On the surface, weight loss sounds like a simple concept: eat fewer calories than you burn, and you'll lose weight.But our world's growing obesity problem has completely changed the way we view weight loss, leading to some truly desperate measures and shocking statistics.Here are ten of the most startling facts about weight loss:1. The whole world needs to lose weight.According to the World Health Organization, 1 billion of the world's inhabitants are overweight. (That's almost equal to the number of people who are malnourished in the world.)Globally, over 22 million children under the age of 5 are considered overweight. This epidemic is largely due to increased consumption of processed foods high in calories and saturated fat, and a decrease in physical activity.2. Nearly two-thirds of Americans are overweight or obese.The World Health Organization estimates that nearly two-thirds of all American adults are overweight. The National Center for Health Statistics recently found that 34% of Americans are clinically obese.3. 50% of American women and 25% of American men are currently on a diet.With numbers like the ones above, it's no wonder most Americans feel the need to count calories.However, society's obsession with thinness comes at a price: Chronic dieting and emerging eating disorders are becoming more common among elementary school children.4. America's top three killers are linked to obesity.National Geographic published some eye-opening facts about mortality in the USA.They found that the top three most statistically likely causes of death were heart disease (with a 1 in 5 chance), cancer (with a 1 in 7 chance), and stroke (with a 1 in 24 chance). All of these have been linked to excess weight.5. Surprisingly, America isn't the world's fattest nation.The World Health Organization gives that dubious honor to Samoa, where more than 93% of the population is overweight or obese. The Pacific isle of Kiribati comes next, with an 82% obesity rate.America rounds out the top three, but is closely followed by Germany (66.5%), Egypt (66%), and Bosnia-Herzegovina (63%).6. The weight loss industry is fat and happy.The obesity epidemic might mean misery for some, but it's certainly padded the pockets of the weight loss industry.In 2007 alone, the American Diatetic Association found that Americans spent $58 billion on weight loss products. Considering that obesity has gone global, you can imagine how lucrative the weight loss industry must be.7. Over half of the diet industry's claims are false.As with any booming industry, there are plenty of unscrupulous sellers trying to prey on people's weight loss dreams. The Federal Trade Commission published a study in 2002 which found that 55% of all weight loss claims "strained credibility".The American Diatetic Association concurs, pointing out the fact that most weight loss products focus on atypical success stories instead of real chances of success.8. Bariatric surgery doesn't always work.Discouraged by multiple failed attempts at weight loss, more people than ever are turning to bariatric surgery. However, there is no evidence that gastric bypass or banding result in permanent weight loss.The University of Virginia conducted a study that revealed gradual weight regain after 6 years post-surgery.9. Diets don't work either.The National Institute of Health has estimated that dieters can expect to regain two-thirds of their lost weight within a year of completing their diet plan. These dieters can expect to regain all of their weight, and possibly more, within 5 years.10. Fortunately, there is a perfect recipe for lasting weight loss.The National Weight Control Registry tracks 3,000 people who have lost more than 30 pounds and kept it off for more than a year.They have found that most of the successful dieters have four behaviors in common: they keep a food journal and monitor their weight; they never skip breakfast; they get an hour of exercise almost every day; and they eat diets consisting of 24% fat, 56% carbs, and 19% lean protein.