Start-up company Calories Exactly is pitting itself against dieters' stalwart WeightWatchers with a new range of foods, each of which contains 100 calories.

The company claims that health-oriented consumers will switch to its range of puddings, crisps and smoothies because of their simple 100-calorie message emblazoned on packs.

"We are making life easier for people who can't be bothered to scour packaging for calorie counts," said Jo Beach, founder of Calories Exactly.

The 11-strong range includes Super Sticky Toffee Choccy pudding and Cheese Curlies crisps and will start from about 55p.

Beach is in talks with Waitrose and other major retailers along with schools following an initial listing in Superdrug. "Weight-Watchers is hindered by not being available to buy everywhere so our plan is to be as widely available as possible," she said.