Most of the weight you lost was lymphatic fluid that enveloped toxins and waste products. The puffiness of the face stretched the skin. The main lymphatic duct responsible for draining the left part of the head and face and about 90 percent of the body's metabolic waste products and turned-over cells, is called "thoracic duct". The right side of the head and face, shoulder and arm are drained by the right lymphatic duct, a much smaller duct. If the thoracic duct is more congested than the right lymphatic duct, which is likely given that the thoracic duct deals with the entire digestive and reproductive system, once you remove the congestion, you are more likely to see the effects of poor circulation, nourishment and waste drainage from the skin in terms of scar formation, such as wrinkles. The sun has little to do with that. It is the internal acidity level of tissues that determines the condition of the skin.