The Real Reason It's So Hard to Lose Weight
Losing weight is hard. Everyone knows this, but did you know there is actually a scientific reason behind it?
减肥很难。这一点所有人都知道，但你是否了解，这背后其实存在科学依据？
The overwhelming majority of people who try to do it don't succeed or end up gaining back what they lose, sometimes more.
绝大多数尝试减肥的人要么以失败告终，要么最终反弹回减掉的体重，有时甚至比之前更重。
It turns out your body actually pushes back when you attempt to slim down. A lot of the push back is driven by changes to hormones.
事实证明，当你试图变瘦时，身体其实会产生“抵抗”。这种“抵抗”在很大程度上是由激素变化引起的。
One of the most important is leptin, a hormone produced by your fat cells. The large your fat cells are, the more leptin they produce. So when you lose weight, leptin levels drop.
其中最重要的一种激素是瘦素（leptin），它由脂肪细胞分泌。脂肪细胞体积越大，分泌的瘦素就越多。因此，当你减肥时，瘦素水平会下降。
Parts of your brain like your hypothalamus interpret less leptin as starvation, and it jumps in and starts telling your body to save energy and to eat more to rebuild those reserves.
大脑中的某些区域（如下丘脑）会将瘦素水平降低解读为“饥饿信号”，随后便会介入，指令身体储存能量，并通过多进食来补充能量储备。
In addition to changing how hungry you feel, a suite of studies have suggested your brain responds to these hormonal changes by making you more aware of all the food you're not eating, and upping the pleasure you feel if you do crave in.
一系列研究表明，除了改变你的饥饿感，大脑对这些激素变化的反应还包括：让你更强烈地意识到那些没吃到的食物，并且当你对某些食物产生渴望时，会放大这种渴望带来的愉悦感。
Here's the really annoying thing: this hormonal starvation signal doesn't stop when you stop dieting.
更让人困扰的是：即使你停止节食，这种激素层面的“饥饿信号”也不会随之消失。
So even when you've stopped restricting calories, your body continues to act like it's being starved — which is a big part of why people who lose weight often gain it back.
因此，即便你不再控制热量摄入，身体仍会持续表现出“处于饥饿状态”的反应——这正是减肥者往往会反弹的重要原因之一。
2025年9月23日于经典龙苑
