A so-called crash diet has serious effects on the heart
Many people have problems with being overweight. For this reason, those affected try to reduce the excess weight in various ways through exercise, dietary changes or diets. So-called crash diets are also increasingly being used. But researchers have now found that a crash diet reduces weight but also reduces heart function.
In their research, scientists from the internationally recognized University of Oxford found that crash diets can lead to a temporary deterioration in heart function. The results of their study were presented at a cardiac imaging conference CMR 2018 in Barcelona, which was organized by the European Society of Cardiology and the Society for Cardiovascular Magnetic Resonance (SCMR).
What is a crash diet?
With a crash diet, people try to lose a lot of weight in the shortest possible time. In return, those affected reduce the daily intake of the calories consumed. Usually, with such a diet, no more than 800 Kcal per day are consumed for a few weeks. If you are planning to go on a crash diet or a very low-calorie diet soon, you should consult a doctor first to be on the safe side, at least if you suffer from heart diseases, the experts advise.
Crash diets can lower blood pressure and reverse diabetes
Crash diets have become increasingly popular in recent years, explains the author Dr. Jennifer Rayner of the Oxford Center for Magnetic Resonance at Oxford University. "These diets have a very low calorie content of 600 to 800 kcal per day and can be effective for losing weight, lowering blood pressure and reversing diabetes, but the effects on the heart have not been investigated," explains the researcher in one Press release.
21 overweight people served as subjects
The study used magnetic resonance imaging (MRI) to examine the influence of a very low-calorie diet on heart function and fat distribution in the abdomen, liver and heart muscle. A total of 21 overweight volunteers participated in the research. The average age of the participants was 52 years, the average body mass index (BMI) was 37 kg / m2.
Effects of the diet on the participants
The participants took a very low-calorie diet of only 600 to 800 kcal per day for eight weeks. Magnetic resonance imaging was performed at the start of the study, after one week and after eight weeks. After just a week, total body fat had dropped six percent, visceral fat had dropped eleven percent and liver fat had dropped 42 percent, the researchers say. Significant improvements in insulin resistance, triglycerides, glucose and blood pressure were also noted.
After just one week, the heart fat content increased by 44 percent
However, there were also negative effects on the body of those affected. After a week, the heart fat content had increased by 44 percent. This resulted in a deterioration in cardiac function, including a deterioration in left ventricular pump function. In addition, the increased fat content in the heart also caused a reduction in so-called diastolic functional parameters.
After seven weeks, the heart fat content returned to normal
At the beginning of the eighth week of the examination, the fat content in the heart had decreased again and the function had returned to normal. In some cases, an improvement was even found. Body fat and cholesterol measurements showed increasing improvements.
Through the diet, the heart muscle initially absorbs too much fat
The metabolic benefits of a very low-calorie diet, such as reducing liver fat and reversing diabetes, are also expected to improve heart function. Instead, the cardiac function deteriorated in the first week before there was an improvement later, the study authors explain.
The sudden loss of calories causes fat to be released into the blood from various parts of the body and absorbed by the heart muscle. The muscle of the heart prefers fat or sugar as fuel and the excess supply of fat deteriorates its function, the expert adds. After an acute period in which the body adapts to a drastic calorie restriction, the fat content and the function of the heart improve again.
Talk to your doctor before dieting
“If you have heart problems, you need to talk to your doctor before starting a very low-calorie diet or fasting. People with heart problems may experience more symptoms at this early stage, so the diet should be monitored, ”explains Dr. Rayner in the press release. Healthy people are unlikely to notice the observed changes in heart function in the early stages of the diet, the doctor adds.
More research is needed
For people with existing heart problems, the crash diet can lead to various health problems. With symptoms of severe heart failure such as shortness of breath or an increased risk of cardiac arrhythmia, such a diet can worsen the condition. However, more research is needed to investigate the effects of acute reduction in heart function in more detail. (as)