Friday, April 13, 2007

It's official: diets make you fatter

THE world's largest study of weight loss has shown diets do not work for the vast majority of slimmers, and most dieters put more weight back on. More than two-thirds pile the kilos straight back on, raising the danger of heart attack, stroke and diabetes. Researchers warned the strain this repeated weight loss and gain places on the body meant most people would have been better off not dieting at all. The findings, published in the American Psychologist journal, follow other research released in 2004 that showed 2.5 million Australians had tried or intended to try a low-carb diet.

Last night, the US scientists behind the latest research - the most thorough and comprehensive analysis of its kind - said dieting simply did not work. The University of California researchers analysed the results of more than 30 studies involving thousands of slimmers. Although the overview did not name specific weight loss plans, popular diets in recent years include the low carbohydrate, high protein Atkins diet and the GI diet, which is rich in slow-burning wholegrain carbohydrates.

Pooling the results of the various studies clearly showed that, while people did lose weight initially, most quickly put all the weight back on. In fact, most people ended up weighing more than they did to begin with. Researcher Dr Traci Mann said: "You can initially lose 5 per cent to 10 per cent of your weight on any number of diets. "But after this honeymoon period, the weight comes back. "We found that the majority of people regained all the weight, plus more."

Dr Mann's research showed that up to two-thirds of dieters put on all the weight they lost - and more - over a four to five-year period. Half of those taking part in one study were more than 5kg heavier five years later, while dieters taking part in another study actually ended up heavier than other volunteers who hadn't tried to lose weight. A four-year study into the health of 19,000 men revealed that most of those who put on weight had dieted in the years before the start of the study.

Bleak as these figures seem, the true picture could be even worse, as it is thought that most people lie about their weight and don't like to tell researchers that their weight has started to creep up again. Weight loss expert Dr Samantha Thomas from Monash University in Melbourne said Australian research supported the US findings. "We've also seen that dieting can be linked to a lot of poor mental health outcomes," she said. "That just means that people take the weight off and feel really great about themselves and when they put the weight on again - which is kind of inevitable with yo-yo dieting - that people become depressed, have really low self-esteem and feel even worse about themselves than when they went on the diet in the first place."

Dr Thomas said people who struggled with their weight often became discouraged when, after embarking on fad diets, they found the results were not long-term. "The really awful thing about dieting is that it's become a cultural or fashionable thing and most people have spent lots of years and thousands of dollars on it, when there's no evidence to suggest that there's long-term weight loss benefits," she said.

Rebecca McPhee from Nutrition Australia agreed: "Dieting works in the short term but it just encourages unhealthy behaviours in the long term because it puts the body under so much strain. "Everyone is time-poor and they want results quickly, so they diet and then regain the weight after going back to eating normally. "If you look at The Biggest Loser, for example, the contestants lose too much weight, far too quickly, and they haven't developed the sort of skills to then go away and manage their diets."



I don't think this should bother anyone too much but it may be worth bearing in mind

If you're like most people you spend at least a few hours a day in the car--whether it's commuting to and from work, running to the grocery store or picking up the kids from a soccer game. But though you might think twice before touching the seat on a public bus or holding the rail on the subway, you probably don't think too much about your car's cleanliness. Sure, there are coffee stains from a few weeks ago on your cup holder and an inch of dust coating your dashboard.

But it isn't hurting anybody, is it? Research shows otherwise. Charles Gerba, a professor at the University of Arizona who has been researching germ hot spots for years, showed in a 2006 study that our cars are littered with bacteria--and in a few places you might not expect. The dashboard, for instance, turned out to have the second-largest amount of microorganisms present. While often untouched, its vents may draw bacteria via the air circulation system. The fact that it's usually the warmest spot in a car, since the sun shines directly on it, also promotes germ growth, says Gerba, who worked on the study with University of Arizona research specialist Sheri Maxwell. A spot where you've spilled food, such as fries or donut crumbs, may look harmless. But spills produced the most bacteria among the car sites tested.

The researchers sampled 11 different sites inside 100 cars in Illinois, Arizona, Florida, California and Washington, D.C., and looked for both mold and bacteria. The study also examined variables such as vehicle type, whether children traveled in the car, geographic location and the gender and marital status of the drivers.

Single people and men proved to have the cleanest cars and those in Arizona had the lowest bacteria numbers, while married people and women had the germiest vehicles. That's because women tend to drive the family car, which holds the car seats and harbors children's germs, the study found. More bacteria were isolated in vans and SUVs, typical family vehicles, than in cars.

But beyond whether you have children, the city you call home can make it easier or harder to keep your car clean. Of the cities tested, Tampa, Fla., ranked highest in average amounts of bacteria. Thanks to its humid, high temperatures, the city's drivers had 10 times more bacteria in their cars than Tucson, Ariz., residents. Higher average monthly rainfall in cities also translated to more bacteria, according to the study, possibly because bacteria can survive longer in moist environments. Cars in Chicago, on the other hand, had 15 times more mold occurrences than those in Tampa due to the differences in temperature.

If your car is suddenly starting to sound like it needs a cleaning, Gerba recommends disinfecting it once a week. Start with any food stains and work your way down to the change holder and steering wheel, the place our hands come into contact with the most. "Don't become overly paranoid," Gerba says. "Just clean the seat before the kids start sticking to the bottom."



Just some problems with the "Obesity" war:

1). It tries to impose behavior change on everybody -- when most of those targeted are not obese and hence have no reason to change their behaviour. It is a form of punishing the innocent and the guilty alike. (It is also typical of Leftist thinking: Scorning the individual and capable of dealing with large groups only).

2). The longevity research all leads to the conclusion that it is people of MIDDLING weight who live longest -- not slim people. So the "epidemic" of obesity is in fact largely an "epidemic" of living longer.

3). It is total calorie intake that makes you fat -- not where you get your calories. Policies that attack only the source of the calories (e.g. "junk food") without addressing total calorie intake are hence pissing into the wind. People involuntarily deprived of their preferred calorie intake from one source are highly likely to seek and find their calories elsewhere.

4). So-called junk food is perfectly nutritious. A big Mac meal comprises meat, bread, salad and potatoes -- which is a mainstream Western diet. If that is bad then we are all in big trouble.

5). Food warriors demonize salt and fat. But we need a daily salt intake to counter salt-loss through perspiration and the research shows that people on salt-restricted diets die SOONER. And Eskimos eat huge amounts of fat with no apparent ill-effects. And the average home-cooked roast dinner has LOTS of fat. Will we ban roast dinners?

6). The foods restricted are often no more calorific than those permitted -- such as milk and fruit-juice drinks.

7). Tendency to weight is mostly genetic and is therefore not readily susceptible to voluntary behaviour change.

8). And when are we going to ban cheese? Cheese is a concentrated calorie bomb and has lots of that wicked animal fat in it too. Wouldn't we all be better off without it? And what about butter and margarine? They are just about pure fat. Surely they should be treated as contraband in kids' lunchboxes! [/sarcasm].

Trans fats:

For one summary of the weak science behind the "trans-fat" hysteria, see here. Trans fats have only a temporary effect on blood chemistry and the evidence of lasting harm from them is dubious. By taking extreme groups in trans fats intake, some weak association with coronary heart disease has at times been shown in some sub-populations but extreme group studies are inherently at risk of confounding with other factors and are intrinsically of little interest to the average person.