# Penn Jillette's 100 lb loss on a no exercise potato diet. Anyone know how that works? **URL:** \ **Category:** In My Humble Opinion\ **Created:** [August 3, 2016, 8:23pm UTC](https://boards.straightdope.com/t/penn-jillettes-100-lb-loss-on-a-no-exercise-potato-diet-anyone-know-how-that-works/761681 "2016-08-03T20:23:55Z")\ **Posts on this page:** 20\ **Page:** 3
**Author:** ![Fuzzy\_Dunlop](https://avatars.discourse-cdn.com/v4/letter/f/848f3c/32.png) [@Fuzzy\_Dunlop](https://boards.straightdope.com/u/Fuzzy_Dunlop)\ **Post date:** [August 4, 2016, 2:47pm UTC](https://boards.straightdope.com/t/penn-jillettes-100-lb-loss-on-a-no-exercise-potato-diet-anyone-know-how-that-works/761681/41 "2016-08-04T14:47:44Z")
> [@beowulff](#): > > Regardless, you can’t ignore thermodynamics. > There bodies may be extracting more calories from a gram of food then they were before, but that can’t be an infinitely efficient process. Right, you can’t fight thermodynamics. A 180 pound man who was formerly a 280 pound man will need to eat far fewer calories to maintain his new weight than a man who has been 180 since high school can eat. That’s a huge disadvantage to the obese and it doesn’t go away with time. If you’re a healthy stable weight now try this thought exercise. Starting tomorrow you have to eat 30% fewer calories just to maintain your weight. Is that going to make weight maintenance easier, harder, or about the same? ---
**Author:** ![Surreal](https://avatars.discourse-cdn.com/v4/letter/s/eada6e/32.png) [@Surreal](https://boards.straightdope.com/u/Surreal)\ **Post date:** [August 4, 2016, 2:50pm UTC](https://boards.straightdope.com/t/penn-jillettes-100-lb-loss-on-a-no-exercise-potato-diet-anyone-know-how-that-works/761681/42 "2016-08-04T14:50:32Z")
Saying weight loss comes down to “calories in vs. calories out” is like saying something sells at a particular price because of “supply and demand”, that successful investing is about “buy low / sell high”, or that that traffic is heavy at 5:00 pm because more cars are getting on the road than exiting the road. “Calories in vs. calories out” is trivially obvious and yields little actionable information, but it gets repeated here as if it were some sort of earth-shattering revelation. ---
**Author:** ![Chimera](https://avatars.discourse-cdn.com/v4/letter/c/8e8cbc/32.png) [@Chimera](https://boards.straightdope.com/u/Chimera)\ **Post date:** [August 4, 2016, 2:55pm UTC](https://boards.straightdope.com/t/penn-jillettes-100-lb-loss-on-a-no-exercise-potato-diet-anyone-know-how-that-works/761681/43 "2016-08-04T14:55:41Z")
Well remember that this is a guy who claims not to believe in moderation and who claims not to do drugs or drink because he’d be an addict. So it makes perfect sense that he’d go on an extreme diet. ---
**Author:** ![jz78817](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/jz78817/32/1028_2.png) [@jz78817](https://boards.straightdope.com/u/jz78817)\ **Post date:** [August 4, 2016, 2:58pm UTC](https://boards.straightdope.com/t/penn-jillettes-100-lb-loss-on-a-no-exercise-potato-diet-anyone-know-how-that-works/761681/44 "2016-08-04T14:58:33Z")
> [@Surreal](#): > > Saying weight loss comes down to “calories in vs. calories out” is like saying something sells at a particular price because of “supply and demand”, that successful investing is about “buy low / sell high”, or that that traffic is heavy at 5:00 pm because more cars are getting on the road than exiting the road. > > “Calories in vs. calories out” is trivially obvious and yields little actionable information, but it gets repeated here as if it were some sort of earth-shattering revelation. I think a most of the people who just (rather smugly) say that have never really had to struggle with their weight. ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [August 4, 2016, 3:40pm UTC](https://boards.straightdope.com/t/penn-jillettes-100-lb-loss-on-a-no-exercise-potato-diet-anyone-know-how-that-works/761681/45 "2016-08-04T15:40:13Z")
> [@Carryon](#): > > It’s the old take in less calories than you expend. > > The thing is potatoes have a horrible reputation for being high in calories and it’s not really true. A plain old potato has about (medium) has about 100 calories. > > Did you ever eat a plain potato? Not much to get excited about. It’s all the delicious things we do to it, like fry it and all the toppings we put on it, that make the potato so good to eat and also make it so high in calories. Potatoes are also extremely high on the satiety scale, they really make you feel full. This could work. I’d use Yukon Gold potatoes, however. ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [August 4, 2016, 3:45pm UTC](https://boards.straightdope.com/t/penn-jillettes-100-lb-loss-on-a-no-exercise-potato-diet-anyone-know-how-that-works/761681/46 "2016-08-04T15:45:34Z")
