if you go on a solid ketonic diet, you can lose 1 pound in 3 days. it less healthy then most diets, but if you keep up on vitamins and minerals with the use of pills, you should be fine. i went on a ketonic diet in my senior year in high school, and lost 35 pounds in 3 months, while gaining a good deal of strength. but like i said, this is a rather unhealthy diet.