I've done quite well on things like Slimming World in the past, but this time I don't think it will be helpful. The main reason is that I don't want to give up the chocolate, but also a running diet needs to have enough calories to cope with the running, and also more protein to help build the muscle strength.

So I use the ever so helpful MyFitnessPal

MyFitnessPal food logging
You give it some information about:
  • Whether you're male or female
  • How much you weigh
  • How tall you are
  • How old you are
  • How active you are
  • How much you want to lose
  • How fast you want to lose it.
And then it tells you what your nutrition goals should be for each day (My handy tip would be to tell it that you're not at all active. Chances are you can track your active calories when you exercise, and you can add those on the app to your daily total).

The best bit is that then you can keep a diary of what you've eaten, and it adds all the nutritional information for that thing. You can also keep track of any exercise you've done and any water you've drank, plus changes in weight.

The food thing even has a barcode scanner and if someone else has eaten the same thing before you, then all the nutritional information will just magically appear on the app. 

There are extra features you can pay for that I've never played with, but all the main functionality is absolutely free. It's really really helpful!