Err, have you been lowering calorie intake relative to your activity and changing metabolic rate? Lighter bodies require less energy both to maintain and move around. If you haven't been adjusting your "dieting" diet it's no wonder you plateaued, because where initially you ran a caloric deficit you're now much closer to equilibrium.

Also, I've intentionally gained weight on cyclical low-carb diets (<5 g carbs each weekday, 1200-1500g carb-up on weekends). It's because I ate a lot.