可以在血管運送的小分子能量主要是葡萄糖與酮體。除了脂肪之外，食物在體內轉化成能量時，都會產生一些酮體，只是脂肪可產生較多的酮體，不管是籍由飲食中的油脂，或是直接消耗體脂肪，酮體是唯一可替代血糖，做為腦細胞的熱量來源，因為酮體不受血腦屏障的影響。

近來生酮飲食引發一股熱潮，但什麼是「生酮」？為什麼「生銅」飲食會這麼熱門呢？生酮飲食對身體有什麼幫助呢？關鍵就在於「酮體酮」。

酮體酮是在肝臟內脂肪代謝的產物，做為供應細胞的能量（ATP）來源之一，人體最主要的能量來源是以葡萄糖（葡萄糖血糖）為主，當體內的葡萄糖不夠時，或是在長期禁食的狀況，身體的能量系統機制就會切換，用燃燒體脂肪來產生酮體做為能量的來源提供人體能量的食物來源有三大類：醣類（碳水化合物），蛋白質，脂肪，食物經由人體的消化，吸收，代謝，會轉化成能量。

酮體除了上述功用以外，還有幾項功能：

1、可作為糖尿病的參考指標

身體長期有太多酮體，會讓血液偏向酸性，長期下來會引起酮酸中毒酮症酸中毒。例如，糖尿病患者身體突然暴瘦，呼氣會酮酸味（發酵的水果味），是因為身體胰島素的問題，長期無法使用體內的葡萄糖，只好消耗體脂肪產生酮體來代替葡萄糖，做為身體能量的來源。血液，尿液中酮酸，可做為糖尿病的檢測之一。

2、和中鏈脂肪酸合作無間

利用中鏈脂肪酸快速獲得酮體，中鏈脂肪酸是指有6-10個碳的脂肪酸。實際上，MCT較少存在自然界，只有在棕櫚仁油，椰子油內含有一些MCT。現在市面上販售的MCT Oil，皆是利用椰子油的水解，分餾，酯化而產生的.MCT它具有比一般食用油（長鏈脂肪酸LCT Long-Chain Triglyceride）較高的代謝率，溶解度佳，吸收率高。也比醣類要經過26個化學反應步驟，才能轉換成能量，來的快速.MCT只要經過3個反應步驟，就可轉換成能量（酮體）提供全身細胞，又可以有效率提供能量給腦細胞。

另外，MCT不會引起心血管阻塞的現象，原因一，MCT不會在體內蓄積，不會轉換成體脂肪，而是直接當能量燃料。原因二，MCT是經由肝門靜脈到肝臟，不像LCT的是經由血液循環到肝臟，當血液有較多的脂肪，就容易在血管內堆積。原因三，脂肪在肝臟代謝後，利用血管運送到全身的細胞，MCT是用酮體的方式在血管中運送，而LCT是用脂蛋白（VLDL，HDL，LDL）方式在血管運送，LDL易沉澱在血管內壁，當越積越多時，就是動脈粥狀硬化的開始。

既然MCT有這些好處，是否飲食中的油脂全改用MCT Oil呢？不建議哦！理由一，身體還是需要有脂肪的存在，脂肪是構成細胞膜，荷爾蒙，神經傳導的成份之一，這些是由長鏈脂肪酸在體內代謝合成。這是MCT無法取代的部分。理由二，人體所需的脂溶性維生素A，d，E，K，都需要脂肪的參與，才能吸收，代謝，運送理由。三， MCT畢竟是加工合成的產品，其發煙點低，不宜高溫大火烹煮。建議直接淋在食物上.MCT跟人造奶油（乳瑪琳人造黃油）是一樣的道理，當初科學界認為奶油，動物性的食用油，是引起心血管疾病的最大殺手，於是發展出人造奶油，早期大為推廣來取代奶油，但現在發現人工的反式脂肪，更易引起身體的發炎現象，這是心血管疾病，癌症的起因。

► 酮體及膳食療法

癲癇是最早運用酮體的膳食療法來改善症狀，研究發現酮體會產生較多的神經傳導物質GABA（γ-氨基丁酸），具有抗痙酸及間接改善腦部不正常放電，可以改善癲癇者的過度興奮及不安。在20世紀初期，法國就發表利用攝取油脂在人體內產生大量的酮體做為改善癲癇者的研究報告，之後美國也發表相關的研究報告，這就是現在最紅的生酮飲食生酮飲食。

