Q Grit doctor, I need advice on how to lose weight. I have read "Run, Fat Bitch, Run" but I don't know how often I need to run before I see results. ZR

A I realise that because this question came to me via Twitter, you were constrained by brevity. Nevertheless, the first thing that struck me about it was that you claim to have read Run, Fat Bitch, Run.

You claim to have read it but not, I note, to have nailed your circuit and to have transformed into a running evangelist. Because, of course, had you acted upon what you had read, you might not have had cause to ask this question in the first place.

I am not a real doctor or a nutritionist, but I recommend that you do the following.

The first thing is to stop reading and pondering when you will see any results. Remind yourself of step 1 in Run, Fat Bitch, Run and get up off the sofa, out the front door and start moving so that you can begin the process by which results become possible. That process doesn't begin while you are sitting on the sofa reading.

If you are very overweight, and are not used to taking regular exercise, all the better.

The weight will fall off as the exercise kickstarts your metabolism into burning more calories. The more often you do it and the less crap you eat between your runs (once you have completed the six steps and can run comfortably round your circuit), the more weight you will lose.

True grit
At some stage, your weight will plateau, at which point you will need to eat even less crap and "grittify" your runs in order to lose more.

But by the time you reach this stage, you will no longer be racing towards some fantasy number on a set of scales. You will be running for so many other reasons because the discipline of regular running enables you to access your better self: the one who genuinely aspires to be fitter and healthier; the one who actually wants to eat less crap and enjoys guzzling water; the one who is sofa-averse and more of a getting-shit-done fiend.

It just so happens that regular running also keeps your waistline in check. In short, it’s a win, win, win situation.

So, you are overweight and want to do something about it. Great. Get moving. While moving, think about where you are going wrong in terms of eating and set about addressing it.

One obvious and relatively easy step to take on the eating front is to rid your home of anything unhealthy, so that come 10pm when your previous bad habit of reaching for the biscuit tin – or whatever and whenever it is – rears its ugly head, you are unable to activate it.

My husband is losing weight almost effortlessly just by giving up that late-night snack. His desire for a chocolate bar or sugary snack each evening cannot be met if there is nothing in the house to satisfy the craving.

And, like all bad habits, once kicked, it is kicked for good. It is amazing how a few terrible eating habits, especially when combined, can literally keep you trapped inside a fat body for years.

By the same token, small obvious changes made together over time can have just as dramatic an impact on your weight loss – especially when taken in conjunction with some serious fat-busting cardiovascular exercise, such as running.

Remind yourself that you are giving up bad habits and cultivating new good ones in order to remain at a normal weight, for the rest of your life.

No more yo-yoing between faddy diets, feeling faint and half-starved and then caving into cake when the cravings get too much.

Not only does remaining on the dieting merry-go-round savage your self-esteem, but it also damages your body too.

Good habits, thankfully, are also difficult to break. I run because it is a habit. It is as much a part of my week as bathing the twins, brushing my teeth or sleeping. It happens without thinking about it too much because I have made it a habit. And keeping it up means I get to enjoy that cake too.

Shift in attitude
It is your attitude that needs a massive shift. Act on what you have read now and once you have completed all the six steps set out in Run, Fat Bitch, Run and are running your circuit comfortably, then get in touch and tell me how great you are feeling, how much fitter and leaner you have become, and how you have your sights set on a half-marathon.

Having your eyes on the prize from the vantage point of the couch is to stay trapped in the same vicious cycle you have been in for years.

There are no short cuts or fast ways to lose weight permanently. There is only taking responsibility for what you put into your mouth and balancing that with a healthy, active lifestyle. Forever. And it only begins when you take that first step. Outside.

Tweet your running queries to Ruth at @gritdoctor

Ruth Field is author of Run, Fat Bitch, Run.