Objective: Internet weight loss programs have become widely available as alternatives to standard treatment, but few data are available on their efficacy. This study aimed to investigate the effectiveness of a structured behavioral weight loss website (VTrim) vs. a commercial weight loss website (http://eDiets.com). Research Methods and Procedures: A randomized, controlled trial was conducted from February 2003 to March 2005, in 124 overweight and obese subjects ages 18 years and older with a BMI of 25 to 39.9 kg/m2 (mean age, 47 ± 9 years; BMI, 32 ± 3 kg/m2; 20% men). Analyses were performed for the 88 subjects who had complete follow‐up data. Participants were randomly assigned to 12‐month VTrim (n = 62) or http://eDiets.com (n = 62) intervention. VTrim participants had access to a therapist‐led structured behavioral weight loss program delivered on‐line. http://eDiets.com subjects had access to a self‐help commercial on‐line weight loss program. Body weight, social support, and use of website components were measured at 0, 6, and 12 months. Results: Repeated‐measures analyses showed that the VTrim group lost significantly more weight than the http://eDiets.com group at 6 months (8.3 ± 7.9 kg vs. 4.1 ± 6.2 kg; p = 0.004) and maintained a greater loss at 12 months (7.8 ± 7.5 kg vs. 3.4 ± 5.8 kg; p = 0.002). More participants in the VTrim group maintained a 5% weight loss goal (65% vs. 37.5%; p = 0.01) at 12 months. Discussion: An on‐line, therapist‐led structured behavioral weight loss website produced greater weight loss than a self‐help commercial website. Because commercial sites have great potential public health impact, future research should investigate the feasibility of incorporating a more structured behavioral program into a commercial application.

Results: There were no significant differences among the groups in weight loss (mean Ϯ SD) from baseline to 18 months (7.6 Ϯ 7.3 kg vs. 5.5 Ϯ 8.9 kg vs. 5.1 Ϯ 6.5 kg, p ϭ 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.

OBJECTIVE:The purpose of this study was to investigate the effectiveness of a weight maintenance program conducted over the Internet. DESIGN: Longitudinal, clinical behavioral weight loss trial with 6-month in-person behavioral obesity treatment followed by a 12-month maintenance program conducted both in-person (frequent in-person support; F-IPS, minimal in-person support; M-IPS) and over the Internet (Internet support; IS). SUBJECTS: A total of 122 healthy, overweight adults (age ¼ 48.4 AE 9.6, BMI ¼ 32.2 AE 4.5 kg=m 2 , 18 male) MEASUREMENTS: Body weight, dietary intake, energy expended in physical activity, attendance, self-monitoring, comfort with technology. RESULTS: Results (n ¼ 101) showed that weight loss did not differ by condition during treatment (8.0 AE 5 vs 11 AE 6.5 vs 9.8 AE 5.9 kg, P ¼ 0.27 for IS, M-IPS and F-IPS, respectively). The IS condition gained significantly more weight than the F-IPS group during the first 6 months of weight maintenance ( þ 2.2 AE 3.8 vs 0 AE 4 kg, P < 0.05) and sustained a significantly smaller weight loss than both in-person support groups at the 1 y follow-up ( 7 5.7 AE 5.9 vs 7 10.4 AE 9.3 vs 7 10.4 AE 6.3 kg, P < 0.05 for IS, M-IPS and F-IPS, respectively). Attendance at maintenance meetings was greater for the F-IPS than the IS condition over the 1 y maintenance program (54 vs 39%, P ¼ 0.04). Acceptability of assigned condition was higher for subjects in the F-IPS than IS condition. CONCLUSION: The results of this study suggest that Internet support does not appear to be as effective as minimal or frequent intensive in-person therapist support for facilitating the long-term maintenance of weight loss.

Supplementation of an Internet weight-loss treatment with monthly in-person meetings did not result in greater weight losses over 12 months. Dynamic, socially supportive, and interactive elements of the Web site may have obviated the need for further interpersonal behavioral counseling.

The objective of this study was to cross-calibrate measurements of body composition by dual-energy X-ray absorptiometry (DXA) with chemical analysis of carcasses of pigs in the pediatric range of body weight. Eighteen pigs (25.5 +/- 7.0 kg; 9.9-32.8% body fat) were scanned in duplicate by using DXA with a Lunar DPX-L densitometer in the pediatric medium and adult fast-detail scan modes. Pigs were then killed and their carcasses analyzed completely. Carcass lean and fat contents were highly correlated with DXA measurement in both scan modes (Pearson r values > 0.98). For lean mass, the relation between carcass content and DXA measures was not significantly different from the line of identity in the adult mode, but was in the pediatric mode. For fat mass, the relations between carcass content and DXA measures were significantly different from the line of identity in both the adult and pediatric modes. In duplicate scans, the reliability of DXA measures of lean mass and fat mass was excellent in both scan modes. Because neither the adult nor the pediatric scan mode provided accurate measures of fat and lean mass, we derived specific correction factors to improve the measurement of total fat and lean compartments, thereby calibrating the Lunar DPX-L to the laboratory standard of carcass analysis in pigs.