Internal Diet Crux

Cross­posted from Pu­tanu­monit.com.


Dieter: Dude, we’re fat. We should do some­thing about it. Any­thing at all, re­ally. How about we stop eat­ing re­fined carbs from an­i­mal sources be­tween 2-7:15 pm each day?

Dad bod: How about we don’t do that? We’re spend­ing so much en­ergy think­ing about diets you’d think that ac­tivity by it­self should make us lose weight. And yet, like ev­ery­thing else we’ve tried, it doesn’t. Maybe we should face re­al­ity and ac­cept that the pounds are there to stay.

Dieter: You mean give up like a lazy fat loser?

Dad bod: More like op­ti­mize al­lo­ca­tion of self-im­prove­ment effort to more fruit­ful pur­suits.

Dieter: I was go­ing to start call­ing you names, but that’s not go­ing to help us have a con­ver­sa­tion. How about we in­tro­duce our­selves in­stead? I’m the part of Ja­cob that hates be­ing over­weight and thinks we need to take diet­ing more se­ri­ously.

Dad bod: And I’m the part that thinks diet­ing in­volves a lot of suffer­ing with no pay­off, and that it’s perfectly OK for Ja­cob to keep liv­ing in­side a portly dad bod.

Dieter: “Portly”, huh? Cu­ri­ous that you didn’t go for any of the less dig­nified syn­onyms, like “pudgy” or “chubby”. Let’s start with the facts: Ja­cob is 185 lbs at 5’9″, which comes out to a BMI of 27.3. That’s smack in the mid­dle of the “Over­weight” BMI range.

In­ter­nal­ized Scott Alexan­der: You know BMI isn’t very sci­en­tific, you should mea­sure your body fat com­po­si­tion and lean mus­cle mass…

Dieter: Shut up, Scott. Ja­cob is of av­er­age height, has an av­er­age body type, and his bones aren’t made of adaman­tium. We’re right in the mid­dle of the range that BMI is cal­ibrated on. We’ve been avoid­ing do­ing body-fat mea­sure­ments be­cause we’re afraid of see­ing the re­sults. Would any­one here not press a but­ton that would make Ja­cob weigh 165 pounds to­mor­row?

Dad bod: I would press that but­ton, but it prob­a­bly doesn’t ex­ist. Ja­cob was 165 lbs at age 18 at the end of com­bat boot camp, and since then has been steadily gain­ing 2 lbs a year. There has been al­most no vari­a­tion around this slow trend-line. Diets, ex­er­cise plans, chang­ing coun­tries, dat­ing su­per fit girls and curvy ones – none of that has made any mea­surable im­pact at all. Since hit­ting age 30 we seem to have sta­bi­lized around 185 lbs. So why do we keep want­ing to “do some­thing about Ja­cob’s weight”?

Dieter: Have we ever re­ally tried a diet plan? Com­mu­nism has been tried and found want­ing, but diet­ing has been found difficult and not tried. At best, we half-assed things like calorie count­ing and carb re­stric­tions for a few weeks at a time. An ev­ery-other-day diet is no diet at all, since all gains are im­me­di­ately re­versed. We must stick to some­thing at least long enough for the ex­pected weight change to be mea­surable.

Dad bod: But a diet we can’t stick to is, in fact, a failed diet. There’s no dial in Ja­cob’s head he can turn up to in­crease willpower. If our track record is half-ass­ing diets for a few weeks, then the out­side view says we should pre­dict fu­ture diet at­tempts to fol­low the same path. Even worse, we’ve tried most of the re­ally ob­vi­ous things and have grown more skep­ti­cal. We should ex­pect to have less diet­ing willpower in the fu­ture, not more.

There are two more rea­sons why I don’t be­lieve we’ll find a diet that works. First of all, nu­tri­tion sci­ence is a hot mess. There seems to be an equal num­ber of ar­gu­ments on each side of any diet­ing ques­tion. Is sugar the en­emy or is ev­ery calorie a calorie? Should we cut carbs, cut fat, or cut in­ter­est­ing food? Snack to main­tain metabolic rate or fast twice a week? Eat food, not too much, mostly plants or eat meat, not too lit­tle, mostly fat? Any sig­nal is over­whelmed by the noise.

Another rea­son for diet-skep­ti­cism is ob­serv­ing peo­ple around us. Ja­cob’s friend Char­lie weighs around 100 lbs but eats more calories than he does each day. I think that she started es­cort­ing not for the money but just to try all the steaks and lob­sters in Man­hat­tan, and she quit es­cort­ing when she got bored of or­der­ing three en­trees at Miche­lin restau­rants.

If we ate like she does we’d as­sume a perfectly spher­i­cal shape. 185 lbs is prob­a­bly as thin as this metabolism gets.

Dieter: Sure, let’s talk other peo­ple. Have you no­ticed that prac­ti­cally no one you hang out with is obese? Ja­cob doesn’t re­ally care, and all his so­cial cir­cles filter heav­ily on cog­ni­tive abil­ity and in­tel­lec­tual in­ter­ests, not on ap­pear­ance. And yet by some mys­te­ri­ous pro­cess, ev­ery per­son you meet in those cir­cles isn’t fat. Were you re­ally born with the slow­est metabolism of any per­son in your so­cial class, or do other peo­ple ac­tu­ally take this more se­ri­ously?

Dad bod: Fair point. But if our so­cial life doesn’t de­pend on be­ing skinny, why bother? It’s not clear that a BMI of 23 is healthier than 27, and Ja­cob is in de­cent shape func­tion­ally. When we play soc­cer, Ja­cob not only has the en­ergy to run back on defense ev­ery time but also to yell at his team­mates for not do­ing the same.

