Intermittent fasting is related to the right eating pattern and has several benefits like:
- Heart health
- Lowered inflammation
- Improved cell repair processes
And burning fat.
Intermittent fasting includes the right eating pattern including the cycles between periods of eating and periods of fasting. There are several types of intermittent fasting, which include 16:8 and 5:2 methods. Different studies give evidence about the strong benefits of meditation for your body and brain.
Intermittent fasting: What is it?
Intermittent fasting depends on when you eat, rather than what foods you eat. Intermittent fasting involves alternate periods of eating and fasting. Most diet plans tell us about what to eat. However, intermittent fasting is more associated with when you eat. Intermittent fasting means that the person eats only at a specific time. Research reveals various health benefits of fasting for a certain amount of time each day or going without meals for a few days in a week.
Johns Hopkins neuroscientist Mark Mattson studied the effects of intermittent fasting for 25 years. The scientist said that our bodies have the ability to go without food for hours at a stretch, even several days or more. In earlier times, before humans learned and practised farming, they were hunters and gatherers. They also survived and thrived for long periods without eating. They spent a great deal of time and energy hunting game and gathering nuts and berries.
Experts point out that it was easier to maintain healthy weight in America about 50 years ago. It was a time when there were no computers, and TV shows turned off at 11 p.m. People went to bed much earlier and stopped eating much before. Moreover, portions were much smaller, people worked and played outside. On the whole, they did more physical work.
With the internet, TV and entertainment are available round the clock, several adults and children stayed awake for longer hours for things like watching TV, scrolling through social media, playing games and chatting online. Also, this meant sitting and snacking all day — and in the large part of the night.
More calories with less activity meant a higher risk of chronic issues such as:
- Obesity
- Type 2 diabetes
- Heart disease
And other illnesses.
Scientific studies showed that intermittent fasting could assist in reversing these trends.
How Does Intermittent Fasting Work?
Intermittent fasting can be followed in various patterns, which are based on choosing regular time periods to eat and fast. For example, you may opt to eat for an eight-hour period each day while fasting for the rest of the time. Otherwise, you may like to eat just a single meal per day twice or thrice in a week. There are so many variations in creating intermittent fasting schedules.
Scientists working on intermittent fasting say that when the body goes without food for hours, it exhausts itself of sugar stores and goes on burning fat. Mattson named this as metabolic switching.
Therefore, it can be said that intermittent fasting works by increasing the period of burning of calories by the body after you consume your last meal. In this process, the body also starts burning fat.
Approaches to Intermittent Fasting
There are varying approaches to intermittent fasting involving an extended fasting window every day. Others can go for full fasting days at specific times every week.
Based on your approach, intermittent fasting generally involves extending the amount of time the body goes without food.
During the fasting state, insulin works on fat cells to release sugar, which the body uses for energy. The basic idea for intermittent fasting being effective is that it uses stored energy allowing weight to go down.
Moreover, there are also a few common approaches to intermittent fasting including:
- Twice-a-week method
- Alternate-day fasting
- And time-restricted eating.
Twice-a-week method
The twice-a-week method, which is also known as 5:2, allows the person to eat a normal and healthy diet for 5 out of 7 days of the week. They will have 2 fasting days, where they will not eat more than 500–800 calories. It is necessary to find out the days when you would fast to ensure that there is at least a single non-fasting day between them.
Alternate-day fasting
Alternate-day fasting involves fasting post a single day. On days of fasting, you stay limited to eating just about 500–800 calories. On non-fasting days, one eats just a normal and healthy diet.
Time-restricted plans
Time-restricted plans involve eating and fasting in two windows, cycles per day. It means that sleep hours will spontaneously extend the fasting window.
There are only a few fasting hours during sleep and people find it easier to follow this method. Common time-restricted eating methods are the 16/8 method and the 14/10 method.
- 16/8 method: On fasting for 16 hours per day, you limit your eating to the remaining 8 hours. For example, eating only between 9 a.m. and 5 p.m. or between noon and 8 pm, you follow this.
