Well bicycling is an endurance sort of thing. Bicycling burns between 30-55 calories per mile (depending on your weight, speed and number of hills). Most of the calories expended will be carbohydrate or fat.

You need about 500 calories of carbohydrate to fuel your nervous system each day. Your body can store between 2,000-2500 calories of carbohydrate. Since this is what gives you your performance in cycling, it feels best to be sure that your carbohydrate stores are "topped off". And pretty near everything I have read has said that complex carbohydrates are best - bread, vegetables, fruits, pasta, rice, potatos, etc.

You want to keep your fat fairly low. Your protein requirements might go up a tad but not much. Any excess protein you eat will merely be converted into carbohydrates anyway (or fat if you eat way too much).

I have found that I can lose weight pretty quickly by doing a bunch of miles and keeping my carbohydrate stores "topped off". But that only works when I have the time to do a bunch of miles.

I also don't fool around with the fancy supplements. I have a lot of background in physiology, biochemistry etc etc and I don't find the case for them very persuasive.

For example a power bar = a snickers bar + half a glass of milk

Better yet eat a banana - sugars, complex carbs, vitamins, electrolytes and a biodegradeable package.