You sure can.
Don't be put off by the common saying that you'll only lose 50% of your excess weight with the band.
It's more accurate to say that losing 50% of your excess weight qualifies you as a weight loss surgery success.
Your chances of losing that much weight without surgery aren't great. I read recently that only half of the participants in a study lost as much as 5% of their body weight through diet alone. So if you had 100 lbs to lose, with a starting weight of 250 lbs, you might lose 12.5 lbs through diligent dieting, or 50 lbs through weight loss surgery. Sounds good to me.
Some people lose no weight, and some people lose 100%+ of their excess weight with the band.
And even losing just 12.5 lbs could have a great benefit to your health.