Since ancient times, many spiritual practices have included dietary fasting.  Today, there are a lot of people claiming that fasting also has a lot of health benefits. And, in fact, research shows that short fasts, lasting anywhere from 20 to 36 hours can in fact reduce some risks for heart disease, diabetes and cancer. I wondered about the benefits of fasting and began researching.  One finding in particular caught my interest and I’d like to share it and my thoughts. The National Institute on Aging conducted a study on mice for which, Mark Mattson, Ph.D., chief of the NIA's Laboratory of Neurosciences fed mice nothing every other day. The mice could eat as much as they wanted on the days in between, and they did. They pigged out. They ended up eating very nearly double what normal mice eat in a day. But fasting every other day caused them to live longer and healthier lives. A lot longer and a lot healthier. Mattson said, "We think what happens is going without food imposes a mild stress on the cells, and cells respond by increasing their ability to cope with more severe stress." He said maybe it's similar to what happens when you lift weights: You stress your muscles and they respond by growing stronger. Near the very end of the study, they injected all the mice (those fasting every other day, and those eating a normal diet) with a toxin that damages the cells in the same part of the brain Alzheimer's damages in humans (the hippocampus). Mattson and his team later looked at the brains of the mice and found that those that had been fasting every other day suffered less damage to their brain cells. I read another article that brought up some very good points. It seems likely that at least an occasional state of hunger would have been fairly common throughout our evolution. Our bodies might be adapted to it. Maybe it creates unnatural problems when the body doesn't ever go hungry. Maybe eating three square meals a day, every day, is unnatural. Going without food for several hours does not cause your metabolism to slow down nor does it wreak havoc with your blood sugar. Short fasts actually improve insulin sensitivity and this is pretty big deal. When your cells are sensitive to the effects of insulin, they do a much better job modulating your blood sugar levels after meals and this makes life a lot easier for your poor old pancreas. Loss of insulin sensitivity is a risk factor for both heart disease and diabetes. For the millions of years mammals have been evolving and right up to our invention of agriculture a short ten thousand years ago, mammals often went hungry many times in an individual's lifetime. Surely our bodies have evolved to handle this. Maybe that's why it is totally accepted by most people in the health profession that human beings gain about a pound a year. Maybe that is part of the body's adaptation to the inevitable lean times the eons have adapted us to. An occasional fast might very well be more natural and very good for us. The key here is SHORT FASTS and OCCASIONAL. You want to slow your metabolism down to where you’re not able to maintain a life of very little caloric intake and then end up gaining weight.