internet‐alone group. Conclusions : These data suggest that there may be short‐term clinical benefit in using a PCD in conjunction with a behavioral Internet‐based weight loss program to enhance weight loss and improve health indicators.     

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.     

Using telehealth to increase participation in weight maintenance programs

Objective: To compare weight regain, satisfaction, and convenience among three weight maintenance programs: telehealth, traditional classes, and no program. Research Methods and Procedures: This quasi‐experimental study compared weight change, satisfaction, and convenience among three program types. The telehealth participants interacted with a registered dietitian (RD) through the web and e‐mail, traditional program participants attended a traditional classroom program, and no program participants received no interaction. Eighty‐seven subjects (14 men and 73 women) were enrolled in the study: 31 traditional, 31 telehealth, and 25 no program participants. Eligibility included participation in a community‐based weight loss program (Colorado Weigh) and minimum 7% weight loss before enrollment. Results: Subject characteristics at baseline were as follows: age, 50 ± 9.3 (standard deviation) years; height, 1.68 ± 0.09 m; weight, 80.5 ± 18.4 kg, with no significant differences between groups. Over 6 months, the traditional group lost 0.5 ± 4.3 kg, the telehealth group lost 0.6 ± 2.5 kg, and the no program group gained 1.7 ± 3.0 kg. Weight change among all three groups was significant (p = 0.02); no program participants gained significantly more weight than the telehealth and traditional groups. There were no differences in overall satisfaction between the telehealth and traditional groups (p = 0.43), but individuals in the telehealth group rated their program as more convenient compared with the traditional group (p = 0.0001). Discussion: These results show the usefulness of telehealth programs in long‐term weight loss maintenance. They may be a useful alternative for those who successfully lose weight in a structured behavioral program but do not choose to participate in a formal behavioral weight loss maintenance program.     

Comparison of Methods to Assess Body Composition Changes during a Period of Weight Loss

Objective: To assess the accuracy of body composition measurements by air displacement plethysmography and bioelectrical impedance analysis (BIA) compared with DXA during weight loss. Research Methods and Procedures: Fifty‐six healthy but overweight participants, 34 women and 22 men (age, 52 ± 8.6 years; weight, 92.2 ± 11.6 kg; BMI, 33.3 ± 2.9 kg/m²) were studied in an outpatient setting before and after 6 months of weight loss (weight loss, 5.6 ± 5.5 kg). Subjects were excluded if they had initiated a new drug therapy within 30 days of randomization, were in a weight loss program, or took a weight loss drug within 90 days of randomization. Subjects were randomly assigned either to a self‐help program, consisting of two 20‐minute sessions with a nutritionist and provision of printed materials and other self‐help resources, or to attendance at meetings of a commercial program (Weight Watchers). Body composition was examined by each of the methods before and after weight loss. Results: BIA (42.4 ± 5.8%) underestimated percentage fat, whereas the BodPod (Siri = 51.7 ± 6.9%; Brozek = 48.5 ± 6.5%) overestimated percentage fat compared with DXA (46.1 ± 7.9%) before weight loss. Correlation coefficients for detecting changes in body composition between DXA and the other methods were relatively high, with Brozek Δfat mass (FM; r² = 0.63), Siri FM (r² = 0.65), tetrapolar BIA percentage fat (r² = 0.57), and Tanita FM (r² = 0.61) being the highest. Discussion: In conclusion, all of the methods were relatively accurate for assessing body composition compared with DXA, although there were biases. Furthermore, each of the methods was sensitive enough to detect changes with 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 ≤ 0.05). Discussion: These results indicate that the technology‐based program needs to be used continuously throughout the intervention period to significantly impact weight loss. Future studies should examine the long‐term and independent effect of this technology on weight loss, and for whom this intervention format is most effective.     

