Losing weight - and learning to focus?

I've recently started a weight loss plan. I am counting calories and eating between 1200 and 1400 calories a day, with a view to losing an initial 9lb. Once I reach that target, I will review and decide whether I would like to lose any further weight. I am not fat, being an average weight for my height, but I once was slim, and would like to be so again.

Leo Babauta, in 'The Power of Less'says that when acquiring a new habit, you should focus on it for 30 days, and not try and make any other changes during that period. I had never counted calories before I started this plan - 17 days' ago - so consider this a habit I need to acquire. So far, I am making quite good progress with the plan, and have lost over 4lb without feeling overly deprived. I noticed, though, that after a fortnight or so this initial success made me feel quite euphoric, and I instantly started thinking about all the other things I could do - start exercising, start learning Korean, and so on.

However, I'm convinced that Leo Babauta is right; as soon as I start thinking about those other new habits or projects I might start, I can feel I am losing interest in my weight loss goal. So I am telling myself repeatedly that 'after 30 days' I will start thinking about those other things, one at a time. In the meantime, I won't distract myself with any new projects until the 30 days is up. Though my weight loss plan may still be ongoing after this time, it should by then be sufficiently automatic that I don't need to think about it too much.

After all, this is the weight gain of a dozen years - so really, concentrating on losing it for 30 days does not seem unreasonable!