Today, tomorrow, learn English naturally. 天天自然学英语
Tired after eating? Here’s why, and how to fix it
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.
“As a registered dietitian (nutritionist), I’ve heard people say that often over my career, so I think it’s fairly common for people to have that response,” said Julie Stefanski, a spokesperson for the Academy of Nutrition and Dietetics.
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 and national spokesperson for the Academy of Nutrition and Dietetics.
After a person eats, the body might 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 get tired after eating isn’t inherently suggestive of something amiss. However, you might think of it as a problem due to cultural norms, particularly in the United States, that “fight against our natural processes” by mandating productivity instead of rest when the body needs it, Stefanski said. “I always think about Spain and people that have told me when they visited places where they do take a siesta,” she added.
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, especially if they’re distracted by multitasking. Not eating breakfast can also lead to overindulging later in the day if excessive hunger makes controlling your appetite difficult, Arévalo said.
“Someone that feels very tired after a meal might consider looking at slowing down their eating and cutting back on their portions a little bit to the point that they’re not overeating,” Stefanski said. “Because no matter what you eat — whether it’s carbs, fat, protein — if you eat a lot more than what your body is designed to handle, your body’s going to spend a long time digesting that food.”
If you can’t always step away from whatever you’re doing to be present with your meal, taking even just five minutes to do so can help, experts 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, Stefanski and Arévalo said. 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 because of how the body metabolizes these items versus sugar or carbs in natural or minimally processed foods.
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.
If your lunch mostly consists of carbs and then dessert on top of that, your blood sugar and insulin levels can rapidly increase.
Then, “a lot of times your blood sugar drops below where you originally started from,” Kirkpatrick said. “That can really be an energy zapper.”
Just like high-sugar foods, sugary drinks can also make you feel tired once the crash hits, Stefanski said. Additionally, alcohol is a sedative, so if you’re commonly having alcoholic beverages with lunch, abstaining 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. That could look like a bean-based soup and a salad with an olive oil-balsamic vinegar dressing; lean proteins such as salmon, white chicken meat 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 having an apple with nut butter instead of grabbing a candy bar. Packing your own food can help you refrain from grazing on vending machine snacks, fast food or free office doughnuts.
“A five-minute walk or something helps to improve circulation and alertness, as well,” Arévalo said.
Poor sleep
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.
You can improve your sleep by making sure you sleep for seven to nine hours per night in an environment that’s cool, dark and quiet. Avoid drinking caffeine at least six hours before your usual bedtime or drinking alcohol before bed. Having a wind-down routine and reserving your bedroom for sleep and sex only can also help.
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.”
