cannot seem to exert enough energy.
Seriously, I'm not suggesting you actually do it, but go and buy the new version of the Atkins book and give it a read. It makes a lot of sense if you are in that situation. There may be a few things in there you find useful and make sense.
It has shown me that carbs & sugar do not equal more energy. You need to train your body, I have more energy now that I have for ages. I used to go through 2 or 3 shirts photographing a wedding but now I keep the same one on all day, my energy levels are more stable and I sweat a lot less. A lot of that could be put down to the weight loss itself but there is something to be said for looking at what you eat and the effect it has on you.
To me it makes total sense that if you do something to loose weight, then stop doing it and go back to bad habits you will quickly put the weight back on. I have started with Atkins and will end with a sustainable diet that I understand and know is healthy but still be able to eat the things I like too. For the moment I need to focus on exercise as I am naturally very lazy!
Cheers
Cris