Tuesday, January 9, 2007

"Traffic Light" food labels



The idea of the Traffic Light scheme is "red: danger". Beware of eating red foods. Danger. You will Become Fat. And then you won't get treated In hospital because You Did It To Yourself.

Nice idea, except in practice healthy eating is much more complicated that this (orange juice is red because of the calories per glass). But even this over-simplification looks like genius compared to the nonsense of the scheme as dictated by the Food Standards Agency. Spot the difference between the two products shown in the photo I took on my last visit to Sainsburys.

Yes, the SAME FOOD is "green: OK" AND "orange: warning" for calories. Why? Because the serving size is different between the two packs. One pack (serving: half of it) is slightly less than twice the size of the other pack (serving: all of it). Duh. Are people really too stupid to work out that eating more of something is likely to be more calories? Any anyway, if you wanted to manipulate the traffic lights, you just manipulate the recommended serving size.

What would be marginally more useful is to work out the calorie density of the food: the calories vs. the weight. So some pasta (150 cals/100g) is much better than cheese (400 cals/100g) simply because the plate of 300g of pasta is just 450 calories compared to the same appetite-satiating lump of cheese of 1200 calories.

But the Food Standards Agency is part of the Government, and they know much more about this than you, me and the supermarkets we choose. Well, instead of fannying around with misleading labels in an attempt to nanny us, how about making nutritional labels mandatory, like the US FDA does? There are still foods on sale in the UK with NO nutritional information labels and it's about time we knew what was in our food so WE can make the choices.

Sunday, January 7, 2007

So cycling is eco-friendly? Not as much as you'd think

"People should make the effort to do their bit" said my wife. We were discussing Global Warming, and how The Sky Is Falling In, etc. This got me thinking. How I know what that means? I bet that most of the received wisdom is wrong. I thought I'd do a bit of research and look at the bicycle. I'm a keen cyclist (I've even been on a 2500km 3 month tour of New Zealand on my Airnimal folding bike). Cycling must be the answer, right? Hmmnn..

A typical car does about 35mpg, or 6.7 litres/100km. At 0.032 gigajoules/litre for gasoline, that works out at 2150 kJ/km.

Cycling burns about 20 calories per kilometer. Obviously a fat person on a 20kg mountain bike burns a lot more. But we can't just use the 20 calorie figure straight: those 20 calories come from food, which has to be grown, harvested, processed, transported, stored and cooked. Which takes energy. Lots of the energy is in transport, and a lot is in the fertilizer (which is made from natural gas). On average, it takes 7 calories of fossil fuel energy to make 1 calorie of food energy. That's an average. It's much worse than average if the food comes from an animal that has to be fed itself (as much as 70:1). And it's horrific if the animal is itself fed on meat (e.g. tiger penis soup). But let's go with the 7:1 average. That puts cycling at 586 kJ/km. That works out at a gasoline equivalent of 107mpg. Good, but not that great. Not compared to a scooter (80-100mpg), or a diesel train per passenger (182mpg). Even an airline seat isn't that bad (66mpg long-haul and 40mpg short-haul).

What this really means is: the situation is complex. The Devil is in the detail (no doubt there are points against my calculations). A blanket "flying is bad", "cycling is good" response is just not right. Which is why the Stern Report recommended a levy on CO2-equivalent emissions, with a trading scheme, and let the market work it out for itself. That means if A is cheaper than B it'll probably be better at slowing climate change, too. Then we just have to do what we've all got a lot of practice and skill at: choosing things based on their price. Simple, eh?