Two-year internet-based randomized controlled trial for weight loss in African-American girls

Objective: A randomized controlled trial tested the efficacy of an internet‐based lifestyle behavior modification program for African‐American girls over a 2‐year period of intervention. Research Methods and Procedures: Fifty‐seven overweight (mean BMI percentile, 98.3) African‐American girls (mean age, 13.2 years) were randomly assigned to an interactive behavioral internet program or an internet health education program, the control condition. Overweight parents were also participants in the study. Forty adolescent‐parent dyads (70%) completed the 2‐year trial. Outcome data including BMI, body weight, body composition, and weight loss behaviors were collected at baseline and at 6‐month intervals. A computer server tracked use of the web sites. Results: An intention‐to‐treat statistical approach was used, with the last observation carried forward. In comparison with the control condition, adolescents in the behavioral program lost more mean body fat (BF) (?1.12 ± 0.47% vs. 0.43 ± 0.47% BF, p < 0.05), and parents in the behavioral program lost significantly more mean body weight (?2.43 ± 0.66 vs. ?0.35 ± 0.64 kg, p < 0.05) during the first 6 months. This weight loss was regained over the next 18 months. After 2 years, differences in fat for adolescents (?0.08 ± 0.71% vs. 0.84 ± 0.72% BF) and weight for parents (?1.1 ± 0.91 vs. ?0.60 ± 0.89 kg) did not differ between the behavioral and control programs. Discussion: An internet‐based weight management program for African‐American adolescent girls and their parents resulted in weight loss during the first 6 months but did not yield long‐term loss due to reduced use of the web site over time.     

A randomized trial testing a contingency-based weight loss intervention involving social reinforcement

Even though behavioral weight loss interventions are conducted in groups, a social contingency (SC) paradigm that capitalizes on the social reinforcement potential of the weight loss group has never been tested. We tested a weight loss intervention in which participation in the weight loss group was contingent upon meeting periodic weight goals. We hypothesized that making access to the group dependent upon weight loss would improve weight outcomes. Participants (N = 62; 84% female; 94% white; age = 51.9 ± 9.0; BMI = 34.7 ± 4.5) were randomized to 6‐months of standard behavioral weight loss (SBWL) or to a behavioral program that included a SC paradigm. Both groups engaged in social cohesion activities. Participants in SC who did not meet weight goals did not attend group meetings; instead, they received individual treatment with a new interventionist and returned to group once their weight goals were met. SC did not improve overall weight loss outcomes (SC: ?10.0 ± 4.9 kg, SBWL: ?10.8 ± 6.4 kg, P = 0.63). Similarly, overall weight loss was not significantly different in the subgroup of participants in the SC and SBWL conditions who did not meet periodic weight loss goals (?7.3 ± 4.1 kg vs. ?7.1 ± 3.5 kg, P = 0.90). Surprisingly, “successful” SC participants (who met their weight goals) actually lost less weight than “successful” SBWL participants (?12.4 ± 3.2 kg vs. ?14.5 ± 4.7 kg, P = 0.02). Whereas contingency‐based treatments have been tested for other health behaviors (e.g., substance abuse), this is the first study to test a SC intervention for weight loss. This approach did not improve overall weight loss outcomes. Our attempt to offer appropriate clinical care by providing individual treatment to SC participants when needed may have mitigated the effects of the SC paradigm.     

Intensive weight loss program improves physical function in older obese adults with knee osteoarthritis

