Low sr urea levels are not indicative of any disease.
Its wonderful that you don't smoke or drink alcohol. There's no need to be concerned regarding your urea levels.
Measurement of
triglycerides alone are not indicative of fat loss and will be increased in various diets containing nuts or like keto diets.
Dieting causes muscle breakdown and will not help you increase your lean body mass.
Instead lose weight in a healthy way by diet control.
Next Steps
Consult a doctor if you have any other symptoms. i myself am available here on practo.