It’s three years since marathon runner Tim Newton started intermittent fasting as part of a low carbohydrate diet to see if he could improve his sports performance.

In four months he’d lost 20lb in weight, had more energy, was enjoying better sleep and improved mood.

It’s safe to say Tim, a high-ranking UK 65+ age group runner, is a now a long-term convert to this way of life.

So much so that he has recently become a local representative of the Public Health Collaboration, a national charity founded by NHS doctors and researchers to promote healthy real food lifestyles to address rising levels of obesity and diabetes.

Tim says there are PHC ambassadors like him across the country, working with GP practices in their local areas to try and support patients in improving their food choices and reducing lifestyle-related disease.

It’s something he feels hugely passionate about - and not just because his marathon times improved by more than 20 minutes in the 18 months after he over-hauled his diet.

“I have a rich and varied real food diet without the blandness of starchy carbs and find I rarely need to eat more than twice a day, even when running up to 60 miles a week,” he says. “I don’t eat until I’ve had my morning run and enjoy a brunch of proteins and healthy fats when I get back.

“For me, intermittent fasting (IF) is more of a consequence of limiting carbohydrate consumption. Very often, I can go 14-16 hours between meals and I am not hungry, which is a total change from how I was before.”

Tim, who runs with the Ipswich Jaffa club, puts this down to the types of “real food” he is now eating - unprocessed foods such as green vegetables, protein and healthy fats.

“The food I eat now satiates me,” he says.

Dr Margriet van Nieuwburg, an Ipswich GP and functional medicine doctor, also has lots to say about intermittent fasting and will be talking about the benefits at an event in Orford on April 22.

IF takes many forms, including the popular 5:2 made famous by BBC’s Dr Michael Mosley and claimed not to help just with weight loss but also to kick start the body’s metabolism in something akin to a spring clean that can benefit almost everyone.

Other cited benefits include improvement of sleep, energy, mood, gut issues, diabetes and pre-diabetes, neurological conditions and several autoimmune diseases.

Dr Margriet, as she likes to be known, says: “This talk will bring science direct to the local community and everyone is welcome to come along; there will be a question and answer session afterwards. IF takes many forms that can be effective, from the 5:2 approach where calories are limited to 600 two days a week, to the 16:8 (hours) where people fast from finishing their evening meal (say 7pm) until lunchtime the next day.

“There are other combinations too – really people can choose the method that best fits in with their lifestyle. The beauty of it is, it’s inexpensive doesn’t require high tech equipment and is easy to follow.”

But what about those who are involved in demanding physical work or are active sports people? As long as good quality nutrient-dense food is eaten in the ‘eating window’ then they too can benefit, she says.

However, she does advise anyone on medication to seek guidance from their GP before embarking on IF.

And healthcare company Bupa warns that IF isn’t appropriate for everyone. For example if you’re pregnant, have a history of eating disorders or have certain medical conditions. Both the National Institute for Health and Care Excellence and the British Dietetic Association also recommend that very low calorie diets should only be done under the supervision of a medical professional. Speaking to your GP or a qualified dietitian is a good place to start, says Bupa.

Its dietitian Rachael Eden adds: “Although many methods of intermittent fasting may now exist, it’s worth noting that the 5:2 Diet was in fact adapted from an evidence-based diet known as the 2-Day Diet. The 2-Day Diet involves reducing your carbohydrate intake on two days of the week, followed by nutritionally balanced meals on the other five days of the week. So for anyone thinking about trying intermittent fasting, I’d recommend looking at the information around the original diet first.”

Dr Margriet will be speaking at Orford Primary School, 11am on Sunday April 22. Entry is £3 per person and any profits made will go to Orford Primary School. To find out more about the Public Health Collaboration go to www.phcuk.org.