An interesting article about obesity was recently linked on Rational Arguments. It's worth a read, especially considering all the misunderstandings people have when it comes to obesity and weight management.
Last week, we had a few lectures about nutrition and exercise, and how the body reacts to lifestyle changes when people try to lose weight. To put it simply, your body can be a real prick when it comes to trying to lose weight. Granted, if you want to lose weight, you certainly can, but it's not always as simple as changing your diet. You might lose some weight that way, but it's going to take a lot more to continue to lose weight, especially if you want to keep that weight off. Either way, your body will put up quite a fight by lowering its energy needs so that even though you're taking in fewer calories, you still won't lose as much weight as you hope/expect.
Obesity is a major problem in the US right now, and it's a more complex problem than people want to admit. Yes, it would be great if it were as simple as going on a diet for a few months, but long-term benefits require greater long-term commitments. And when the obesity problem starts in childhood, it's going to be even harder to get those children to change their unhealthy habits when they reach adulthood. The article isn't trying to make excuses for obesity, but it does well in explaining the more complex nature of the obesity epidemic we're experiencing right now.