The myth: All fats are bad for you
The truth: A moderate amount of fat is an essential part of a healthy, balanced diet. For example, fats include omega-3 fatty acids, found in oily fish, which help power the brain and protect the heart. Fats also help the body absorb vitamins A, D and E.
Learn more about the fats that are good for your health
The myth: Saturated fats aren't the enemy any more
The truth: This is currently a fierce area of debate – following a headline-grabbing Cambridge University study, which found no significant link between saturated fats and heart disease. However, the researchers did highlight a strong association between the consumption of trans fats and heart conditions.
Trans fats are found in hydrogenated vegetable oils, which are used for frying and sometimes added to processed foods, such as cakes and biscuits. UK adults should consume no more than 5g trans fats each day, say current NHS guidelines. And the good news is that most of us are sticking well within these limits.
But saturated fats – found in red meat products, dairy food, biscuits, cakes and pastries – certainly aren't off the hook. Most of us eat too much of them, which raises our levels of artery-clogging cholesterol. The average man should eat no more than 30g each day, and the average woman should stick to 20g or less. The lesson? Everything in moderation.
Fats: the good, the bad and the ugly
The myth: Fat alone makes you fat
The truth: Eat too much of anything and you'll put on weight. In fact, sugar is generally considered to be a bigger culprit than fat.
'Sugar is nothing more than empty calories,' insists nutritionist Dr Marilyn Glenville (www.marilynglenville.com). 'It gives you no nutritional value at all. Worse than that, because sugar is devoid of nutrients, your body has to use other stored nutrients in order to digest it. So not only are you getting absolutely no vital vitamins and minerals from the sugar, but your body is also losing valuable nutrients by eating it.'
However, it doesn't come down to a straight contest between saturated fats and sugar: chances are you need to cut down on both in order to maintain a healthy weight.
Ten ways to eat less sugar
The myth: Low-fat foods are a healthy choice
The truth: Not necessarily. Just because a product is low in fat, it doesn't mean it's good for you. 'When food companies create low-fat food, what they normally do is remove the fat and replace it with sweeteners, artificial flavourings and additives to replace the mouth-feel and taste you lose from removing the fat,' says nutritionist Shona Wilkinson (www.superfooduk.com). So always check the nutrition label carefully before you buy.
Ten ‘health’ foods to look out for
The myth: Full-fat milk contains more calcium
The truth: Actually, the opposite is true. Skimmed milk boasts more bone-building calcium than semi-skimmed, which in turn has more than full-fat. Full-fat milk is also higher in saturated fats and total calories, of course. But it does come out on top when it comes to other important nutrients: the cream contains immunity-boosting vitamins A, D, E and K.
Interestingly, people who consume the most high-fat dairy products have a slightly lower risk – eight per cent – of being overweight or obese, according to a recent study of 18,438 women, published in the American Journal of Clinical Nutrition. Obviously, this doesn't mean we can all consume as much milk, cheese and butter as we like without fearing the consequences: it simply demonstrates how full-fat foods can be part of a balanced diet.
Learn more about the health benefits of calcium
The myth: Olive oil is super-healthy
The truth: Olive oil is a rich source of monounsaturated fats, which help raise levels of 'good' HDL cholesterol while keeping 'bad' LDL cholesterol in check. So yes, it's an excellent choice. Heat it up to high temperatures, however, and those monounsaturated fats can transform into not-so-healthy saturated or trans fats. An alternative? Antioxidant-rich sesame oil fares a little better when heated.
Learn more about the health benefits of the different oils we eat
The myth: Eggs are a bad choice
The truth: Yes, egg yolks do contain dietary cholesterol – which was once the argument for giving them a wide berth. But they're also a great source of high-quality protein.
'Let go of any idea that eggs are bad for you,' Wilkinson insists. 'The choline in the egg yolk can actually help prevent the accumulation of cholesterol and fat in the liver. Choline is the universal building block for all cell membranes – and it's especially important for the brain.'
Ten reasons to eat more eggs