Ask the Diet Doctor: Is Diet or Exercise Best for Losing Belly Fat?

問問飲食方面的醫師：節食或是運動真的是瘦肚子的最好方法嗎?     資料來源：Shape 網站

Q: What's the best way to lose belly fat: diet or exercise?

       什麼是瘦肚子的最好方法? 只靠節食? 還是只靠運動?

A: You really need both, and here's why: Losing fat (all kinds of fat, not just the belly fat that covers your lower abs) requires an energy deficit. At the end of the day, you need your body to realize that it didn't take in enough caloric currency to pay for your daily efforts, forcing it to tap into its energy savings account (stored fat). The greater this deficit, the more weight you will lose.

     你真正需要的是兩方面的搭配，這裡告訴你為什麼：減肥(所謂的脂肪，不僅單指你的小肚肚的脂肪更包含你的下腹部)著重在能量赤字。一天結束後，你需要你的身體去實現這個能量赤字，它沒有獲取足夠的熱量貨幣來供給你的日常支出，迫使它進入其熱量儲蓄帳戶（儲存的脂肪）提取。這一赤字越大，你所失去的重量越多。

Diet and exercise can both help you create an energy deficit and lose weight, but I'm assuming you don't just want what works, you want what works best. What gives you the biggest return for the time you invest.

    節食跟運動都能幫助你創造出能量赤字及減重，我假設你不僅要怎麼做、還要怎麼做到最好，在這段期間你所投入的能帶給你多大的回報。

Why Just Dieting Doesn't Work in the Long Run   為什麼單靠節食無法長久
There are numerous hormones that impact weight loss, but for the sake of brevity we're going to focus on two: leptin and ghrelin. Leptin is a hormone released by your fat cells that signals you to eat less and burn more calories. Scientists have called leptin a "fat loss thermostat." The more active leptin in your system, the more fat you are going to burn. Drastically cutting calories decreases leptin release and its ability to signal the brain, making weight loss harder and eventually slower. This forces you to keep eating fewer and fewer calories to get the same weight-loss results.

   有許多體內的荷爾蒙影響著減肥，簡單點，我們著重在其中兩種上面：瘦體激素以及飢餓激素。瘦體激素是由脂肪細胞所釋出的荷爾蒙，讓你吃的更少且燃燒更多卡路里。科學家們稱之為「減重調節器」。在你的身體系統中分泌的越多，你所燃燒的脂肪就越多。大幅度的削減卡路里的攝取同時也降低瘦體激素的分泌，而它的作用在於提醒大腦，而造成減重越來越困難且日趨緩慢。這迫使你吃得越來越少、攝取更少的卡路里，得到的結果卻是你的體重一點也沒變。

If cutting calories is your only weight-loss strategy, you'll need to keep your calories low for a very long time to ensure that you don't gain the weight back. Many people justify this, telling themselves "it's worth it and I'll just adjust to eating less." Unfortunately, research shows that you don't adjust to eating less and that even after a year of calorie restriction, one of your hunger hormones, grehlin, is as high as ever, making you as hungry as the first day you set out on your lean body journey.

如果減少卡路里攝取是你唯一的減重策略，那你必須要維持一段非常漫長的時間以防你復胖。許多人以此為據並告訴自己「這是值得的，我只是調整飲食去吃的很少」不幸的是，研究報告顯示節食無法持久即使經過一年的卡路里限制，你其中一種飢餓賀爾蒙-飢餓激素，一如往常般地居高不下，讓你的飢餓感絲毫不減的像你下定決心要踏上這段減重之旅的那天一樣。

If cutting calories yields such unfavorable changes in fat loss hormones, why don't we just forget cutting calories and hit the gym to burn belly fat?

  那如果節食會造成像是減重賀爾蒙流失這樣不好的變化，我們為何不捨棄節食而改去健身房去運動燃燒脂肪呢??

Why Just Exercising Doesn't Work in the Long Run   為什麼單靠運動無法長久
The health benefits of regular exercise are too many to count. But as anyone who has lost a lot of weight can attest, burning off your extra flab at the gym is a long and arduous process. And if you aren't using a modestly calorie-restricted diet to support your efforts, it's even longer. This is primarily because eating extra calories takes no time at all (I'll just have one more heaping tablespoon of peanut butter), while burning off those calories can take more than an hour, depending on your preferred mode of exercise. There just isn't enough time in the day! What's more, numerous studies show that exercise (especially aerobic exercise) alone does not cause significant and long-term weight loss.

規律的運動對於健康的益處不勝枚舉，但藉此減下大量體重的人們可以證明，在健身房裡燃燒掉多餘鬆弛的脂肪是條漫長且艱辛的過程，假使你沒有適當地克制熱量的攝取來支持你的努力，這將會更加漫長，最主要的因素是吃額外的卡路里不用花多久(我就多吃了這麼一湯匙的花生醬而已)，當你燃燒卡里卻要花上一個小時甚至更久，當然這將取決於你的運動模式而定，而且一天之內能運動的時間有限! 更何況，許多研究顯示，鍛鍊(特別是有氧運動)本身並不造成顯著且長期的的減重。

The combination of diet and exercise works best for weight loss. Why? Because Optimal weight loss is about creating an energy deficit and optimizing weight-loss hormones that will allow for sustained and permanent weight loss.

  結合運動及飲食控制對於減重是最好的方式，為什麼呢?因為最佳的減重方式就是創造一個能量赤字和減肥賀爾蒙的平衡，這將能讓你的減重更持續且長久。

An optimal weight-loss approach calls for you to reduce your calories enough that you begin to lose weight but not so aggressively that you disrupt your fat-loss hormonal balance. Then, add in exercise to support your diet-induced calorie deficit. This creates a even larger deficit while manipulating hormones that allow for faster fat burning. This is the best way to lose belly fat.

  一個最佳減肥方法需要減少你所攝取的卡路里足以讓你開始減肥但沒有那麼強勢地擾亂你減肥荷爾蒙的平衡。然後，增加運動來支持你的飲食所創造的熱量赤字。這將創建一個更大的逆差，同時刺激分泌激素，使脂肪燃燒更快。這就是最好的方法減掉肚子上的脂肪。