THE trendy fad of “intermittent fasting” could add years to your life and get you slim, experts claim.
Researchers have found that limiting eating to set hours or days cuts blood pressure, cholesterol and resting heart rates – warding off heart attacks and strokes.
US-based scientists have now revealed that as well as weight loss, the eating style may also help improve the body’s metabolism to the point where it slows ageing.
Study lead, Professor Mark Mattson, a neuroscientist at Johns Hopkins University, Baltimore, Maryland, has analysed the effects of fasting for more than two decades.
We could soon consider adding information about intermittent fasting to medical school curricula
Professor Mark Mattson
He was so impressed with the results of the diet he adopted it himself back in the 90s.
Prof Mattson said: “We are at a transition point where we could soon consider adding information about intermittent fasting to medical school curricula alongside standard advice about healthy diets and exercise.”
His findings, published in The New England Journal of Medicine, show that fasting can trigger “metabolic switching” and evolutionary adaptation.
Metabolic switching is understood to be a process whereby cells use up their “fuel stores” and convert fat to energy.
Studies show that aside from helping with metabolism, fasting has also been linked with decreased blood pressure, cholesterol and resting heart rates.
It may also help control blood sugar levels, increase resistance to stress and suppress inflammation.
Intermittent fasting: What is the difference between the 5:2 and the 16:8 diet?
The 5:2 diet
The 5:2 diet is based on the idea of intermittent fasting, and still scoffing sweet treats like cake when you fancy.
Dieters eat normally for five days of the week and severely restrict their calories for the other two.
The part-time aspect appeals to many people because there is no restriction on what you eat for five days of the week.
On the fasting days, dieters are meant to eat 25 percent of their recommended calorie total – 500cals for women and 600cals for men.
By only fasting intermittently, you can stop your body going into starvation mode and storing up fat.
The 16:8 diet
The 16:8 diet allows you to eat for eight hours of the day, while fasting for the remaining 16 hours.
It stems from the book 8 Hour Diet by author David Zinczenko and editor-in-chief of Men’s Health Peter Moore.
They suggest that a longer fasting time between eating gives the body the time it needs to process the food and burn away extra fat stores.
This diet doesn’t suggest you cram all your food into an eight-hour window.
Instead, it encourages the consumption of balanced foods that can burn fat and boost overall health.
Experts suggest dieters opt for lean meat, eggs, dairy, vegetables, nuts and beans each day during their eight hour window.
For the remaining 16 hours, dieters can consumer water, tea and coffee.
Four studies in both animals and people found intermittent fasting decreased blood pressure, cholesterol and resting heart rates – warding off heart attacks and strokes.
It can also reduce other risk factors associated with obesity and diabetes, said Prof Mattson.
He cited two studies at the University Hospital of South Manchester NHS Foundation Trust of 100 overweight British women.
Those on the 5:2 diet lost the same amount of weight as peers who restricted calories – but more dangerous belly fat that gathers around the organs melted away.
They also fared better on measures of insulin sensitivity.
Recent preliminary studies suggest intermittent fasting could hold the key to combating Alzheimer’s disease.
One multi-centre clinical trial at the University of Toronto in April found 220 healthy, non-obese adults who maintained a calorie restricted diet for two years showed signs of improved memory in a battery of cognitive tests.
Prof Mattson said that if proof is found, the fasting – or a drug that mimics it – may offer interventions that can stave off neuro-degeneration and dementia.
‘Unwilling’ to fast
Most people eat three meals a day on top of snacks and do not experience the metabolic switch – or the suggested benefits, said Prof Mattson.
He added that the specific mechanisms behind the phenomenon are still not fully understood, and some people are “unable or unwilling” to stick to fasting.
But with guidance and patience, it can be incorporated into their lives.
It takes time for the body to adjust – and get beyond the initial hunger pangs and irritability that accompany it.
Prof Mattson said: “Patients should be advised that feeling hungry and irritable is common initially and usually passes after two weeks to a month as the body and brain become accustomed to the new habit.”
To get over this hurdle he suggests GPs advise patients to gradually increase the duration and frequency of the fasting periods over the course of several months – instead of ‘going cold turkey.’
As with all lifestyle changes it is important for physicians to know the science so they can communicate potential benefits, harms and challenges – and offer help, said Prof Mattson.