Realistic weight control?

I am 23, 255 lbs and 5'10". I drink one soda a day, eat two meals(which is usually balanced between carbs/meats and veggies) and a snack. I am fairly active...I can run up and down a bunch of steps without feeling like I am out of air, but I don't really look to portray myself as a 'jogger' or some crap like that. I consume fast food as sparingly as possible, some weeks I won't eat any but some weeks I will end up eating that **** twice, due to a hectic schedule. Now, assuming that I am not going to go into a true fitness montage here...what small changes can I make that can yield true results over a period of time? I've tried only drinking water, I've tried cutting out most meats...nothing works. I'm not all that upset about my appearance either, so I guess my first problem is lack of motivation. How unhealthy is someone at my height/weight?

Both of the below answers I have read were great, I wish I could have picked two for the best answer. I think that there are some changes here that are easy for me to make and stick to with some forethought. Thanks so much for the input.

well, your BMI (body mass index) is 36.6--a healthy bmi lies at about 24.5 so you may be overweight--assuming youre not a bodybuilder. i see that your biggest mistake, which sooo many people make, is that you are NOT eating enough! i stress this so much but its so important- you need to have a good breakfast with whole grains, protien, and hopefully a piece of fruit. then aim to eat a small (300 calorie) meal about every 3 hours, this will get your metabolism running high and give you tons of energy. not to mention burning fat. but it seems you are pretty busy to keep thinking about food that often so if youd carry almonds and other protein filled snacks in your vehicle or in your desk or wherever! as for the fitness, small changes you could make are parking your car further from wherever you need to go. it saves time trying to find that *perfect* spot anyway! and just don't think lazy, if youve got a message to tell someone at the office, instead of calling them or email, get up and go tell them yourself. small things like that add up big time. good luck friend.

You're best bet is to probably start tracking everything you consume. What kinds of veggies are you eating? Are the meats you are eating breaded? If you find that you are consuming alot of white foods,this will likely explain the problem. The main category of white foods consist of flour,sugar, and high carbs. These foods will inhibit your ability to lose weight. Start out the day with a glass of water to hydrate your body. Have a serving of fiber rich cereal. If you eat bread try to have whole grain. Eliminate the sugars and all of the bad carbs (white veggies included) because your body will burn those off before it will ever burn existing fat sources. You should also stop soda and fruit juices altogether. It is a complete waste of calories. Diet soda is also a bad alternative due to the aspartame. Only use skim milk with cereal. Have water,unsweetened tea and coffee totalling 64oz.per day. Try to eat 6 times a day (3 small meals and 3 snacks) to keep your body in calorie burning mode. Make sure to have 5 veggie servings and 2-3 fruit servings a day along with protein. A typical snack for me is a handful of grapes or 1/2 dozen strawberriews or celery with a tsp of peanut butter. 2 weeks on this self made plan and I am down 8 lbs.Good luck toyou :)