Four possible benefits of fasting, according to science
When people want to lose weight, the potential benefits of fasting can seem very appealing, as just eating for a certain amount of time means you’re potentially consuming fewer calories.
But what is fasting? According to a registered dietitian Marcelo Fiuzo (opens in new tab)spokesperson for British Dietetic Association (opens in new tab), fasting means not consuming calories for a certain time frame. It can be ‘intermittent’, which means you alternate between eating and fasting, or ‘extended’, which generally means fasting from two days onwards.
“Intermittent fastingespecially time-restricted eating like 5:2 or 16:8, has become popular in recent years,” she adds. “It involves eating for a limited period of time each day, usually eight to ten hours.”
In addition to weight loss, many people fast solely for the potential benefits, including better gut and heart health, as well as lower blood pressure. But it’s important to note that fasting does not guarantee these results and is not suitable for everyone – especially anyone with an eating disorder, pregnant women, diabetics, the elderly and children.
In this article, we’ll talk more with Fiuz about the potential benefits of fasting, and take a look at some of the drawbacks.
What does fasting do to the body?
Before we look at the potential benefits of fasting, it’s important to know what it actually does to the body.
Fiuza explains: “During fasting, the body makes numerous metabolic adaptations in order to continue to function optimally in the absence of external fuel (food). In the first few hours of fasting, the body resorts to its glycogen stores for energy. When they are used up, a metabolic change occurs in which the body begins to break down fatty acids into ketones which are then used as a source of energy.
Marcela Fiuza is an award-winning registered dietitian based in London, UK. She has a decade of experience working in the National Health Service, private practice and the commercial sector. She has a Masters in Nutrition and a Post Graduate Diploma in Dietetics from King’s College London. She is a member and media spokesperson for the British Dietetic Association.
“The timing of this metabolic change depends on what your last meal was, how much energy you use, and how much glycogen is stored in your liver. On average, he can go 12-26 hours without food.”
Of course, not all benefits are guaranteed. “Many studies, mostly in animal models, suggest benefits from fasting, and more and more evidence is emerging from human trials,” says Fiuza.
“But more research is needed until we can fully understand the long-term effects of fasting on human health.”
One possible benefit of fasting is that it can trigger a process called autophagy – your body’s cellular recycling system. Acting as a kind of quality control for your cells, autophagy allows the body to break down and reuse old cell parts so they can work more efficiently.
Put simply, it’s the body’s way of keeping house and getting rid of mutated cells that could develop into cancer or neurological conditions like Alzheimer’s or Parkinson’s, according to a study in EMBO magazine (opens in new tab).
The process of autophagy begins after a period of fasting and could be an evolutionary throwback to our hunter-gatherer days, when humans would go without food for longer due to the laborious nature of finding food.
Researchers are studying the role of autophagy in potentially preventing and fighting disease, Fiuza says. “Evidence from a study published in Science Direct (opens in new tab) suggests that fasting may improve autophagy.” Another study, published in Autophagy Journal (opens in new tab)found that regular fasting can ‘reset’ the body and help it work more efficiently by clearing cellular debris.
2. Improved gut health
It’s here evidence (opens in new tab) suggest that a radical change in diet, such as fasting, could change the microbial composition of the gut and change what the gut bacteria do.
Fiuza told Live Science, “Some forms of fasting can be beneficial for the gut microbiome, which is related to the array.” health benefits from improved metabolic health, reduced risk of cancer, heart disease and obesity.”
Other studies have shown this alternating fasting (24 hours of eating normally followed by 24 hours of fasting) promoted ‘bacterial clearance’ that could support the health of the gut microbiome.
3. Healthy heart and blood sugar levels
Fasting can also improve the body’s response to the hormone insulin, which controls blood sugar levels. When your blood sugar is regulated, it reduces your risk of weight gain and diabetes, two risk factors for cardiovascular disease and other heart-related health problems.
Fiuza adds that intermittent fasting may also improve it heart health by reducing low-density lipoprotein (LDL), or bad cholesterol, as well as “positive effects on blood pressure regulation and reducing inflammation,” but more research is still needed in this area.
4. Weight loss
Fasting has gained popularity because many people see it as a way to lose weight. “It can potentially help some people lose weight in the short term,” admits Fiuza. “Although it does not appear to be superior to other types of calorie-restricted diets for this purpose.” And finally, to lose weight, you have to be in caloric deficit.
A systematic review in a peer-reviewed journal Canadian family doctor (opens in new tab) found that in all 27 studies examined, intermittent fasting resulted in weight loss, ranging from 0.8% to 13.0% of initial body weight.
But as with all extreme diet plans, there are some downsides to consider, says Fiuza.
“There are potential side effects of fasting, but they usually go away over time. The main ones are lethargy, irritability and headache, but there is also a risk of eating disorders for those who have a predisposition to eating disorders.
“Extended fasting is much more intense than intermittent fasting, and anyone considering it should talk to their healthcare provider beforehand. Intermittent fasting may not be suitable for everyone.
“People who are pregnant or have type 1 diabetes, suffer from an eating disorder or take medication with food, as well as children and the elderly, should avoid fasting.”
If the post doesn’t sound appealing, check out our guide to Mediterranean diet instead of that.
This article is for informational purposes only and is not intended to provide medical advice.
#benefits #fasting #science