Overweight and obesity is always brought up when the topics of nutrition and health are mentioned. As much as being in those weight categories can lead to various metabolic diseases, being on the lower spectrum of the weight categories – underweight, is also worrisome as it leads to a variety of health problems that can be damaging in a long run.
当提到营养和健康的话题，我们总是会提到超重和肥胖。尽管这些体重类别会导致各种代谢疾病，但处于体重类别的较低范围——体重不足，也令人担忧，因为它会导致各种健康问题，从长远来看可能会造成损害。
Underweight for adult is defined as body mass index (BMI) of less than 18.5 kgm–². The calculation is as follows:
成人体重不足的定义是体重指数 (BMI) 低于 18.5 kgm-²。计算如下：
| BMI | = | Weight (kg) |
| Height (m) x Height (m) | ||
For instance, a person weighing 40 kg with the height of 1.55 m would have a BMI of 16.6 kgm-2 (40 kg ÷ [1.55 m x 1.55 m]), which makes them fall in the underweight category.
例如，一个体重 40 公斤、身高 1.55 m 的人的 BMI 为 16.6 kgm-2（40 kg ÷ [1.55 m x 1.55 m]），这使他们属于体重不足的类别。
So, why exactly is being underweight a concern? An underweight person may experience the following health problems:
那么，为什么体重不足是一个问题？体重不足的人可能会遇到以下健康问题：
- Nutritional deficiency / 缺乏营养
Inadequate food intake may cause energy and protein deficiency, along with vitamins and minerals such as zinc, iron, folate, and calcium.
摄取不足的食物可能导致能量和蛋白质的缺乏，以及维生素和矿物质，如锌、铁、叶酸和钙的不足。
- Infertility / 不孕症
Inadequate nutrient can cause hormonal imbalance, which in turn can affect a person’s fertility.
营养不足会导致荷尔蒙失调，进而影响一个人的生育能力。
- Weakened immune system / 免疫系统减弱
With nutritional deficiency, production and activation of the immune system can be impaired, causing it to weaken.
缺乏营养会导致免疫系统的产生和激活受到损害，从而导致其减弱。
- Anaemia / 贫血
Inadequacy of nutrients such as folate and iron can result to poor production of red blood cells, leading to anaemia.
叶酸和铁质等营养素不足会导致红细胞生成不良，从而导致贫血。
- Low muscle mass / 低肌肉量
Inadequate nutrient intake, particularly protein, can cause muscle wasting, reduced muscle strength and mass.
营养摄取不足，尤其是蛋白质，会导致肌肉萎缩、肌肉力量和质量下降。
- Bone weakness and fracture / 骨骼无力和骨折
As a result of undernutrition, bones become more fragile and therefore leading to fracture.
由于营养不良，骨骼会变得更加脆弱，从而导致骨折。
- Heart problem / 心脏问题
Mineral disturbance and cardiac muscle wasting due to malnutrition can cause heart problem including fast, slow or irregular heartbeat.
营养不良所引起的矿物质紊乱和心肌萎缩会导致心脏问题，包括心跳快、慢或不规则。
- Low body temperature / 低体温
Low calorie intake leads to low metabolic rate and low muscle mass, which can result in low heat production and difficulty in preserving heat.
低热量的摄取会导致低代谢率和低肌肉质量，从而导致产热量低和难以保温。
Then, what are the causes of underweight? We will discuss in detail about this topic on the next part of our post.
那么，体重不足的原因有哪些呢？我们将在文章的下一部分详细讨论这个主题。
