Losing weight with GNUplot

Posted on December 25, 2005, under general.

Last summer, myself and Noirin went to Manhattan, and had a brilliant time, If you havn’t seen it already, we kept a travel blog of the whole thing, and I’m sure we’ll go back there at some stage.

As amazing and exciting as it was, the many tasty meals, donuts, hot-dogs and even (yum) baked Alaska that New York had to offer did some serious damage to my health. Although I don’t normally over-eat (at least according to my Doctors), I’ve never been slim, and I’ve probably been in the clinically overweight since I was 15 years old. After New York, I weighed in at 112 Kg (17.5 stone/245 lbs), which is into the obese range for my height of 190 cm (6′ 3″). So I decided to do something about it.

Having done Physics in College, I’ve always been a bit mystified by the whole weight-loss industry, because the figures never seem to add up to me. Terms like Calories and KiloJoule mean very specific things, and the conservation of energy principle is something I’m more than prepared to give the benefit of doubt. And yet, when you add the numbers up the value of exercise is absurdly small, but it’s nearly always key.

My fitness levels are o.k., I cycle and walk quite a lot and can walk or cycle for hours a day without any problem, I can even out-run most people my age, and my physical strength is o.k. too. So whenever I’ve done the numbers I’ve always figured that I’d need to devote many hours a day to exercise in order to have any meaningful affect. After all, just one donut is about the same an hour of cycling, for crying out loud. How am I supposed to find that time?

Well, after doing some initial reading, I discovered that there are some factors which cause me problems. I was eating things in the wrong order, meaning that although I had a fine calorie-per-day count, I wasn’t giving my system a chance to digest it properly. Spending 3 nights a week in Trinity College also meant that I was generally eating late, quite often I’d have 1500 calories of food after 10:30pm, which is just insane, and probably caused my insomnia too. I wasn’t putting on weight in general though, so I just had to lose it, which was something positive.

From cutting out any snacks and completely overhauling my lunch, I lost just over 6Kg (14 lbs/1 stone) in two months, which isn’t bad. But then I did some more research, and came across the excellent book: The Hacker’s Diet. This book is a no-nonsense approach to the subject, and explains it all in terms of process control and energy conservation. Things that make sense, and it really does work. More or less since I read it, I’ve been following it, and have lost even more weight. Here’s the GNUPlot:

Graph of weight over time

I update that graph on a daily basis (when I have measurements) and for reference: Apachecon US 2005 starts on day 40. Right now I weigh just under 91Kg (201 pounds/14 Stone 4 pounds), and for the first time I’m way actually in the healthy weight range. I’ve lost 19 Kg (42 pounds/3 stone) and 12 cm (5 inches) from my waistline too, and my XL t-shirts now look ridiculous on me. And there are other changes too, I’m surprised to find my watch dangling loosely on my arm and frequently find it on the underside of my wrist (wasn’t expecting that), cycling is a lot easier now (since the engine has higher power/weight ratio) and my centre of mass has moved too, which I can actually notice leaning back on a chair.

It’s bizarre, but it feels really good. Still, there’s more to go, my target weight is 77Kg (170 lbs / 12 stone, 2 lbs) , which I should be able to reach within the next 3 months, but I’m well over half-way there, and already feeling pretty good for it. It absolutely improves just about every aspect of your life, I’m even sleeping a lot better.

The weird thing is, I have so much leeway in the planning, that I can still frequently eat out on the spur of the moment, and have horrendously unhealthy meals, and still lose weight. As long as I account for it, and take action, it all works.

The approach from the book has been working well for me, too well in fact, my rate of loss has been too fast, and I’ve had to add supplements to my diet. Since I haven’t really been feeling hungry, it just goes to show what a little organisation and planning can do. I also really like the systematic approach to measurement taking and plotting which the book includes. Most books recommend you weigh yourself once a week, to avoid the noise of daily water changes.

