Archive for the ‘Food’ Category

Nerdvana: The important maths of supermarket self-service checkout queue speed.

Nerdvana: The important maths of supermarket self-service queue speed.

Nerdvana: The important maths of supermarket self-service queue speed.


My heart sank a touch on Tuesday at the potentially dire state of public maths. While queuing at the supermarket, there were two neighbouring banks of self-service tills each with six people queuing. The issue? One had four tills, the other two.

This blog is dedicated to the inspiration that is Dr Sheldon Cooper

It seems many people had avoided the simple maths, doable either by observable instinct or observation, that the first tranche of tills had an average 1.5 people queuing per till, while the second had three people.

When I tweeted and Facebooked this, many people came up with potential reasons for the queue disparity. In this case none were true, but they do bear examination.

  • “They may have seen old or stupid people ahead.” While I’m not sure I accept the assertion that older people are any less capable, or that you can judge by looking at someone’s self-service checkout skills, I’ll ignore that for a second.If you were unlucky enough to be stuck behind a till-doofus, maths plays a part here too…

    Bank of two tills: A doofus blocking it reduces the number of tills by 50%

    Bank of four tills: A doofus blocking it reduces the number of tills by 25%.

    Therefore it would need double the doofuses (or is it doofi?) to have the same impact with more tills. Thus, even with one potential doofus in the queue, the bank of four tills wins.

  • “People may’ve been counting the items each person had.” These were basket-only queues. So the item range is, let’s say, from one to 20. Yet the time taken to check out does not vary in line with the number of items – it doesn’t take twice as long to check out two items as it does for one.

    Much of self-service time is spent starting, sorting bags, paying and dealing with ‘unexpected items in the bagging area’. This substantially reduces the risk of this playing a huge factor, and with six people in the queue you’re likely to be moving towards a more normalised variance in each queue anyway.

  • “Alcohol and dangerous goods.” This one is bang on, as they require a member of staff to sign the customer through, causing a delay. However, the impact follows on much the same lines as the doofus argument above.
  • “The queue you join always moves more slowly after you’ve joined it.” Many feel they have empirical data to prove the truth of this (ie, it’s happened to us all). Even if we exclude memory bias (we remember the bad times more than the good) and accept it as a rock-solid certainty of Sod, it is irrelevant.

    By definition, this rule applies regardless of the queue joined, therefore it’s ‘on both sides of the equation’ and thus can be cancelled out. In other words, if you’re going to be unlucky, you may as well be unlucky in the queue with the better chance of moving more quickly.

  • “Some people may want to queue longer.” I must admit I hadn’t thought of the perverse motivation factor. I had assumed everyone would want to reduce queuing time to a minimum. However, I’m wrong. There are of course some strange fetishes out there, and self-service queuing could be one of them.

    Surely though, this is only a relatively small proportion of our great island nation. Even for just one of the six people in the bad-maths queue, to be so en-fetished seems unlikely. However, let’s assume they were. Even so, that leaves two others who shouldn’t have been there.

  • “People are too stressed or tired to work it out.”While for a geek like me it is counter-intuitive (I was massively busy and rushed, so therefore working out relative queue speed was a priority, not something to ignore), I accept the likelihood of this thesis.

    Yet that does sort-of take me back to where I started.This is a very simple bit of what should be intuitive maths. I wonder whether the fact people feel too tired to do it is a result of poor applied mathematics skills? In truth, all you need do is look and see one block has more tills, but the queue is the same length.

As for the empirical result? I joined the queue of four tills as the seventh member, and exactly as the maths would predict, arrived at a till at almost exactly the same time as the person who was fourth in the other queue.

The Calorie Saving Expert diet

The Calorie Saving Expert diet

The Calorie Saving Expert diet

Many MoneySaving techniques can be applied to dieting/healthy eating – I know, I do it myself. It’s all about adopting a ‘should I spend the calories?’ attitude…

I’m writing this after a discussion on my regular Radio 5 Live Consumer Panel slot. While in the studio, the UK Chief Medical officer was interviewed and I got involved, talking about how I manage my calorie intake (see my I lost 1 stone six pounds blog).

So I thought I would jot down a few, calorie saving expert (or more accurately amateur enthusiast in this case) thoughts…

  • It’s all about scarce resources  

    In the same way as the amount we have to spend is limited, so is the amount of calories we can consume. Overeating and overspending both have negative effects, one too many pounds the other too few.

    Unlike money though, the maximum calorie consumption we each can have is more egalitarian, there are far less differences between what we can eat (about 2,000 calories per day for women, 2,500 for men – but with some variance due to exercise levels – and reduced if you’re trying to lose as opposed to maintain weight).

    Of course fat intake and what you eat in terms of fruit and veg matters too, but I’m going to stick with calories for simplicity.

  • Check the cost before you buy

    The only way to know if you can afford something is to check the price, the same is true with calories. The calorie differences between ‘sandwiches’ for example can be huge – don’t assume they’re all the same. 

  • Be aware of the calories in your pocket

    It’s about thinking of the bigger picture – how many calories you have a day or a week. If you’re not good at keeping a mental track, then note it down on a piece of paper so you can budget.

  • Think of the opportunity cost

    The most important idea is about trading off one calorie for another. So while you may fancy ‘another coffee’, if that’s a milky coffee it could be 200 or 300 calories. Would you prefer that or a Mars bar? Or even a bigger meal in the evening? Being aware of the calories allows you to manage what you eat by saving now for spending later.

  • Beware spending calories on drinks

    When I first lost weight this was the biggest lesson. Drinks, especially fizzy drinks or fruit juice are usually full of calories. By shifting to low or no calorie drinks (including water or non-milky coffee/tea) you recoup loads of calories which are better to eat.

