I am not an expert but IMHO I am convinced that there are 3 reasons why no carb diets work:
-most of us generally have a habit of consuming much larger of portions of carbs than we need to, and they contain lots of calories!
-we usually accompany those carbs with fattening things, such as butter with potatoes/bread, sauces with pasta etc. By cutting out the carbs, the calories in the sauce etc are also eliminated
-protein makes you feel full more quickly than carbs (and certain types are lower calorie than most carbs, eg lean meat/fish/eggs, cooked healthily) so again, you cut out calories and don't feel like you are starving yourself.
HOWEVER like any diet, once you come off it, you will put weight back on...and any diet that eliminates an entire food group can't possibly be healthy. Also, if like me you adore most carbs, you will find it very difficult to stick to.
As a compromise, why not just try cutting out carbs after, say 3pm - so afternoon snack and evening meal is just protein and fruit/veg, maybe a bit of chocolate/glass of wine as treat. I have found this really effective in the past and it avoids the horrible side effects and feeling of deprivation that a no carb diet would involve. Have plenty of porridge/granola/low GI carb based breakfast and low GI carbs at lunch time with healthy accompaniments and snacks and you will probably notice a difference pretty quickly, especially if you are exercising too (when you definitely need carbs).