This review assessed the efficacy of Internet-delivered weight loss programmes. The author concluded that the Internet may be an alternative to traditional face-to-face weight loss programmes; however, the results from weight loss maintenance programmes were equivocal. The author's cautious conclusion reflects the results of the included studies, but small data sets and uncertain quality limit the robustness of the conclusions.

To determine the efficacy of Internet-delivered weight loss programmes.

PubMed, CINAHL, the Cochrane Library and ClinicalTrials.gov were searched for published articles up to June 2005; the search terms were reported. The Internet and references of relevant articles were also checked.

Study designs of evaluations included in the review

Randomised controlled trials (RCTs) were eligible for inclusion in the review.

Specific interventions included in the review

Studies using the Internet for at least one mode of delivery for weight loss treatment were eligible for inclusion. Five of the included studies examined a stand-alone Internet-based weight loss programme or an Internet-based weight loss programme as part of a more comprehensive health programme; the duration of treatment ranged from 6 to 12 months. Three of the included studies examined Internet-based behavioural weight loss maintenance programmes; the duration of treatment ranged from 15 weeks to 6 months.

Participants included in the review

Studies of overweight and/or obese adults were eligible for inclusion. The majority of the participants in the weight loss programmes were women. Where reported, the age of the participants ranged from 30 to 62 years.

Outcomes assessed in the review

Studies that reported weight loss, measured by change in pounds or kilograms, were eligible for inclusion in the review.

How were decisions on the relevance of primary studies made?

The author did not state how the papers were selected for the review, or how many reviewers performed the selection.

The author did not state that they assessed the validity of the primary studies. However, they did present attrition rates for weight loss programmes.

The author did not state how the data were extracted for the review, or how many reviewers performed the data extraction.

How were the studies combined?

The studies were combined in a narrative.

How were differences between studies investigated?

Differences between the individual studies were highlighted in the body of the text.

Eight studies (n=791) were included in the review.

The results for between-group differences in the text and tables differed. The values reported below were taken from the text.

Weight loss (5 studies, n=375, range: 39 to 104).

Two studies reported that Internet programmes were associated with significantly greater weight loss than control or usual care treatments: -2.2 versus +1.0 kg (p=0.002) and 1.63 versus +0.21 kg (p=0.003), respectively. Two studies reported that adding behaviour therapy or e-counselling to Internet programmes was associated with significantly greater weight loss than the Internet programmes alone: -4.4 versus -2.0 kg (p=0.04) and -4.0 versus -1.7 kg (p<0.001), respectively. One small study (n=46) comparing a commercial programme available via the Internet to a public 16-lesson step-by-step manual programme found that the manual programme group lost significantly more weight at 16 and 52 weeks than the Internet group: -3.3 versus -0.8 kg at 52 weeks (p=0.04).

Weight loss maintenance (3 studies, n=418, range: 46 to 250).

Two studies found no statistically significant differences in weight maintenance between Internet programmes and in-person or control groups. One study (n=122) found that the Internet group sustained a significantly lower weight loss than the minimal in-person or frequent in-person support group at the end of the 1-year maintenance period: -5.7 kg versus -10.4 kg versus -10.4 kg (p<0.5).

The results suggest that the Internet may be an alternative to traditional face-to-face weight loss programmes.

The review question was supported by clear inclusion criteria. Several sources were searched for relevant articles, but it is unclear whether the search was restricted by language and there were no attempts to locate unpublished material. It is unclear whether methods to minimise reviewer error or bias in the selection of studies or extraction of data were employed. The validity of the primary studies was not assessed. There were discrepancies between results reported in the tables and the text. The narrative synthesis was appropriate given the differences between the included studies. The author highlighted the fact that as the participants included in the studies were predominantly white, educated women, generalisation of the findings is limited. Only two of the included studies compared weight loss and face-to-face programmes, so evidence was limited. The author's cautious conclusion reflects the results of the included studies, but small data sets and uncertain quality limit the robustness of the conclusions.

Practice: The author stated that although Internet-based programmes may not be any more effective in producing weight loss than traditional face-to-face programmes they may offer advantages in time and cost-savings.

Research: The author stated that further research is required to determine the applicability of Internet-based weight loss programmes across different age, ethnic and socioeconomic groups.

This is a critical abstract of a systematic review that meets the criteria for inclusion on DARE. Each critical abstract contains a brief summary of the review methods, results and conclusions followed by a detailed critical assessment on the reliability of the review and the conclusions drawn.