The alternate day fasting diet, also known as alternate day dieting, is a weight-loss plan that has been popular for several decades and involves alternating days of extreme calorie restriction with days of eating normally. The diet is based on a large body of research that indicates intermittent fasting might contribute to long-term weight loss, a decreased risk of diabetes, lower blood pressure, lower cholesterol levels and an increased lifespan. While the alternate day fasting diet has many advantages, there are a number of disadvantages that can make it an unsuccessful weight-loss choice.
According to the Weightlossresources.co.uk site, the idea that periodic calorie restriction leads to improved health, weight loss and a longer lifespan has been around since the 1930s, when research with calorie-restricted mice was conducted with similar results. Since then, a variety of diet books featuring the concept of alternate day fasting as basic precept have become popular, including "The Longevity Diet" by Brian Delaney and Lisa Walford and 'The Alternate Day Diet" by Drs. James Johnson and Donald Laub.
According to Diet Spotlight, there are two main ways to follow an alternate day fasting diet. The first is to alternate days of complete fasting -- eating no foods whatsoever, consuming only tea, coffee, water and chewing sugar-free gum -- with eating normally. The second is to alternate days of drastically reduced calorie intake with days of eating a normal diet. If you choose to follow the second option, you should aim to consume one-fifth of your normal caloric intake on fasting days, which works out to about 400 calories for women and 500 calories for men. If these restrictions are too difficult, you can try increasing your caloric intake to 700 calories if you are a woman and to 875 calories if you are a man. When based on a 2,000-calorie daily diet for women and a 2,500-calorie daily diet for men, this is approximately 25 percent to 35 percent of the normal intake.
"Elle" magazine's online site reports that a study at the Louisiana-based Pennington Biomedical Research Center conducted in 2005 showed that participants lost about 4 percent of their body fat and 2.5 percent of their total weight after only three weeks fon an alternate day fasting diet. "Elle" also reports that researchers from the National Institute of Aging theorized in 2003 that intermittent fasting helped trigger the SIRT1 gene, a gene thought to both stimulate cells to release fat for use as an energy source and to deactivate the genes responsible for promoting fat storage. Other research conducted by Krista Varady at the University of California at Berkeley indicate that this type of on-one-day, off-the-next-day diet can protect against diabetes and excessive weight gain.
Diet Spotlight reports that following the alternate day fasting diet has the potential of helping you lose weight, lengthening your lifespan and decreasing both your blood pressure and overall circulating cholesterol level. Research indicates that the program also might help decrease the risk of developing certain types of cancers. According to nutrition expert Krista Varady, the diet plan also has a psychological advantage: People tend to stick to the diet better since, even when they become hungry on fasting days, they know they have a free day to look forward to.
James Hill, the director of the University of Colorado's Center for Human Nutrition, told "Elle" that he did not believe an alternate day fasting diet was a successful strategy for long-term weight loss. According to Hill, "Once people return to eating normally, they'll regain the weight." Much of the research on the benefits of intermittent fasting has focused on the results in mice -- few studies support the claims of longevity and better health in humans following the program. In addition, people following the diet in research studies reported feeling extremely cranky and irritable on fasting days.