Health Magazine had a review of the diet a while back:
http://www.health.com/health/web/DietGuide/curves_complete.html
The “magic” of the Curves exercise plan is that you don’t waste time trying to fit in cardiovascular exercise before or after you hit the resistance machines. Instead, you do cardio moves between repetitions on the machines. That’s great for the time-deprived exerciser. This type of workout will no doubt help people get in better shape, but health professionals would probably say not to stop there. Current recommendations tell Americans to aim for 30 to 60 minutes of exercise each day, not just three times a week. As for the meal plans, the very low-carb or low-calorie limit dictated by the initial 2-week phase is definitely restrictive. Phase two is more realistic with its 1,600 calories or 40 to 60 grams of carbs. The 2,500 to 3,000 calories allowed during the maintenance phase could be a little high for some women, particularly for those who are petite.
Does the diet take and keep weight off? Unclear. There are plenty of anecdotal success stories in the book but no scientific findings—at least not yet. Baylor College of Medicine has accepted funds from the company to conduct clinical trials on the program. Is the diet healthy? That’s up for debate. Without long-term data on the safety and effectiveness of low-carb diets, it’s hard to endorse the skimpy 20 grams of carbs allowed on the carb-sensitive plan. Early reports suggest that in the short term a low-carb diet may be OK, but many health professionals are still skeptical. At 1,200 calories per day, the calorie-sensitive plan is probably safe, but that limit may be a bit low for most women, especially on the days they’re doing the 30-minute workout. A diet of 1,500 or 1,600 calories is probably more realistic.
What do the experts say? Registered dietitian Dawn Jackson Blatner, a spokeswoman for the American Dietetic Association who does weight counseling at Northwestern Memorial Wellness Institute in Chicago, gives Curves a C grade. She says it features some positive messages, and she likes the focus on eating regular meals with plenty of vegetables and mostly lean protein. On the other hand, “the carbohydrate-sensitive plan strictly limits healthy foods such as fruit and whole grains,” Blatner says. “And the diet doesn’t offer many real-life strategies for healthy eating and healthy lifestyle changes to help this become a lifelong plan.” Registered dietitian Jane Kirby, who reviewed the program in Dieting for Dummies (Wiley, second edition, 2003), likes that exercise is a part of the regimen but questions why the author puts so little emphasis on calories as a means of aiding weight loss. “Calories in versus calories out is the bottom line for weight loss,” Kirby writes.
Who should consider the diet? Women dieters, since the fitness centers are for women only. Those who have a limited amount of time for exercise or who usually feel uncomfortable visiting a health club might like this approach.
Bottom line: While any program that gets people moving is great, the food plans in the initial 2-week phase seem too restrictive.
I had looked at one of the clubs and honestly I didn't like that the time you could go work out was so limited...
You could always get a trial membership (I think it was Klondike's sugar free ice cream treats that had a free trial membership on their packaging) and see if you really like it before committing..