注释：
dietitian: n
表示" 饮食学家；营养学家"，means "a specialist in the study of nutrition"，如：became a dietitian not because I'm enamored of nutrients but because I love food.我成为饮食专家不是因为我对营养物质感兴趣而是因为我喜欢食物。
Dietetics: n
表示"营养学"，means "the scientific study of food preparation and intake"，如：I heard that she was majoring in dietetics. 我听说她是学营养学的。
postprandial：adj
表示"餐后的"，means "following a meal (especially dinner);"，如：His postprandial nap was disturbed by the arrival of the boss. 老板一到打断了他餐后打盹。
somnolence: n
表示" 嗜睡"，means "a very sleepy state"，如：Somnolence was the most common side effect, but the drug was generally well tolerated.主要的副作用是嗜睡，但在这个药物整体上是可以被接受的。
colloquially: adv
表示" 口语地；俗语地"，means "with the use of colloquial expressions"，如：Limestone is colloquially called cyan stone. 石灰岩的俗称是青石。
physiology: n
表示" 生理学；生理机能"，means "the branch of the biological sciences dealing with the functioning of organisms"，如：She knows physiology from beginning to end.她对生理学这门学科了如指掌。
serotonin: n
表示"血清素"，如：Once in the brain, the tryptophan is converted to serotonin.一旦进入大脑，色氨酸会被转化成血清素。
tryptophan: n
表示" [化]色氨酸"，means "an amino acid that occurs in proteins; is essential for growth and normal metabolism; a precursor of niacin"，如：She rates dozens of foods for their levels of tryptophan. 她对数十种食物的色氨酸水平进行了估计。
amiss: adj
表示"有毛病的；出差错的"，means "not functioning properly;"，如：Something is amiss when a boy does not eat for days. 一个孩子几天不吃东西一定是有什么毛病了。
siesta: n
表示" 午睡"，means "a nap in the early afternoon (especially in hot countries)"，如：I went upstairs for my afternoon siesta. 我上楼去睡午觉。
slog: n
表示 苦工；长途跋涉""，如：It was a long slog to the top of the mountain.到山顶的路漫长而艰难。
satiated：adj
表示"充分满足的；对 ... 厌倦的"，means "supplied (especially fed) to satisfactio"，如：He was satiated with pleasure. 他厌倦了享乐。
metabolize: v
表示" (使)产生代谢变化"，如：Our bodies constantly metabolize the food we eat. 我们吃的食物在体内不停分解产生代谢变化。
insulin: n
表示" 胰岛素"，means "hormone secreted by the isles of Langerhans in the pancreas; regulates storage of glycogen in the liver and accelerates oxidation of sugar in cells"，如：They were all dependent on supplemental insulin. 他们都依赖于外源胰岛素。
sedative: n; adj
1. n表示" 镇静剂"，如：The doctor gave him a sedative to help him sleep.医生给了他镇静剂帮助他入睡。
2. adj表示" 使安静的；使镇静的"，如：The doctor gave her a sedative medicine and she then slept for eight hours.医生给她一种镇静药后她睡了八小时。
leptin: n
表示"【生化】瘦素，瘦蛋白"，如：revious studies looking at the ability of leptin to reduce hunger in human volunteers has proved disappointing.此前，瘦素对志愿者饥饿欲望降低作用研究的试验结果令人失望。
palatable: adj
表示"美味的；使人愉快的；遂心如意的"，如：Mother provides palatable meals for our family every day.母亲每天为家人烹制美味的三餐。
hemoglobin: n
表示" 血红蛋白"，hemo前缀解释为血；globin解释为球蛋白，如：Your hemoglobin should be checked.你的血红蛋白需要检查一下。
中文简要说明：
忙完一个上午的工作，许多人喜欢来一客美味的午餐犒赏自己或转换心情，以迎接下午的挑战，但不少人却在饱餐一顿后，反而感到昏昏欲睡，失去专注力，这样的现象在医学上称为「餐后嗜睡」（postprandial somnolence），或食物昏迷（food coma），多半是因为吃太饱、吃错食物、睡眠不足所造成，但也有可能是身体出状况的警讯，
根据美国有线电视新闻网（CNN）报导，人体在进食后会产生血清素，这是一种帮助稳定情绪、促进睡眠的脑激素，摄取高蛋白质食物特别容易促进血清素分泌，因此改变饮食内容是避免饭后嗜睡的第一步。
◆以原型、低升糖食物为主
美国营养及糖尿病学院（Academy of Nutrition and Dietetics, AND）指出，脂肪的分子比蛋白质或碳水化合物大上许多，是最难消化的营养成分，应该避免在午餐时间吃太多；此外，添加糖（added sugar）或精致碳水化合物，像是白面包、加糖的玉米片、白饭等，因为会快速升高血糖，也容易让人产生疲倦感。
因此，选择均衡的饮食或点心变得相当重要。美国克里夫兰诊所（Cleveland Clinic）营养师克里斯汀．柯尔帕特里克（Kristin Kirkpatrick）建议，应该以天然或加工有限的「原型食物」（whole foods）为主，其中的纤维质能减缓人体吸收糖分的速度，像是豆类、蔬菜、水果、鲑鱼和鸡肉，搭配橄榄油或坚果抹酱，能提供更稳定、持久的能量。
◆拥有充足的睡眠
睡眠可以调节人体激素，包括消化系统激素。一个人若是睡眠不足，身体可能会抑制瘦体素的分泌，或升高饥饿素，向大脑发出「喂我」的指令。缺乏充分休息也会对决策力、情绪控制和调节食物摄取的大脑区域产生负面影响，让人更难抵抗对美食的渴望。
◆恐为糖尿病前兆
AND表示，美国有很多人罹患糖尿病、或前期糖尿病而不自知，如果调整饮食内容后，还是经常感到饭后昏昏欲睡，可以请医生测量你的糖化血色素，若是血糖偏高，代表身体代谢机能出现问题，导致血液中的胰岛素含量过高，需配合医生指示进行饮食控制和药物治疗。
留言微信公众号《自然学英语LearnNaturally》，可咨询更多！