The various causes and types of low blood pressure are mostly unrelated to diet and therefore won't respond to food. However, postprandial hypotension is blood pressure that drops lower than normal after a meal and is more common in older adults. Symptoms include feeling lightheaded, dizzy, weak and/or sleepy after eating. With a few minor dietary changes, you may be able to keep your blood pressure up after you eat if you have this type of hypotension.
Low Blood Pressure and Eating
Under normal circumstances, your body diverts extra blood to your digestive system to help with the complicated job of breaking down food. To keep blood pressure normal during this process, your blood vessels narrow and your heart works harder to pump blood throughout your body. This goes smoothly for most people. However, an older person's body doesn't manage blood pressure changes as well as younger person's, which increases susceptibility to a post-meal blood pressure drop.
Eat Fewer High-Glycemic Carbohydrates
Your body digests high-glycemic carbohydrates quickly because they're made up of sugars with a simple structure. The simpler the structure, the faster your body absorbs them. Unfortunately, the rapid transit from your stomach to your small intestine contributes to a post-meal drop in blood pressure, according to the Harvard Health Publications. Examples of rapidly digesting carbs include white potatoes, white bread, white rice and other foods that are sugary or made with refined white flour. Cut back on these foods and replace them with slower-digesting foods like protein, whole grains, beans and other legumes.
Eat Smaller Meals
If you're used to having three large meals throughout the day, switching to smaller, more frequent meals may help keep your blood pressure from dipping below normal. Smaller meals put less stress on your digestive system because your body doesn't have to work as hard or reroute as much extra blood to your stomach and intestines. Try having six or even seven smaller meals spaced throughout the day, recommends Harvard Health.
Fluid balance plays a key role in keeping your blood pressure stable, and dehydration can cause your blood pressure to dip. It's crucial to keep hydrated by drinking plenty of water throughout the day. In addition, drinking 12 to 18 ounces of water about 15 minutes before meals can help prevent your blood pressure from plummeting, according to Harvard Health. It may also help to take it easy for about an hour after eating. The drop in blood pressure typically occurs 30 to 60 minutes post meal. Harvard Health recommends sitting or lying during this time if possible.
A Note on Sodium
Have your doctor evaluate your sodium intake. Your body only needs a small amount of sodium -- about 180 to 500 milligrams per day, according to the Centers for Disease Control and Prevention -- to function properly. This amount is easily found naturally in everyday foods. Ask your doctor whether increasing your salt intake will help keep your blood pressure stable.