Is a consequence of any operation the body releases cortisol which as the effective retaining body fluid.. It was liposuction is "leaky". As time passes the body will dispel this water. This may take several weeks.
Swelling and fluid retention always happens after liposucton and a weigh gain of 10 pounds is not unusual However, swelling of one leg is an symptom that you need to tell your doctor about - you should call your surgeon.
You should be seen by your plastic surgeon to be sure you do not have blood clots in your legs.
The smoking and inactivity increase your risk. One sided swelling is cause for concern.
Please stop smoking, become more active and contact your surgeon promptly.
This does not mean you have a complication - people can gain a lot of weight after liposuction.
But you need care after surgery that cannot be provided long-distance. With best wishes.
Ignore all of those weight issues and swelling issues after surgery and anesthesia! These take time to resolve! The one concerning issue you wrote is one sided swelling of legs. Check with your plastic surgeon regarding that ASAP! This could be from surgery however could also be a more serious issue. Best Wishes!!