Sounds like you have a slow moving digestive cycle. When you eat less, it makes it even more difficult to have elimination because there is not much in the digestive tract to push through. In other words there is a lack of momentum. I would encourage you to add fruits back into your diet. These should actually help any yeast issues (speaking from experience), and give you some very needed calories to help with the weight loss. In fact you might like to experiment with a fruit fast. Many here including myself have done this with great results.