Triglycerides are the form in which fat is packaged and stored in the body. They are present in higher amounts in the bloodstream after a meal, when excess calories are being stored for later use. People with certain conditions may have persistently higher circulating levels of triglycerides. Elevated serum triglycerides can indicate increased risk for heart disease. When triglyceride blood level is checked, it is important to have no food or beverage intake for eight to 12 hours prior to the test. This assures the result is not a reflection of recent dietary carbohydrate or fat intake.
Step 1
Have a full balanced meal eight to 12 hours prior to the triglyceride blood test (the time frame depends on the lab's or your doctor's instructions). If the test is scheduled for 8 a.m., for example, the last meal should be completed by 8 p.m. for a 12-hour fast. Include a good source of protein, carbohydrate and fat in order to maintain a feeling of fullness well into the evening. A significant evening meal should also help prevent discomfort from hunger pangs early in the morning.
Step 2
Consume no food within eight to 12 hours of the triglyceride test time. Even a light snack may affect the test results. All types of food contribute calories and will be converted to triglycerides for storage after digestion and absorption. The American Association for Clinical Chemistry estimates the intake of food can raise triglyceride measurements five to 10 times higher than fasting levels.
Step 3
Consume no beverages within eight to 12 hours of the triglyceride test time. Milk, juice, soda and sweetened tea all are sources of carbohydrate from sugar and will be converted to triglycerides in the blood. Alcohol also affects triglyceride levels. Specific instructions from the individual laboratory will outline whether or not water or black coffee or tea is allowed. It is safest to take nothing by mouth prior to the test to prevent altering results.
Step 4
Consult with a personal physician or the testing laboratory regarding recommendations for prescription or over-the-counter medications to be taken during the fasting period. According to the National Institutes of Health, there are several categories of medications that can increase triglyceride measurements. Likewise, other medications can decrease triglyceride measurements, including seemingly benign supplements such as vitamin C and fish oils.
Tips and Warnings
- Drink plenty of fluid the day prior to the test to avoid feeling dehydrated the night after fasting. It is helpful to maintain a usual diet for several days prior to the test for the most consistently reliable results.
- Diabetics should check with a personal physician regarding changes in insulin instructions during an overnight fast.