> [@Fuzzy\_Dunlop](#): > > The evidence is what’s simple. Study after study after study shows that your odds of success at keeping weight off for the long term is exceedingly poor. Often low single digits. > > In most of the studies I’ve read, long term weight loss is usually defined as 1 year. In my opinion, 1 year should be the _starting point_ where you can even claim you’ve lost weight. Long term weight loss ought to be 10-20 years. Yet even with the 1 year definition all the evidence shows there’s no empirical reason to expect you’ll be able to keep the weight off just by making lifestyle changes or by crash dieting. > > So really, the science shows you won’t be able to maintain your weight loss. Ignoring it and saying you’ll just have willpower is just obstinately ignoring what science tells us about weight loss. Well, it depends. You can certainlt take off a weight gain and keep it off. I had a sedentary high stress job and put on 50# over a few years. I went on high protein, low carb, and lost it back. After 30 years I have put back on and taken off around 10#. But I dont need to stay on a "diet’ to keep the 50# off. Just to lose that 10# (which I gain back). ---
**Author:** ![DigitalC](https://avatars.discourse-cdn.com/v4/letter/d/ebca7d/32.png) [@DigitalC](https://boards.straightdope.com/u/DigitalC)\ **Post date:** [August 4, 2016, 3:46pm UTC](https://boards.straightdope.com/t/penn-jillettes-100-lb-loss-on-a-no-exercise-potato-diet-anyone-know-how-that-works/761681/47 "2016-08-04T15:46:47Z")
> [@CandidGamera](#): > > I’ll chime in with an anecdotal data point : I tried to lose weight by stepping up my exercise AND reducing portion size on all the foods I normally ate. > > Nada. Rock-solid stable weight. Sustained the effort for months without a significant deviation. Still exercising, and I believe I’m still eating less, but I stopped caring about that part so much. > > Tried a second variation : I normally drink two cans of soda a day. Tried cutting back to one, with no other changes, saving me 120-150 calories a day. > > I actually slightly gained weight, but was more or less stable. > > Bottom line : Your metabolism rate matters, and it WILL adjust. And other factors feed into it, like how much sleep you’re getting. Your mistake was measuring weight instead of body fat %. If you reduced your calorie intake and started exercising you were replacing that fat with muscle, even if you gained weight this is a positive result. ---
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [August 4, 2016, 4:20pm UTC](https://boards.straightdope.com/t/penn-jillettes-100-lb-loss-on-a-no-exercise-potato-diet-anyone-know-how-that-works/761681/48 "2016-08-04T16:20:44Z")
> [@beowulff](#): > > Regardless, you can’t ignore thermodynamics. > There bodies may be extracting more calories from a gram of food then they were before, but that can’t be an infinitely efficient process. You can argue with me. And you can bring up the guy in the gym. But I’ve provided cites from actual medical doctors who study obesity for a living. Are you going to continue arguing with them? And let’s get off the slippery slope. Nobody claimed it’s an infinite process. We’re not talking about people weighing ten pounds or ten thousand pounds. This is about people who have real world human weights. A person who weighs three hundred pounds can not drop down to two hundred pounds by just reducing his calorie intake by ten or twenty percent. He’ll be consuming less calories but he’ll stay at three hundred pounds. At best, he’ll drop some weight at the beginning but then he’ll go back to three hundred pounds. That’s the weight his body wants to maintain. Now this guy can go on a more extreme diet and lose a hundred pounds. But he can’t act like he’s a normal two hundred pound guy and eat what a normal two hundred pound guy eats. Because when he does, he’ll start gaining weight back and go back to two hundred pounds. Even though another guy, who’s eating the same amount of calories, can maintain his two hundred pound weight. That’s the key point. Once you’ve reached a certain weight, your body will always try to get you back to that weight. You can’t lose weight and have your body adjust to a new normal. Even years after you’ve lost the weight your body will still be trying to get it back. ---
