Presto! is Penn Jillette’s memoir of losing 100 pounds in 3 months – how he did it, why he did it the unusual way he did, and the physical, mental, and emotional changes it brought. Having been swayed by Critical Mas’s post on the potato hack and read the (e)book on the subject, I wanted to see if I could strain Penn’s book for ideas, tips, or just some new thinking.

Penn’s disclaimer in the book, interviews, and Q&As promoting the book, is if you take health advice from a magician, you’re an asshole and deserve to die. Or put more delicately: his path was his path and it worked for him. So, take the book for what it is, sift it, and behave responsibly.

That said, it’s still quite a story. Having lived a large life – he weighed 320 pounds and was on high dosages of eight different blood pressure medications – his doctor recommended a stomach sleeve following a health crisis that put him in the hospital.

Jillette reports taking the news calmly and then pondering his next moves. The doctor said they needed to wait 3 months before doing the surgery; Jillette saw this as his opportunity for an extreme challenge of the sort that has defined his life. If he could lower his weight by 100 pounds in 90 days, he could be taken off many of his medications and could avoid surgery for the stomach sleeve. I have to say, were I faced with that prospect, I’d have probably gone for the extreme choice myself.

Penn is an interesting guy, who does think differently from the herd and enjoys the company of others who think differently, so the book is full of his opinions on lots of things. That said, I skimmed many passages because his humor, such as it is, tends to the verbal smackdown and fast patter of his act. If he reads the audiobook version of this, it may be more enjoyable. But I doubt it. I don’t think he’s as funny as he thinks he is. But this is his personality, so I got used to filtering out the noise for the interesting detail underneath.

What, if anything, am I taking away from his book?

• It’s winter now, so feel the cold more often. Penn’s advisor, an odd and provocative fellow named Ray Cronise, prescribed contrasting showers of hot (10 seconds) and cold (20 seconds) for 5 minutes or so, ending with cold water for as long as he could stand it. Cronise maintains that the body will burn more calories trying to keep its trunk and brain warm than it will burn with exercise.
• According to Penn, Cronise said the modern world has eliminated three things that all wild animals must deal with: darkness, cold, and hunger. Our bodies, he says, are built to survive a winter that never comes. Cronise’s program for Penn introduced more cold and more hunger to encourage his body to burn its stored calories.
• For the 90-day crash diet, Cronise prohibited any form of exercise because “You can’t outrun your mouth.” He focused on Penn eating only vegetables, no processed foods, no salt or sugar, and later on, only minimal seasoning. (Penn favored Tabasco.)
• After the body has lost the fat, then Cronise permitted him to start exercising to restore the muscle; don’t confuse the body by promoting two different processes at the same time, according to Cronise. Penn said that when he started lifting weights again, he was very weak. But the leaner muscle he gained felt “stronger” than the marbled fat-and-muscle he had before.
• For his maintenance diet, Penn uses Dr. Joel Fuhrman’s books and dietary program as a guide. He likes Fuhrman’s uncompromising attitude to the subject: losing weight and eating right is hard. To paraphrase Fuhrman: I’m not here to make it easy, I’m here to tell you what you need to do.
• Penn now eats only whole plants, with no animals or animal products. He will allow himself a “Rare and Appropriate” meal(s) once or twice a month, but only if someone else is paying or it’s a special occasion, like a birthday or anniversary.
• He was monitored by his doctor throughout the 3 months and taken off blood pressure medications as appropriate, but this was a delicate process. The remaining medicines had to be balanced and tweaked to ensure he wouldn’t have another health crisis. On Episode 233 of his podcast, Penn reported that he is still on some BP meds because his heart is still enlarged. After a few years, when his body has adjusted to the change, then the heart may reduce in size and he can go off more meds.
• Penn wondered about the social awkwardness of not eating with others at a restaurant. What he found was that it was awkward for about 20 seconds, and then everyone else settled down to their eating while he drank decaf coffee and carbonated water (my favored dinner drinks for years now). A lot of the food we shovel into our mouths has to do with imagined social harmony rather than real hunger.
• And fasting is also an option. I will fast 16-22 hours once or twice a week, or at least skip breakfast several times a week. Fasting is one of the few techniques that makes sense to me. It’s binary – you’re either eating or you’re not – so it’s hard for me to cheat; it’s easy for me; and it always teaches me about the difference between cravings and real hunger.
• At the end of the first two weeks, where he ate only potatoes, Penn broke his cravings to the salty/fatty/sugared food that had been a staple of his eating life for 60 years. He wondered if he would miss his favorite foods, and he didn’t – because he had lost his craving for them.
• As an aside, Penn relates going on a celebrity cooking show and being quickly trained by a popular Las Vegas chef. The keys to winning are to pick 5 dishes and have a good story to go with each one; we’re wired for stories and emotion, and telling the story as the dish is prepared lands with the judges more effectively than the food alone. (Training and association, folks.) Also, the way to make any food taste good? Fat, then salt to cover the fat, then sugar to cut the saltiness, then more salt to cut the sweetness, then more oil over everything, ad infinitum.
• Losing weight made him lighter – physically and emotionally. Losing the fat helped him also level his moods. I’ve found this to be the case for myself, also.

Update, 2017-01-19

Penn made it clear he was not writing a how-to book and that his advisor, Ray Cronise, was writing his own book (yet to be published), so Penn was deliberately vague on details. The CalorieLab site extracted from Penn’s book all the details it could and subjected the book to the kind of skeptical (and somewhat sarcastic) appraisal that the ol’ Penn Jillette of Bullshit! fame would admire. The comments to the CalorieLab post offer good discussion; some of the commenters support CalorieLab’s view, some are skeptical of Penn, some support Penn. But as Penn said from the start: don’t look to him for diet or medical advice. You have to look out for yourself.

Updated on 2026-01-10