科学拯救吃货：你为什么总是饿？

These 11 things will help explain why your belly's been growling.

这11个原因帮你解释为什么你的肚子一直在咕咕叫。

You're dehydrated

身体缺水了

"Mild dehydration is often masked as feelings of hunger, when really your body just needs fluids," says Alissa Rumsey, RD, spokesperson for the American Academy of Nutrition and Dietetics. The confusion happens in the hypothalamus, the part of the brain that regulates both appetite and thirst.

注册营养师兼美国营养与饮食学会的发言人艾丽萨·拉姆齐说：“当你的身体真的需要补充水分时，轻度脱水经常让人感觉好像是饿了”。这种混淆的感觉发生在下丘脑——大脑里控制饥和渴的部分。

When dehydration sets in, wires get crossed in the hypothalamus, leading you to grab a bag of chips when you really need a bottle of water. "Prevent it by staying on top of your fluid intake, starting with a glass of water first thing in the morning," advises Rumsey. "If you feel hungry, and you haven't drank much that day, try drinking a glass of water and waiting 15 to 20 minutes to see if your hunger subsides."

当身体开始脱水，传送信号的神经在下丘脑交叉混乱，导致你其实只需要一瓶水、却抓了一包薯条。拉姆齐建议说：“你可以通过优先补充水分来避免这种情况，早上一起来就先喝一杯水。如果你感觉饿了、这一天喝水又比较少，那么喝杯水试试，再等15-20分钟看看饥饿感是不是减轻了。”

You're a restless sleeper

没睡好觉

By the time you wake after a night of poor sleep, two hormones linked to appetite have already begun conspiring against you. "Too little sleep can lead to surging levels of ghrelin, a hormone that stimulates appetite, as well as decreased levels of leptin, a hormone that causes feelings of fullness," says Rumsey. Lack of shuteye on a regular basis makes you ravenous for another reason. After poor sleep, you're more likely to have serious fatigue and brain fog. Your system, desperate for a shot of energy, triggers cravings for sugar carbs, even if you're not actually hungry. Aim for 7 to 8 hours of sleep a night, and you'll get your energy level and hunger hormones back on track.

早上从一宿很差的睡眠中醒来时，两种与食欲有关的激素已经开始造反了。拉姆齐说：“睡眠太少会导致胃饥饿素（促进食欲的激素）飙升和瘦素（使人有饱腹感觉的激素）下降”。经常缺乏睡眠是使你感到饿，这种现象还有一个原因：睡眠缺乏后，你更有可能产生严重的大脑疲劳和脑雾。即使你不饿，你的身体系统也会出发对碳水化合物、糖类的渴望。保证每晚睡眠时间达到7-8小时，能量需求和胃饥饿素才能恢复正常。

You load up on starchy carbs

吃太多淀粉类的碳水化合物

Ever notice how one doughnut or cookie leaves you unable to resist eating another... until the whole box is just crumbs? That's your brain on starchy carbs. "Simple carbs, the kind found in sugary, white flour foods likepastries, crackers and cookies, spike your blood sugar levels quickly, then leave them plunging soon after," says Moon.

你有没有注意过一块甜甜圈或曲奇饼干是怎样使你嘴不能停的？当你停下来时，你却发现盒子里只剩一些碎渣子了。那是因为你的大脑受淀粉类碳水化合物影响了。莫恩说：“含糖的白面粉做的食物比如说甜点、饼干和曲奇饼干里含有单糖，这种单糖会使你的血糖飙升，然后又骤降。”

That blood sugar plunge causes intense hunger for more sugary carbs and the cycle continues." Keep fluctuating blood sugar levels from sending you on a cravings roller coaster by avoiding simple-carb foods as much as possible. Get your carb fix with the complex, filling kind that contains lots of fiber. Almonds, apples, chia seeds and pistachios are healthy options that ward off hunger pangs", suggests Moon.

血糖骤降导致你强烈需要更多糖类，然后如此循环往复。莫恩建议说：“尽量避免吃含单糖的食物，否则你那上下波动的血糖含量会使你的食欲像过山车一样。把含碳水化合物食物和富含纤维素的复杂饱腹型的食物搭配。杏仁、苹果、奇异子和开心果都是健康的选择，能阻挡饿得难受的感觉。”

You're a stress case

压力大

Who hasn't dealt with a high-pressure workday or relationship rough spot by giving into cravings for a pint of Rocky Road? But stress has a sneakier way of making you voracious. When you're tense, your system ramps up production of the stress hormones adrenaline and cortisol, says Rumsey. Elevated levels of these hormones trick your system into thinking it's under attack and needs energy, so your appetite starts raging. Stress also reduces levels of the brain chemicalserotonin, and that can make you feel hungry when you aren't, says Moon. Consider it a case for making it to yoga class more often, or cranking up a soothing playlist on your commute home.

因工作压力过大或恋爱关系紧张而猛吃一品脱的巧克力蛋糕，这样的经历谁没经历过呢？但压力使你变得贪吃还不止这一个经历。拉姆齐说，当你紧张时，你的身体系统会增加压力荷尔蒙肾上腺素和皮质醇的分泌。这些激素的上升会使你的身体系统误以为遭受攻击、并需要能量，所以你的食欲猛增。“压力也会减少大脑里的化学物质——血清素，这就使你在不饿的时候也感到饿”，莫恩这样说。想要解决这个问题，考虑多去上瑜伽课吧，或下班回家的路上把舒缓的音乐声音调大。

You drink too much alcohol

酒喝太多了

That pre-dinner cocktail or glass of wine meant to whet your appetite before dinner actually does just that, stimulating a feeling of hunger even if your stomach is full, says Moon. A small study published in the journal Appetite backs this up, finding that people were more likely to consume foods higher in calories after drinking alcohol. And because boozedehydrates you, it can trick you into thinking you need food when your body is really calling for water. Offset the effect by eating before you drink, and make sure to alternate your cocktails with water so you stay hydrated, says Rumsey.

莫恩说：“在正餐前喝鸡尾酒或一杯葡萄酒可以有效促进食欲，即使你很饱也能产生饥饿感”。出版在《食欲》杂志上的一项小研究支持这个说法，研究发现人们喝酒之后更有可能吃高热量的食物。因为喝酒使你脱水，所以这时候你的身体真正需要的是水，而你却误以为自己需要吃的。拉姆齐说，喝酒之前先吃点东西来消除这种影响，并确保交替喝下鸡尾酒和水，以保证身体不缺水。