Objective: Physical function and body composition in older obese adults with knee osteoarthritis (OA) were examined after intensive weight loss. Research Methods and Procedures: Older obese adults (n = 87; ≥60 years; BMI ≥ 30.0 kg/m²) with symptomatic knee OA and difficulty with daily activities were recruited for a 6‐month trial. Participants were randomized into either a weight stable (WS) or weight loss (WL) program. Participants in WL (10% weight loss goal) were prescribed a 1000 kcal/d energy deficit diet with exercise 3 d/wk. WS participants attended health information sessions. Body composition and physical function (Western Ontario and McMaster University Osteoarthritis Index, 6‐minute walking distance, and stair climb time) were assessed at baseline and 6 months. Statistical analysis included univariate analysis of covariance on 6‐month measurements using baseline values as covariates. Associations between physical function and body composition were performed. Results: Body weight decreased 8.7 ± 0.8% in WL and 0.0 ± 0.7% in WS. Body fat and fat‐free mass were lower for WL than WS at 6 months (estimated means: fat = 38.1 ± 0.4% vs. 40.9 ± 0.4%, respectively; fat‐free mass = 56.7 ± 0.4 vs. 58.8 ± 0.4 kg, respectively). WL had better function than WS, with lower Western Ontario and McMaster University Osteoarthritis Index scores, greater 6‐minute walk distance, and faster stair climb time (p < 0.05). Changes in function were associated with weight loss in the entire cohort. Discussion: An intensive weight loss intervention incorporating energy deficit diet and exercise training improves physical function in older obese adults with knee OA. Greater improvements in function were observed in those with the most weight loss.     

Weight loss strategies for obese adults: personalized weight management program vs. standard care

Objective: The objective of this study was to evaluate the effect of a 32‐week personalized Polar weight management program (PWMP) compared with standard care (SC) on body weight, body composition, waist circumference, and cardiorespiratory fitness in overweight or obese adults. Research Methods and Procedures: Overweight or obese (29 ± 2 kg/m²) men and women (n = 74) 38 ± 5 years of age were randomly assigned into either PWMP (men = 20, women = 21) or SC (men = 15, women = 18). Both groups managed their own diet and exercise program after receiving the same standardized nutrition and physical activity advice. PWMP also received a weight management system with literature to enable the design of a personalized diet and exercise weight loss program. Body weight and body composition, waist circumference, and cardiorespiratory fitness were measured at weeks 0, 16, and 32. Results: Eighty percent of participants completed the 32‐week intervention, with a greater proportion of the dropouts being women (PWMP: 2 men vs. 7 women; SC: 2 men vs. 4 women). At 32 weeks, PWMP completers had significantly (p < 0.001) greater losses in body weight [6.2 ± 3.4 vs. 2.6 ± 3.6 (standard deviation) kg], fat mass (5.9 ± 3.4 vs. 2.2 ± 3.6 kg), and waist circumference (4.4 ± 4.5 vs. 1.0 ± 3.6 cm). Weight loss and fat loss were explained by the exercise energy expenditure completed and not by weekly exercise duration. Discussion: More effective weight loss was achieved after treatment with the PWMP compared with SC. The results suggest that the PWMP enables effective weight loss through tools that support self‐monitoring without the requirement of more costly approaches to program supervision.     

Maintenance of weight loss in overweight middle-aged women through the Internet

Objective: The purpose of this study was to compare weight regain in a group of perimenopausal women (48.0 ± 4.4 years old), randomized to a 12‐month weight maintenance Internet intervention or to self‐directed weight maintenance after a 4‐month weight loss treatment. Methods and Procedures: After a 4‐month behavioral weight loss program, 135 women were randomized to either Internet or self‐directed groups. The Internet group (n = 66) used a website to gain information and complete logs concerning their weight, diet, and exercise progress over a 12‐month follow‐up. The 69 self‐directed women had no contact with study staff. All women were measured for weight and body composition, and diet intake, and were interviewed using the 7‐day physical activity questionnaires at baseline, 4 months, and 16 months. Results: At the end of the 12‐month follow‐up, the Internet and self‐directed groups had regained on average 0.4 ± 5.0 kg and 0.6 ± 4.0 kg, respectively (P = 0.5). In within‐group analyses, Internet diet‐log entries were correlated with follow‐up weight change (r = ?0.29; P < 0.05) and moderately with change in exercise energy expenditure (EEE; r = 0.44; P < 0.01). Follow‐up weight change was not correlated with change in dietary intake. Discussion: While significant weight loss was maintained over follow‐up by both groups of women, Internet use did not surpass self‐direction in helping to sustain weight loss. Among Internet users, Internet use was related to weight change and EEE.     