  • Need crisps, go low calorie

    While I adore crisps, the fat and calorie content of a pack of McCoy’s or Walkers can be huge, easily over 200 calories. For a very little switch to French Fries, Quavers, Hula Hoops, Monster Munch (normal-sized, not a grab-bag) you get a similar effect but with less than half the calories spent.

  • Earn more to spend more

    If you want a calorie splurge, you need to work for it (bit like with cash). So go for a long run, do some serious exercise and then you can feel comfortable about going for a big feast knowing you’ve earned it.

  • Follow the calorie mantas

    The Martin’s Money Mantras for spending money are well established, but they work equally well on calories. The questions for if you’re skint, work well for those who are dieting:

    Do I need it?

    Can I afford it?

    Have I checked if less calories are available in something else?

  • Crack the eating impulses

    The host of techniques to stop you spending when you don’t need to, can be applied to eating too. The most potent is about planning.

    Pre-arranging what you eat, so you know what your next meal is and when it’s coming help control the urges and let you stick within your calorie budget.

  • Demotivate yourself

    I should probably build a calorie equivalent of the Demotivator tool, that could work out how many calories and therefore pounds you would save by giving up your usual latte a day.  Yet the principle is similar, cutting out a few unnecessary treats doesn’t feel like much, but if you do it regularly it can have a big effect over a long period.

Of course no-one’s saying it’s easy. And just like with debt, a change of circumstance, mental health and focus have just as much to do with it as pure ‘don’t overspend’ yet maybe phrasing it this way will help some.

Please let me know using the links below any more lessons from money that can be applied to dieting.


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Kit Kat Crunching Crime

The victim: a 2 finger Kit KatWhile this may sound trivial, and indeed is, I need to admit horror at something my friend Richard did at our house over the weekend.

He had a Kit Kat two finger packet, and instead of breaking it into fingers, simply bit across both fingers as if it was a single bar, entirely ignoring the Kit Kat’s multi-sectioned functionality.

I’m not sure why, but I was quite shocked at this, it seemed plain wrong. Is it just me?

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Yo! All you can eat sushi – like a child in a sweetie shop

Last night Mrs MSE and I headed out to use the 40% off Yo! Sushi deal from the restaurant vouchers list. When we got to the restaurant in the Whiteleys Centre in Bayswater, frustratingly it was closed for a private function.

As the voucher’s only valid on Tuesday and Wednesday nights, I asked if it was possible that they could stamp it for a different night, as we were missing out. The girl at the reception gave me a strange look and told me she would go and get the boss.

Thirty seconds later a lady walked round the corner and said, “Hi, my name’s My Ly I’m the marketing manager for Yo! Sushi. It’s great to see you here Martin – we’d love you to come in” (I hadn’t said my name).

By bizarre coincidence we’d stumbled upon the opening party for the refurbishment of that branch, and trial of its new experimental menu. She actually told me that they had thought about inviting me but (correctly) knew that I don’t go to such dos.

As we were there it seemed like a good idea, yet I was slightly concerned about the photographer. The last thing I want to do is be in the marketing brochure so anyone would think there was an implied recommendation. Yet she was happy to have the snapper leave us alone.

Once in I felt like a child in a sweetie shop: I love sushi – it’s my favourite food – so the ability to simply take whatever dish I wanted (and as many as I wanted!) was fantastic. Even though I’m lucky enough to be able to afford to get whatever I want when I am usually there, there’s a freedom when it’s totally free that’s just different.

Better still, Yo! sushi normally does the bill by counting up the number of different coloured plates you’ve had. Yet here they were clearing away the plates so there was no evidence, making it much more comfortable to over-scoff in luxury.

The only downside was that we had planned to play Scrabble over dinner, and as the place was full of cool designers and we were guests that felt a little rude. Still, the new food was good, and My introduced us to the history of the place, as well as chatting about what future vouchers would be coming up (watch this space).

It’ll be interesting to see if they introduce the salmon beetroot maki roll, which tastes a lot better than it sounds, as a regular.

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Pine nuts: strange taste warning…

This is perhaps the most bizarre blog I’ve ever written. Yet I thought I should warn people about pine nuts. For the last five days I’ve been complaining about a strange after-taste when I eat anything; it’s almost but not quite metallic.

Having had a filling a couple of weeks ago I thought it might be that but nothing seemed wrong. Yet the taste persists and it’s been driving me up the wall.

So I decided to use Google to look up strange tastes and I found the following:

  • Chinese pine nut taste problems.
  • Wikipedia on pine nuts: Risks of eating pine nuts. The eating of pine nuts can cause serious taste disturbances, developing 1-3 days after consumption and lasting for days or weeks. A bitter, metallic taste is described. In general, a minority of pine nuts on the market present this problem. Though very unpleasant, there does not seem to be a real health concern.
  • European Journal of Health. Taste disturbances after pine nut eating.

Now do note I wasn’t looking for pine nuts; you wouldn’t exactly think to would you? Yet the taste disturbance was EXACTLY what I’d described. And no surprise, for the last fortnight I’ve twice had a new salad from a ‘select your own salad ingredients’ place and i’ve asked for pine nuts in it, having never really eaten them before.

While it’s not a scientific diagnosis, and I’m not a medical person, the correlation is pretty strong. Strange taste in mouth – newly started eating pine nuts – Google full of pine nut taste distruptions.

Needless to say… they’re off my menu from now on.

PS. Seems there’s a trend happening here; the day after I wrote this the Mail published this story: Pine Mouth Puzzle

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