Barely a week goes by without news of another ‘wonder diet’ hitting the headlines. along with the bedroom antics of the Premier League’s finest and the latest on Cheryl Cole’s next career move, new ways of losing a pound or two have become a red top staple. and the tabloids aren’t the only ones fascinated by celebrity diets and, indeed, diets in general. At any given time, one third of women and a fifth of men are on some sort of restricted eating plan, either for health purposes or simply to shift a pound or two. But it’s in the celebrity world that diets and dieting have become all encompassing. Beyonce has waxed lyrical about the merits of the maple syrup detox – a seriously tough fast, which involves consuming nothing but a concoction of lemon juice, water and maple syrup for 11 days straight – while Kate Winslet is a devotee of face mapping. Although extreme fasts have proven too challenging for mainstream success, protein-based diets such as the Dukan – championed by Carole and Pippa Middleton – and the Atkins have caught on, netting their creators a windfall in the process. these fashionable high-protein diets owe their success to a physiological process known as ‘ketosis’ which is what happens when the body switches from metabolising glucose as energy (as happens when you eat carbohydrates) and turns instead to converting stored body fat into energy – which results in weight loss. The diets offer an unlimited amount of proteins such as eggs, fish, steak, chicken, turkey, lean ham, seafood, cheese and milk, and both the Atkins and Dukan diets commence with an initial assault phase which involves eating three high protein meals a day for at least a week with little or no grains, fruit or vegetables. Small amounts of bread, cereals, rice, fruit, salad and vegetables are slowly reintroduced over the following weeks, although if you follow the diet plans to the letter, you’ll never really be able to tuck into a sandwich guilt-free ever again – it’s a lifelong pledge. High protein diets have a runaway success rate in terms of weight loss, and in our body obsessed, time-starved culture, offer a failsafe quick-fix that works. However, they come with a string of nasty side effects including severe tiredness, muscle weakness, dizziness, constipation and insomnia. The diets have also come under attack from health organisations who regard them as controversial, unscientific and even dangerous. The British Nutrition Foundation advises nutritionists against recommending them to their clients saying ‘there are safety concerns about very-high protein diets and caution should therefore be exercised in promoting them’ while health experts agree they are undoing the hard work that’s been done in teaching people the basic principles of a healthy balanced diet. even the British Dietetic Association [BDA] has weighed in, saying that the Dukan Diet has ‘no solid science behind it at all’ and singling it out as the worst celebrity diet of 2011. ‘Sadly, there is no magic wand you can wave,’ says the BDA’s Sian Porter. ‘There is no wonder diet you can follow without some nutritional or health risk and most are offering a short-term fix to a long term problem.’ Health risk or not, thanks to their success as a dietary quick fix, high protein diets aren’t going away and so popular have they become, supermarkets are seeing a spike in sales of steak and chicken – in some cases of as much as 50 per cent. But this is where the new high protein diets become environmentally problematic. whereas 80s favourites such as the cabbage soup diet were largely based on vegetables, the increased demand for red meat puts pressure on the planet in ways that no amount of cabbages could match. according to a UN Food and Agriculture Organisation [FAO] report, meat production accounts for 18 per cent of greenhouse gas emissions, with a sizeable chunk produced while the animal is still alive. Livestock consume more than half of all wheat and barley grown in the UK and around 90 per cent of the world’s soya harvest. Growing these crops requires a vast amount of energy and also takes up a considerable amount of land. Most of what farmland is left is dedicated to the animals themselves – currently 30 per cent of the Earth’s surface is used for rearing domestic stock. along with land use, comes the impact of animal rearing on water resources. it takes thousands more litres of water to produce a kilo of beef than to grow a kilo of grains, vegetables or pulses while local water supplies have been known to become polluted by manure, antibiotics and hormones that run into streams and rivers. Then there’s the subject of the methane, a greenhouse gas that has 25 times the global warming impact of carbon dioxide. it is naturally produced by bacteria that breakdown organic matter and is mainly found in the stomachs of animals. But while methane is naturally occurring, intensive farming has seen an increase in the amount released into the atmosphere, and cows and sheep are responsible for 37 per cent of the total methane generated by human activity. this is due to the fact that cows are intensively reared in cramped conditions and fed on cheap corn and soy-based products instead of being allowed to roam and graze in grassy pastures as they are naturally meant to do.  The UN regards our current appetite for animal products as unsustainable and a study by the United Nations Environment Programme [UNEP] found that by replacing 40 per cent of our red meat intake with chicken, seafood and cereals, we would be able to reduce global emissions by around eight per cent. But even seafood has concerns associated with it too, not least the impact of over fishing and the pollution caused by aquaculture. Deep sea trawling, where the nets are dragged over the ocean floor, is destroying the fragile underwater eco-system and there are also innocent causalities, with the Vegetarian Society estimating that 300,000 whales, dolphins and porpoises are killed every year as ‘by-catch’ from fishing industries. Most researchers agree that a vegetarian diet creates the least environmental damage. However, it’s not everyone’s preferred choice.

So is there a way of eating sustainably? Jasper Kenter, a researcher in Environmental Sustainability at the University of Aberdeen, has been studying the environmental impact of food and has this simple advice on eating responsibly: ‘Eat fish that has been approved by the Marine Stewardship Council, eat locally sourced meat which has been raised on locally grown grains and eat vegetables that are seasonal over local because growing out of season foods is more energy intensive than meat production.’ It’s simple advice that goes a long way to protecting the planet but will fans of the Atkins and Dukan diets take note? while quick fix, celebrity endorsed diets remain a red top and supermarket staple, it seems unlikely and that could have serious repercussions – both for the environment and for our health.Five shocking facts about protein diets• Over two million farm animals are slaughtered for food every day in the UK alone• A Duke University study found that 68 per cent of Atkins dieters reported experiencing constipation, 60 per cent noted increased headaches, 38 per cent said they had bad breath, 35 per cent got muscle cramps and almost a quarter said that they felt generally weaker while on the diet.• 70 per cent of Amazon deforestation is caused by local farmers in search of new grazing pastures for cattle• An estimated 3,500 seals are killed in Scotland alone each year as they are considered a threat to farmed salmon• according to the Land Institute, if everyone switched to high protein, low carb diets, an extra 250 million acres of farmland would be required just to produce feed grains.

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