Compared to daily calorie restriction diets, intermittent energy restriction clears fat, an important risk factor for cardiovascular disease from the blood quicker, finds a new study. Intermittent energy restriction is 5:2 diet. The findings of the study are published in the British Journal of Nutrition.
In the first study of its kind, scientists from the University of Surrey examined the impact of the 5:2 diet on the body's ability to metabolize and clear fat and glucose after a meal and compared it to the effects of weight-loss achieved via a more conventional daily calorie restriction diet. Previous studies in this field have predominantly focused on blood risk markers taken in the fasted state, which only tend to be, in for the minority of the time, overnight.
During the study, overweight participants were assigned to either the fasting diet or a daily calorie restriction diet and were required to lose five per cent of their weight. Those on the 5:2 diet ate normally for five days and for their two fasting days consumed 600 calories, using LighterLife Fast Foodpacks, whilst those on the daily diet were advised to eat 600 calories less per day than their estimated requirements for weight maintenance (in the study women ate approx. 1400 calories, men ate approx. 1900 calories/day).
Scientists found that following weight-loss , participants who followed the 5:2 diet cleared the fat (triglyceride) from a meal given to them more efficiently than the participants undertaking the daily diet. Although there were no differences in post meal glucose handling, scientists were surprised to find differences between the diets in c-peptide (a marker of insulin secretion from the pancreas) following the meal, the significance of which will need further investigation.
The study also found a greater reduction in systolic blood pressure (the pressure in your blood vessels when your heart beats) in participants on the 5:2 diet. Systolic blood pressure was reduced by 9% of following the 5:2, compared to a small 2% increase among those on the daily diet. A reduction in systolic blood pressure reduces pressure on arteries, potentially lessening incidences of heart attacks and strokes.
Dr Rona Antoni, Research Fellow in Nutritional Metabolism at the University of Surrey, said: "As seen in this study, some of our participants struggled to tolerate the 5:2 diet, which suggests that this approach is not suited to everybody; ultimately the key to dieting success is finding an approach you can sustain long term.
"But for those who do well and are able stick to the 5:2 diet, it could potentially have a beneficial impact on some important risk markers for cardiovascular disease, in some cases more so than daily dieting. However, we need further studies to confirm our findings, to understand the underlying mechanisms and to improve the tolerability of the 5:2 diet."