Are you a cowering, diet- obsessed wreck, meticulously measuring your carbs and counting out individual salt granules on to your plate? Headlines like "Fat Britain: tackling the obesity epidemic", and "Food additives murdered my horse" (OK, we made the second one up) can't help to steady your stress levels.
There are so many health scare stories these days that it's all too easy to feel that our modern lifestyles are a sure-fire route to an early grave. However, two seasoned physicians are keen to counter this idea. Global Warming and Other Bollocks is a book put together by professors Stanley Feldman and Vincent Marks in the hope of blasting away various media scare stories (or in some places, received scientific wisdom). These include dietary misconceptions about salt, carbohydrate and junk-food intake. They are all areas of intense scientific debate, with a wide variety of opinions; screaming out of left-field, the pair hope not so much to reposition scientific consensus as to inject a much-needed tonic of common sense into the debate.
"We did it because we were fed up with people appearing to know too much and being overcome by dogma, which is just meaningless," says Marks. "I have always adhered to an axiom which is that when we all know something, it is probably wrong." With that in mind, we line up a gang of "monster myths" and let our pair of professors put the other side.
Eating salt is not bad for us
Many scientists, along with the Government's Food Standards Agency, think that too much salt can cause everything from heart attacks to strokes and kidney disease. Feldman and Marks believe the risks are overblown. This is because of our reliance, they say, on antiquated medical research in which patients were treated for high blood pressure with a lowered salt intake (before drugs were available).
"This seldom worked," they write. "Nevertheless, the myth has persisted." When results of 11 of the most scientifically credible studies of the effects of salt in the diet were analysed by the internationally recognised Cochrane Collaboration, the effect of salt on blood pressure was found to be negligible.
Salt is an essential food and without it we would die. Sweating is impossible without it, and strenuous exercise by those with depleted levels of salt can lead to overheating and death.
Just look at the Japanese, say the professors. They have double the European salt intake, yet have a longer life expectancy and less problem with blood pressure. "Lots of salt is nowhere near as bad as we are led to believe by campaigning groups," says Marks.
There's no obesity epidemic
It depends how you define "epidemic". The dictionary says it's defined by a "sudden onset"; our professors say our population's increasing corpulence has been around for 100 years or more; they also say we often confuse being overweight with being obese, anyway – these days our newspapers and magazines generally call being overweight and obese the same thing. The world's population has got fatter as food supplies have become more readily available for more people. Equally, people generally get plumper as they get older, and, with an ageing population, an increase in average weight is to be expected.
And while the very obese would once have died young, now they are living longer, so there are more obese people alive at any one time.
While the pair acknowledge that obesity can predispose you to chronic illnesses, they question the arbitrariness of the Body Mass Index (BMI), the traditional means of assessing obesity, which tells us nothing about the proportion of body weight that is fat – the real test of obesity. "What we are saying is that the means for assessing obesity need to be looked at again; it is normal, for example, for people to put on weight if they are a bit older," they write. Additionally, they say, it is a myth that obesity is simply cause by gluttony; it can be hormonal or genetic.
Being fat is not so bad for us anyway
Several large studies from the National Institutes of Health in the US, involving thousands of healthy people, have shown that there is little to differentiate between the life spans of people with a BMI of 20 (within the "ideal" range) and those with one of 30. The findings have been replicated in many other countries. Yet still, say the professors, healthy people with a BMI of 25-30 are labelled "overweight".
What's more, data suggests that, from the perspective of longevity, as we get older, a higher BMI may actually be an advantage. The "ideal" weight increases progressively, and by the age of 70, a BMI of 28 is ideal, as opposed to one of 20 for young adults.
There's no such thing as junk food
Did you know the much-maligned Turkey Twizzler contains the same amount of amino acids as turkey breast? And do, please, bear in mind that corned beef is no less nutritious than any other meat product.
Our authors believe that the phrase "junk food" is an oxymoron. "It's either food or it's junk. That phrase is just a fashion," says Marks. They believe (contrary to the views of many scientists, who argue that saturated fats are one of the worst things for you, especially in large quantities) that, provided you have a mixed diet of carbohydrate, fat and protein, together with sufficient essential vitamins and trace substances, there is no evidence any particular food product should be avoided. They are particularly baffled by the antagonism to burgers, pointing out that almost every national cuisine traditionally has an equivalent, mince-based food.
