Losing weight - difficult, yes. Impossible, no...
I've run into a couple discussions lately - in this somewhat trollish FWF thread and today on Megan McCardle's blog making the claim that losing weight is impossible, that nobody can lose, say, 100 pounds and keep it off for any appreciable amount of time, because we aren't wired to lose that much weight.
I say that is bullshit, and I think I have some authority in the matter. Below is a series of pictures taken of me by my parents in December of each year from 2004 to 2008. I've posted them here before, but if you have never seen them:
When I decided that I needed to lose weight, in March of 2005, I weighed around 250 pounds and wore 46" pants. FWIW, I'm about 5"5". I currently weigh about 150 pounds and can fit into a pair of 34" pants on a good day (unless they are, like, skinny hipster jeans).
When I've posted these pictures on other forums, I usually get some complements about the weight I've lost. While that's nice, the point isn't that I'm special because I lost a bunch of weight. Quite the opposite, actually. I'm not some sort of superhuman with unusual willpower. I certainly have yet to figure out how to be as successful in, say, my career or my love life. So it's not that I have some amazing ability to achieve goals that other people lack. If I could do it, chances are a lot of other people also could, if they are willing to put in the effort.
What I did was pretty basic - watched what I ate, paying special attention to cutting back on fat, and adding exercise - which started out as 30 minutes of walking and eventually grew to 90 minutes on a Precor. I don't watch what I eat nearly as carefully as I used to, but I still try to eat healthy most of the time, and I try to exercise pretty much daily.
Did I have some advantages that other people lack? Some. I work for a college, so we have a nice gym, with long hours (at least during the school year) and a convenient location. I have enough free time that I could exercise - although when I started out, I was working 6 days a week and taking grad classes at night. I have enough income to pay for my gym membership and decent food. But I suspect there are a number of people who could do it - and I know some who have.
I've also heard "you'll just end up gaining the weight back". That is possible. I've managed to keep it off for the last 3+ years, give or take 10 pounds or so. But when I gain or lose those 10 pounds, it's usually traceable to something I've done eating-habit wise. And if I gain back a significant amount of weight, it will be because I either stopped exercising or because I became even less careful about what I eat. In other words, it will be because of something I did, not because weight just magically reappears on the body.
I don't deny that losing weight is hard - food tastes good. Exercise isn't all that fun, and it's even less fun when you are the fat guy in the gym, doing a slow workout and sweating like a pig next to some model-looking chick who is going twice as fast on the treadmill next to you and not breaking a sweat. But you know what sucks more than working out or having a protein bar for breakfast instead of 6 donuts? Dying young of obesity-related causes.