The 5:2 diet: What’s it all about?

It’s the latest diet ‘craze’ around just now. Headlines such as ‘Diet for only 2 days and lose weight’ ‘Eat whatever you want 5 days per week and still lose weight’ and of course the Horizon programme investigating it’s beneficial effect in Alzheimer's disease have all contributed to its increasing popularity. Add into this, celebrities and others in the public eye all endorsing its success, and more and more people are getting on board. It works on the principle of intermittent fasting. By significantly reducing your energy intake for 2 days per week, you can (in theory) eat what you like for the rest of the week, while still creating an energy deficit and therefore losing weight.

But what is it, why does it work & is it really the solution to long term weight loss?

The basics:

• Eat whatever you like 5 days per week
• Reduce calorie intake to ~ 25% of your energy needs (roughly 500 – 600 calories/day) for 2 days (doesn’t need to be consecutive days)  

And that’s it!

One of the attractive things about this diet is the lack of ‘rules’ to follow. There are no points or calories to count everyday and you don’t need to live on meal replacement shakes or exclude ‘treat’ foods. It also benefits from the fact that a 2 day diet sounds a lot more attractive that watching what you eat every day.

Is it practical?

Think about this. You have a busy family and time you all get chance to catch up is around the dinner table, will this be affected by not eating every couple of days? More importantly, if young children see parents adopting this type of routine, are they more likely to develop disordered eating patterns in the future.

If your working life involves business meetings with clients and regular dinner functions, are you comfortable with explaining that actually this is your ‘fasting’ day so you wont be eating? Ok, so people will argue that you could plan your fasting days around these commitments but is it sustainable? Or just an additional stress to an already hectic schedule. Finally if you enjoy going to the gym or playing any kind of sport we all know having enough energy for the required activity is crucial. Would you be compromising on the health and social benefits of this by being unable to take part on your fasting days? Thinking about your current lifestyle and the impact of significantly reduced energy intake for 2 days every week it vital before deciding if this is the right approach for you.

Claims of health benefits:

• Weight loss
• May help prevent diseases including heart disease, stroke, Alzheimer’s and other forms of dementia, type 2 diabetes and cancer 

Up to this point, there have been limited studies carried out in humans to suggest recommending eating in this way. Short term data exists to indicate a weight loss effect but there is little evidence for its long term success. It should be noted that the above health benefits are not exclusive to this diet. Just a 5% reduction in body weight is proven to result in significant health improvements.

Many people have had success with this dieting approach but is it really the solution?

One of the things people struggle with when trying to lose weight is the decision making. ‘What should I have for breakfast’ ‘Are cereal bars OK?’ ‘I’m feeling really hungry but I really shouldn’t have this chocolate biscuit’. It’s this constant decision making which affects sustainability of the weight loss attempt. Common reasons include ‘it’s too hard’, ‘all I think about is food’, ‘I don’t know what I should be eating’, ‘’I’ve had a bad day & blown it, there’s no point in carrying on’. By removing decision making for 2 days per week, it seems mentally easier to cope with. Some people find that this is less challenging than employing calorie restriction every day.

But what about the other 5 days?

The people behind this diet claim that you can eat ‘whatever you like’ however in reality, if you were to consume excessive calories, even with 2 days fasting, you will not lose weight. They rely on the fact that while following this plan, you change your thoughts around eating on non fasting days, and subconsciously reduce intake so not to exceed basic energy needs.

Is it for everyone?

If you are generally fit and well, following this eating pattern should not cause any side effects. However, certain people including children and teenagers, Type 1 + 2 diabetics, pregnant ladies, those with immune disorders or any other medical condition should consult their doctor prior to starting. In addition there is a risk of becoming deficient in certain vitamins and minerals if adequate intake is not consumed during non fasting days.

To sum up..

As with all ‘diets’ or weight loss plans, long term success is determined by individual motivation and compliance. Lifestyle and behaviour changes have proven to elicit the greatest, sustainable weight loss.

Key questions to ask yourself are:

‘Am I happy with what I’m eating?’

‘Can I see myself eating in this way forever?’

‘Am I still able to socialise with friends without worrying about what eat?’

If the answer is ‘No’ it’s unlikely that this is the solution for you. It’s very easy to fall in to the dieting cycle with periods of significant weight gain and loss over a number of years. This can have a negative psychological effect and can lead to frustration and anxiety around lack of weight control.

There are many success stories with the 5:2 eating pattern but I am still sceptical as to whether this is just the latest in a long line of dieting ‘fads’. The proof will be with further research and long term follow up of individuals who continue with this intermittent fasting plan. I still believe that a moderate calorie restriction combined with physical activity is the best way to reach your weight loss goals, while also improving mood and fitness.

Thanks for reading :)