- 14/10 method: On fasting for 14 hours of the day, you only get to eat during the rest of 10 hours. This involves eating between 10 a.m. and 8 p.m.
- Other versions of fasting are the 18/6 and the highly restrictive 20/4 version of fasting.
People may follow such patterns of eating and fasting for a certain number of times a week to every day.
A few people like to follow the fasting pattern in the long term. A research study was done on intermittent fasting patterns. The study involved limiting one’s daily time window of eating for countering weight gain over time. It could also give the desirable weight loss results. The results also showed that lowering the number of large meals and eating smaller meals helps minimize weight gain and gives weight loss over time.
There are longer periods without food, like 24-, 36-, 48- and 72-hour fasting periods, may not be truly better for you, and rather can be dangerous. Also, remember that going for a longer time without food can make your body prone to storing a higher amount of fat responding to starvation.
Mattson’s research shows that it may take two to four weeks before the body becomes accustomed to intermittent fasting. You may feel hungry or cranky when you are not used to your new routine. However, he observed that research subjects adjusted and stuck with the plan as they noticed feeling better.
What can I eat during intermittent fasting?
During times when you don’t eat, you can take water and zero-calorie beverages if black coffee and tea are permitted.
When you resume eating, “eating normally” would again require discipline. Research reveals that you may not lose weight or achieve fitness goals taking high-calorie junk food or super-sized fried items and treats.
Some experts allow different kinds of foods to be taken during intermittent fasting. This involves having nutritious food where people can savor their mealtime experience for greater satisfaction and better health.
A Mediterranean diet is one of the best diets aligned with intermittent fasting. It comprises healthy components such as:
- Leafy greens
- Healthy fats,
- Lean protein,
- Complex and unrefined carbohydrates of whole grains.
Intermittent Fasting Helps You Lose Weight and Visceral Fat
Intermittent fasting is helpful in losing weight and involves eating fewer meals during the day. If you are not eating more during the other meals and taking fewer calories, you will end up losing weight.
Additionally, intermittent fasting improves hormonal secretion and promotes weight loss. For example, lower insulin levels, higher HGH levels, and increased norepinephrine levels bring about a higher breakdown of body fat for energy.
Therefore, short-term fasting improves your metabolism and helps burn even more calories.
In a 2022 study involving 131 people with obesity, researchers discovered that people that took part in 12 weeks of intermittent fasting lost an average of 9% of their body weight. The results were much better than people who took to other weight loss methods.
This study involved a 5:2 intermittent fasting plan, where participants followed a restricted diet for 2 days and participated in a 5-day program.
In a 2020 review of 27 studies, intermittent fasting participants lost 0.8–13% of the baseline body weight.
In another trial in 2020, researchers focused on people following the 16:8 method. People that fasted for 16 hours per day and ate within the 8-hour window.
However, it was discovered that people who fasted did not lose a significant amount of weight than people who took three meals per day. The researchers also found that a few participants of the fasting program lost a significant amount of lean muscle mass.
More studies are needed to understand the effect of fasting on muscle loss. However, overall, intermittent fasting proves to be a potentially powerful weight loss tool.
Evidence-based Health Benefits of Intermittent Fasting
#1 Intermittent Fasting Benefits: Improvement in function of hormones, cells, and genes
With a restrain on eating, several changes start occurring in your body. The body experiences changes in hormone levels mobilizing the stored body fat making it more accessible for important cellular repair processes.
Here are a few changes that happen in your body due to intermittent fasting:
- Insulin level: Your blood level of insulin may abruptly fall down and this promotes fat burning.
- Human growth hormone (HGH) level: The blood level of HGH can suddenly increase. Higher HGH levels promote fat burning, muscle gain and give numerous other benefits.
- Cellular repair: Cellular repair begins and it helps in removing waste material from cells.
- Gene expression: Several genes related to longevity get activated. This is what helps give protection against disease.
There are several benefits of intermittent fasting, which are related to changes in hormones, cellular function, and gene expression.
