Wednesday, August 1, 2012

Shangri La Diet: It Works!

This post is getting a lot of hits, months after I wrote it, so I ought to qualify it. In the initial month of trying the Shangri-La diet, it seemed to work a treat. After that it got complicated, and there are several further posts on this blog about what went wrong and how I tried to get it working again.  

I certainly weigh less than before I tried it, but the amazing initial success lasted for exactly a month and then failed, in exactly the manner that habitual dieter friends have told me that any 'miracle diet' always does. 

After that, I had to hack it a bit to get it to start working again, and that required that I understood the mechanism by which it is supposed to work. I then experienced a couple of months of slow weight loss.

I am sure that this (modified version) works for me. Your mileage may vary, but I do recommend you try it. You'll know quickly whether it works for you, but if it does, watch out carefully for signs that you're getting used to the taste of the tasteless calorie source, and take appropriate action. The version that worked for me is:

Drink 300 calories worth of extra-light olive oil first thing every morning and immediately wash the taste away with water. Let nothing except plain water pass your lips for one hour after that. Apart from that, eat whatever you like, whenever, for whatever reason. It doesn't matter in the slightest if you miss the odd day.

Here's the original post:

Well, in a qualified way.

The favourite notch on my belt has moved one place smaller. I'm visibly thinner and feel it. And the appetite loss is undeniable. I've pretty much forgotten what it's like to be hungry.

I'm slightly annoyed to have found evidence for something so silly on my first attempt to run an experiment on myself, and I strongly suspect that I've done something wrong, but I can't figure out what.

There are various reasons to believe that I've fooled myself here, but I don't find any of them really convincing:

Primarily, I've smoked more this month than I was expecting: There've been many cricket matches to play, many birthdays to celebrate, an old friend died and there were two associated wakes, and the Town Bumps races led to entire week of heavy drinking.

So I've essentially been drunk for the entire month. When you're drunk your willpower goes, and this tends to lead to smoking. But I'm nowhere near back to my usual rate.

But this may well be the whole reason for the weight loss. If a mild increase in smoking works this well I'm surprised it's not recommended for health reasons. I mean, it's obviously deadly, but I think most people would swap ten years of old age for a lifetime of obesity. And I've never heard anyone recommending heavy drinking as a route to weight loss!

My second reason for doubting myself is that I found I wanted the Shangri-La diet to work. It's clearly ridiculous, in fact if you were wanting to come up with a parody Placebo-Diet backed up with crazy pseudoscience you'd be hard-pressed to do better than this. The only improvement I can think of is to use sugar-pills instead of olive oil. And that's apparently pretty much what the original version Seth Roberts came up with was like.

Originally I was interested in checking out a hoax that appears to have convinced many people despite a complete lack of rigorous evidence. But the minute I noticed the appetite loss I started to believe, and I found I wanted it to be true. Around half-way through the month I noticed that I could wear my belt comfortably on a tighter notch in the morning, and I found myself trying to wear it on that notch throughout the day even though it became uncomfortable.

However, I've noticed this effect, and I've tried to counter it, using the defence that Eliezer Yudkowsky has called the Litany of Tarski: "If this works then I want to think it works. If this does not work then I want to think it does not work. Let me not become attached to beliefs I may not want."

And I'm pretty sure now, after 30 days, that it's moved slightly more than a whole notch. My belt is comfortable on its third notch in the morning and stays there all day now. At the beginning of the month I wrote that it was notch two in the morning and needing loosening to notch one as the day wore on.

So I'm calling this as a qualified success for Seth Roberts and Shangri-La. I'll update as planned so:

The odds of this result for the Willpower theory I guessed at 5/126. for Shangri La 50/137. For Helplessness 5/126

And I took my prior to be H60:W39:S1

So I update to H 60*5/126: W 39*5/126 : S 50/137

Multiplying through and rounding off: H55:W36:S9

And suddenly I'm shocked! This doesn't reflect my current beliefs at all.

I've tried this new thing. It clearly works. Emotionally I'm convinced that it works, and I'm going to keep trying it for the next month and I now confidently expect that it will continue to work.

Bayes is telling me that I don't have enough evidence to update my beliefs like this.

