We’ve long been told that crash diets are usually unsustainable and ineffective, with most of us regaining the weight (and then some) after returning to our normal eating habits.
And now, new research by the University of Oxford may have just identified another big reason to avoid extreme dieting: it could affect your heart…
The team used MRI scans to assess the impact of eating just 800 calories a day on 21 obese participants. (That’s equal to 1,000 fewer calories than the new recommended daily guidelines for adults.)
After just one week of the crash diet, the volunteers’ heart fat had actually increased by a significant 44%. The scientists also noted a marked deterioration in the participants’ heart function, including the ability to pump blood.
Lead author Dr Jennifer Rayner, who presented the findings at the European Society of Cardiology’s annual meeting, said the results were surprising: ‘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.
‘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 continued.
‘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.’
Scientists are now warning people with existing heart problems that a very low-calorie diet could exacerbate their condition.
Dr Rayner continued: ‘If you have heart problems, you need to check with your doctor before embarking on a very low-calorie diet or fasting.
‘People with a cardiac problem could well experience more symptoms at this early time point, so the diet should be supervised. Caution is needed in people with heart disease.’
As we all know, slow and steady usually wins the race when it comes to healthy weight loss, so check out our top tips for losing a stone without dieting…
