I have suddenly started to gain weight. All my life I had a stable weight. Why is that?
This is difficult to answer in a few lines. My first suspicion would be your life style and second would be you thyroid gland. In addition, if you take medications like the birth control pill or an antidepressant, they can also cause weight gain. Best advice is to see a doctor and get a complete check up. In the meantime, change your life style, eat healthy and walk regularly.
