Sure is. Just depends how you go about it and how dedicated you are to getting it done. "Get er done."

Very achievable. Just watch your diet and, most importantly, get your butt moving every day. You can easily do it. :D

It would be more sustainable if you were to change our lifestyle for the longterm. Eating more healthily and a good regular exercise routine. I think they say a good aim to loose is around 2lb per week. If you're anything like me, anything to harsh will put you off at the start. Fad diets are good for shifting weight quickly, keeping it off though is the hard part, hence lifestyle changes being more sustainable.

Absolutely it is possible. You have to be committed to it though. I agree with HampshireHog, you might as well live like this from now on if you want to keep the weight off. And once you do start to see improvement, you will not want to stop, trust me. What I would recommend to you is first of all, start eating more often. This may go against conventional wisdom for losing weight, but it will speed up your metabolism and help you burn off your calories instead of storing them as fat. Eat 5-7 smaller meals a day. Each meal should consist of about 30-40 grams of lean protein (chicken breast, tuna, turkey, lean fish, egg whites) and about 30 grams of complex carbohydrates (brown rice, whole wheat bread, sweet potatoes, oatmeal).Start to lower your carbs as the day goes on so that by the last meal you are taking in just protein and no carbs. Take at least three servings of vegetables a day as well and one serving of fruit in the morning and one after your workout.Do away with sugary sodas and drink mostly just water, and plenty of it. You should also consider supplementing with whey protein powder, especially right after a workout to feed your muscles what they need to grow. As for workouts, it depends if you want to train with weights as well as do cardio. I would recommend weight training because building muscle requires calories which will help you burn fat, not to mention the calories burned during the workout itself. Also, you dont want to lose fat and just look like a scrawny guy, do you? You should workout 4 or 5 days a week for about an hour at a time. Pick two bodyparts per workout to focus on and do 3-4 exercises per bodypart for 3 sets of 10-15 reps each. Make sure to give each muscle group plenty of days to rest before working it out again. Be sure to stretch out and warm up before every workout. This is crucial to avoid injury. For cardio, timing is very important. The two best times to do cardio are right when you wake up and right after you lift weights. The reason being this is when your glycogen levels are lowest and you dont have any carbs to burn for fuel so your body will have to use fat reserves. Do cardio 3-4 times a week for 30-45 minute sessions each. Get at least 8 hours of sleep every night and refrain from drugs, alcohol, and tobacco. As you can see, this is not just a workout plan, but a whole new way of life. Adjusting to it will be hard at first, but take it slow and once you get going you will feel great about yourself. The first couple of weeks is when you will lose the most weight as your body changes. After that it will start to slow down, but stay focused and gradually increase the intensity. Seeing the results will be all the motivation you need to reach your goals.