The company currently only has three bread products and is introducing nine additions to arrive on shelf at one of the key times in the weight loss calendar.
It predicted first-year sales of the new range would reach £3.5m and turn WeightWatchers into a leading player in the healthy bakery category.
The nine new products consist of chilled ready-to-cook garlic & herb petit pain, garlic & herb ciabatta, dough balls and garlic coriander naan, as well as ambient bagels, petit pain, pitta, chapattis and wraps.
Each of the low-calorie variants is high in fibre and features recommended serving sizes on pack.
The range has an rsp of between 89p and £1.29. Rivermill Foods will manufacture the breads under licence for WeightWatchers.
The additions would target growth categories and were the kind of products many dieters would previously have avoided, said Rivermill managing director Andrew Chesters. "This launch is the largest brand entry into the bakery, morning goods and chilled bread market," he said.
"We are confident these breads will fast become a staple purchase in the fast-growing health market.
"Compared with equivalent bread products, the WeightWatchers breads are 20% lower in calories and 40% higher in fibre per 100g. Obviously the fact that they are portion controlled makes it even easier for the consumer to stick to their diet and succeed."
The new range will be available in the major retailers from January - with the exception of Sainsbury's, which told WeightWatchers it did not have space to stock the products.
The launch will coincide with the £9m marketing campaign running under the WeightWatchers is Changing banner, which aired for the first time last month.
It will include television and radio advertising.
The WeightWatchers brand has increased 11.5% in value to £293m this year [TNS] and has 55% household penetration.