Extreme fat loss calls for extreme effort, such as a combo of intermittent fasting (IF) and extended steady-state cardio.
While this sounds like a recipe for muscle wasting to bodybuilders and physique athletes, the results were surprising. Sports scientists at the University of Illinois at Chicago examined four groups of overweight people who either did IF, cardio (40 minutes at five percent of max heart rate), both, or nothing at all. (In this experiment, IF entailed alternating regular days of eating with days of eating one meal that consisted of 25 percent of daily calories.) After 12 weeks, the group who engaged in IF and cardio lost the most weight (twice as much as the fasting-only group) but lost almost no muscle. The IF/cardio group also improved their markers of cardiovascular disease.