Mediators of Weight Loss and Weight Loss Maintenance in Middle‐aged Women

Long‐term behavioral self‐regulation is the hallmark of successful weight control. We tested mediators of weight loss and weight loss maintenance in middle‐aged women who participated in a randomized controlled 12‐month weight management intervention. Overweight and obese women (N = 225, BMI = 31.3 ± 4.1 kg/m²) were randomly assigned to a control or a 1‐year group intervention designed to promote autonomous self‐regulation of body weight. Key exercise, eating behavior, and body image variables were assessed before and after the program, and tested as mediators of weight loss (12 months, 86% retention) and weight loss maintenance (24 months, 81% retention). Multiple mediation was employed and an intention‐to‐treat analysis conducted. Treatment effects were observed for all putative mediators (Effect size: 0.32–0.79, P < 0.01 vs. controls). Weight change was ?7.3 ± 5.9% (12‐month) and ?5.5 ± 5.0% (24‐month) in the intervention group and ?1.7 ± 5.0% and ?2.2 ± 7.5% in controls. Change in most psychosocial variables was associated with 12‐month weight change, but only flexible cognitive restraint (P < 0.01), disinhibition (P < 0.05), exercise self‐efficacy (P < 0.001), exercise intrinsic motivation (P < 0.01), and body dissatisfaction (P < 0.05) predicted 24‐month weight change. Lower emotional eating, increased flexible cognitive restraint, and fewer exercise barriers mediated 12‐month weight loss (R² = 0.31, P < 0.001; effect ratio: 0.37), but only flexible restraint and exercise self‐efficacy mediated 24‐month weight loss (R² = 0.17, P < 0.001; effect ratio: 0.89). This is the first study to evaluate self‐regulation mediators of weight loss and 2‐year weight loss maintenance, in a large sample of overweight women. Results show that lowering emotional eating and adopting a flexible dietary restraint pattern are critical for sustained weight loss. For long‐term success, interventions must also be effective in promoting exercise intrinsic motivation and self‐efficacy.     

Randomized trial of a multifaceted commercial weight loss program

Objective: To test whether a commercial weight loss program promotes greater weight loss in overweight or obese women compared with control conditions and to describe the effect on plasma lipids, carotenoids, hormones, and fitness. Research Methods and Procedures: Overweight or obese women were randomized to commercial weight loss program or control conditions (n = 35 each). Results: At randomization, participants were 41.1 (11.4) (mean [standard deviation]) years, BMI 34.0 (3.5) kg/m², and weight 92.0 (11.1) kg. At 6 months, change in weight by intent‐to‐treat (ITT) analysis was ?7.2 (6.7) kg and ?7.8% (7.2%) in the intervention group vs. ?0.3 (3.9) kg and ?0.3% (4.5%) in the control group (n = 35 for each; p < 0.01). One‐year ITT analysis revealed significantly greater change in weight, percent weight, BMI, and waist and hip circumferences in the intervention vs. control group. Completers at 1 year exhibited change in weight of ?7.3 (10.4) kg for the intervention group (n = 32) vs. ?0.7 (5.6) kg for controls (n = 33) (p < 0.01), and ?7.8% (11.1%) weight change for the intervention group vs. ?0.7% (6.2%) for controls (p < 0.01). High‐density lipoprotein (HDL) cholesterol concentration increased significantly in the intervention group. Fasting serum insulin decreased in the intervention but increased in the control group at 6 months (p < 0.01), remaining different at 1 year (p = 0.05). Discussion: The commercial program successfully facilitated weight loss, which was notably maintained at 1 year, and promoted favorable changes in plasma lipid and hormone concentrations.     

