This week I was asked to comment in my role as media spokesperson for the British Dietetic Association…. on the 5:2 diet which Philip Schofield has been following. Here is the article.
The 5:2 diet is an intermittent fasting diet where you eat normally 5 days a week and fast, eating just 500kcals per day for 2 days of the week. There is some evidene showing that this can work for some people. However large scale studies following people over a longer period of time are needed to confirm this. As a dietitian the evidence base is key. So here is my summary of Pros and Cons:
Pros:
1. The 5:2 diet works as the 2 days of eating 500kcals mean that overall you eat less calories. Eating less calories obviously favours weight loss.
2. There is some evidence showing that this style of diet can work but it is only a couple of studies and it is not long term evidence. Most people want the weight to come off and stay off for good. We don’t know the long term effects of the 5:2 diet yet.
3. Intermittent fasting may help improve insulin sensitivity although more research is needed to back this up (http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3017674/).
4. Fasting can lead to you being more in touch with your hunger cues and responding to them more appropriately.
Cons:
1. The fasting days can lead to lower energy, poor mood and concentration and a preoccupation with food as well as problems sleeping on fast nights. So you end up not able to eat much but constantly wanting to and being grumpy and tired about it! Exercising on these fasting days can be very difficult.
2. You can eat a completely unbalanced diet and end up with a poor nutritional intake as this diet focuses on calories and not getting the right nutrition and balance. In the long term eating an unbalanced diet can increase the health risks of chronic disease. For example focusing on eating 5 or more portion of fruit and vegetables, including wholegrains in your diet and having 3 portions of calcium foods per day are important nutritionally but are not considered in an intermittant fasting diet.
3. Although the 5:2 diet is meant to be a long term solution, for most people it isn’t a sustainable way to eat and it takes a lot of discipline. For long term weight loss, long term lifestyle changes are needed. The risk with this diet is that people lose the weight, then find they cannot stick to the fasting principles and put it all back on again. Yo-yo dieting has been shown to be detrimental and can lead to the weight creeping up over the years.
Have you tried the 5:2 diet? What are your thoughts?