He says there’s good evidence showing that fasting increases longevity, can help patients on chemotherapy and can even improve energy levels. It’s also been shown to help patients with Type 2 diabetes and decrease the inflammation associated with arthritis, he says, but as yet, “no one has done good controlled studies on skin.”

What we believe, he says, is that people with skin conditions that involve inflammation – such as acne and psoriasis, could benefit from intermittent fasting because they are decreasing the amount of poor quality carbohydrates they eat that set off an inflammatory response.

Ms Pearson says there are a number of intermittent fasting diets and she explained the differences between some of the more popular ones and the effect they have on weight loss and skin rejuvenation.

In this scenario people restrict the hours that they allow themselves to eat in each day. For example, you’d eat only between the hours of 11am and 7pm. Outside of those hours you’d drink plenty of water.

According to Ms Pearson the good thing about this type of diet is that it works for weight loss even though there’s no calorie restriction involved and “it’s great for people who don’t like breakfast.” She also said the studies showed that those who’d tried it also reported they slept better. But, she says, it doesn’t suit all people – if you like to graze, it may not be for you. And, unfortunately, in terms of skin rejuvenation, the fasting is just not long enough.

Next comes the intermittent fasting like the 5:2 diet where you have 24 hours twice a week of no food, only water. (Some people vary this by eating 500 calories for women and 600 for men a day.)

The good things about this diet, according to Ms Pearson is that it reduces insulin levels and helps with weight loss. It also helps people change their eating behaviour in the long term as they start reading labels and thinking more about what they eat and the number of calories in their food choices, she says. The downside is “making sure all the nutrients are covered,” she says.

Next, we pull out the big guns – the Periodic Fast. This is where the real changes start to kick in.

As horrendous as this sounds (too me at least!) this involves not eating for around 5 days in a row. Studies show that after 4-5 days the body starts to invoke self-preservation mechanisms such as autophagy, where the old and damaged cells are broken down and removed. In addition, there’s an increase in stem cell generation – which can be great for skin rejuvenation.

So, not only can this help you shed a handful of pounds in a week, it can also make you look fresher. But, it’s not for everyone. It is not suitable for people with diabetes or heart conditions and if you are considering this, consult with your doctor first to make sure you don’t have any other contraindications.

It can make people feel faint, tired and give them headaches initially, but then they move into what’s known as a ‘ketosis high’ and say they feel more alert and have improved concentration.

It’s also important to note that you don’t exercise and that you do drink at least 3 litres of water a day.

Now, if 5 days of complete starvation isn’t your cup of water, then there is what’s known as the Fasting Mimicking Diet or FMD. In this diet you get the benefits of the water only diet, but you get to eat specific foods that contain certain amino acids that don’t trigger nutrient receptors. These include olives, nuts, seeds and soya based foods, and other plant based meals such as vegetable soup.

One example of a ready made diet plan for this type of diet is Prolon. These ready made meals are designed to make you feel less hungry but trick the body into thinks its fasting.

According to Ms Pearson this type of diet can help reduce the risk of diabetes, coronary heart disease and has been shown to reduce visceral fat -the dangerous type of fat accumulates around the belly and the heart. And, you also get all the skin rejuventation benefits.

Again though, consult with your GP if you’re thinking of doing this kind of diet as it may not be suitable for everyone.

In theory, people do this type of fasting for 5 days every 25 days for 3 months and then repeat it a few times a year or continue on every month.

In terms of what happens in your body – this timetable gives you a glimpse.

Days 1-2 – entering Ketosis (where the body starts to use the sugars in the cells rather than circulating sugars for energy. Your breath may be a bit smelly.)
Days 3-5 – cell preservation and autophagy start
Days 4-5 – Stem cell production increases and you’ll start to reap the benefits of the rejuvenation and regeneration process.

Ms Pearson says studies show this type of diet can:

– improve cognitive performance,
– increase longevity,
– decrease abdominal fat,
– decrease systemic inflammation
– improve blood glucose, cholesterol, triglycerides and blood pressure
– increase stem cell production which improves skin and makes it look healthy, and,
– increase energy levels (believe it or not!)

After completing the diet it’s important to reintroduce foods slowly by starting with things that are easily digestible such as soups and smoothies, Ms Pearson says.