Modest Lifestyle Intervention and Glucose Tolerance in Obese African Americans

Objective: Previous studies have demonstrated the benefit of short‐term diets on glucose tolerance in obese individuals. The purpose of this study was to evaluate the effectiveness of modest lifestyle changes in maintaining improvements in glucose tolerance induced by short‐term energy restriction in obese African Americans with impaired glucose tolerance or type 2 diabetes mellitus. Research Methods and Procedures: An intervention group (n = 45; 47 ± 1 year [mean ± SE]), 105 ± 4 kg; body mass index: 39 ± 1 kg/m²) received an energy‐restricted diet (943 ± 26 kcal/d) for 1 week, followed by a lifestyle program of reduced dietary fat (?125 kcal/d) and increased physical activity (+125 kcal/d) for 1 year. Body weight and plasma concentrations of glucose, insulin, and C‐peptide during an oral glucose tolerance test were measured at baseline, 1‐week, and 4‐month intervals. A control group (n = 24; 48 ± 1 year; 110 ± 5 kg; body mass index: 41 ± 2 kg/m²) underwent these measurements at 4‐month intervals. Results: No changes in weight or glucose tolerance were observed in the control group. The intervention group had significant (p < 0.05) improvements in body weight and glucose tolerance in response to the 1‐week diet, which persisted for 4 months (p < 0.001 vs. control for change in weight). A total of 19 subjects (42%) continued the intervention program for 1 year, with sustained improvements (weight: ?4.6 ± 1.0 kg; p < 0.001 vs. control; oral glucose tolerance test glucose area: ?103 ± 44 mM · min; p < 0.05 vs. control). Discussion: A modest lifestyle program facilitates weight loss and enables improvements in glucose tolerance to be maintained in obese individuals with abnormal glucose tolerance. However, attrition was high, despite the mild nature of the program.     

Three-year weight change in successful weight losers who lost weight on a low-carbohydrate diet

Objective: The purpose of this study was to evaluate long‐term weight loss and eating and exercise behaviors of successful weight losers who lost weight using a low‐carbohydrate diet. Research Methods and Procedures: This study examined 3‐year changes in weight, diet, and physical activity in 891 subjects (96 low‐carbohydrate dieters and 795 others) who enrolled in the National Weight Control Registry between 1998 and 2001 and reported ≥30‐lb weight loss and ≥1 year weight loss maintenance. Results: Only 10.8% of participants reported losing weight after a low‐carbohydrate diet. At entry into the study, low‐carbohydrate diet users reported consuming more kcal/d (mean ± SD, 1895 ± 452 vs. 1398 ± 574); fewer calories in weekly physical activity (1595 ± 2499 vs. 2542 ± 2301); more calories from fat (64.0 ± 7.9% vs. 30.9 ± 13.1%), saturated fat (23.8 ± 4.1 vs. 10.5 ± 5.2), monounsaturated fat (24.4 ± 3.7 vs. 11.0 ± 5.1), and polyunsaturated fat (8.6 ± 2.7 vs. 5.5 ± 2.9); and less dietary restraint (10.8 ± 2.9 vs. 14.9 ± 3.9) compared with other Registry members. These differences persisted over time. No differences in 3‐year weight regain were observed between low‐carbohydrate dieters and other Registry members in intent‐to‐treat analyses (7.0 ± 7.1 vs. 5.7 ± 8.7 kg). Discussion: It is possible to achieve and maintain long‐term weight loss using a low‐carbohydrate diet. The long‐term health effects of weight loss associated with a high‐fat diet and low activity level merits further investigation.     

A Primary Care Intervention for Weight Loss: Results of a Randomized Controlled Pilot Study