We need to bear in mind, say the authors, that in 1930 a burger manufacturer demonstrated that a student survived for 13 weeks eating only hamburgers and drinking water.
It is the overall diet, not individual foods, that affect our health. So, by the same token, there is no such thing as a "health food" – no amount of goji berries will compensate for a truly bad diet.
Vitamins are a waste of money
Well, that increasingly seems to the consensus, doesn't it (recent studies, part-funded by the German chemicals firm BASF, discovered that there were no significant effects on rates of heart disease after taking vitamins E and C). There seems to be, they claim, no evidence that anyone in the developed world, eating a normal mixed diet, is likely to suffer from vitamin deficiency or benefit from additional supplementary vitamins. The obvious exception is those who are not exposed to sunlight (for example, through hospitalisation), who might lack vitamin D, or those on a vegan diet who need to ramp up the vitamin B12. "Taking an excess of some vitamins may be dangerous," they write. "Any excess of vitamin C, a common additive, is immediately excreted in the urine."
There's nothing wrong with food additives
The phrase "no additives or preservatives" is a common box-front boast; but should we be that bothered? Very few foods, point out the authors, are eaten without having undergone some process to alter the chemical nature of one or more of their constituents – indeed, cooking alters the chemical nature of many foods. Many foods also contain tiny amounts of substances – cyanide in almonds, for example, or potassium in bananas – that would be hazardous in large amounts, which is worth bearing in mind when we're fretting about which foods are "pure".
The authors claim that the recent emphasis on "organic being best" can sometimes be misleading. A ban on the use of chemicals and pesticides in food, they claim, would reduce the worldwide availability of food. This would be most keenly felt by those in the developing world. "It would make all of us vulnerable to the effects of fungal contamination," says Marks. "Organic farming would reduce the agricultural yield by 30 to 40 per cent." With regard to preservatives, if we baked bread ourselves it would go mouldy in two days; the stuff we buy in the shops lasts much longer. And that can only be a good thing.
Carbs are not the enemy
Carbohydrates are made of simple sugars and are one of the most plentiful organic compounds on earth; so how come they have become a byword for digestive evil – that devilish, prolific recruiter on behalf of thighs, bums and tums?
"You can't possibly live an active and healthy lifestyle by totally eschewing carbohydrates; for example, we can only get about 20 per cent of our energy from protein," says Professor Marks. The authors take issue with the fact that we consider sugar as bad for us. While it might rot our teeth, it is essentially the end product when all carbohydrate is broken down. "Once it is in the bloodstream, the metabolic effects of glucose and its impact on bodyweight are the same irrespective of its source."
There's no need to fear cholesterol
In 1989, the results were published of a massive study supported by the World Health Organisation (WHO), investigating the causes of cardiovascular disease. They showed, among other findings, that the mortality rate from heart disease in Finland was five times higher than in France, despite the fact that cholesterol levels were the same for both nations. And, since the 1960s, heart disease has fallen in New Zealand, Australia, the USA and Canada, while fat consumption has stayed at 40 per cent.
So why do we view cholesterol as a ticket to heart disease? The professors suggest that the pharmaceutical industry has a vested interest in "keeping the cholesterol story going" as statins are perceived to lower cholesterol levels. "A lot of the attempts to measure cholesterol levels in the general population to test how they fluctuate have been unsuccessful; it has always been hard to measure and to see how statins can improve people's health."
Swine flu has been over-hyped
The WHO forecasts that the next flu pandemic will lead to the death of 2-7 million people around the world, with the numbers affected getting into the billions, with a cost of $800bn (£494bn), though there is little sign of this so far. Regarding the chances of you actually dying, maybe we had something to worry about with avian flu, claim the authors, in which mortality rates were around 60 per cent, but the chances of you getting swine flu and then carking it are very slim indeed.
"It's not like when measles was transferred to Hawaii and it killed the entire population; it's an inconvenience, nothing more," says Marks. "The thing is, what we have at the moment is nothing more than you would ordinarily see in winter anyway." The writer claims that a lot of the older population suffered from the same strain in 1977, which is one of the reasons that children are much more susceptible to it. "After all, it is not like people in their 20s, 30s and 40s are dying from it now."