Having a job that forces you to sit in a cubicle or office all day presents some interesting challenges if you're trying to lose or even maintain your weight. The same basic rules that apply to everyone else will help you lose weight. You need to eat less calories than you burn and if you're sitting down all day, you'll have to be even more careful about what foods your diet is made up of.
Start by estimating how many calories your body burns per day by using the Calorie Calculator. This tool will help you get started with a strategy to either lose or maintain your weight. Keep in mind that since you don't move around for a big chunk of the day, this calculator will probably overestimate the amount of calories you burn. Once you get a starting estimate, make it your goal to take in less calories than you burn. This will cause weight loss.
Again, since you are inactive for most of the day, exercise is even more important to you. Once you get home, as tired as you may be, you need to find time to go running, walking, weightlifting or take part in any other form of exercise you enjoy. If you aren't accustomed to this sort of activity, start off slow.
Start exercising 2 times per week and move it up to 3, 4 and then 5 times each week after that. You can also start with smaller and easier sessions. For example if you choose running, don't start going 5 miles your first week. Begin at a 1/2 mile then move up slowly. These small steps will allow you to better adjust to the changes you make and increase the likelihood that you'll stick to them. If you're more of a morning person, consider going to the gym before work. You can also try going during your lunch break if your schedule allows it.
The types of food you eat can also help you lose weight. Stay away from junk food that is high in sugar (doughnuts, honey buns, soda, coffee with excessive amounts of sugar). These calories are digested quickly and in a situation such as sitting down all day, aren't needed by your body. Calories that aren't burned up right away will be stored as fat leading to weight gain. Eat foods that are high in complex carbs (whole wheat, fruits, vegetables, oats) since they are digested a lot slower.
You should also eat smaller more frequent meals as this will help your body utilize the energy more efficiently. Don't forget to eat breakfast, even if you don't have enough time. It can be something small and easy but you have to eat something first thing in the morning. Also try packing your own lunch instead of going out and getting hamburgers, tacos or pizzas. Sandwiches, salads, tuna, pasta, rice and chicken are all great ways to cut back on calories.
The Bottom Line
Losing weight isn't impossible even if you do have to sit in front of a computer all day long. These situations require more careful planning than active jobs, but with small steps, you will see a difference.