I ate well (no dieting) and began exercising.
The details . . .
The main thing is I eat whenever I get hungry, but I also try to pay attention and stop when I'm not hungry (as opposed to eating until I'm totally stuffed).
I also try to eat protein with every meal, snack with healthy food between meals and stay away from fried food and fast food. An example of a 'normal' day would be:
Breakfast . . . Old fashion oats with protein powder mixed in (plus a little Agave to sweeten it)
if I get hungry before lunch, I eat a fruit like a banana
Lunch is something like a grilled chicken sandwich on a wheat bun with a side salad or cup of soup
Afternoon snack is a Greens+ chocolate protein bar
If I get hungry again before dinner I eat a fruit like an apple
Dinner is some kind of meat (usually beef or chicken), vegetables and brown rice
Exercise . . . I just started walking the dog in the morning until one day, without expecting to do it, I felt like I had a lot of energy and began to jog. I increased the distances on the jogging as they became easier. I also went back to bjj a couple of times per week and have begun throwing in some body weight workouts.
Nothing magic and nothing difficult, really. If I had to say which factor played the biggest part, I'd say it was consistency.