Ok when I first read this I may have skimmed it lol so ill do some commentary on it When your body stops getting food it goes into a starvation mode and saves fat.
Starvation mode may be bs but I have my doubts your body will go ape using up a lot of fat from a one day fast The weight you will lose (not much) will be mostly water and muscle tissue.
You would only lose muscle if you lifted weights that day and your body didn't have any protein in its stomach to repair the muscles, but the lost muscle would be a fairly small amount. This is bad because not only will you have to start eating again but since you now have less muscle, and therefore a slower metabolism as opposed to when you began fasting, you will gain even more fat on top of the fat that your body stored while you fasted. The only time your body will start burning fat when you are not eating and I mean noticeable amounts is when it can no longer burn muscle proteins as a fuel source. By the time that happens you're close to death.
You know what just disregard everything from this cause its like 50/50 truths and broscience. Never again will I skim something and post it. This is a very ineffective way to lose weight because you will not lose any fat really and you will put on even more fat when you restart your regular eating habits. Want to lose the fat? Stop eating carbohydrate dense processed foods. If it's in a box, carton or packet it's often bad. Stick to lean proteins, fruits and veggies and get some exercise. You simply cannot lose weight in the long term without changing your eating habits altogether.
Rather than starve yourself, you will do far better to strictly limit or eliminate (apart from the occasional treat) refined (processed) carbohydrates. If you are unsure what refined (processed) carbohydrates are, see the page link for a list, further down this page, listed under Related Questions. If you couple this will cardio exercise, you will lose weight.
I tried it. I must say I do not have an addictive personality or focus much on my body or looks. I did it in an attempt to try and personally understand friends of mine. I started at 176lbs and initial weight loss was quick probably due to emptying my body of the waste over the first couple of days. I drank only water and tea, white with one, as I normally would. I did my normal work involving moderate exercise and lost 11lbs. Worrying and unexpected symptoms nearing the 7 days were: problems with vision flickering & focusing; giddiness and fatigue started very early when exertion was needed. Please note: Half the weight was back on within a couple of days. Losing weight fast is not a viable method for people who need to lose weight, and is definitely very dangerous to people who have little weight to lose.
You may lose a little bit of weight by starving yourself for a week because you body will become so hungry that it will start to eat fat and muscle tissue. You will likely also feel week, tired, irritable, and sick because you are not consuming necessary daily vitamins. This will also make your metabolism slow down which will hinder weight loss. After your fasting period, you are likely to gain any weight you may have lost back.
Actually, if you starve yourself for long enough your metabolism will go into "starvation mode" and slow down. This is why recovering anorexics gain more weight back than they originally had before the eating disorder.
If you're really going to do the drastic scary weight loss strategy, eat a small amount every day, divided into four or five small snacks. An intake of a small portion of food every few hours throughout the day will speed up your metabolism, and you're guaranteed to still lose weight in a very small amount of time because of the substantial decrease in calories.
The real reason why people gain weight after fasting (starving) is because they go straight to heavy foods that requires a lot of chemical reactions to take place at once to break it down and your stomach just isn't used to that after starving it for prolonged periods of time, When you do start to eat its best to start of with small foods like soup and smoothies. Don't eat big meals. You have to let your body get used to eating again and yes exercise is recommended to keep the weight off. Not extreme exercise though.
I don't take it to the extreme of NOT eating anything. I don't eat breakfast. I eat a small cup of chunk light tuna (3 oz or so) for lunch, drink plenty of water throughout the day. I hit the gym and do plenty of cardio exercise (cardio exercise the key to major weight loss because it burns lots of fat). For dinner I have perhaps a cup of soup or a small piece of chicken or nothing. No its not healthy at all, but not eating anything is not very smart. I went from 235 - 205 in the last month. So, I lost 30 pounds (but then I have a lot to lose). I don't have fatigue or any health problems of which I am aware.
I would like to add that I drastically cut down on calories for around 2 weeks for my birthday party. I lost a stone (14 pounds) in 2 weeks and I actually still ate, just very little. When i started eating again (not quite normally, but around 1500 calories a day) I haven't gained any of it back at all. I'm really happy with my weight now, and eat three healthy meals a day just small amount each meal. I wanted to add this because I read a lot of answers saying that you only lose water weight if you starve yourself.
If you're going to give up food for a week try going on the lemonade diet that way your body won't be starving and you'll be cleaning out your system. You can lose up to 20 pounds if you stay on it for 10 days.
Eliminate, or strictly limit (apart from the occasional treat) refined (processed carbohydrates) and get your carbohydrates from natural sources. Couple this with cardio exercise, such as walking for weight loss, or running or jogging of you prefer, and you will do far better than starving yourself.
Read more:
http://wiki.answers.com/Q/How_much_weight_can_you_lose_by_not_eating_for_a_week#ixzz1kXlMN4nl