Crash diets may stop the heart pumping properly, a new study by Oxford¹ University has found.

英国牛津大学的一项最新研究表明，“崩溃饮食法”可能会引发心脏问题。

Researchers at Oxford University said people suffering from heart problems should seek medical advice before adopting a low calorie diet.

牛津大学的研究人员表示，心脏有问题的人，在进行长期低热量进食或节食之前需要咨询医生意见。

The new study used magnetic resonance² imaging (MRI) to investigate the impact of eating fewer than 800 calories a day on heart function and the distribution of fat in the abdomen³, liver, and heart muscle.

这项新研究通过磁共振成像技术来调查每天摄入少于800卡路里的热量对心脏功能的影响，以及腹部、肝脏和心脏肌肉的脂肪分布。

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 intake⁴ by drinking diet-shakes to dramatically to lose weight or drastically cutting meals.

营养学家建议男性每天应该摄入大约2500卡路里的热量，女性应摄入2000卡路里热量，以保持健康体重。但是很多人为了减肥，大大降低热量摄入。

"Crash diets, also called meal replacement⁵ 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.

研究报告的第一作者、牛津大学核磁共振中心临床研究员珍妮弗·雷纳博士指出：“在过去的几年里，“崩溃饮食法”，也被称为饮食替代方案，已经变得越来越流行。”

"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 diabetes⁶. But the effects on the heart have not been studied until now."

“这种饮食法每天摄入的热量非常低，仅为600-800卡路里，虽然的确可以有效控制体重、降低血压、减轻糖尿病症状，但是它对心脏的影响却一直被忽略。”

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 chronic⁷ angina.

最近一项调查表明，多达2/3的英国人都在长期节食，其中80万人患有心力衰竭症状，另有近200万人患有慢性心绞痛。

The research was carried out on 21 obese⁸ 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.

这项研究是针对21名肥胖志愿者进行的，他们平均年龄为52岁，身体质量指数为37。这些志愿者每天摄入的热量为600至800卡路里，持续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 cholesterol⁹, triglycerides, glucose¹⁰ and blood pressure.

一周以后，他们的总体脂、腹内脂肪和肝脏脂肪分别平均显著降低了6%、11%和42%，胰岛素耐受性显著增强，总胆固醇、甘油三酯、血糖和血压均得到控制。

However, after one week, heart fat content had risen by 44 per cent and there was a noteable deterioration¹¹ in heart function, including the heart's ability to pump blood.

然而，一周后，他们的心脏脂肪含量飙升44%，包括输送血液在内的心脏功能大大减弱。

Dr Rayner said: "The metabolic¹² 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."

雷纳博士说：“低热量饮食带来的代谢改善，包括肝脏脂肪含量的降低、糖尿病症状的减轻等，本来将有望改善心脏功能，可是，心脏功能在开始改善前的第一周变得更糟。”

"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 restriction¹³, the fat content and function of the heart improved."

“卡路里摄入的突然降低，导致身体不同部位脂肪被溶解后进入血液循环，然后被心肌吸收。”她补充道。“心肌从脂肪或血糖中吸收动能，但是如果吸入的脂肪过多，则会损害心脏功能。直到身体适应了大大降低的卡路里摄入量之后，心脏的脂肪含量和功能才会得以改善。”