蛋白质在我们的身体机能中发挥着重要的作用。如果缺了蛋白质，身体的正常运作就会受到影响。我们如何知道自己的身体缺了蛋白质呢？下面小译就给大家介绍一些蛋白质缺乏时的症状，一起来看看吧~
Food cravings
总想吃东西
If you always feel hungry and have cravings for food and snacks, it may be because of a low protein, high-carb and sugar diet. The problem could be that you have unlimited access to high-calorie food in which the amount of protein is low in comparison to its calorie count.
如果你总是觉得饿，总想吃东西或零食，那可能是因为你的饮食中蛋白质含量过低、而碳水化合物和糖类含量过高。这可能是由于你吃了过多的高热量食物，在这些食物中，蛋白质的含量与热量相比是非常低的。
Loss of muscle mass and joint pain
肌肉量减少、关节痛
Muscles are the body's largest reservoir of protein. Muscle weakness, pain, and loss of mass is a sign of a protein deficiency. A study says this is commonly found in elderly people. Protein is essential for muscle growth and maintenance.
肌肉是人体蛋白质储存量最大的组织。肌无力、肌肉疼痛以及肌肉量减少是蛋白质缺乏的表现。有研究表明，以上现象在老年人中很常见。蛋白质对于肌肉的生长和保持是非常关键的。
Skin and nail problems
皮肤和指甲出现问题
A protein deficiency can result in making your nails weak, brittle and in few cases, you will observe white bands and brownish spots on the nails.
缺乏蛋白质会使你的指甲变脆弱易碎。在少数情况下，你还会看到指甲上有白色竖纹和褐色斑点。
A protein deficiency can affect the skin as well, as protein enables cell regeneration, produces new cells, and replaces dead ones. If this happens, you will notice your skin feeling dry, flaky and cracked.
缺乏蛋白质也会影响皮肤，因为蛋白质能促进细胞再生，去除死细胞，产生新细胞。如果你缺乏蛋白质，你会发现自己的皮肤变干、变薄甚至开裂。
Hair loss
脱发
Our hair is made up of 90% protein known as keratin. If you don't get enough nutrients, your hair may thin and fade in color. This happens because the body stops using protein for non-essential things like hair growth in an effort to preserve it.
我们的头发是由一种叫做角蛋白的蛋白质组成的，其含量高达90%。如果你摄入的营养不足，你的头发就会变得细软并会失去光泽。这是因为如果蛋白质不足，身体会停止使用蛋白质来维持一些不太重要的功能，如毛发生长，从而维持身体的正常运作。
Fatty liver
脂肪肝
Fatty liver is one of the most common symptoms of a protein deficiency and if left untreated, can cause fatty liver disease, causing inflammation, liver scarring, and potential liver failure.
脂肪肝是缺乏蛋白质最常见的症状之一。如果不及时治疗，会导致脂肪肝病，引起炎症、肝脏瘢痕，甚至可能导致肝衰竭。
This is a common condition in those who consume a lot of alcohol, obese people, and even kids.
脂肪肝在酗酒与肥胖人群中极为常见，甚至也会出现在儿童当中。
Increased risk of bone fractures
骨折风险增加
Just like muscles, a low intake of protein can affect the bones as well. Not having enough protein leads to weakening of the bones, thus increasing the risk of bone fractures. This is mostly because “Protein is needed for calcium absorption and helping with bone metabolism,” says Dr.Axe.
除了会影响肌肉外，蛋白质摄入量过低也会影响骨骼。蛋白质不足会导致骨骼疏松，进而增加骨折的风险。阿克斯医生说，这主要是由于“人体需要蛋白质来帮助钙吸收与骨骼代谢”。
Sleep deprivation
失眠
If you have trouble sleeping or suffer from sleep deprivation, it is likely linked to a protein deficiency. Proteins from the food we eat act as building blocks for tryptophan, an amino acid that causes drowsiness. It indicates that we must eat protein-rich food near bedtime to get better sleep.
如果你睡眠不足或失眠，这很可能与缺乏蛋白质有关。我们从食物中摄取的蛋白质中含有色氨酸，而色氨酸是一种会使人产生睡意的氨基酸。这表明，我们必须在睡前吃富含蛋白质的食物才能有更好的睡眠。
Brain fog
脑雾
It is very important to get a proper intake of protein to support healthy brain function. If you experience lack of motivation, poor memory or trouble with learning anything new, it's a sign that you are protein deficient. A study says that dopamine, epinephrine, and serotonin are neurotransmitters that your body needs in order to focus.
摄入适量蛋白质来维持大脑功能健康是非常重要的。如果你缺乏动力、记忆力差，或者学习吃力，这可能是你缺乏蛋白质的标志。一项研究表明，多巴胺、肾上腺素和血清素是人体在集中注意力时所需的神经递质。
According to the USDA, the recommended minimum daily intake of protein for adults is 56 g per day for men, 46 g per day for women — and for kids, it varies from 19 g to 34 g depending on their age. This may vary if you are pregnant or ill.
美国农业部建议的成年男性每日蛋白质最低摄入量为56克，女性为46克，儿童的摄入量根据年龄的不同，从19克到34克不等。如果怀孕或生病，摄入量可能也会有所不同。