Given how unlikely I thought this theory was a priori, the fact that my test has landed on its central prediction should most likely indicate that some other theory is true, but that my weight loss happened by accident.

I can completely buy that now I've thought about it. The helplessness and willpower theories have had some of their probability mass stolen by the mad Shangri-La theory, but a one-person test (even if I had made accurate priors and controlled outside factors, which I didn't even attempt), is nowhere near enough to give Shangri-La an edge.

In fact the sheer dodginess of my one-person trial, and the placebo effect and various other expectation effects mean that I shouldn't update even this much, but if I had found no effect and refused to do the full update then I'd accuse myself of being biased, so sod that.

So I'm going to try to believe that there's a ten per cent probability that the Shangri-La Diet works. I don't think my brain's really set up for that!


  1. When I took statistics in college (and again in graduate school), I found the section on Bayes to be confusing. I'm still confused.

    In any case, here is my experience with the Shangri-La diet:

    1. Your graph is most impressive! I get the impression that 2008 was a conventional diet and rebound. Can't have been much fun.

      But it looks like Shangri-La really worked for you. Did you stop at 88kg because you're happy with that, or is that where the Shangri-La effect bottomed out?

      Don't take the Bayes stuff too seriously.

      I'm no statistician and I'm treating it like a set of independent trials (As if you were trying to work out what dice your friend is rolling if he tells you only the results). I imagine that there are considerably better ways to do this.

      On the other hand, I also took statistics in college (I'm a maths grad), and I found the frequentist approach so baffling that I dropped the subject.

      Bayes seems transparently clear (a branch of probability theory rather than a separate ad-hoc thing).

      My probability-related intuitions are all 'parallel universe'-type foolishness, but despite the foolishness, they don't tend to lead me to make mistakes when solving real problems.

      I've written a number of Bayes-related posts, trying to capture the intuition without using scary symbols. Here are a couple:

      and here was an attempt to figure out whether England or Australia were better at cricket during the last Ashes series, using the simplest possible models and the five win/lose/draw results:

      For a sane (and detailed) approach, try David Mackay's beautiful Information Theory, Inference, and Learning Algorithms:

      or ET Jaynes combative and fun: 'Probability Theory: The Logic of Science'

  2. "All diets work in the short run" seems like a good rule of thumb. Especially diets that require you to eat something nauseating (like oil) and/or boring (like sugar water). People lose weight in the first month of, say, an "eat lots of celery" or "eat lots of carrots" diet too. You force yourself to do something weird with your diet and it's disorienting. Eventually your body either adapts to the new diet or you run out of willpower and reject it.

    My experience was that I lost about 10-15 pounds when I tried Shangri-la, but couldn't force myself to stay on it (the oil became more nauseating and the appetite suppression effect tapered off) and I gained all the weight back within ~6 months.

    Another thing to keep in mind is regression toward the mean - people tend to start and stick to bizarre diets when they are *unusually heavy* and then credit the diet for a return to their own "normal".

    1. Glen, I hate to sound like a fan-boy but your experiences sound like what Seth Roberts' theory predicts!

      My friend Ruth told me the 'any diet works for a bit' idea, so I've added into my second go at this experiment:

      The weird thing is that you found the oil becoming nauseating. Normally you'd find an unpleasant stimulus losing its power with practice, I think, as long as it doesn't do harm.

      I've always quite liked Olive Oil. I've been known to drink the real thing out of the bottle. Drinking the tasteless stuff is a bit weird (I literally can't tell I've drunk it except that my teeth feel slippery), but it's not nauseating.

      In fact I'm starting to look forward to it, which is vexing because it probably means that I'm starting to make the flavour-calorie association that will wreck the scheme.

      I'm currently seeking even more flavourless oils.

      Did you try the sugar-water version? I'm a bit reluctant to try that since I don't think it's a good idea to screw with your glucose metabolism in that way.

      I know about regression. One reason I tried this experiment is because the conventional advice and Seth Roberts advice are directly opposed. Trying S-L should make you *heavier*, especially if you're not really trying to lose weight. I'm actively trying not to try!

      If Seth's theory is correct, then there are actually loads of diet hacks that could work for you even if you can't stand the oil.

      If it's not, then it should fail for me. But your experience seems to confirm his theory rather than refute it.