I wrote up a big chunk of prose on diet and deleted most of it. If you can make one major change in your diet, simply eating higher quality food will automatically help with a lot of the calorie intake and other little tweaks in diet that the fitness and nutrition crowd talk about. You don’t even have to get into micronutrient content and glycemic index, etc. It’s actually pretty hard to overeat if you’re eating the right things; you get full.
Higher quality means more fresh, unprepared, non-prepackaged foods. Lots of salads, lean meats and seafood, fruits, nuts, some dairy. Few plain starches like bread and pasta (both prepared foods anyway) cut out as much added sugar as you can, and make sure to get adequate protein. Eating enough protein is especially important if you’re on a calorie-restricted diet and you’re trying to keep muscle.
With your calorie intake and macronutrient balance as described, you will lose muscle. You may lose fat at the same time, but you will be costing yourself some of whatever muscle you’ve got right now. The floor for the average man is 1800 calories. If you’re active, you’ll need more. 1000 is a starvation diet for a small woman who spends the entire day in bed. You would be much better off eating an adequate amount of good food.
As far as exercise goes, there’s a quote I’ve heard kicked around: “The best exercise is whatever you’re not doing.” Everyone has weak points. Finding and fixing these makes you fitter, and can have synergistic effects on other aspects of performance. I personally do CrossFit, which at its core is a little bit of everything. The goal is to turn out a supreme generalist. One day you might be doing heavy squats, the next calisthenics, another running a 5 k.
I’ve been doing CrossFit-style workouts for the last couple of years. It worked very well for me, even with limited time devoted to exercise. I only get to work out about 2–4 days a week, most of the workouts are done in less than an hour. I’m stronger and faster than anyone else I know who is anywhere close to my age, and can outperform people half my age. I am not, by any stretch of the imagination, an exceptional athlete. I give credit to the exercise methodology, including the large amount of variation. The variety in routines also helps keep me from getting bored, and the admonishment to address your weaknesses and challenge yourself keeps me from skipping stuff I don’t like.
You don’t start with the prescribed levels for Workout Of the Day, you scale it and work toward doing it as prescribed (or as they say it: as Rx’ed). I scale to about 90% of the prescribed weight most of the time, partly because I’m still lacking about 5–6 kg of muscle I’d need for moving the full load. I cut a set, or do a smaller amount of reps if I think I can’t handle the full amount. I take a look at what the desired stimulus is, try to guess at what I can do based on past workouts, and try to push myself to do just a little more each time.
The main page workouts are designed to challenge a fairly elite level of athlete if done balls-out at full intensity. I’m just above average for a CrossFitter. If I could work out 6 days a week consistently I might get into a more advanced bracket.