**Author:** ![dracoi](https://avatars.discourse-cdn.com/v4/letter/d/90db22/32.png) [@dracoi](https://boards.straightdope.com/u/dracoi)\ **Post date:** [August 4, 2016, 4:30pm UTC](https://boards.straightdope.com/t/penn-jillettes-100-lb-loss-on-a-no-exercise-potato-diet-anyone-know-how-that-works/761681/49 "2016-08-04T16:30:47Z")
> [@Surreal](#): > > Saying weight loss comes down to “calories in vs. calories out” is like saying something sells at a particular price because of “supply and demand”, that successful investing is about “buy low / sell high”, or that that traffic is heavy at 5:00 pm because more cars are getting on the road than exiting the road. > > “Calories in vs. calories out” is trivially obvious and yields little actionable information, but it gets repeated here as if it were some sort of earth-shattering revelation. It wouldn’t need to get repeated so much if people weren’t so busy concocting ridiculous diets that are often both unhealthy and ineffective, and then making untrue claims about why they work. Sometimes the diet formulas people have amount to “After I studied for hours, I put on pink socks, and I passed the test! Pink socks improved my grades!” or “I went to the hospital and they gave me this flimsy gown. Afterward, I felt better, proving that clothes are killing us!” If not eating bread (to pick an example we hear about a lot) helps you to lose weight, then I’m all for it, but don’t start preaching about how carbohydrates are the only reason people gain weight. Calories in/calories out is the reason people change weight and if bread is a problem for you, it’s a matter of hunger signalling or eating habits. ---
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [August 4, 2016, 4:33pm UTC](https://boards.straightdope.com/t/penn-jillettes-100-lb-loss-on-a-no-exercise-potato-diet-anyone-know-how-that-works/761681/50 "2016-08-04T16:33:02Z")
> [@Surreal](#): > > Saying weight loss comes down to “calories in vs. calories out” is like saying something sells at a particular price because of “supply and demand”, that successful investing is about “buy low / sell high”, or that that traffic is heavy at 5:00 pm because more cars are getting on the road than exiting the road. > > “Calories in vs. calories out” is trivially obvious and yields little actionable information, but it gets repeated here as if it were some sort of earth-shattering revelation. The main counterargument is that calories don’t have the one-to-one relationship to pounds that people assume. Say you have somebody on a 2500 calorie a day diet. And they reduce that to 2250 calories. According to the “calories in vs. calories out” theory, that person will lose weight - they’re consuming ten percent less calories. They should gradually lose weight until they reach the weight that their new 2250 calorie a day diet can support and then maintain that new weight. But you’ll find it doesn’t work that way. A person can consume fewer calories and maintain the same weight they started with. ---
**Author:** ![Dendarii\_Dame](https://avatars.discourse-cdn.com/v4/letter/d/bbce88/32.png) [@Dendarii\_Dame](https://boards.straightdope.com/u/Dendarii_Dame)\ **Post date:** [August 4, 2016, 4:39pm UTC](https://boards.straightdope.com/t/penn-jillettes-100-lb-loss-on-a-no-exercise-potato-diet-anyone-know-how-that-works/761681/51 "2016-08-04T16:39:00Z")
Read a review of the book in which Penn says to get a second opinion if you’re going for weight loss–and not to use his book as a first opinion. ---
**Author:** ![Fuzzy\_Dunlop](https://avatars.discourse-cdn.com/v4/letter/f/848f3c/32.png) [@Fuzzy\_Dunlop](https://boards.straightdope.com/u/Fuzzy_Dunlop)\ **Post date:** [August 4, 2016, 5:18pm UTC](https://boards.straightdope.com/t/penn-jillettes-100-lb-loss-on-a-no-exercise-potato-diet-anyone-know-how-that-works/761681/52 "2016-08-04T17:18:27Z")
> [@DrDeth](#): > > Well, it depends. You can certainlt take off a weight gain and keep it off. I had a sedentary high stress job and put on 50# over a few years. I went on high protein, low carb, and lost it back. After 30 years I have put back on and taken off around 10#. But I dont need to stay on a "diet’ to keep the 50# off. Just to lose that 10# (which I gain back). That’s super for you, but my point is actual research shows that it is extremely rare that works. If an obese person has tried to lose weight and failed to keep it off, they’re not being irrational when they say that just eating fewer calories doesn’t work for them. They may actually be completely unaware of the voluminous scientific research confirming this, and are simply discouraged and dispirited. But even though they’re not aware of it, we know that scientifically speaking the evidence is clear that lifestyle changes won’t lead to long term weight loss. ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [August 4, 2016, 5:38pm UTC](https://boards.straightdope.com/t/penn-jillettes-100-lb-loss-on-a-no-exercise-potato-diet-anyone-know-how-that-works/761681/53 "2016-08-04T17:38:26Z")
