So, how healthy is your salad?

Be careful when you're opting for a salad for a healthy, diet-friendly lunch or dinner. As Jacqui Ripley shows, some of them can be loaded with calories. We put the popular salads and dressings to the test.

Potato salad

Calories: 287. Fat: 26.5g

This can be unhealthy because it is loaded with mayonnaise and therefore fat. "Potatoes in themselves aren't bad because they deliver lots of fibre and are a good source of potassium and vitamin C," says Dr Hannah Theobald of the British Nutrition Foundation. "It's the mayonnaise that's the downfall."

Theobald suggests making your own. "This way you can use whole, unpeeled baby potatoes to avoid losing vitamin C content through chopping; add chopped spring onions and mix in a lowfat yoghurt dressing instead of mayonnaise."

Star rating: 2/10

Caesar salad

Calories: 500. Fat: 40g

Iceberg lettuce typically used has few nutrients and is essentially fibre and water. With salad leaves, the darker the green, the more nutritious it is. This salad is also laden with fat thanks to the Parmesan cheese, creamy dressing and croutons, which are high in both fat and calories.

Use a low-calorie dressing, such as a fat-free vinaigrette. And for a nutritional punch add lean protein such as a chicken breast.

Coleslaw

Calories: 258. Fat: 26.4g

A great source of fibre, vitamins A and C, beta-carotene and folic acid, the shredded carrot in coleslaw is a nutritional powerhouse. However, the benefits are depleted by adding mayonnaise. Instead, make your own coleslaw with fat-reduced mayonnaise or low-fat yoghurt.

Star rating: 3/10

Waldorf salad

Calories: 193. Fat: 17.7g

The original Waldorf salad was made only with apples, celery and mayonnaise, but its popularity increased with the addition of chopped walnuts.

Nuts are frequently frowned upon because of their high fat content, but studies found that three ounces of walnuts a day resulted in a drop in LDL (bad) cholesterol. "Low-fat mayonnaise and non-fat yoghurt are healthier ways of updating this classic salad," says Theobald.

Star rating: 5/10

Tuna, sweetcorn and pasta

Calories: 203. Fat: 12.2g

Although not too bad in nutritional value - it is full of protein and carbohydrates - this salad's high fat content comes from the oil used in the canned tuna. Try tuna in spring water or brine, or go for other types of fish, such as mackerel or salmon, which are better sources of omega-3 fats. Prawns are a good choice, too, because they are low in fat, good for vitamin B12 and are rich in the fat-soluble vitamins A, E and D.

Star Rating: 4/10

Tuna, sweetcorn and pasta

Calories: 130. Fat: 12.5g

Tomatoes are high in vitamin C and are good for vitamin A. In addition tomatoes contain lycopene - an antioxidant with cancer-preventing qualities. Go easy on the cheese. Although full of calcium and vitamin B2, it's high in fat and salt content. Add olives (less than 10 calories each) for their monounsaturated fatty acid, which has been shown to help fight heart disease.

Star rating: 8/10

Rice salad

Calories: 166. Fat: 7.5g

"A good, healthy option, but avoid couscous salads as the couscous may have been cooked in butter," says Theobald. If possible, go for brown rice rather than white. It is full of fibre, protein, B vitamins, iron and essential fatty acids. And add some raw peppers - they're excellent sources of vitamins A and C.

Star rating: 6/10

Bean salad

Calories: 147. Fat: 9.3g

A good choice providing it is not doused in olive oil. Beans are not only high in protein, but you get a good dose of B vitamins, iron and they're high in fibre. Beans are also high in carbohydrates and have a low glycaemic index, which means a bean salad will digest slowly and you'll feel fuller for longer.

Star rating: 7/10

All figures based on a 100g portion of salad (small main course).