Another nod of agreement from me for the general principle of recording your stats daily.

I go a little further, having written a simple program that draws slightly more expressive charts than what a quick Excel job will produce, colour coding just about everything in a green=good, blue=neutral, red=bad kind of way.

In particular, I track total calories consumed, "bad" calories consumed, and calories expended during exercise. I plot these as a single blue bar for each day, with the total height being the total calories. I colour the top part of the bar red to show how much of the total came from bad calories, and shift the bar down to start below the zero line and colour the lower part green to show how much exercise calories offset the intake. I know I'm getting sloppy if the tops of the bars start going up, and it's easy to see from the red and green whether it's due to eating too much junk or not exercising enough.

This approach makes the height of the bar relative to the zero line a daily "calorie balance". I label each bar with the balance figure, in green if it's under 1,500, blue for up to 2,000, and red for over 2,000. Again, the visual reinforcement is great: it feels like I want to get lots of green numbers, and I feel guilty if I get lots of red numbers, even though rationally I know that a red number is not actually that much.

I do realise that effective weight control isn't really as simple as this crude calorie balance approximation, but the chart serves its purpose. Throw in a graph of weight (a marker every day, again coloured for reinforcement, so it's green when I hit a new low, blue if I equal the previous low, and red if it's above the previous low) plotted above the calorie balance, and perhaps a line showing body fat percentage as well, and everything looks much nicer if you can get it green. It also starts to show patterns of real progress quite quickly: you can see a general downward trend in weight and body fat within a few days, and over time you start to see that when you slack off on the diet or exercise it really does lead to pausing or reversing the downward trends.

After doing this for several months and losing a fair amount of weight, I concluded that the recommended calorie intakes for adults don't work for me at all. Despite being over 6' and despite doing a fair bit of dancing in my social life, I do not require anything like the 2,500 daily calories recommended for an adult male to maintain my weight. Consuming around 2,000 calories per day is plenty for me, unless I'm planning a particularly long or intensive workout, in which case I eat more accordingly. As soon as I learned to ignore the official advice and adjusted all my expectations down by 500 calories per day, I permanently stopped my weight drifting up as it had been for a few months before I started this exercise, and started it back towards a level I consider acceptable.

Finally, a few things are really bad for calorie balance, and you don't necessarily realise unless you're actively checking what you're eating and drinking. Fizzy, sugared drinks are the kiss of death for any diet, but you have to be careful with "diet" versions as well, as they sometimes have secondary effects that cause you to be more hungry and thus eat more than you otherwise would! Also, if you're an "everything tastes better with cheese" person, you might want to moderate your dairy intake. Cutting down sharply on these two things alone reduced my daily calorie balance enough to be losing a substantial amount of weight, before I even started improving my exercise regime and looked at other parts of my diet.