REVIEWED BY DANIELLE TRUSSONI
At 27, Yale grad MacDonald had a 40-in. waist, a drinking problem, mounting debt and dead-end jobs. So he targeted all his problems with an extreme version of thrift: He downed 800 calories a day, mostly lentils and tuna; four years later he was slim and married with twins. Not a trick you'd want to try, perhaps, but if you're thinking about tightening your belt, the charming Hermit just might get you started.