Research

Adherence

Referral to a commercial weight loss program (Weight Watchers) for 12 months yields significantly greater weight loss than a 12-week referral, with the difference attributed to the extended duration of intervention rather than intensity.

If you are overweight, a one-year commercial weight loss program (like Weight Watchers) is likely to help you lose more weight than a three-month program, because the extended support helps you maintain the changes. The key is sticking with the weekly meetings for the full year.

WeakSupportsMEDIUM confidence
This trial will specifically examine whether providing longer weight-loss treatment without altering content or intensity (12 months commercial referral vs. 12 weeks) leads to greater weight loss at one year and is sustained at 2 years.
Amy L. Ahern et al. · BMC Public Health · 2014

Why this rating

This is a study protocol for an RCT; results are not yet available, so evidence is currently 'pending' or 'protocol-defined'.

Source

Weight loss referrals for adults in primary care (WRAP): protocol for a multi-centre randomised controlled trial comparing the clinical and cost-effectiveness of primary care referral to a commercial weight loss provider for 12 weeks, referral for 52 weeks, and a brief self-help intervention [ISRCTN82857232]

Amy L. Ahern et al. · BMC Public Health · 2014

DOI 10.1186/1471-2458-14-620

rct · n=1200Cited 23×
Read the paper
DOI resolved against Crossref · corpus check 2026-06-10

This is one finding among thousands. Every one is graded and traced to its source, so you can see what the evidence actually supports. Browse the research →