Triglycerides, the major form of fat in the body and in food, perform important functions required for health, but an excess of fat in the blood contributes to heart disease, obesity and other health problems. Triglycerides such as those stored in the body and those found in saturated fat, butter, whole milk and dairy products, meat, poultry and some fish provide 9 calories of energy per gram.
According to the USDA Dietary Guidelines for Americans, a healthy diet includes 20 percent to 35 percent fat, with no more than 10 percent of calories coming from saturated fat.
Identification
The body both consumes and stores fat in the form of a triglyceride, a molecule of glycerol with three fatty acids attached. To determine triglyceride levels in the blood, a doctor orders a fasting lipid blood profile test, which requires a blood draw rather than a finger prick.
Function
Fat, in the form of triglycerides, provides energy for work and play. It insulates the body to keep warm and cushions vital organs against shock and damage. Fat also helps the body use protein and carbohydrate more effectively. Triglycerides in foods help transport fat-soluble vitamins A, D, E and K and essential fatty acids. Using fat to provide energy during metabolism helps reserve protein for other important uses.
Testing
Healthy adults should have triglyceride testing done once every five years to evaluate heart disease risk. People with identified risk factors or ongoing high triglyceride treatment should test more frequently. To treat above normal triglyceride levels, the doctor may order a dietitian referral for help in bringing triglyceride levels into a normal range.
Categories
Four categories describe the concentration of triglycerides in a blood sample. According to the American Heart Association, a triglyceride level categorized as normal is less than 150mg of triglyceride per deciliter of blood. A borderline high level is 150mg to 199mg per deciliter. A high triglyceride level is 200mg to 499mg, and a very high triglyceride level is 500mg or more per deciliter of blood.
Significance
Normal triglyceride levels promote health by ensuring the availability of energy and delivering certain vitamins to the cells, but high triglyceride levels contribute to heart disease and chronic health problems. Often, people with high triglycerides have no symptoms, so adults should routinely have triglycerides tested.
Considerations
To achieve normal triglyceride levels, eat a heart healthy diet, exercise and avoid tobacco smoke. People with high triglycerides tend to also have high total cholesterol with high LDL, or bad cholesterol levels, and low HDL, or good cholesterol levels. High triglycerides often relate to modifiable factors such as obesity, sedentary lifestyle, alcohol consumption or a diet with more than 60 percent of calories coming from carbohydrates or underlying genetic disorders.
Uncontrolled diabetes may cause high triglycerides, as may certain prescription drugs known as protease inhibitors, beta blockers, estrogens and beta blockers. The addition of medication may help achieve normal triglyceride levels if diet and physical activity alone do not.
References
- USDA: Dietary Guidelines for Americans
- American Heart Association: What Your Cholesterol Levels Mean
- "Understanding Nutrition (Ninth Edition)"; Eleanor Noss Whitney and Sharon Rady Rolfes; 2002.
- Lab Tests Online: Triglyceride Tests
