How long does it take to start to lose weight when you juice fast?

It really depends on how much juice you consume during the day, but you should start losing weight with in a week. I don't recommend only juice, your body needs vitamins and minerals that you can't get from just drinking juice.

Try a balanced diet consisting of lean meats, low fat dairy products, lots of grains, fruits and vegetables. Try to have more meals but in small portions so you will not feel like you are starving yourself.

I would also try to be more active like using stairs instead of elevators, parking far so you will walk more to get to places this way you burn extra calories.

Juice diets have a lot of good, they are great for detoxing, weight loss aid, energy and to expel toxins. But you need to remember to maintain your intake of vitamins and nutrients. For instance pure juice contains little or no fiber, so you need to create bulk to keep bowels moving. There's really no bad side effects associated with juice fasting unless a medical conditions exists like diabetes or certain juices interacting badly with precription drugs. As far a specific amount of time everyone loses weight at different rates, but you really need to check with your Doctor and ask what you need to take (i.e. supplements) and additional food necessary to maintain a healthy fast. Especially if your fast is going to last more than a couple of days.

You should start dropping pounds right away. I did it for a week and lost 15lbs. I gained back 5 of it when I started eating again but then the rest stayed off. Juice fasting is perfectly healthy if you do it right and works wonders on your general health. For a first fast I would not recommend doing more than five days and get your own juicer. The pasteurization process gets rid of a lot of the natural nutrients that your body needs. Drink teas too, especially red and white, they have a lot antioxidants that are good for you. The hardest part is going to be the first three days and after that it becomes fairly routine. If your doing it for awhile enimas will help clean out the colon. You're going to loss a lot of energy so don't do it during a stressful or busy time or acids will build up in your stomach and you could get an ulcer. It also important to ease back into foods when breaking the fast. Start with fresh fruits and vegetables moving tto cooked foods and then bread and lastly dairy. Your stomach will have shrunk so it won't be hard to keep off the weight just maintain eating small portions several times a day and you'll be fine.
Remember it is important to be able to recognize the return of real hunger and to actually break the fast because you don't want to go from fasting to starving. Be careful and think it through before you consider fasting