Dieter: Imag­ine play­ing soc­cer with a 20-pound weight strapped around your stom­ach. That’s what we’re do­ing right now. Do­ing a ton of sports while fat prob­a­bly built up some im­pres­sive mus­cle un­der­neath the adi­pose tis­sue. Let’s un­leash it!

And speak­ing of soc­cer: I don’t feel the ex­tra pounds while run­ning back on defense. I feel them when we de­cide to play shirts vs. skins and I get that sud­den rush of panic think­ing I may have to take my shirt off.

Dad bod: That panic is just in your head, no­body else re­ally cares. What if you just stopped wor­ry­ing about how you look like with your shirt off?

Dieter: If we “just stopped wor­ry­ing”, how soon would it be be­fore I hit 205 lbs? When that hap­pens, the panic will be there ev­ery time I un­dress to take a shower and have to see my­self in the mir­ror, in­stead of ev­ery other week.

Dad bod: It’s hard to ar­gue when you have both hope and fear on your side. Let’s deal with them one by one. What would make you give up on diet­ing?

Dieter: If we ac­tu­ally full-assed a diet for a long enough pe­riod of time and didn’t see any im­prove­ment at all, I’ll prob­a­bly give up. If we make an un­usual effort I’ll know that in case we fail we’ll never be able to sum­mon the same effort again.

What would con­vince you that diet­ing is pos­si­ble?

Dad bod: I think if we ever ac­tu­ally saw a re­sult, that would give me all the mo­ti­va­tion and be­lief I need. Un­til we see it on our­selves, in the mir­ror and on the scale, our Sys­tem 1 will never be­lieve that diet­ing works no mat­ter how many peo­ple tell our Sys­tem 2 about their slow-carb-pa­leo schemes.

Scott: Sounds like you’re both ready to stake a bet on a sci­en­tific ex­per­i­ment! Dieter, what do you pre­dict?

Dieter: I think that we can lose at least one pound a month by com­mit­ting to a rea­son­able diet. A 4-pound shift should be visi­ble over a reg­u­lar day-to-day fluc­tu­a­tion of 1-2 pounds, so we’ll need to diet for four months.

Dad bod: Fair. I pre­dict that do­ing a diet for four months isn’t go­ing to make Ja­cob lose 4 pounds. What should we try?

Dieter: We’ll do in­ter­mit­tent fast­ing: only eat­ing within an 8-hour win­dow ev­ery day, plus count­ing calories to stay be­low our to­tal daily en­ergy ex­pen­di­ture. Peo­ple also say that sugar is bad so we’ll try to avoid sug­ary foods, es­pe­cially in the morn­ing. And full-ass­ing means we’ll have to ac­tu­ally do the thing at least 6 out of 7 days each week.

Scott: Wait, are we do­ing in­ter­mit­tent fast­ing just be­cause a cou­ple of friends and a pod­cast men­tioned it? That’s not rigor­ous! We should do a meta-anal­y­sis of nu­tri­tion ap­proaches, cross-refer­ence them with how well the sub­jects match Ja­cob’s vari­ables…

Dad bod: Shut up, Scott.

Dieter: Yeah, if there’s any­thing Dad bod hates more than do­ing diet­ing is re­search­ing diets. If we start dig­ging into books, we’ll never get to the ac­tual thing. Hope­fully, this is the sort of diet that can es­tab­lish some healthier habits even af­ter we no longer track it.

Dad bod: Also, in­ter­mit­tent fast­ing does seem eas­ier to im­ple­ment. It’s not hard to lie to your­self about por­tion size, but 8 pm is 8 pm.

How do we make sure we ac­tu­ally stick to the diet for four months? I would cur­rently bet on us mak­ing it 6 weeks at most.

Dieter: With Bee­minder, of course! Here’s the diet tracker goal, with an ex­pla­na­tion of the point sys­tem. I get a point for each day that we stick to the 8-hour win­dow and the calorie limit, and lose points for go­ing over. The goal is also pub­lic, so all read­ers in­clud­ing my mom can see both my weight and how well I’m stick­ing to the diet. If on Au­gust 1st I weigh more than 183 lbs, I’ll be ready to give up on the en­ter­prise.

Dad bod: And if we go be­low 181 for sev­eral days straight, I pre­dict be­ing ex­cited enough to keep at it. If we fail to ac­tu­ally im­ple­ment the diet or end up at 182.5 lbs af­ter four months of suffer­ing, I guess we’ll be back to square one.

I’m still not sure we’ll be able to stick to this plan for four months, and I don’t feel in­ter­nally sur­prised when I vi­su­al­ize us ut­terly failing and giv­ing up with a bunch of ex­cuses around early June. On the other hand, the com­bined in­cen­tive of so­cial pres­sure, sci­en­tific rigor, and the chance to shut you up once and for all is mo­ti­vat­ing enough that I won’t be shocked if we suc­ceed.

Good luck, psy­cho!

Dieter: And same to you, fatso!


I con­ducted this con­ver­sa­tion be­tween parts of my­self dur­ing a men­tor’s work­shop at the Cen­ter for Ap­plied Ra­tion­al­ity, and it in­volves a few CFAR tech­niques. I’d also like to thank the fol­low­ing CFAR men­tors:

  • Qiaochu, who en­couraged me to write more vuln­er­a­ble things on Pu­tanu­monit in­stead of just build­ing mod­els for fun.

  • Mr. A, who talked with me about diet­ing and also en­couraged me to dive into top­ics I’m un­in­formed on and could look stupid writ­ing about.

  • Ms. L, who tran­scribed this con­ver­sa­tion as I was hav­ing it out loud. Ms. L mis­heard “Dad bod” and thought that I named the anti-diet voice “Dead body”. She stuck to her job as fa­cil­i­ta­tor even as she grew in­creas­ingly con­fused about why I’m talk­ing to a corpse.