> [@Fuzzy\_Dunlop](#): > > That’s super for you, but my point is actual research shows that it is extremely rare that works. If an obese person has tried to lose weight and failed to keep it off, they’re not being irrational when they say that just eating fewer calories doesn’t work for them. > > They may actually be completely unaware of the voluminous scientific research confirming this, and are simply discouraged and dispirited. But even though they’re not aware of it, we know that scientifically speaking the evidence is clear that lifestyle changes won’t lead to long term weight loss. You’re not really reading my history. My weight has always been around 240, then it shot up to 290 for a couple years, but I was able to lose\* that \*and keep it off for decades now. However, losing weight below that 240 has been impossible on any sort of LT basis. I can lose ten, then gain it back. So, yes, you can lose a weight _gain_- and keep it off. It’s very hard to lose from your base and keep it off. For those that say “its simple- eat less and exercise more” indeed adding exercise makes you healthier and converts some fat into muscle (which weighs more). But unless you are locked into a cell, you simply will not lose any significant weight from your base over the long term. A few things could help- if your diet doesn’t have enuf fiber (which is very common) adding two tablespoons of that orange powder stuff nitely could have you lose a few pounds and that will stay off as long as you keep with the fiber. That’s because you are constipated now. If you get more than 5% of your body weight from this, I will be surprised. However, all is not lost. Let us say your base weight is 200#. Adding fiber brings it down to say 195, then exercise converts 10 # of fat to muscle. Then eating healthier makes you healthier. You have only lost a few pounds, but you’ll feel a lot better. And, you might not gain anymore weight. ---
**Author:** ![Randolph](https://avatars.discourse-cdn.com/v4/letter/r/e5b9ba/32.png) [@Randolph](https://boards.straightdope.com/u/Randolph)\ **Post date:** [August 4, 2016, 5:47pm UTC](https://boards.straightdope.com/t/penn-jillettes-100-lb-loss-on-a-no-exercise-potato-diet-anyone-know-how-that-works/761681/54 "2016-08-04T17:47:12Z")
Just how Penn lost his weight doesn’t so much matter as _kcal_ o_ut \< kcal in_. That’s all that really mattered in the end to his body. What matters to you as a very very unique person is not so much the _hows_ of the matter, but the _whys_. Certain ways of thinking about situations can alter your confidence in loads of ways. You can do things like set up charts both flow- and otherwise. Ask for lots of advice on message boards and use it as you see fit. Or not. You’ll never see fit. Not in a jillion years. Loser. ---
**Author:** ![Little\_Nemo](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/little_nemo/32/3120_2.png) [@Little\_Nemo](https://boards.straightdope.com/u/Little_Nemo)\ **Post date:** [August 4, 2016, 5:56pm UTC](https://boards.straightdope.com/t/penn-jillettes-100-lb-loss-on-a-no-exercise-potato-diet-anyone-know-how-that-works/761681/55 "2016-08-04T17:56:40Z")
> [@Randolph](#): > > Just how Penn lost his weight doesn’t so much matter as _kcal_ > o_ut \< kcal in_. That’s all that really mattered in the end to > his body. What matters to you as a very very unique person is > not so much the _hows_ of the matter, but the _whys_. > > Certain ways of thinking about situations can alter your confidence in > loads of ways. You can do things like set up charts both flow- > and otherwise. Ask for lots of advice on message boards and use it as > you see fit. Or not. You’ll never see fit. Not in a jillion years. Loser. And crystals. Because I knew this woman who wore a crystal necklace and she totally lost some weight. So it happened and it’s a scientific fact that you can lose weight with the power of crystals. ---
**Author:** ![Fiddle\_Peghead](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/fiddle_peghead/32/3506_2.png) [@Fiddle\_Peghead](https://boards.straightdope.com/u/Fiddle_Peghead)\ **Post date:** [August 4, 2016, 5:59pm UTC](https://boards.straightdope.com/t/penn-jillettes-100-lb-loss-on-a-no-exercise-potato-diet-anyone-know-how-that-works/761681/56 "2016-08-04T17:59:47Z")
The master discusses a [milk and potatoes diet](http://www.straightdope.com/columns/read/2828/could-i-survive-on-nothing-but-potatoes-and-milk). Seems you could survive fairly well, if you added a bit of oatmeal or peas. ---
