Most green drinks are very powerful detoxers and will cause a lot of waste to be passed into the bloodstream, through the liver and kidneys and out through the colon. As the blood is filtered of these toxins the skin will soon take on a clearer appearance since blood feeds the skin. It usually takes me about three days to notice a difference though, you are very fortunate. The looser britches is probably because of lost water. When you don't use a lot of water to dilute food in the digestive system, your body will eliminate a lot. This reduces bloat and swelling in the legs and belly especially. Your lack of energy is also the result of rapid and powerful detox. Your body is working hard to cleanse and needs to be treated gently with plenty of rest.

You may need to treat green drink fasting like water fasting-it is that powerful. Start out fasting one day a week, then try three days a month. Once your body begins to cleanse it will tolerate fasting much better. If you need to slow down the detox so you can function day to day, try adding some carrot and apple juices. Both of these juices are sweet enough to supply the body with needed carbohydrates for energy, but, both are also strong in nutrients and antioxidants.

Like you, I learned about how powerful green drink fasting can be, but it is also probably the healthiest way to fast. I want to do some more when the weather gets a little warmer. Perhaps we can share experiences then.