Think 'light' coloured olive oil is lighter in calorie content or eating carbs can give you love handles? Well, in that case you need a reality check, because all these notions are mere myths, say two Sydney-based dieticians.

Susie Burrell and Karen Fischer, nutritionist and author of The Healthy Skin Diet, have come up with a list of the top food myths that people have been following blindly for years.

According to Burrell and Fischer, the top food myths are:

• Oysters are an aphrodisiac

Oysters don't have a secret chemical agent that boosts your sex drive. Though they do have zinc, which is beneficial for men, they won't do any good to the sex life.

"Zinc is linked to the sexual hormone but does not have an effect on libido. However, some people say oysters are an aphrodisiac because they look like parts of the female anatomy," WAtoday.com.au quoted Burrell, as saying.

• Long-life milk is full of chemicals

Milk does not need preservatives to sit on a cupboard shelf for months, for it's preservation secret lies in the application of high-temperature technologies.

Fischer said: "Milk is heated to 135 degrees then quickly cooled. That makes 'bad' bacteria perish, but all the minerals are retained. So long life milk is great as a standby if you run out of fresh milk."

• Light olive oil is 'light' on calories

The 'light' refers to the colour, not the fat content.

• It is not safe to re-freeze meat after it has thawed

It is actually safe to thaw and refreeze meat, but on needs to be very careful dong that. The meat must be thawed in a fridge at five degrees or less. At this temperature, most bacteria responsible for food poisoning cannot grow and those that can, do so very slowly and are killed by subsequent cooking.

• Carbohydrates cause you to gain weight

Carbohydrates do not cause weight gain unless they contribute to excess calorie intake. The same holds true for protein and fat. Burrell said it's all in the selection.

"The trouble with carbs is they can be easy to overeat. If they are highly processed, like white flour and pasta, it is turned into sugar quickly and means you don't stay full for long. So you need to choose the right sort," she said.

• Fresh veggies are better than frozen

A large number of frozen veggies are just as nutritious, or in some cases even more nutritious, than fresh ones. Frozen vegetables are usually processed within hours of picking, which prevents the loss of many nutrients during the freezing process, therefore they keep their high vitamin and mineral content.

• The healthier option at a restaurant is a vegetarian dish

This depends on the dish, but some vegetarian meals are high in fat, especially if they're fried or are made with cheese or pastry.

Burrell said: "The problem with vegetarian meals is that cream-based sauce or butter is used to make them tasty. If you choose a pasta or risotto it has to be very plain tomato sauce to be the low-fat option."

• It's best not to eat after 7 pm

It's not the time but the type of food which you eat that counts. Eating more calories than you burn will make you gain weight. But late snacking can push your calorie intake over the edge.

Fischer said: "Eating just before you go to bed can hamper sleep patterns in that it messes with your insulin. I'd suggest you don't eat for two to three hours before bed."

• Fat-free equals calorie-free

Binging on fat-free foods may ward off the guilt-factor linked with gaining weight, but a lot of fat-free foods have the same amount or even more calories than regular versions.

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