Mild tachycardia, or elevated heart rate, in a healthy person can be a routine physiological response. The term for tachycardia that occurs after eating is postprandial tachycardia.
Postprandial tachycardia is known to occur in humans, where the increase has been measured through the intestinal blood flow, which is driven by the increased heart rate. Blood flow to the intestines after eating a meal generally maximizes about 30 minutes after eating (to meet the demands of the digestion process), when the blood flow to the intestines is approximately 130 percent of the fasting rate.
Increased heart rate is generally triggered by the neurotransmitters acetylcholine and norepinephrine, which are released in response to physical or mental stress, such as exercise, fear or the anticipation of impending activity or stress. The normal tachycardia that is precipitated by eating is not triggered by either of these chemicals, and the exact triggering mechanism remains poorly understood.
The duration of the elevation in the heart rate varies, so if you want to measure your heart rate at rest, wait at least two hours after eating. If the reaction lasts longer than two hours or your heart feels as though it is pounding or throbbing in your chest, consult a doctor. This may be a sign of poor digestion, food allergies or heart or lung problems. In the physiologic postprandial tachycardia, most people don't notice the elevated pulse.
Certain food and drink items may cause or enhance postprandial tachycardia. These include caffeinated soft drinks, coffee, tea, and high-sugar or carbohydrate-laden foods. Some people have a noticeable response to salty foods or items containing monosodium glutamate. People with poor digestion, acid reflux and hernias are more likely to experience a racing heart after eating.
A practical thing to do is keeping a dietary diary of your diet and heart rate. Record your resting heart rate each morning before you get out of bed, and then take your pulse again before and after each meal. Note what you had for the meal and any other factors that might influence your heart rate, including exercise and stress. Discuss any other symptoms you have with your doctor, such as dizziness, breathlessness or heartburn.