If you are salt-sensitive, you may be retaining water just due to the sodium in your food. I find that eating even two slices of bacon will give me puffy feet for two days. I didn't used to be salt sensitive but it has gotten worse as I get older. I think you mentioned that you're in SoCal -- heat can also cause fluid retention -- mine is always worse in the summer months. However, if you do strenuous exercise you don't want to go too low on sodium, either. The only way to know is to track your food for a few days (the sodium content -- you can look it up on-line) and then cut back on the high-sodium foods if it's high and see what happens. A percentage of your 60-lbs. will definitely be retained fluid.
These are some of the worst culprits: pickles, cured meats (pepperoni, salami, bacon), salty cheeses like Feta, fast food (those delish McD fries!!!), commercially processed foods (e.g. things canned in brine, like sauerkraut or canned soups -- these are salt bombs!)
If you eat more fresh food (produce, meat, eggs, etc. prepared at home) and salt them lightly, you can cut your sodium intake back a great deal.
Broccoli (one cup) = 64 mg. sodium
One cup Panera broccoli cheddar soup = 1028 mg. sodium
1/2 cup serving of baked potato, no salt added = 3 mg. sodium
French fries (fast-food) = over 250 mg. sodium
Home cooking with fresh foods saves a HUGE amount of sodium from getting into your body and wreaking havoc with your fluid retention.