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ATLANTA — 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 sleep at your desk .
“As a registered dietitian, I’ve heard people say that often over the course of my career, so I think it’s pretty common for people to get that response,” says Julie Stefanski, a spokeswoman for the Academy of Nutrition and Dietetics.
Feeling tired after lunch, or after meals in general, is known as postprandial somnolence – or colloquially, 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 and national spokeswoman for the Academy of Nutrition and Dietetics.
After a person eats, the body may produce more serotonin, a neurotransmitter that regulates sleep and mood — especially if the food was high in the essential amino acid tryptophan, which is found in proteins such as chicken, cheese and fish, according to the Cleveland Clinic.
The tendency to feel tired after eating does not in itself indicate anything wrong. But you might think of it as a problem because of cultural norms, especially in the United States, that “fight our natural processes” by mandating productivity instead of rest when the body needs it, Stefanski said. “I always think of Spain and people who have told me when they visited places where they take a siesta,” she added.
But there can be additional factors that exacerbate this natural response, making it feel like a chore to get through the rest of the workday or other activities. Here’s what to look out for and how to make adjustments.
Heavy or sugary meals
When it comes to why you feel too tired after eating, a common reason is consuming meals that are heavy in terms of quantity or quality.
Some people overeat instead of stopping when they feel comfortably full, especially if they are distracted by multitasking. Skipping breakfast can also lead to overconsumption later in the day if excessive hunger makes it difficult to control your appetite, Arévalo said.
“Someone who feels very tired after a meal might consider slowing down their eating and cutting back on their portions a bit to the point that they don’t overeat,” Stefanski said. “Because no matter what you eat—whether it’s carbohydrates, fat, protein—if you eat much more than what your body is designed to handle, your body will take a long time to digest that food.”
If you can’t always step away from whatever you’re doing to be present with your meal, taking just five minutes to do so can help, experts said.
However, sometimes the composition of certain foods can contribute to fatigue. Fats are the most difficult nutrient to digest because their molecules are much larger than proteins or carbohydrates, Stefanski and Arévalo said. If you ate a meal high in fat – such as fried food or pizza – it could make you feel tired. Meals high in added sugar or refined or highly processed carbohydrates can have the same effect because of how the body metabolizes these items compared to sugar or carbohydrates in natural or minimally processed foods.
The fiber in so-called whole foods slows down the absorption of sugar in the body, meaning 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.
If your lunch consists mostly of carbohydrates and then dessert on top of that, your blood sugar and insulin levels can rise quickly.
Then, “a lot of times your blood sugar drops below where you originally started,” Kirkpatrick said. “It can really be an energy zapper.”
Like high-sugar foods, sugary drinks can also make you feel tired when the crash hits, Stefanski said. Plus, alcohol is a sedative, so if you often have alcoholic beverages at lunch, abstinence is one of the first places to start, she added.
Choosing more balanced meals and snacks can help you feel less tired after eating, experts said. It could look like a bean-based soup and a salad with an olive oil-balsamic vinegar dressing; lean proteins such as salmon, white chicken or beans; and other toppings that aren’t high in sugar, Kirkpatrick said. A whole grain wrap with white turkey meat, cheese and vegetables is another option. And if you’re in a pinch, try getting an apple with nut butter instead of grabbing a candy bar. Packing your own food can help you avoid grazing on vending machine snacks, fast food or free office donuts.
“A five-minute walk or something also helps improve circulation and alertness,” Arévalo said.
Bad sleep
Sleep regulates your hormones, including your digestive hormones, according to Kirkpatrick. And if you’re sleep-deprived, your body is likely to suppress the hormone leptin that signals “I’m full and don’t need more” or raise 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.
You can improve your sleep by making sure you sleep for seven to nine hours a night in an environment that is cool, dark and quiet. Avoid drinking caffeine at least six hours before your usual bedtime or drinking alcohol before bed. Having a relaxing routine and reserving your bedroom only for sleep and sex can also help.
Problems with blood sugar
For some people, post-meal fatigue may signal something more serious.
“Statistics show right now that many people in the United States have diabetes or prediabetes and don’t know it,” Stefanski said. When someone can’t metabolize carbohydrates properly and therefore has a high amount of insulin in the blood, it can decrease energy levels, she added.
If you regularly feel drowsy after eating, even after making dietary adjustments, ask your doctor to do 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 it’s high,” she said, “it shows that your body is struggling to metabolize food and metabolize carbohydrates.”