Some prepared salads sold at UK supermarkets contain more fat than a McDonalds Big Mac and fries, a consumer watchdog revealed today (25 June).

According to a new report from Which? that sampled 20 supermarket salads, among the worst offenders were salads available at Asda and Morrisions.

The Smedleys Atlantic Prawn Marie Rose Salad, sold at Morrisons and other supermarkets, was found to contain 855 calories and 66.3g fat. Meanwhile, with a content of 13% mayonnaise and 10% Caesar dressing, Asda Chicken Caesar Salad contained 41g of fat.

This compares to the 820 calories and 40g of fat contained in a Big Mac and French fries from McDonalds.

Salads available at more upmarket retailers were not found to be much healthier. For example, Marks and Spencer Pasta with Tomato & Basil Chicken salad had 760 calories and 46g of fat, the report said.

"People will buy salad as a healthy option - but they are often mistaken in this assumption," a spokesperson for Which? told just-food.

"While labels are there to provide guidelines, these can often be confusing and misleading," the spokesperson added.

Which? emphasised that Tesco's Tuna Layered Salad listed calories for half a pack, rather than showing the 550 calories and 41g fat found in a full salad.

Tesco was unavailable for comment as just-food went to press.