Not so naughty: Dark chocolate scores higher than blueberries on the oxygen radical absorbance capacity scale
Blueberries contain more anti-oxidants than other fruit
Blueberries are known as a superfood, due to their high level of anti-oxidants (molecules thought to help protect us from cancer- causing free radicals). But that does not mean they are superior to other fruits.
Angela says: 'Blueberries score highly on the oxygen radical absorbance capacity (ORAC) scale, but scientists are finding foods that are even higher - including dark chocolate.
'Even if blueberries top the scale, they are only rich in one family of anti-oxidants, anthocyanin, which is found in other fruits, like grapes.'
And the far cheaper red grape is actually higher up the ORAC scale.
Low-fat foods help you lose weight
Whether it be cereal bars, yoghurts or ready meals, low-fat options are always tempting if you are desperate to lose weight. But not only are they likely to be stuffed full of sugar, carbs and synthetic sweeteners, they could also have just as many calories as the 'high-fat' alternative.
'Particularly with sweeter low-fat foods, the extra sugar used means it might have a similar calorie content to the regular option,' says Angela. 'It might be better to just have a smaller serving of the standard dish, with more fat but less sugar.'
Eating at night makes you fat
Calories are calories, whether eaten during the morning, noon or night. Studies using monkeys found the animals stayed the same weight whether they had six per cent of their food at night or 65 per cent - the body burns them off at the same rate during sleep.
But avoiding food in the evenings may still help you lose weight. Angela says: 'People tend to snack all evening in front of the TV, especially if they have eaten very little all day.'
Good for you: A boiled egg has only 75 calories
Eggs raise cholesterol levels
First we were told to 'go to work on an egg', then we were warned eggs are bad for the heart. Now, it seems the first advice was better.
Although eggs contain cholesterol, our body varies the amount it produces, so simply makes less if we eat an egg.
Research by the University of Surrey found that, after eating a two-egg-a-day diet for 12 weeks, none of the test subjects had raised cholesterol levels.
And as well as being low in calories (75 in a boiled egg), they contain vitamin D, vitamin B-12 and other nutrients.
Coffee dehydrates your body
We all know that coffee can make us dehydrated, right? Wrong.
A whopping 50 per cent of Britons limit their intake, believing it's a diuretic (a substance which causes the body to lose fluid by making the kidneys produce more urine).
But, in fact, it has no such effect on regular drinkers. Nutritionist Angela Dowden says: 'New converts could be taking more trips to the loo. But your body gets used to it and coffee counts towards your daily fluid intake.'
Eating margarine is bad for your heart
This used to be true, as marge was previously packed with trans fats - hydrogenated fats that raise bad cholesterol and reduce good cholesterol, increasing the risk of heart disease and diabetes.
But after a consumer backlash the spreads on our shelves have been reformulated with healthy poly and mono-unsaturated fats.
Angela says: 'Margarine is a healthier option than butter.'
Daily fluid intake: Coffee counts
Decaf coffee won't affect your energy levels
It may come as a shock, but decaffeinated coffee does contain caffeine - although only a tiny 5mg compared with the normal 90mg or more in a filter coffee.
But rather than having no effect on you, research has shown it may make you sleepier than no coffee.
Dr Crystal Haskell, of Northumbria University, found levels of caffeine less than 10mg actually made people feel more tired, with weaker memory skills.
She puts this down to the body countering the effect of the expected caffeine high.
Always keep fruit and veg in the fridge
You probably don't give a second thought before sticking fruit and veg in the fridge. But by keeping things cool, you may be losing out.
Scientists in Oklahoma in the U.S discovered that a watermelon left at room temperature had double the levels of beta-carotene and 20 per cent more lycopene - both antioxidants - after two weeks than one stored in the fridge.
Bananas and peaches are also more nutritious at 20 degrees.
Your body needs eight glasses of water a day
If you've been drinking two litres of water a day, it turns out you might have been wasting your time.
When doctors at the University of Pennsylvania in the U.S. examined the benefits of drinking this much water, they found no evidence that it led to clearer skin, boosted weight loss or helped the body to detox.
Angela says: 'The amount of water a person needs varies - thirst is the best indicator. Check the shade of your urine - if it's straw-coloured or paler you are probably drinking enough.'
Not best served chilled: Fruit like blueberries
When slimming, eat little and often
Which is better for you - three hearty meals or six little ones? Diet books might advise you to 'eat little and often', but you're no more likely to lose weight this way.
Australian scientist Dr Michelle Palmer compared weight loss in people eating in both ways and found they lost the same amount. The only difference was the six-mini-meal group was more likely to put the weight back on.
Angela says: 'Eating little and often can control hunger, but there's a danger that by eating more often you eat more calories.'
Raw vegetables are better
While you may not fancy a raw veg diet, general wisdom maintains that the more you cook vegetables, the more nutrients they lose. But this is not necessarily true.
Carrots are a case in point. Angela says: 'When cooked, the damage to the cells means three times as much betacarotene is released - an anti-oxidant thought to help protect skin.'
White meat is lower in fat than red meat
Often dieters eat chicken as a healthy choice, but it could be fattier than a lean cut of red meat.
'The myth probably dates back to when butchers' cuts were fattier,' says Angela. 'Now, the fat content is virtually the same.'
A lean sirloin steak has as little as 5g of fat per 100g, while chicken thighs may have up to 9g per 100g.
Pale vegetables have fewer nutrients
We've been taught it's best to eat vegetables with vibrant colours, whether it's deep green spinach, purple beetroot or red cabbage.
While this is a good rule, Angela says, white vegetables should not be dismissed.
White cabbage is full of vitamins A, B, C and K, along with calcium, iron and fibre, while cauliflower is a great source of anti-oxidants, vitamin C and folate.