Our liver produces cholesterol, but it also takes in cholesterol from food. Eating too many high-fat foods can raise your cholesterol levels. Obesity and inactivity also cause high cholesterol levels. If you are overweight, you probably have a higher triglyceride level. If you never exercise and are generally inactive, it can lower your HDL (good cholesterol). Your family history also affects your cholesterol levels. Research has shown that families with high cholesterol tend to run through the family. The family member who has it, you can have it too. Smoking also causes high cholesterol.