I have to admit that after I met up a friend from university and discovered how healthy he was I decided to get fitter/slimmer. I'm 46, 5'11" and weighed 176 pounds mid July. The lowest I registered recently was 158 pounds. I just did a lot more mileage on the bike. I can't say that I push myself cycling but get a few decent hills. I do a few exercises (pushups, situps) a couple of times a week (15-20 minutes).
My typical diet is as follows:
breakfast: bowl of muesli with skimmed milk
lunch: an apple or two
dinner: whatever my wife cooks - normally a healthy meal with a glass of orange juice
I allow myself a chocolate biscuit + a couple of sweets (candies) in the evening. I probably drink a little too much coffee but do try to drink low calorie juice (i.e. a squash that you mix down with water = 5 cals).
I normally cycle just after lunch. Workdays (I work from home) I do 12-15 miles. Weekends I try to do 20 + 40 mile rides. For the long rides I add glucose to the low calorie fruit juice and have a banana half way round.