This is a load of crap. Measurements are the bread and butter of science, and more is always better than fewer. So I’ve been making daily measurements and plotting using the weighted average method outlined in the book. I had been working on a system based on the Mean Value Theorem, but the simplistic weighted average is working out just fine, so I think I’ll stick with that. I’ve been working it out by hand and have a very simple shell script to produce the graphs, using Excel would have been a bit to burdensome.

If you ever feel like losing weight, I can highly recommend the book, and along with abother book or two on good nutrition (which it really doesn’t cover) you should be set to go. Best of all, the whole thing is free and on-line! Do consult a Doctor though, it can be easy to leave yourself with some nutrient deficiencies, and they’ll be able to advise you on what rates are healthy and what else you may need to take into consideration. I’ve definitely learned that the principle of understanding all of a problem in order to solve it definitely applies just as much to your own body as with anything else. Once I found out in what ways your body can actually be entirely predictable, and that it isn’t just a huge vague biological process with unpredictable outcomes it becomes a lot easier to have some confidence that your exertions of will-power will actually have a definable, measurable, effect.

I already had the fitness part in place, so that it’s more dramatic, but all the same, it’s amazing what some understanding can achieve. Now let’s see how Christmas and the New Year go.

10 Replies to "Losing weight with GNUplot"


Kae Verens  on December 26, 2005

cool! I must read that book. I am 5’4″ and about 11.5 Stone, which makes me overweight (BMI of 27.5, according to http://nhlbisupport.com/bmi/). The funny thing, for me, is that for years, from 17-24 or so, I was about 10 stone, then I suddenly flew up to over 12 stone (and was diagnosed as a depressive), and am finding it incredibly difficult to get rid of that excess weight.
I understand what you mean about the exercise not appearing to do anything – I walk at least four miles every day (distance from home to work), yet it does nothing for me.
I’m going to give that Hacker’s Diet thing a whirl. Thanks, Colm.


Somewhere out there! » That time of year again. This time I follow the plan!  on January 12, 2006

[...] Losing weight with Gnuplot [...]


Colin » The Hacker’s Diet  on January 31, 2006

[...] So over Christmas I noticed that I had become more “cuddly” than normal and decided I needed to lose some weight as part of a general get healthy policy. At the same time colmmacc posted this article on losing weight with gnuplot. He brought to my attention The Hacker’s Diet which is a great reference written by an Engineer and so it builds a systems model for the body and weight gain / loss. [...]


Can i really? » Blog Archive » The weekend of dublin  on March 1, 2006

[...] The official reason for me being in dublin was to get CACert assured. Noirin (thank you!) had arranged a meetup, with 2 CACert assurers present. We ended up meeting in a pub in stillorgan after some plan changing due to the riots earlier that day. I’d been told that conall (of tcd netsoc fame) and colmmacc (of redbrick, heanet, apache fame) were to be there. And, indeed, they were. I however didn’t recognise colm (whom i’ve met before) for a good 25 minutes, and was even pondering asking noirin if colm was going to turn up. Eventually the penny-dropped. Colm has lost at least 3 stone since i’d last seen him (and i’d even _read_ that blog post). Anyway, thanks to both conall and colmmacc for assuring CACert that i (a) to exist and (b) am who i say i am. [...]


adamp  on May 28, 2006

Nice Site. Very informative.


Adam, New Balance


spain  on June 27, 2006

this website is soooooooooo borin ahhhhhhhhh


Chris M.  on October 19, 2006

I went down from 80kg to 69kg in a month from a diet of oats in the morning and greens in the evening. All washed down by plain water. Nothing bulky and starchy during lunchtime. Exercise…just power walks….4 times a week. The result? Almost can do a somersault whilst putting on my shirt..whatever.

But your regime seems a kinder approach.


Butea Superba  on November 1, 2006

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Chris  on August 6, 2008

Is it possible that you share the GnuPlot code of the chart?

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