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Personalized feedback increases the effectiveness of online weight loss programs

Sherrington A, Newham J, Bell R, et al. Systematic review and meta-analysis of internet-delivered interventions providing personalized feedback for weight loss in overweight and obese adults Obes Rev. 2016; 17: 541-551.

Review question

Are Internet-delivered weight loss programs with personalized feedback more effective than other weight loss programs for overweight and obese adults?


With more adults accessing the internet, online weight loss programs delivered may be an alternative to traditional in-person programs to maximize convenience for the participant and reduce program costs. Previous reports have stated online weight loss programs are effective but it is not clear which aspects of these programs are most important for losing weight.

How the review was done

Researchers did a systematic review and meta-analysis of 12 randomized controlled trials including 3547 overweight adults (body mass index (BMI) greater than 25 kg/m2).

Key features of the studies were:

  • Internet-delivered weight loss programs with personalized feedback (via web-based messages or email) were delivered to participants over a range of 3 to 24 months.
  • Participants’ body weight was measured at the program end as well as at 3, 6 and 12 (or more) month follow-up periods.  Body fat, waist circumference and BMI were also measured.
  • Measurements of study participants were compared to control groups who were on a wait list for the program, received printed information, and/or were directed to online weight loss resources without personal feedback.

Quality assessment of studies revealed that only 2 studies had a low risk of bias.

What the researchers found

Participants in internet weight loss programs with personalized feedback lost on average over 2kg more than those in control groups receiving no personalized feedback. These benefits were only shown at 3 to 6 months, however; at 12 months or longer there was not a significant difference in weight loss between people in the study groups vs control groups.  Different programs also included different types of personalized feedback (eg. feedback on performance, information about consequences, self-monitoring, goal setting). There was too much variability to determine which types of feedback may be the most effective.


Internet-delivered weight loss programs that provide personalized feedback are more effective than programs that do not provide this type of support, especially in the short-term. Studies lasting more than 12 months or longer are needed to assess whether these types of programs lead to long-term weight loss.



Control group
A group that receives either no treatment or a standard treatment.
Advanced statistical methods contrasting and combining results from different studies.
Randomized controlled trials
Studies where people are assigned to one of the treatments purely by chance.
Risk of bias
Possibility of some systematic error in the studies.
Systematic review
A comprehensive evaluation of the available research evidence on a particular topic.

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