If the liver has to do some of the kidneys work, it can't do it's own job efficiently. As a result, it metabolizes less fat, more fat remains stored in the body, and weight loss stops. Drinking enough water is the best treatment for fluid retention. When the body does not get adequate water, it perceives this as a threat to survival and begins to hold on to every drop. This shows up as swollen feet, hands and legs.
Diuretics offer a temporary solution at best.
They force out stored water along with essential nutrients. Again, the body perceives this as a threat and will rapidly replace lost water. Thus, the condition quickly returns. The best way to overcome the problem of water retention is to give the body what it needs - plenty of water. Only then will the excess stored water be released.