At 4 years out, you should absolutely be eating more than 1000 calories a day especially with exercise. Are you at goal? Are you still trying to lose?

Not sure where you got the 140 pounds... The BMI chart says "normal" (not overweight) for a woman 5'7" is between 120 and 160 (140 is average). BMI does not take into account body fat %. If your body fat is 25% or less, your actual weight is pretty irrelevant. that should be your goal, not a hard number (weight is useful because easier to measure).

I am 5'5%, 135 lbs and 22% body fat. People guess my weight at 120-125 because muscle is more compact. I wear a smaller size than a friend of mine who is 5'5" 130 lbs - because her body fat % is higher than mine.

Long term dieting at a very low calorie count basically "trains" your body to learn how to exist on fewer calories, so that when you start eating a little more, you gain weight when you otherwise would not have. For example, if your body normally needs 1200 calories just to survive a coma (i.e. BMR), and you spent a year or two eating only 900 calories (and not laying in a coma), your body would respond by figuring out how to survive - by getting rid of muscle, because it requires more calories than fat to maintain, and by making you more tired, so you move less (and expend fewer calories. Then when you finally start eating 1200 calories again - instead of maintaining your weight or even losing weight (assuming you are actually not in a coma), those calories are seen as "excess" and not required because you taught it to exist on 900. So it stores them as fat. This happens all the time in people who "yo-yo" diet, even without WLS. They diet by restricting too far for too long, lose precious muscle which lowers their BMR so that when they start eating normal (what they could eat before and maintain their weight without gaining) again they gain . Each time they yo-yo, the calories needed to gain weight gets smaller and smaller because they keep losing more and more muscle.

Focus on fitness for awhile. If you dont already, start some kind of weight-bearing muscle exercise (lifting weights, or bodyweight exercises). Do it often, whole body, and consistently. Then eat to support your body - gradually INCREASE your calories while increasing your activity (beyond the weight bearing, walk a little more, fidget, be more active and cut back on sitting on the couch watching tv - move your body).

You can lose the exact same amount of weight by burning 2000 calories a day and eating "only 1500" as you would sitting on your *kitten* all day and burning only 1400 calories and only eating 900. But eating more is so much better - your hair and nails will be stronger and shinier, you will have more energy (calories are a measure of energy - food=calories=energy), your mood will be better, your body shape will be better. You really dont want to lose "weight", you want to lose "fat"... muscle gives your body its shape - your butt is a muscle, without working it you will end up with a flat and unattractive butt despite hitting your goal weight. Your shoulders , arms and legs will be almost skeletal but that layer of fat around your middle hips and waist will stubbornly stick around. Muscle reshapes your body.

Do some research and ask some questions! but cutting calories is not the answer. Eat enough to survive, and move more. Gradually increase both together over time. If you gain weight right now on 1400 calories a day, that is sad and unnecessary. Start by eating 1200 and work on increasing your activity until you are slowing losing weight (over a few weeks). Then increase to 1300 and move slightly more - not running marathons here, just getting off your butt during the day as much as possible. Aim to not sit for more than a few minutes or something. Get a fitbit and focus on increasing step counts a little more each week. After a few weeks of 1300 and still losing slowly, increase again. Keep it up and I promise, eventually you will be able to eat 1700-1800 and still slowly lose weight, and you will be much, much happier. It will take awhile to reassure your body that the food will keep coming, so take it slow.

Look for a group on here called "Eat more to weigh less" - they are not based around WLS, and we are different than most people, but after 4 years you should really be close to a "normal" person. So read it thoroughly and apply it to your own body adjusting for your situation. I am 44 yrs old, 5'5", 135 pounds and 22% body fat. I wear a 6/8. I average 1800-2000 calories a day and maintain my weight just fine. I am also 4 years out of VSG (june 2011).

Look into convict conditioning or "you are your own gym" . I believe both are free, and use total body and are progressive (which you want). Take your time and work into it. No need for a gym or even equipment for awhile. Those both use just your body weight. Another would be the "primal blueprint" workout - he has a whole site about eating but if you keep looking you will find his instructions for 4 core exercises - pushups, pullups, squats and planks. Those 4 work every major muscle in your body. He has instructions for progressing on those - i.e. for pushups, you start standing against a wall and gradually work your way down to the floor as you get stronger. So you can really start anywhere with all 4 of them.

Definitely work on the eating and calories though - they are most important for weight loss, but also most important for energy and health. Dont cut too far for too long. You need a plan that is something you can keep up for life. You dont want to have to eat 1000 calories forever, but if you do it long enough, you will almost have to to avoid weight gain. Its just not necessary - but you have to work at it.