Once you get past the broad-brush facts of weight reduction, like burn more calories than you take in, you get into the details, and as has been said before, the devil is in the details.
Calories: there is a difference in the fat that excess calories will make you gain depending on the food that the calories come from, for instance, 300 calories from fried eggs and bacon and/or sausauge will put/keep less fat on you than would 300 calories from milk and cereal.
Timing: This also has a great deal to do with how much weight you keep/lose, for instance, if you eat a slice of pie or cake at 6:00 am and then have a normal day, the pie or cake will impact you less than if you have it at 6:00 pm.
Water retention: People say, "Oh, its only water", but a pound of water will show up as a pound on the scales the same as if you ate a pound of anything else, so avoid excesses of foods that cause water retention, especially late in the day (see Timing)
Exercise: An exercycyle, with both upper and lower body workout potential is a good start, but the most important thing is BE FAITHFUL to the program, like, if you start looking for excuses to not exercise you are dead meat on a stick, for what it boils down to is the first thing you have to get if you are going to lose weight and be healthier is some will power, and let me tell you, IT AIN'T FOR SALE ! !
A good starting practice would be to adjust your schedule to do 5 minutes of exercise before each meal, and after a week, you will find that you are able to increase your time a little, up to, maybe a half hour before each meal, and do NOT look for excuses to skip, instead, if you have a schedule conflict, do your exercises in advance that you are likely to miss, and while it might not have the same health benefits as doing them at the proper time, it WILL strengthen your inner discipline, which is a very important aspect of a successful program.
Visualize an upside down triangle, flat on top and pointy on the bottom, and let this represent the size of your meals for the day: Big, wide heavy meal at breakfast, smaller at lunch, and least of all at supper (dinner), and NOTHING AT ALL after 6:00 pm.
Can you do it ? ?
Sure you can, 'cause I did, and I am the world's biggest wimp, but I made up my mind that I was tired of being fat and wheezing after a little effort, and on top of that, I didn't want to die early, and at 72 I am in better shape than when I was 40.
A good idea is to keep grapes or other such food for when you get the munchies.
Put your exercycle where you can look out a window, if you have a view, and that will help.
Good luck -- you can do it, but it will not be easy, but it will be worth it.