針對癲癇患者的生酮飲食設計，是用油脂來代替醣類做為主要能量供應，由高脂肪產生大量的酮體來改善痙孿的症狀。但是，要讓身體產生酮體的狀態，一天攝取的總熱量比例，油脂類需要佔80％，蛋白質，醣類各佔10％，但一天飲食中油脂佔了80％，實在很難讓人下嚥，尤其是對癲癇病童而言更是高難度。於是研究了油脂類別與在人體的代謝路徑，來改善此現象，將80％一般油脂類（長鏈脂肪酸），改成60％中鏈脂肪酸（MCT，Medium-Chain Triglyceride）。

因此，應用MCT Oil的膳食療法，來獲得酮體做為主要能量供應。不適合癲癇患者，也適合低油飲食的患者，利用中鏈脂肪酸代替一般的脂肪作為熱量來源。例如，胰臟炎，膽囊疾病（膽囊炎，膽結石，膽管阻塞等），高脂蛋白血症I，V型，脂肪異常（脂肪消化，吸收，運送，代謝），先天缺肉鹼...等。

而現在流行的減重飲食，不管是生酮飲食，限糖/低糖飲食，若有使用到MCT Oil，一天所需脂肪的50~70％是可以用中鏈脂肪酸取代，但最多3~4湯匙。而醣類，蛋白質的攝取量一定要維持身體每天的最基本生理代謝需求。每日醣類攝取量，約2個拳頭大小，醣類含水果，米飯，麵食，根莖類蔬菜（地瓜/紅薯，馬鈴薯/土豆，南瓜，豆類）。每日蛋白質攝取量，每公斤體重1公克蛋白質。

生酮飲食能吃什麼？

Today's RECIPE: Chicken Caesar Salad Tacos by @thejoshelkin!! THIS is why we LOVE Keto!! LET'S GO!⁣ 👇⁣ --- ANNOUNCEMENT: Together, we're starting a FREE Keto Support Community! ➡️ Join Us! - Link In Bio ⬅️ --- INGREDIENTS Taco Filling: 4 chicken tenders OR 1 skinless, boneless chicken breast cut into 4 strips 1/2 lb chopped bacon 2 cups chopped romaine lettuce 2 tbsp garlic powder Taco Shells: 2 cups shredded parmesan cheese Dressing 2 eggs yolks 3 cloves of garlic 2 tbsp Worcestershire sauce 1/4 cup shredded parmesan cheese 2 tbsp lemon juice 1 tbsp anchovy paste 2 tbsp dijon mustard 1/2 cup olive oil Instructions Filling Season the chicken strips (or sliced breast) with salt and pepper. Pan fry for 5 minutes each side. Set aside. Fry the bacon in a pot until crispy. Degrease the bacon, and combine with the garlic powder. Taco Shell Add 1 cup of parmesan cheese to a medium high heat frying pan. Spread the cheese making sure it covers the entire pan. Fry until the cheese starts to crips and bubble. Take the cheese out and form in a taco holder. Dressing Combine the eggs, garlic, worcestershire, shredded parmesan, lemon juice, anchovy paste, dijon mustard and olive oil in a blender. Season with salt and pepper. Assembly Coat the romaine with the caesar dressing. Add the lettuce to the hardened parmesan cheese shell. Top the lettuce with the garlic bacon bits, chicken and extra dressing. . . . #ketogenicliving #ketogenicfood #fatisfuel #ketofoods #realfood #ketostrong #ketofriendly #ketoon #myketolife #lowcarbmeals #eatfatlosefat #ketosis #ketocooking #ketoweightlossjourney #lowcarbbeating #ketodinner #healthy #ketocommitted #dietitian #ketogenic #easyketo #highfatlowcarb #healthyfats #weightlossfoods #lowcarbbideas #ketolicious #highfat

593 Likes, 18 Comments - Keto Diet Tips (@ketodiettip) on Instagram: "Today's RECIPE: Chicken Caesar Salad Tacos by @thejoshelkin!! THIS is why we LOVE Keto!! LET'S GO!⁣..."

