The campaign promotes Weight Watchers' new points plan, which it describes as the biggest change to the global business in 15 years.
The ads – one of which will feature a male dieter for the first time – are based around members enjoying the improved flexibility of the new plan. The ProPoints system now includes a "weekly allowance" of extra points to spend on food or drink, such as wine or a curry, which might otherwise be seen an as indulgence for dieters.
Testimonials will also feature heavily in the ads in the New Year, along with a push for its online business, which has doubled in size in the past two years.
The campaign, created by McCann Erickson, includes a 16-week run of TV, radio and press ads, as well as an online and direct mail campaign.
Lindsay Reisser-Weston, vice president of marketing, said: "We have committed to a record level of investment to ensure mass awareness of the ProPoints plan.
"From the advertising and in-meeting look to local marketing and our food range, this campaign has been designed to drive brand reappraisal among existing and potential new members."
About one-fifth of its two million member-base are recruited in January, but Reisser-Weston said she expected bumper numbers due to the launch of ProPoints.
The ProPoints system, which soft launched in the UK in November, moves away from counting only sat-fats and calories to a more scientific base, measuring fat, protein, fibre and carbohydrates, as well as taking into account the energy used in digestion.
The points for all foods have been recalculated, including a decision to make all fruit zero points.