**Author:** ![Fuzzy\_Dunlop](https://avatars.discourse-cdn.com/v4/letter/f/848f3c/32.png) [@Fuzzy\_Dunlop](https://boards.straightdope.com/u/Fuzzy_Dunlop)\ **Post date:** [August 4, 2016, 6:02pm UTC](https://boards.straightdope.com/t/penn-jillettes-100-lb-loss-on-a-no-exercise-potato-diet-anyone-know-how-that-works/761681/57 "2016-08-04T18:02:29Z")
> [@DrDeth](#): > > You’re not really reading my history. My weight has always been around 240, then it shot up to 290 for a couple years, but I was able to lose\* that \*and keep it off for decades now. However, losing weight below that 240 has been impossible on any sort of LT basis. I can lose ten, then gain it back. > > So, yes, you can lose a weight _gain_- and keep it off. It’s very hard to lose from your base and keep it off. > > For those that say “its simple- eat less and exercise more” indeed adding exercise makes you healthier and converts some fat into muscle (which weighs more). But unless you are locked into a cell, you simply will not lose any significant weight from your base over the long term. > > A few things could help- if your diet doesn’t have enuf fiber (which is very common) adding two tablespoons of that orange powder stuff nitely could have you lose a few pounds and that will stay off as long as you keep with the fiber. That’s because you are constipated now. If you get more than 5% of your body weight from this, I will be surprised. > > However, all is not lost. Let us say your base weight is 200#. Adding fiber brings it down to say 195, then exercise converts 10 # of fat to muscle. Then eating healthier makes you healthier. You have only lost a few pounds, but you’ll feel a lot better. And, you might not gain anymore weight. Yeah I did pick up on that excess weight not really being your norm and I agree the fact that the excess 50 pounds wasn’t “normal” for you probably made it easier to lose. My point was that we need to look at your success for what it is - an anomalous success that the average obese person can’t reasonably expect to copy given the medical evidence. So I’d say, if you an obese adult who has never seriously tried lifestyle changes, you should totally give it a shot. Go in optimistic. If you have decent medical insurance and can work medically with a doctor or other health professionals I highly recommend it. On the other hand, if you are obese and you’ve tried making permanent changes and couldn’t keep the weight off, you should at least be aware that all the medical research into obesity tells us that this is the expected outcome. This is especially important considering how many uneducated people there are out there who’re happy to insist the obese could lose weight if they just tried. ---
**Author:** ![DrDeth](https://avatars.discourse-cdn.com/v4/letter/d/b487fb/32.png) [@DrDeth](https://boards.straightdope.com/u/DrDeth)\ **Post date:** [August 4, 2016, 7:37pm UTC](https://boards.straightdope.com/t/penn-jillettes-100-lb-loss-on-a-no-exercise-potato-diet-anyone-know-how-that-works/761681/58 "2016-08-04T19:37:38Z")
> [@DrDeth](#): > > However, all is not lost. Let us say your base weight is 200#. Adding fiber brings it down to say 195, then exercise converts 10 # of fat to muscle. Then eating healthier makes you healthier. You have only lost a few pounds, but you’ll feel a lot better. And, you might not gain anymore weight. One more thing- if **your MD** sez you are retaining\* excess\* water, and prescribes a diuretic, you will lose a few pounds (maybe even 10#!) of excess water- which is still good for your health \*in this case. \* Note that in order for this to be a healthy weight loss, it needs your MD to say you are retaining excess water. ---
**Author:** ![CandidGamera](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/candidgamera/32/2878_2.png) [@CandidGamera](https://boards.straightdope.com/u/CandidGamera)\ **Post date:** [August 5, 2016, 1:56pm UTC](https://boards.straightdope.com/t/penn-jillettes-100-lb-loss-on-a-no-exercise-potato-diet-anyone-know-how-that-works/761681/59 "2016-08-05T13:56:38Z")
> [@DigitalC](#): > > Your mistake was measuring weight instead of body fat %. If you reduced your calorie intake and started exercising you were replacing that fat with muscle, even if you gained weight this is a positive result. Then theoretically, since more muscle should equal more calories burned, losing weight should still eventually occur. Regardless, I think you agree that it’s not as simple as calories in and out. ---
**Author:** ![Dendarii\_Dame](https://avatars.discourse-cdn.com/v4/letter/d/bbce88/32.png) [@Dendarii\_Dame](https://boards.straightdope.com/u/Dendarii_Dame)\ **Post date:** [August 5, 2016, 2:02pm UTC](https://boards.straightdope.com/t/penn-jillettes-100-lb-loss-on-a-no-exercise-potato-diet-anyone-know-how-that-works/761681/60 "2016-08-05T14:02:25Z")
My husband says Penn could have done the following exercise: Teller-ups. [Previous page](https://boards.straightdope.com/t/penn-jillettes-100-lb-loss-on-a-no-exercise-potato-diet-anyone-know-how-that-works/761681.md?page=2) [Next page](https://boards.straightdope.com/t/penn-jillettes-100-lb-loss-on-a-no-exercise-potato-diet-anyone-know-how-that-works/761681.md?page=4)