I have a formerly very overweight cousin, who, the last time I met her, I didn't even recognize, she was so much thinner. When I asked how she did it, she mentioned the usual, better eating, eating less, exercise, but also mentioned that it really helped her to fast for one day every week.

Now, I know that long periods of severely restricting calories can be extremely detrimental to both weight loss efforts and general health, but this seemed to work for her. Is she an anomaly, or is it that this actually works if not done to excess?

I've heard this one before, but I can't see how it would be good for weight loss. (I'm not a dietician or anything... and I am a biochemist, but I know nothing about humans/animals, so this is just a guess.) The most effective way to lose weight is to make your body as inefficient as possible, by providing it with frequent small amounts of food. It seems like much of the benefit from not eating for a day would be lost due to your body storing up more fat the next day when you do eat.

Now, I can't comment on doing it purely for health (not weight loss) reasons... my dad was doing that for a while, but I never really looked into the science behind it, since I just wouldn't ever want to do it!

i don't know how this would help either. My fear would be the day after a fast i would be so ravenous i would eat everything in site. I know a lot of people on the site here that swear by fluctuating their calorie intake...say for example on day they eat 1200 cal and the next 1800 cals but the average week they eat an average of 1500 cals. some people state it helps their body keep guiessing. I just dont think i could ever fast and dont' really think its something i would want to do...but that's just my opinion.

Perhaps for your cousin it gives her a "mental edge" and a feeling of total control, which can be important for long-term success. Physically, I don't think anyone needs to fast to lose weight, and I doubt it is the most productive way to use a whole day -- BUT all of us are different and if it works for her and she feels good and is healthy, then I'm happy for her!

I don't know. I've lost lots and lots of weight, am so far maintaining that loss and never, ever went without eating. I LIKE food. I LIKE to eat. I NEED to eat. Food gives me the energy and vitamins I need to live. I simply do not see the point in doing WITHOUT food. I mean, aren't we supposed to eat in order to function? Why do without it? Why? I just don't get it . If I go too many hours without eating (which rarely occurs because I do my best to AVOID it), I start to feel lousy. Lousy. Why would I want that feeling - only WAAAAAAAY worse, once a week? Why in the world would I want to risk my health?

I'm sorry and please forgive me, but I think that is an awful plan. Just awful. It's not all about being thin. I want to be healthy. I want boundless energy and stamina. I want good eyesight, strong hair and nails, good bone health, muscle strength, I want to prevent diseases, I want to make the most of every day. Just my 1/2 cent.

Many people fast for religious reasons. It doesn't seem to harm them if it is done for a very short period of time. Don'rt think it is really that good for dieting purposes.

It is called intermittent fasting and the theory is that it provides a your body with a rest from continuously processing food. The body did not evolve like that and it has only been in recent evolutionary history that food has been so readily available. IF also releases certain chemicals to help mobilize body fat. I can't think of the name of the chemical off hand. I will hunt it down if anyone wants.

I am currently doing a short term fat loss program so I am not fasting currently but I normally do IF from after dinner on Saturday to dinner on Sunday. It is a straight 24 hour fast but only skipping 2 meals. This has help facilitate fat loss and not interfered with my heavy weight lifting routine. I will resume with IF when this current program is completed.

IF is also not meant for purely weight loss. It is a lifestyle switch, like low carb or a ketogenic diet, whose purpose is an overall increase in health.

I had this concern at first but most intermittent fasters only fast for 18 to 24 hours. The body can not adapt that quickly. The body's first response is to find energy somewhere. If you are using your muscles regularly it will not steal from those. It's first place is stored glycogen, once that is used (usually about the 12 hour mark) the body will begin mobilizing body fat and burning it as fuel. The fast then ends before the body has time to switch into preservation mode. That is only a concern in longer fasts.

Fasting is definitely not for everyone. Some people don't like the way they feel while fasting but some people have increased energy and increased mental clarity. That was my experience. I am far more productive the day I fast than any other day of the week. It has also taught me that being hungry is not the end of the world. I no longer get stressed when I am hungry.

As for binging the day after, I imagine if you have existing problems with food then fasting would not be a good choice for you. Most people do eat more the meal after the fast is broken and then return to normal eating. That one meal in excess does not add up to what would have been eaten in an entire 24 hour period. IF averages out to be about the same calorie consumption as a traditional reduced calorie diet but is a lot easier to follow for many people. This has been what I have learned from talking to fasters and reading fasting blogs.

IF is really more of a lifestyle switch than a "diet plan" but there are those that use it as such.

I'm with Robin on this one. Our bodies need fuel to work and be healthy. There is no evidence that depriving your body when it's hungry will make you healthier. That grumbling you hear in your stomach is a signal from your body saying, "feed me!" Why ignore your body's needs? I'm not talking about giving into a craving here, but poviding your body with what it needs to function.

You can achieve healthy fat loss by eating a little less every day than is needed to maintain your current weight. This might take longer than starving yourself one day a week, but from my view it's more important to lose weight safely rather than quickly.

Also keep in mind that the internet is full of misinformation about fasting, crash diets and weight loss drugs. Googling something does not constitute research, and will not give you an accurate picture of how something will really affect you. The body is an incredibly complex machine. Any treatment you apply to it will trigger a complex cascade of molecular processes. The affects of fasting (or anything else for that matter) are just not as simple as a change in leptin levels.

Just out of curiosity, where are you getting your information?

Evidently a few scientific studies have been done on intermittent fasting and calorie restriction, but not many in humans. Calorie restriction is, of course, what most of us consider "dieting." This is a good starting point:

http://en.wikipedia.org/wiki/Calorie_restriction

It mentions intermittent fasting toward the bottom of the article.

The idea seems to be that eating less is a good thing, compared to "free feeding."

Jay

IF is not a quick fix to weight loss, no more than low carb is.

There is good info on the web from some very well educated people. You just have to know how to sift through all of the junk.

No it is not as simple as that.

I am running out of the door right now but when I have more time I will post some studies that have been done on IF and CR.

I'm anxious to see what kind of websites people use to get medical information. I really worry about our society's reliance on Google and Wikipedia to do research, because so much of the available content is incomplete, overly simplistic, or just plain wrong. I've read countless reports of research studies on websites and in newspapers that are incredibly misleading. The only way to really know what the research shows is by diving head first into the scientific literature and taking a critical look at the data. Few people outside of research actually do that, and the unfortunate consequence is widespread misinformation.

Joel Furhman, who wrote Eat To Live, also authored a book called "Fasting And Eating For Health". If you have never read any of his stuff, E2L, which is practiced by some people on this board and Fasting For Health is a good place to start.

And he's a real doctor, if you can believe that.

I really would recommend checking him out, but I would also like to show that just because it's "progressive" or on the fringe does not mean the only research is some improperly referenced wiki entry. Many have put this to practice and have had remarkable results, myself included.

Jen, I didn't mean to imply that the information published on the web comes from some cracked-out hippy commune or something!

I just think it's important to note that just because something is written on Wikipedia (or even in a book published by a doctor) doesn't mean it's based on sound research. Joel Furhman is a real doctor, but he doesn't agree with a lot of other real doctors out there about what is best for the human body. He's a pretty big critic of the South Beach Diet, actually, which was proposed by another doctor and supported by many in the medical community. There is so much inconsistency in the data, and consequently a lot of disagreement about how to interpret it. I just think it's important to remember that this is a very complicated issue... much more so than the way it's presented to the general public.