MYTH: Counting kJ is an outdated exercise.

Keep counting! The kilojoule is an energy-measuring unit. It "explains" one aspect of food: the amount on energy we could potentially derive from it. Many factors play a role in our energy balance. We need to find the balance between energy consumed and energy used. On the consumption side, the factors are:

MYTH: If I eat fat-free, I will lose weight.

You'll also get ill. Fat is essential for the normal functioning of many of your body's systems. It's also an important taste factor, influencing flavour and "mouth feel", so cutting it out completely will leave you feeling deprived. If you allow yourself only low or fat-free foods, you'll miss out on the healthy fats found in olives, avocado, salmon, mackerel, nuts and seeds.

If you want to lose weight, you need to make a trade-off with yourself when it comes to fat. Limit your intake to 40-50g a day. Choosing what you eat with care (limited-fat foods, lean meat etc) will give you "space" in your diet for treats like olive oil (1 teaspoon equals 5g of fat), avocado (1/2 a small one equals 5g) or salmon (100g equals 5g fat).

MYTH: Only if I have blood pressure problems, need I worry about my salt intake.

The upper recommended level for salt intake is 6g, yet the average intake for Westerners is 10-12g. Most is the result of salt added during processing, cooking, or at the table. Those excesses may lead to water retention and high blood pressure.

Research also shows that salt could play a role in the way we digest food. A meal with a high salt content passes through the stomach faster, which could influence the insulin levels in the blood. That's associated with increased susceptibility to insulin resistance, which in turn is associated with weight gain.

MYTH: Sugar and starch are fattening

Yay! Not necessarily! It's not sugar that's the problem; it's abundant in our natural foods. Carbohydrates are the preferred source of energy for the human body. The problem is how we consume it.

Granulated sugar provides empty kilojoules, and it's recommended that not more than 10% of your energy intake should come from refined sugar. On a daily consumption of 6200 kJ, you'd average 200g of carbohydrates, so you'd be allowed 20g (4t) of refined sugar.

Your average can of fizzy drink has about double this. By comparison, a medium piece of fruit and a slice of bread would provide about 15g of carbohydrates, with extra nutrients as an added bonus.