Perhaps you've been eating healthily, switching your usual fast-food lunch for a salad from a supermarket.

If you haven't been seeing the results you'd like, it could be because that innocent-sounding salad contains more calories and fat than a Big Mac.

Researchers from Which? magazine looked at 20 pre-made salads sold by major UK retailers. They found that the worst offender, Smedleys Atlantic Prawn Marie Rose Salad (300g), contained 855 calories and 66.3g fat. This compared unfavourably with a Big Mac (820 calories, 40g of fat).

Manufacturers were also accused of misleading labeling. One tuna salad (350g) had 550 calories in total, but the serving size given on the front was for half the pack - 225 calories. Dieters in a hurry could easily miss this recommended serving size.

If you're trying to cut your fat intake, you might want to think twice about that store-bought salad.

Here are a few tips for avoiding those extra calories:

  • Check labels carefully. Find out the total fat and calorie content for the amount of salad that you'll be eating (probably the whole 300g - 350g).
  • Look for light ranges.
  • Beware of dressings, which clock up fat and calories. Even if you're opting for a salad with lean meat, fish or seafood (like prawns), the dressing could be making it significantly less healthy.
  • Make your own fresh salads. This way you'll know exactly what's gone into them.