Don't fall for these rip-off fads!

What do you really know about the food you eat and the creams you smear on yourself? Learn a little about them and save some money whilst you're at it!

Health is important, so it's worth spending good money on it, but we can't forget the science behind it. There are many companies offering a variety of health products, with new types of diets, books and creams coming out all the time. Many of these fad products and diets have no scientific basis, and lots of them are eventually shown to be a waste of money. What's worse is we believe in them without even asking for evidence.

Did you know...

• 40% of our body heat is lost through our heads?
• More people commit suicide in the winter months?
• Eating later at night makes you fatter?
• Our hair and fingernails continue to grow when we die?
• Turkey makes us especially drowsy?

If you knew these things, you knew wrong.

We lose less than 10% of our body heat through our heads, more people around the world commit suicide in warmer months, skin recedes when we die which gives the appearance of hair and nails growing, turkey makes you no more drowsy than anything else high in protein and carbohydrates, and eating later doesn't make you fatter.

(It's the total calories you eat in the day that matters, not when you eat. If you eat late, many of those calories are stored as fat overnight, but you'll burn just as much of that fat the following day so long as you're eating the right amount of calories...That's not to say that eating late doesn't cause other, non weight-related problems, though.)

How these myths occur

Health myths are spread around by folk tales, nutritionists (who don't need scientific qualifications) and by companies touting their latest products. We believe them despite the vast amount of quality counter evidence that often exists.

Studies on health advice and products

When I read about some new health idea, I want to read about the studies that have been conducted and who did it. All too often, all you get is:

'(Our) five-day detox plan encouraged people to drink water and includes ingredients that battle against toxins and help protect from the dangers of free radicals.'

Notice how they covered their backs by saying it at least 'encouraged people to drink water'. This is quite a typical defence. Here's a similar example of that technique:

'All (our) products undergo rigorous testing and evaluation to ensure that our claims are accurate and noticeable by our consumers.'

The get-out clause here is 'noticeable by our consumers'. We don't know under what conditions this company tested its products, but 'noticeable to our consumers' is not a scientific way of measuring the results. People's perceptions can be influenced by what they expect or hope to see, or even by what they're told they should see.

Both of these quotes sound reassuringly scientific, but neither of them, when they were made, were supported by any evidence or description of the trials conducted. This doesn't compare well with proper studies by groups that we can be pretty sure are independent. Such is the case with detoxing, which has a lot of quality evidence against it. Here's just one example.

An example of a quality report on low-carb diets was revealed in a BBC report this week. This is another fad that the scientific community is constantly damning.

Anti-wrinkle cream

I hope I've already saved you money on detox products. Another thing that quality, independent studies have failed to find evidence for includes eye anti-wrinkle creams.

The most recent study was from Which? It's a good example of a study that's more likely to be independent and reliable. Firstly because Which? is, for health products at least, probably independent. Secondly, in its report it went to great lengths to explain how it conducted the trials, how many people were involved, what controls it used, and so on. These are the sorts of details often missing from such things as detox products, no matter how plausibly the 'science' behind them is described by the seller.

Which? found that cheap moisturiser, in this case Simple Kind to Skin Replenishing Rich Moisturiser at 26p per 10ml (£3.21 per 125ml bottle), worked as well as all the best performing specialist creams. Many specialist creams were less effective, including StriVectin-SD Eye Cream, which costs £11.75 per 10ml.

Some tips

'It works because I use it and I'm still alive and feeling healthier than before so I know it works!'

Remember that our minds are quite weak. We can convince ourselves something is true because we think we see it happening or we want to believe it. I've barely scratched the surface here with health myths, so the best thing is to start thinking scientifically.

You might like to begin by reading a couple of sources that are good at putting health studies into plain English, such as the Sense About Science website and BBC News' Health section, but you should always get a few different views, such as from the World Health Organisation and the Food Standards Agency.

The old 'pyramid diet' of high carbs, less meat and fish, and little fat, salt and sugar, combined with drinking plenty of fluids, has been proven time and again in quality studies for decades. The benefits of sun cream and moisturiser have been proved many times over, too. Don't throw your money away on specialist products or 'super foods' till you're certain they offer extra benefits.

More: How to look beautiful on a budget | Save money on your health care