Something else to think about is the effect of weight loss and regain on your metabolism.
The muscles that you have in your body are little furnaces that burn calories and keep your metabolism running as high as possible. Every pound of muscle that you have burns 20 - 25 calories per day - yay!!
But ... when you lose weight without exercising, studies show that up to 50% of what you lose is muscle and the rest is fat. What that means is that your metabolism slows down as it loses its little calorie burners.
Ah, but when you regain weight, it comes back on as 100% fat. The lost muscle is NOT replaced unless you actively lift weights to regain it. The net result is that you've changed your body composition - the percentages of fat and muscle - and your metabolism is slowed down. The next attempt at dieting is harder because your metabolism is slower and burning fewer calories than it did the first time around.
Many cycles of yo-yo dieting without muscle building exercise can really put your metabolism in the slow lane by stripping off a huge amount of your muscle mass. We do metabolic and body fat testing at the gym where I work and frequently see women who have spent their lifetimes on the diet rollercoaster and consequently have shockingly high body fat percentages, along with the metabolisms of turtles. Which stinks.
The only way to avoid this loss of muscle is to lift weights to sustain and increase your muscle mass the whole time that you're dieting. This will keep your metabolism ticking along and let you burn as many calories as possible - helpful for both weight loss and maintenance. What's really cool is that you can actually INCREASE the number of calories that your body burns every day by adding some muscle - I've managed to raise my resting metabolic rate by more than 200 calories per day by adding some additional muscle. And I'm very, very happy to have those 200 calories to play with every day!
Maybe something else to consider?