When most people realise they need to change something about their lifestyle to improve their health or fitness, they almost always look at adding to it first. They’ll start running or swimming, or start a diet, or join a gym. Few people take the time to analyse (and then, of course, break) their bad habits before anything else, and that means missing out on some great - and potentially very low effort and low maintenance - opportunities.

The problem is that most of us don’t know what all of our bad habits are. We think of the ones we do know about as just a part of our lifestyles - innocent little quirks or harmless vices to be indulged, nothing more. It certainly never occurs to us that an evening spent in front of the telly is a bad thing, or a wasted opportunity - even if we’re not watching anything in particular. One chocolate bar a week? We think of it as merely a treat, no implications or real effects. Can of coke with lunch? It’s only a can …

Of course, we’re wrong. An evening in front of the telly could be 4 or 5 hours. That’s a serious chunk of time - easily enough time to see real people, read a book, cook something new, go for a run (or walk) or go to a course. A chocolate bar a week is only 300 calories. One can of coke is 139 calories. One evening a week, for a year, though, is enough time to learn the basics of a new language (to holiday standard). One chocolate bar a week is 15,600 calories (almost 5 pounds (11kg) of bodyfat). One can of coke a day is … wait for it … 50,735 calories a year (over 14 pounds (32kg) of bodyfat).

Take a moment to reflect on that. A lot of people have at least a can of fizzy drink with their lunch, a chocolate bar a week and spend the evening in front of the TV. They could lose over 19lbs (43kg) of weight and learn a new language in a year, just by cutting down on a couple of bad habits.

Bad habits add up over time, just like good ones do.

The trick is to identify these habits (and then learn to break them, or even better to outright replace them with good ones).

The first step is to be more conscious of your actions. Learn to monitor yourself. Keeping a food (and drink) diary is boring, but a really excellent way to learn about your own eating habits. If you’re having trouble keeping it going, try using a Seinfeldian Chain (thanks, Monica). Keeping a TV diary (or even better, sorting yourself out a TV planner and only watching what you really want to see) or an internet diary serves the same use.

Diaries like that only work if you look at them. Writing everything down and then letting it gather dust is counterproductive. So the next step is to take time to look at what you’ve eaten in the previous month. What you find might shock you - great, time to make some changes (and you’ll be able to see where you need to start). It might be that it all looks ok (again, great, you’re eating well).

Once you’ve identified and started to replace your bad habits, the fight is not yet over. People have a tendency to find things to fill their time, and you might end up replacing one bad habit with another. In that respect bad habits are a lot like weeds. You can clear them out, but you’ll always need to be vigilant if you want to stay clear of them.

I cut down on TV only to replace it by spending time online. I gave up World of Warcraft but spent more time in the pub. I stopped going to the pub as much and started watching more TV. There were some (like smoking and soft drinks) that I’ve just stopped without replacing them with something as bad. Overall, I’ve reduced my bad habits considerably and I am now aware of the ones I still need to address.

Do you know what your bad habits are? Did keeping diaries (food, TV, exercise) work for you? Do you have any tips to help other readers? Share in the comments!