研究發現 盲目節食減肥可能會毀了心臟

Crash diets may stop the heart pumping properly, a new study by Oxford University has found.
英國牛津大學的一項最新研究表明，“崩潰飲食法”可能會引發心臟問題。

Researchers at Oxford University said people suffering from heart problems should seek medical advice before adopting a low calorie diet.
牛津大學的研究人員表示，心臟有問題的人，在進行長期低熱量進食或節食之前需要諮詢醫生意見。

The new study used magnetic resonance imaging (MRI) to investigate the impact of eating fewer than 800 calories a day on heart function and the distribution of fat in the abdomen, liver, and heart muscle.
這項新研究通過磁共振成像技術來調查每天攝入少於800卡路里的熱量對心臟功能的影響，以及腹部、肝臟和心臟肌肉的脂肪分佈。

Nutritionists recommend that men consume around 2,500 calories a day and women 2,000 calories to maintain a healthy weight. But many people now cut their daily intake by drinking diet-shakes to dramatically to lose weight or drastically cutting meals.
營養學家建議男性每天應該攝入大約2500卡路里的熱量，女性應攝入2000卡路里熱量，以保持健康體重。但是很多人爲了減肥，大大降低熱量攝入。

"Crash diets, also called meal replacement programmes, have become increasingly fashionable in the past few years," said lead author Dr Jennifer Rayner, clinical research fellow, Oxford Centre for Magnetic Resonance, at the Oxford University.
研究報告的第一作者、牛津大學核磁共振中心臨牀研究員珍妮弗·雷納博士指出：“在過去的幾年裏，“崩潰飲食法”，也被稱爲飲食替代方案，已經變得越來越流行。”

"These diets have a very low calorie content of 600 to 800 kcal per day and can be effective for losing weight, reducing blood pressure, and reversing diabetes. But the effects on the heart have not been studied until now."
“這種飲食法每天攝入的熱量非常低，僅爲600-800卡路里，雖然的確可以有效控制體重、降低血壓、減輕糖尿病症狀，但是它對心臟的影響卻一直被忽略。”

Recent research found that two thirds of Britons are on a diet most of the time, but there are 800,000 people living with heart failure and nearly two million living with chronic angina.
最近一項調查表明，多達2/3的英國人都在長期節食，其中80萬人患有心力衰竭症狀，另有近200萬人患有慢性心絞痛。

The research was carried out on 21 obese volunteers, of an average age of 52 and BMI of 37. Participants consumed a very low calorie diet of 600 to 800 kcal per day for eight weeks.
這項研究是針對21名肥胖志願者進行的，他們平均年齡爲52歲，身體質量指數爲37。這些志願者每天攝入的熱量爲600至800卡路里，持續8周。

After one week, total body fat, visceral fat and liver fat had all significantly fallen by an average of 6 per cent, 11 per cent, and 42 per cent, respectively, accompanied by significant improvements in insulin resistance, fasting total cholesterol, triglycerides, glucose and blood pressure.
一週以後，他們的總體脂、腹內脂肪和肝臟脂肪分別平均顯著降低了6%、11%和42%，胰島素耐受性顯著增強，總膽固醇、甘油三酯、血糖和血壓均得到控制。

However, after one week, heart fat content had risen by 44 per cent and there was a noteable deterioration in heart function, including the heart's ability to pump blood.
然而，一週後，他們的心臟脂肪含量飆升44%，包括輸送血液在內的心臟功能大大減弱。

Dr Rayner said: "The metabolic improvements with a very low calorie diet, such as a reduction in liver fat and reversal of diabetes, would be expected to improve heart function. Instead, heart function got worse in the first week before starting to improve."
雷納博士說：“低熱量飲食帶來的代謝改善，包括肝臟脂肪含量的降低、糖尿病症狀的減輕等，本來將有望改善心臟功能，可是，心臟功能在開始改善前的第一週變得更糟。”

"The sudden drop in calories causes fat to be released from different parts of the body into the blood and be taken up by the heart muscle," she added. "The heart muscle prefers to choose between fat or sugar as fuel and being swamped by fat worsens its function. After the acute period in which the body is adjusting to dramatic calorie restriction, the fat content and function of the heart improved."
“卡路里攝入的突然降低，導致身體不同部位脂肪被溶解後進入血液循環，然後被心肌吸收。”她補充道。“心肌從脂肪或血糖中吸收動能，但是如果吸入的脂肪過多，則會損害心臟功能。直到身體適應了大大降低的卡路里攝入量之後，心臟的脂肪含量和功能纔會得以改善。”