“lose weight”是英语中高频常用动词短语，核心含义和用法如下：
字面直译为“失去体重”，实际表达“减肥；体重减轻”——指通过节食、运动、调整生活方式或医疗干预等，使体重下降的行为或结果。
作为及物动词短语（`lose`是及物动词，`weight`是宾语），主语通常是“人”，基本结构为：主语 + lose weight。
可通过添加修饰成分（方式、程度、目的等）扩展表达：
说明通过何种途径减肥：
I want to lose weight by exercising more (通过多运动减肥).
She lost weight by cutting out sugar and fried food (通过戒糖和油炸食品减肥).
具体数量：lose + 数字 + 重量单位（如`kilograms/pounds`），可加`in weight`（更正式）：
He lost 5 kilograms (in weight) last month (他上个月减了5公斤).
模糊程度：用`a lot of/some/a little`等修饰：
She’s lost a lot of weight since she started running (她开始跑步后瘦了很多).
I need to lose weight for my health (为了健康，我需要减肥).
She’s trying to lose weight before her wedding (她在婚礼前努力减肥).
适用于各种时态，体现不同时间的减肥行为或结果：
一般现在时：He loses weight easily when he eats less (他少吃时容易瘦).
一般过去时：I lost weight last summer by swimming every day (去年夏天我每天游泳减肥).
现在完成时：We have lost some weight since we gave up soda (戒 soda 后我们瘦了一些).
将来时：She will lose weight if she sticks to the diet (如果坚持节食，她会瘦).
lose weight quickly/safely/gradually：快速/安全/逐渐减肥
Crash diets make you lose weight quickly but you’ll gain it back (极端节食让你快速减肥，但会反弹).
put weight back on：体重反弹（减肥后又增重）
Don’t skip meals—you’ll just put weight back on later (别跳过正餐，否则之后会反弹).
1、 不用所有格：不能说“lose his/her weight”，直接说“sb. loses weight”（某人减肥）。
错误：He wants to lose his weight. → 正确：He wants to lose weight.
2、 定冠词的使用：一般不用`the`，除非特指某部分体重（如“假期涨的体重”）：
Did you lose the weight you gained over Christmas? (你减掉圣诞期间涨的体重了吗？)
同义词（口语）：`shed pounds`（摆脱磅数，即减肥）、`drop weight`（体重下降）
She shed 20 pounds by doing HIIT (她做HIIT减了20磅).
反义词：`gain weight`（增重）、`put on weight`（增重）
I’ve put on weight since I stopped going to the gym (停止健身后我增重了).
例句：Do you know any healthy ways to lose weight? (你知道健康的减肥方法吗？)
对话：
A: You look slimmer! Did you lose weight? (你看起来更瘦了！减肥了吗？)
B: Yes! I’ve been eating more fruits and vegetables, and I walk 30 minutes every day. (是的！我吃更多果蔬，每天走30分钟。)
A: That’s a smart way to lose weight! (这是聪明的减肥方式！)
总之，“lose weight”是描述“减肥”最常用的短语，覆盖“主动减肥”和“被动体重下降”（如生病后瘦）的场景，搭配灵活，是日常交流和健康话题的核心表达。