Hi Natasha! Congrats on considering some serious steps to address your health concerns. I would agree with everything that has already been posted here. I would ask you a few questions also...like, how old are you? Has your weight been an issue all your life? Are you a yo-yo dieter? A compulsive over-eater? Are you making great progress in eating nutritiously? Do you try to eat a healthy nutrition plan most of the time?
I am 51 years old and have battled this all my life and I am a compulsive overeater, yo-you dieter. I have lost and gained and lost and gained large amounts of weight in the past 30 years - 40, 50, 60, 80 and even 100 pounds and lots of 5 and 10 pounds in between all that. Most recent was the 100 pound loss of which I gained back over 70. I have since lost another 40 of of the 70. I have always always always looked for a quick answer to my obesity and I have done some modified fasting and water only fasting. But recently I have embraced a new method (for me, the method has been around forever), that method is exploring/eating a healthier diet and taking more time in reaching my goal of 80 - 100 pounds more to lose.
I highly recommend reading a book titled "Eat to Live" by Joel Fuhrman and "Fasting and Eating for Health", same author. For overweight folks he does not recommend fasting at the onset, rather, get your sound nutrtion plan going and lose weight that way. When you get very close to your goal weight you may consider a shorter fast at that time. But the message is clear: if you are not willing to make the dietary changes necessary to maintain a major weight loss, why bother with the water fast? It will only come back on again. Fuhrman's plan in the strictest sense will give a weight loss of about 25 pounds in 6 weeks which is fabulous. This would also support working out and exercising which is not recommended by most experts when on a water fast. They recommend a state of rest for the body while fasting and exercising and physical exersion is very difficult.
I went on a 39 day master cleanse (lost 35 pounds) and a 9 day Water Fast (lost 21 pounds). Currently, I am eating a modified vegetarian diet and exercising daily. Fuhrman is by no means the only expert on the subject but he is a medical doctor who is using fasting and nutrition to reverse and cure serious chronic diseases (diabetes, heart disease, auto-immune etc etc) in his patients in New Jersey. Sustained and major weight loss occurs in his patients largely due to adherence to his eating plan.
That last paragraph addresses the first major problem with Water Fasting for weight loss. That being, if you are not planning to change your eating habits, don't put your body through the stress of a fast. If you have your mind made up that you are going to change your nutrition program to a healthy one, that is great. I would tend to agree with the others on that matter, do that now (the healthy eating) and postpone the water fast. Water Fasting is a serious regime intended to address chronic diseases and other illnesses etc. Not that obesity is not a serious issue...but if one isn't willing to eat right...what then? Better to find out now if a proper eating plan will stick.
The second problem with Water Fasting for weight loss is in order to lose a substantial amount of weight (in your case, 70 pounds) you would have to undergo a very long fast and most experts do not recommend fasting over 10 days (some say 3 days) without intense medical supervision. Some folks have had years of experience fasting and are confident they can fast for longer periods without assistance, but experience and knowledge is the key. And even in those cases, many experienced fasters still want the supervision.
I hope you will stick around...we have lots in common. Read up on some of the leading research in this field. If you are still serious about fasting, please keep up posted. We will try to help in any way we can. I am relatively new to all this, but others have much more experience.
Here is an excerpt listing some possible side effects of water fasting:
"There are many risks to water-only fasting and we want you to be aware of them prior to your decision to undertake a water-only fast. Because you will not be eating any food, you will most certainly experience weakness throughout the water fast, and lose weight. It can take some time after fasting to regain strength. A very common occurrence is dizziness and fainting, especially on rising from a laying or seating position. Other common and unpleasant symptoms are heart arrhythmia, palpitations, dehydration, nausea, vomiting, skin rashes, sore throat, mucus discharge, low back pain, increased menstrual flow, irregular or anovulatory cycles, hair loss, gastric irritation, passing of kidney or gall stones and emotional disturbances. There is also the possibility of alterations to your body’s basic mechanisms and electrolytes, which could cause heart problems such as a heart attack or vascular problems such as a stroke."
I took this from the fasting link of True North, a clinic in California. The link is listed below if you want to check it out. There are other respected sources as well. Information is a great ally!