A dieting craze in Sweden has been blamed for a surprise surge in cholesterol levels that may be putting people at increased risk of heart disease.
The link was uncovered by a 25-year study looking at diet and heart disease risk factors in the north of the country.
An unexpected rise in population cholesterol followed an increase in fat consumption in 2004, reversing earlier trends.
At the same time there was an explosion in the popularity of low carbohydrate/high fat (LCHF) diets in Sweden. The diets focus on cutting out sugar and starch while upping intake of fats, including saturated fat.
Its proponents, such as Dr Annika Dahlqvist, who is credited with starting the Swedish craze, argue that it helps maintain normal weight and blood sugar while freeing people to eat their favourite foods.
A poll last year suggested that a quarter of Swedes had at least partly adopted an LCHF diet. Around 5% had taken it up seriously, leading the DietDoctor website to hail a "Swedish low carb revolution". There were even reports of stores running out of butter due to increasing demand.
The new study was launched in 1986 after concerns about the high incidence of heart disease in northern Sweden.
Stop the fad diets: Natural ways to lose weight...
Natural Weight Loss Aids
Green tea is rich in the antioxidant called catechin which help speed up metabolism and burn fat quicker. It also contributes towards lowering LDL cholesterol (bad cholesterol).
Pinapples contain high levels of an enzyme called bromelain that aids digestion and prevents inflammation and swelling in the gut, which can lead to constipation and weight gain.
Green Coffee Beans
Green coffee bean extracts help reduce the absorption of fat and glucose in the gut, as well as insulin levels, which improve metabolic function. <a href="http://www.huffingtonpost.co.uk/2012/03/28/green-coffee-new-weight-loss-food_n_1384970.html?ref=uk-lifestyle" target="_hplink">Read more about the weight-loss benefits of green coffee beans here</a>.
Although drinking water alone won't shift the pounds, drinking a glass of it before you eat will make you eat less and suppress your appetite. It also keep you hydrated throughout the day and will keep hunger pangs at bay, because hunger is mostly driven by dehydration.
Having an egg for breakfast keeps you feeling fuller for longer as it acts like a bulking agent in the stomach. It also staves off hunger pangs because the protein prevents the blood sugar level spikes, which lead to food cravings.
Eating half a grapefruit before each meal or drinking grapefruit juice three times a day helps aid weight loss. The fruit's phytochemicals reduce insulin levels, a process that forces the body to convert calories into energy rather than fat.
Beans and pulses contain cholecystokinin, a natural appetite suppressant as they stay in the stomach longer. They also help keep blood sugar on an even keel, so you can stave off hunger longer.
A little bit of cinnamon a day can help control post-meal insulin spikes, which make you feel peckish. A recent study by U.S. Department of Agriculture showed that just a quarter teaspoon of cinnamon a day lowered the blood sugar and cholesterol levels.
Scientists analysed data on food and nutrient intake, body weight, height and cholesterol levels compiled from more than 140,000 measurements and questionnaires between 1986 and 2010.
The results showed an initial reduction in fat consumption and cholesterol levels throughout the 1990s. This coincided with the nationwide introduction of an education and food labelling programme aimed at improving diet and health.
The Vasterbotten Intervention Programme (VIP) continues to this day.
After 2004, there was an unexpected change. Levels of total and saturated fat intake began to increase until they were higher than they were in 1986.
Blood cholesterol levels remained roughly unaltered between 2002 and 2007, but then showed a sharp rise.
In 2010 the average cholesterol level for men was around 5.5 millimoles per litre of blood, and for women slightly less. This was despite a significant increase in the number of people taking cholesterol-lowering drugs.
In earlier years, cholesterol levels had declined from a peak of more than six millimoles in 1986.
Over the whole 25-year period there was no sign that dieting of any kind helped people lose weight. Average body mass index (BMI), a measurement relating weight and height, showed a consistent rise in both men and women.
Professor Ingegerd Johansson, from the Umeå University, who led the research published in Nutrition Journal, said: "The association between nutrition and health is complex. It involves specific food components, interactions among those food components, and interactions with genetic factors and individual needs.
"While low carbohydrate/high fat diets may help short-term weight loss, these results of this Swedish study demonstrate that long-term weight loss is not maintained and that this diet increases blood cholesterol, which has a major impact on risk of cardiovascular disease."
In their paper, the researchers said the marked increase in cholesterol levels after 2007 was "a deep concern".
They added: "After 2004 fat intake increased, especially saturated fat and butter-based spread for bread and butter for cooking.
"Supportive opinions in media for high-fat diets seem to have had an impact on consumer behaviours. Initially beneficial and thereafter deleterious changes in blood cholesterol paralleled these trends in food selection, whereas a claimed weight reduction by high-fat diets was not seen in the most recent years.
"In contrast, BMI increased continuously over the 25-year period. These changes in risk factors may have important effects on primary and secondary prevention of CVD (cardiovascular disease)."
Forget fatty foods - here are unusual (and slightly bizarre) things that could be making you gain weight...
Unlikely Things That Are Making You Fat
Research by psychotherapist Dawn Billings discovered that snooping at your partners phone or Facebook can lead to piling on the pounds. Billings claims that if you find something you didn't want to see, the stress of it all triggers the cortisol hormone, which interferes with the appetite-regulating hormone, letin. This can lead to an increase in hunger, making us lean towards emotional food binges.
Scientists from the <a href="http://www.mountsinai.org/" target="_hplink">Mount Sinai Medical Center</a> claim that phthalates, the chemicals found in 70% of cosmetics including shampoo, throw the body's weight control system off kilter. These chemicals are also linked to depressing testosterone levels in the body, which can increase the risk of weight gain
Recent research by the<a href="http://www.nia.nih.gov/" target="_hplink"> National Institute of Aging</a> found people who are highly emotional, organised and disciplined are more likely to be overweight. They also found that impulsive people have higher BMI's than those who are more relaxed and laid back.
Although its sole purpose is to disguise any unsightly lumps or bumps, it could give wearers a false sense of security, meaning they ditch diets as they know their pair of <a href="http://www.spanx.com/home/index.jsp" target="_hplink">Spanx</a> knickers will hold in their muffin top.
Those who guzzle diet fizzy drinks in the false hope that they're being healthier than drinking the full fat version, are still at risk of gaining weight. According to a study by the <a href="http://www.utexas.edu/" target="_hplink">University of Texas</a>, people who drink diet drinks see their waistbands expand 70% faster than those who drank normal fizzy drinks. This is because they believe they can drink more because of its lower calorie-count.
Falling in love can make you fat, research by the <a href="http://www.uconn.edu/" target="_hplink">University of Connecticut</a> has discovered. Otherwise known as the 'boyfriend layer', when a relationship becomes more established, couples tend to relax their fitness regime, eat out more - and eat more food. This is because new couples 'bond' over food and spend a lot of time doing sedentary things, like lounging on the sofa or in bed.
Women who are fed up at work are more likely to comfort eat, a study by the <a href="http://www.umassmed.edu/index.aspx" target="_hplink">University of Massachusetts Medical School</a> has found. Those who are hacked off with their everyday routine find comfort in 'emotional eating' when stressed and anxious rather than eating when hungry.
Lack of sleep disrupts the body's natural circadian pattern, which controls moods, alertness and appetite over a 24-hour period. If this is altered, it causes an imbalance in the leptin hormone (the hormone that tells us when we're full) and the ghrelin hormone (the hormone that tells us when we need food for energy). If these are out of control for regular periods, it can lead to weight gain.