Re: [問題] 一天吃五餐會不會蛋白質超量？

看板MuscleBeach作者ermae (Bigbear)時間13年前 (2010/10/17 21:13)推噓9(9推 0噓 1→)

留言10則, 10人參與討論串2/2 (看更多)

最近對一餐可以吸收30克蛋白質這個說法也感到懷疑昨天剛好找到一篇原文在 http://www.tomvenuto.com/asktom/protein_grams_per_meal.shtml 先給這篇文章的答案:基本上是你吃多少就吸收多少作者是Tom Venuto，NSCA(美國肌力與體能訓練協會)認證的個人教練下面是部份翻譯 Q: Dear Tom: I know approximately what my protein needs are by bodyweight and activity level (about 180 grams), but the question I have always had is: how much protein can I eat/drink at one time? I have heard that only 30 grams can be digested at a time. I eat 5 times a day like you recommend, but supposing I only ate 3 times a day; that would be 60 grams of protein per meal. Would half of the protein be wasted? Q:親愛的湯姆根據我的體重跟運動程度，我算出我每天大約需要180公克的蛋白質，可是我總有一個疑問，就是我每次到底該攝取多少呢？我有聽說過每次只能吸收30克。因此我如同你所建議的一天吃五餐，但如果一天減少到三餐，那每次不就需要60克了嗎？這樣不就有一半的蛋白質被浪費掉？ A: Thirty grams of protein per meal seems to have become one of those "nutrition rules of thumb" that has been passed around so long that it has become accepted as an "unbreakable nutrition law." Some people claim that the human body can only digest 30 grams of protein per sitting (others claim the limit is 40 grams). A:這種每餐只能攝取30克的蛋白質的觀念似乎已經深植人心，並被視為營養攝取的準則有些人宣稱每餐你只能吸收30公克的蛋白質，還有一些人則說上限是40。 There has been a lot of research done on protein needs, although not much of it has focused specifically on the maximum amount digestible per meal. There have been studies where a large bolus of protein was eaten at one time rather than in small, frequent meals, and yet positive nitrogen balance was achieved. This would suggest that the 30 grams per meal limit does not exist and that 60 grams over three meals would allow your body to utilize the majority of that 180 grams. 目前有許多關於蛋白質的研究，儘管很多研究並不是針對每餐最多可以吸收多少。然而有些研究指出一次攝取大量的蛋白質與多次攝取少量的蛋白質相比仍維持正向的氮平衡(也就是說身體攝入蛋白質的量大於排出的量)。因此可見每餐30克的限制似乎不存在，所以若你吃三餐，每餐含有60克蛋白質，身體可利用的最大蛋白質量就是180克。 30-40 grams per meal may be a pretty good rule of thumb for bodybuilding diets with an eating frequency of 5-6 small meals per day (slightly less for females). However, I have never found any research which says that the body has a "30 grams at a time" absolute limit and it doesn't seem likely that one fixed amount could apply to every person in every situation, with no accounting for body weight and activity level. 當然一天吃5-6餐，每餐30-40克的蛋白質對於那些要長肌肉的人來說的確是好的基本原則。但不論如何，我找不到任何一篇研究指出"身體一次最多只能吸收30克的蛋白質"，而每個人在不同狀況、不同體重跟不同運動程度之下也不可能只用同一條準則。 Some people think that the 30 grams of protein "rule" was started by protein supplement company marketing because thats the amount of protein they put into each serving of their product. However, looking at these examples, you can see that 30-35 grams of protein per meal is pretty close to the average amount that's consumed on a typical bodybuilding diet. My belief is that this is where the 30-gram "rule" came from - it's simply an average figure. But just because the "average" comes out to around 30 grams per meal, doesn’t mean that 30 grams is the most that you can digest. 有些人認為這個30克的原則是從那些賣蛋白質補品的廠商開始行銷而來的，因為他們在每份的產品裡都大約含有這個量的蛋白質。不論如何，你可以發現每餐30-35克的攝取很接近要增重的飲食菜單。我相信它就是這樣來的，不過就是個平均值。但不是因為每餐平均攝取30克就代表能吸收的就只有這些而已。 The digestibility rate of high quality protein sources is 94 to 97% and even the protein in grains and beans is 78-85% digestible. Generally what happens with a large meal, including a large protein intake, is that the meal will simply take longer to digest, but the body will increase the rate of gastric emptying and nutrient absorption in response to the larger food intake. So while the 5 or 6 small meals a day is an accepted practice among bodybuilders, there doesn't seem to be any proof that you couldn't utilize the protein if you took it across only 3 meals instead. 對於高品質的蛋白質來源，吸收率大約是94-97%，而在穀物跟豆類則是78-85%。當你吃了大餐，也有一堆蛋白質，需要消化比較久，不過身體會加速把胃排空以及吸收養分，來因應這一餐。所以當健美人士少量多餐時，並不表示你不能在這三餐內好好吸收蛋白質。 On the other hand, if the total amount of protein exceeds what your body requires and if you are in a caloric surplus, you can convert the excess into body fat. Although protein is the least likely of the macronutrients to be converted to fat (due to an energy inefficient conversion process), a caloric surplus will always lead to fat deposition, even if the surplus comes from protein. In a caloric deficit, protein consumed beyond the body's needs for skeletal muscle and body tissue protein synthesis can be converted to glucose through a process called gluconeogensis. 另一方面，如果蛋白質攝取量超出身體所需，則你就有多餘的卡路里會轉換成脂肪。儘管蛋白質是最難被轉換成脂肪(由於轉換途徑沒有效率的緣故)，多餘的仍會轉變成脂肪。如果卡路里不足，則身體若有多餘的蛋白質(超出骨骼肌和組織所需)也會由糖質新生轉變成醣類。 Bottom line: Even large protein servings can be digested and absorbed, and it appears there is no 30 gram absolute limit. On the other hand, huge servings of protein at one time are not necessary for muscle growth. Beyond what is needed for growth, repair and energy, an excess of protein can get "wasted" if you are referring to being stored as fat or burned for energy. 最後，即使並沒以30克的界線，一餐攝取超大量的蛋白質對於肌肉成長是不必要的，若是超出成長、修復跟能量所需，多餘的蛋白質就會被浪費。也就是存成脂肪或是被當成能量代謝。參考文獻: 1. Plant proteins in relation to human protein and amino acid nutrition. Young V. and Pellet P., American Journal of clinical Nutrition. 59. pp 1203S-1202S. 1994 2. Protein pulse feeding improves protein retention in elderly women. Arnal, M, et al. American Journal of clinical Nutrition. 69. 1202-1208. 1999 -- ※ 發信站: 批踢踢實業坊(ptt.cc) ◆ From: 218.35.25.28

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