My recent triglycerides were at 450! how long can this number take to change with diet and exercise? Is it fat that takes long to work out of blood?

HaveSeen ↓↓↓ 1 month. Triglycerides within the lipoprotein particles are the way our body moves fat molecules around in the water outside cells. What make Trig levels still be elevated when fasting for 12 hrs or longer? Largely 2 issues: A high carb/low fat diet &/or increase body fat stores which are not being burned (no ketosis, little movement/exercise), along with relatively rare major genetic variations.
Depends. Some of those numbers relate to your genes and some relate to your lifestyle. If you are overweight and your lifestyle is sedentary the changes will occur slowly. You need patience and motivation, this two will help you for sure. Also some medications are available to help you lower the triglicerides levels.
Fairly quickly. If you are compliant with weight reduction diet and exercise. Eat 3 meals/d and avoid snacks. Avoid alcohol, particularly inbetween meals. If you're overweight and Insulin resistant, high tg is one of the first signs of diabetes in the near future. Decrease fatty and junk food. Make sure the rest of your lipid panel is ok> sometimes medication is needed for tg or glucose control.