I live alone and I cook about 5 or 6 times a week. The other 1 or 2 I go to a restaurant (Real one, not fast food) with friends. I spend almost no time on cooking as most of the time I cook the ultimate 'fast food' using a wok.
I bought a Wok cookbook at a second hand store and started cooking. Takes about 10-15 minutes to prepare my dinner (including prep time) and I use fresh vegetables and meat.
For work I prepare salads withe iceberg salad and make 5 of them on the Sunday. The iceberg salad is so it stays fresh. For those 5 I take about 20 minutes to one hour, depending on my mood.
So that is not even 2 hours per week I spend cooking.
The most important part of all this is planning. I started by writing down what I would eat for the whole week and bought accordingly. I now have enough experience that my shopping-list looks like:
2 crops iceberg
5 x for salad (e.g. for 5 days, smoked salmon, shrimps, tuna, mozzarella,
1 chicken filet (Good for 2 or 3 days wok)
1 x fish
1 x veal
1 x pork
1 x bag mixed vegetables for wok
2 x different vegetables
Then if needed different sorts of rice, different sorts of noodles, soya sauce, garlic, coriander, pipe onion, eggs.
I only need to do groceries once per week, so no time loss there either.
To me cooking each day is better then re-heating food. the sole thing that helped me do this was the planning part. Writing down what I was going to eat the coming week. That and buying a book about cooking with a wok and the looking for combinations that would taste good AND are fast to do.