Technology review: Jawbone UP, tried and tested It feels slightly stalkerish to log on throughout the day and see that he's eaten a cheese sandwich and had a cup of coffee. But it also awakens the hugely competitive element within me. On the third day I connect at lunchtime and see he's taken more steps, so I go up to the gym for 15 minutes to quickly top up. We could adjust our settings to tweet each other automatically when we reach a certain goal, but I'm not sure that would improve our relationship. Logging food using the app is easy if you eat a lot of packaged food - you can scan the barcode and the app works out calories, sodium and saturated fat levels. It also provides a "word cloud" of your most-eaten meals - my boyfriend seems to be subsisting primarily on scallops and porridge. But if you cook or eat out you can get only rough approximations from a fairly limited library of suggestions, although UP is compatible with other health and fitness apps, including MyFitnessPal, which has a vast database of existing foods and allows you to input ingredients from a recipe to get accurate calories. Still, data-entering everything you eat is a bit of a faff. My boyfriend says he's going to eat only food with barcodes from now on. After a month my UP knows I don't sleep very well - I have less than two hours" deep sleep per night, whereas most UP band users get closer to four. The app delivers daily "insights" based on your data. At first they are quite generic and pretty useless, but later in my trial I get more targeted suggestions, such as eating pumpkin seeds before bed to improve my quality of sleep and supplying a weblink to a study that explains why. One of the best features is the "trends" function. It gives two parallel timelines: how much sleep you've had, with how many steps you've taken underneath. The day I took 29,561 steps was the night I slept the best, with four hours of deep sleep; when I took only 8,930 steps one day, my deep sleep was reduced to one hour and 46 minutes. Perhaps that's blindingly obvious, but my sleep graphs seemed to mirror my steps graph even when the differences in distance were not so dramatic. I don't know if I'll keep wearing my band - I feel as if I need a break from constantly analysing myself - but my boyfriend is going to stick with it. And I can't stop recommending it to other people; surely everyone needs to track how much they move, eat and sleep, at least their averages. With the help of Jawbone UP I made my way through a period of not having a kitchen and eating out for three meals a day, yet still losing four kilos in weight, and it did prove to my boyfriend that I take more exercise than him - the ultimate "I told you so." But it also made me realise I need to find a way to sleep better, rather than just accept feeling tired all the time. Because that is what UP does best - it forces you to see the things that you already knew weren't quite right. £99, jawbone.com/up Nike+ FuelBand SE Nike doesn't care what you eat or how well you sleep; it measures how active you are and rewards you in 'NikeFuel. The simplicity of Nike+ FuelBand SE, the latest version of the band launched this month, is what is most appealing. There is no manual data entry, and it now automatically connects to your iPhone via Bluetooth. And if you're already using Nike apps, such as Nike+ or Nike Running, then you're already used to the lingo. But it is not available on Android. £129, nike.com/fuelband Fitbit Flex Fitbit has been doing activity trackers for a while, but the Flex is its first bracelet. Broadly speaking it is very similar to the UP. The bendable rubber bracelet is thicker and plainer than the UP and charging isn't easy. But the main advantage is that it syncs directly with your phone via Bluetooth, so keeping your data current is much easier than with the UP. £79.99, fitbit.com/uk Basis B1 The Basis B1 is not yet available in Britain (and has no release date yet) but for serious self-quantifiers (or athletes), it might be worth holding out for. $199, mybasis.com