Most primary care providers (PCPs), constrained by time and resources, cannot provide intensive behavioral counseling for obesity. This study evaluated the effect of using medical assistants (MAs) as weight loss counselors. The study was a randomized controlled trial conducted in two primary care offices at an academic medical center. Patients (n = 50) had a BMI of 27–50 kg/m² and no contraindications to weight loss. They were randomized to quarterly PCP visits and weight loss materials (Control group) or to the same approach combined with eight visits with a MA over 6 months (Brief Counseling). Outcomes included change in weight and cardiovascular risk factors (glucose, lipids, blood pressure, and waist circumference). Patients in the Brief Counseling and Control groups lost 4.4 ± 0.6 kg (5.1 ± 0.7% of initial weight) and 0.9 ± 0.6 kg (1.0 ± 0.7%), respectively, at month 6 (P < 0.001). There were no significant differences between groups for changes in cardiovascular risk factors. Brief Counseling patients regained weight between month 6 and month 12, when MA visits were discontinued. Attrition was 10% after 6 months and 6% after 12 months. Brief Counseling by MAs induced significant weight loss during 6 months. Office‐based obesity treatment should be tested in larger trials and should include weight loss maintenance counseling.     

Predictors of Weight Maintenance

PASMAN, WILRIKE J., WIM H.M. SARIS, AND MARGRIET S. WESTERTERP-PLANTENGA. Predictors of weight maintenance. Obes Res. 1999;7:43–50. Objective : To obtain predictors of weight maintenance after a weight-loss intervention. Research Methods and Procedures : An overall analysis of data from two-long intervention studies [n = 67 women; age: 37.9±1.0 years; body weight (BW): 87.0±1.2 kg; body mass index: 32.1±0.5 kg-m^?2; % body fat: 42.4±0.5%]. Subjects were measured before a very low energy diet (month 0), after the very low energy diet of 2 months (month 2) and after a 14-month follow-up phase (at 16 months), in which fiber or a carbohydrate-containing food supplement was supplied. The baseline measurements and the changes in parameters induced by the diet intervention were used to predict the changes in BW in the follow-up phase [ΔBW(2–16)]. Results : Multiple regression analysis revealed that 50% (p<0.71) of the variability in weight regain could be explained by pphysiological and behavioral factors. These were: frequency of previous dieting (r² = 0.27, p<0.05), hunger score (measured with the three-factor eating behavior questionnaire), and change in 24-hour resting metabolic rate (RMR). Frequent dieters showed significantly more weight regain than less frequent dieters (8.8±1.0 kg vs. 5.1 ±0.8 kg, p<0.01). Subjects having parents with obesity regained almost significantly more weight than subjects with lean parents (8.5±0.2 kg vs. 5.1±1.5 kg, respectively; p = 0.06). Discussion : Physiological (ΔRMR-24 hours) and behavioral factors (previous frequency of dieting and hunger score) predicted failure of weight maintenance and, as such, can be used to identify women who are at risk for weight regain.     

Combining Weight‐Loss Counseling with the Weight Watchers Plan for Obese Breast Cancer Survivors

Objective: The objective was to develop effective weight‐loss methods for women who have had breast cancer, because obesity may result in an adverse prognosis. Research Methods and Procedures: This randomized pilot study tested an individualized approach toward weight loss in obese women who have had a diagnosis of breast cancer. An individualized approach was applied either alone or combined with the commercial Weight Watchers program. Forty‐eight women (body mass index of 30 to 44 kg/m²) were enrolled. Results: Weight change after 12 months of intervention was as follows (mean ± SD): 0.85 ± 6.0 kg in the control group, ?2.6 ± 5.9 kg in the Weight Watchers group, ?8.0 ± 5.5 kg in the individualized group, and ?9.4 ± 8.6 kg in the comprehensive group that used both individualized counseling and Weight Watchers. Weight loss relative to control was statistically significant in the comprehensive group 3, 6, and 12 months after randomization, whereas weight loss in the individualized group was significant only at 12 months. Weight loss of 10% or more of initial body weight was observed in 6 of 10 women in the comprehensive group at 12 months. In the comprehensive and Weight Watchers–only groups, weight loss was significantly related to frequency of attendance at Weight Watchers meetings, and attendance was more frequent in the comprehensive group. Discussion: These data indicate that the most weight loss was achieved when the counseling approach combined both Weight Watchers and individualized contacts. This was effective even though most of the individualized contacts were by telephone.