Perhaps the reason for the drop out rate is that carbs are so addictive! My half-Italian wife can't face the idea of no pasta, bread, rice, potatoes, ice cream, etc. What I work on is lowering carb portions (and increasing fat) and finding workable alternatives so that she doesn't feel deprived.

I've found so many great ideas here, for example frozen blueberries (or other berries) in heavy cream with a little stevia makes a cold creamy treat that can satisfy the desire for ice cream. Lately, I've been adding greek yogurt to it, and its even more like ice cream.

For Thanksgiving I made garlic cauliflower mashed "potatoes" and a pumpkin cheesecake - partly for myself of course. But my kids had some of the regular and the faux mashed potatoes. They came back for seconds on the caulifower!

Another point is that low carb can be delicious and satisfying (and healthy) - but you have to get comfortable in your kitchen. It really requires that you prepare stuff yourself, so that you can control the ingredients. This, of course, is a bit of a time commitment. I think its much harder to sustain a healthy low carb lifestyle by eating packaged or restaurant food.