After a busy morning, lunch can feel like just the pick-me-up you need — but sometimes the meal you thought would energize you is the very thing that makes you want to nap at your desk.
Feeling tired after lunch, or post meals in general, is known as postprandial somnolence — or, colloquially, the food coma.
Part of this phenomenon is due to basic physiology: When humans eat, most of our blood goes to the digestive organs to process the food, said Sandra Arévalo, director of community health and wellness at Montefiore Nyack Hospital in New York state.
The tendency to get tired after eating isn’t inherently suggestive of something amiss. But there can be additional factors that exacerbate this natural response, making getting through the rest of the workday or any activities feel like a slog. Here’s what to watch out for and how to make adjustments.
Heavy or sugary meals
When it comes to why you feel overly tired after eating, a common cause is consuming meals that are heavy in terms of quantity or quality.
Some people overeat instead of stopping when they feel comfortably satiated. Not eating breakfast can also lead to overindulging later in the day if excessive hunger makes controlling your appetite difficult, Arévalo said.
Sometimes, however, the makeup of certain foods can contribute to tiredness. Fats are the hardest nutrient to digest because their molecules are much larger than those of protein or carbs, said Julie Stefanski, a spokesperson for the Academy of Nutrition and Dietetics. If you had a meal high in fat — such as fried foods or pizza — that could make you feel tired. Meals high in added sugar or refined or highly processed carbohydrates can have the same effect.
The fiber in so-called whole foods slows the absorption of sugar into the body, which means they don’t cause blood sugar or insulin spikes and instead give you more stable, lasting energy, said Kristin Kirkpatrick, a registered dietitian at the Cleveland Clinic.
“A five-minute walk or something helps to improve circulation and alertness, as well,” Arévalo said.
Sleep regulates your hormones, including your digestive ones, according to Kirkpatrick. And if you’re sleep-deprived, your body’s likely to suppress the hormone called leptin that signals “I’m full and don’t need any more” or elevate ghrelin, the hormone that commands “feed me,” she explained. Being insufficiently rested can also negatively affect your decision-making skills, emotional regulation and a brain region that regulates food intake, making it harder to resist cravings for highly palatable foods.
Blood sugar issues
For some people, post-meal fatigue can signal something more serious.
“Statistics show right now that a lot of people in the US have diabetes or prediabetes and don’t know it,” Stefanski said. When someone can’t properly metabolize carbs and therefore has a high amount of insulin in the blood, that can diminish energy levels, she added.
If you regularly feel drowsy after eating even after making dietary adjustments, ask your doctor to administer the hemoglobin A1c test. The test measures average blood sugar levels and shows how much glucose is attached to hemoglobin in red blood cells, Stefanski said.
“If that’s high,” she said, “it shows that your body is struggling to metabolize food and metabolize carbohydrates.”