Julia is correct - the only clinical data on actually sustaining weight loss at this time is more related to lifestyle changes than actual "diets".
My previous employer has been working on an FDA approved weight loss franchise for over 12 years. They're still many years away from having a product on the market, all based upon hormones naturally in each of us that are designed to regulate food intake and weight.
The problem is that most of us eat for different reasons, and that's the hardest thing to change. We tend to be emotional, stress, celebratory eaters.
Calories in vs. calories out is the recipe, but it's not that simple, and there is NO clinical evidence on record that I can find (only testimonials) that the acai berry diet has any merit - if it did, pharmaceutical companies would have been all over it a long time ago.
A diabetic cookbook can provide a really great approach to changing meal planning coupled with your gym membership. If possible, find a bunch of 5K, 10K or even half-marathons to enroll in and set goals that are hard to break to help get you on track.
Good luck!
Most weight loss programs have a failure rate within 1 year with at least all of the weight (if not more regained). Changing your relationship with food is really the only way to be successful at this time, and I'm right there with you needing to lose about 10 lbs.