Smoky Chicken & Cauliflower "Rice" Bowls @mealpreprecipes 🌶️ . 💯 If you don't know how to start ketodiet properly or do you want to lose possibly 5-10 lbs in the first week alone with keto ?⁣⁣⁣⁣⁣⁣⁣⁣⁣⁣⁣ 💪 Join our 28-Day Keto Challenge NOW to start a successful weight-loss journey and enjoy a new lifestyle!⁣⁣⁣⁣⁣⁣⁣⁣⁣⁣⁣⁣ ➡️ LINK IN BIO @ketodiettip ⬅️⁣⁣⁣⁣⁣⁣⁣⁣ . . Recipe credit by @cleanfoodcrush . To make the cauliflower "rice" you can purchase frozen or fresh "riced" cauliflower as most grocers do carry it these days. OR, make it yourself: I used the cleaned, & trimmed florets of 2 small/medium heads of organic cauliflower. Working in batches, place cauliflower florets into a food processor and pulse until just broken into rice-sized pieces. Do not over-pulse, or you'll have mush. . . makes about 4 servings . . Ingredients: 4 skinless boneless chicken breasts, about 1.5 lbs. 2 Tbsp olive oil, or avocado oil, divided 1.5 Tbsps smoked paprika 1 tsp garlic powder 1 tsp ground cumin sea salt and fresh ground black pepper 2 red bell peppers, chopped 1 large red onion, chopped 3-4 garlic cloves, pressed 4 cups cauliflower rice 1 large avocado, or 2 small ones, pitted and chopped 2 fresh limes 2 green onions, sliced Instructions: Place your chicken in a shallow dish, and sprinkle with smoked paprika, garlic powder, cumin, sea salt and pepper. Drizzle one tablespoon of oil and, using your hands rub it on all sides to coat well with the seasonings. Set aside for a few minutes to marinate. Preheat a gas grill, stovetop grill pan, or a cast iron pan over medium high heat. . . . . . #ketogenicliving #ketogenicfood #fatisfuel #ketofoods #realfood #ketostrong #ketofriendly #ketoon #myketolife #lowcarbmeals #eatfatlosefat #ketosis #ketocooking #ketoweightlossjourney #lowcarbbeating #ketodinner #healthy #ketocommitted #dietitian #ketogenic #easyketo #highfatlowcarb #healthyfats #weightlossfoods #lowcarbbideas #ketolicious #highfat

820 Likes, 15 Comments - Keto Diet Tips (@ketodiettip) on Instagram: "Smoky Chicken & Cauliflower "Rice" Bowls @mealpreprecipes 🌶️ . 💯 If you don't know how to start..."

或是簡單煎個牛排，炒個四季豆也可以！

Bacon Wrapped Filet Mignon topped with seared Scallops, Broccolini & a White Wine Shallot Cream Sauce on the side 🔥🔥⁣ ⁣ White Wine Shallot Cream Sauce ⁣ 3/8 cup heavy whipping cream ⁣ 3 tbs white wine ⁣ 2 tbs butter ⁣ 1/2 shallot⁣ 3 cloves garlic ⁣ 1/2 tsp Fresh cracked pepper ⁣ 1/4 tsp salt⁣ ⁣ ⁣⁣ 😕 If you don't know how to start ketodiet properly or do you want to lose possibly 5-10 lbs in the first week alone with ketolifestyle ? You can click link in our bio to get Everything You Need for keto Success. Imagine... armed with 4-week meal plan, 7 Keto guide books about ketomacros , intermittentfasting etc , and the 3 bonus guides... you'll be able to start strong and finish strong with 28 day keto challeng. 💪⁣⁣⁣ 👉 Check the ➡️ 𝐋𝐈𝐍𝐊 𝐈𝐍 𝐁𝐈𝐎 @ketodiettip ⬅️⁣⁣⁣⁣⁣ ⁣ ⁣ Pic by @tagsketojourney⁣ 👉 Tag @ketodiettip your pic for a feature!⁣⁣ ❤️ Follow us for keto recipes and tips⁣⁣ ⁣ ⁣ #keto #ketolife #ketogenic #ketosis #ketogenicdiet #ketofam #ketones #ketogeniclifestyle #ketoweightloss #ketocommunity #ketoaf #ketoliving #ketofriendly #dailyketomeme #ketomeme #ketomemes #ketojourney #ketofastosis #fatfueled #ketobreakfast #ketoadapted #omad #ketoapproved #fatadapted #deeperstateketo #ketomeal #lowcarbdiet #lowcarb⁣⁣⁣

460 Likes, 6 Comments - Keto Diet Tips (@ketodiettip) on Instagram: "Bacon Wrapped Filet Mignon topped with seared Scallops, Broccolini & a White Wine Shallot Cream..."

飲食