#2 Intermittent Fasting Benefits: May lower insulin resistance and risk for Type 2 Diabetes
Intermittent fasting has several major benefits for insulin resistance leading to a significant reduction in blood sugar levels. Whatever reduces insulin resistance can also help lower your blood sugar levels for protecting against type 2 diabetes. In a 2022 review of 10 studies on intermittent fasting, the authors found fasting blood sugar lowered averagely by about 0.15 millimoles per liter.
A 2018 study in diabetic mice showed that intermittent fasting improved survival rates that protected against diabetic retinopathy, a diabetic complication that may cause blindness. There is a lot of evidence suggesting that intermittent fasting is highly protective for people at risk of developing Type 2 Diabetes.
Moreover, intermittent fasting can produce results that can vary in men and women. A 2015 study reported in a 2017 meta-analysis, revealed that blood sugar regulation in women worsened post a 3-week intermittent fasting protocol, while men had an improvement in blood sugar regulation.
Consequently, it is understood that women may require taking a more gradual approach for minimizing the possible negative effects on reproductive health, bone health, and general well-being.
Women having diabetes and taking certain medications, or those who are pregnant or breastfeeding should talk to their doctor before entering into the intermittent fasting plan.
#3 Intermittent Fasting Benefits: Intermittent Fasting lowers oxidative stress and inflammation inside the body
Oxidative stress is a vital factor leading to ageing and various chronic diseases. It occurs due to free radicals, certain unstable molecules, which react with and damage several important molecules such as protein and DNA.
A 2018 review showed that intermittent fasting increased the body’s resistance to oxidative stress. Additionally, a 2019 study suggests that intermittent fasting also helps in lowering inflammation, leading to many diseases.
#4 Intermittent Fasting Benefits: May be beneficial for heart health
Heart disease is one of the important reasons for death. There are several health markers or risk factors associated with heart disease.
Intermittent fasting has been shown to ameliorate several risk factors for heart disease, including:
- Blood sugar levels
- Blood pressure
- Blood triglycerides
- Total and LDL (bad) cholesterol
- Inflammatory markers
Is intermittent fasting safe?
People do not take to Intermittent fasting just for managing chronic conditions such as high cholesterol, arthritis, and irritable bowel syndrome, but also for simpler things like weight management. However, it’s important to talk to your primary care practitioner before starting with intermittent fasting. Intermittent fasting should not be done by:
- Children and teens less than 18.
- Pregnant or breastfeeding women.
- People with type 1 diabetes taking insulin.
- People with a History of Eating Disorders.
Potential risks in General
Research also suggests that Intermittent Fasting affects calorie intake significantly and also lowers bone strength and bone density.
Latest reviews of studies also reveal that intermittent fasting may not negatively impact mineral density in the bones like calorie-restricted diets.
There can also be other possible side effects of intermittent fasting, such as:
- Headaches
- Tiredness
- Constipation
- Overeating during non-fasting periods
Understanding various health risks, women require taking a different approach to intermittent fasting than men. It’s necessary to make small and gradual changes over several months in place of drastic ones in a small time period, and this is what helps minimize unwanted side effects. It’s necessary to talk to your doctor to discuss the potential risks of intermittent fasting and ascertain if you’re following the right method.
Fasting in people with Type I Diabetes
Various clinical trials show that intermittent fasting is safe in people with Type 2 Diabetes, but more research is needed to understand the effects of Intermittent Fasting. People with Type I Diabetes take insulin. Intermittent fasting can lead to an eating pattern where patients can get unsafe levels of hypoglycemia during fasting period.
People not belonging to these categories can take to intermittent fasting safely while continuing the regimen indefinitely. The fact is that such a lifestyle change can give several benefits. Understand that intermittent fasting can have varied effects on different kinds of people. However, if you experience unusual anxiety, nausea, headaches, or such symptoms after you start intermittent fasting, it is important to consult your doctor.
An important point to understand is that like nutrition is personal, so are the results of intermittent fasting. Research shows that different people respond differently to food. Even identical twins will have unique food responses suggesting that our metabolic health is not only based on genes alone but also based on other factors and has a deeper connection. Therefore, intermittent fasting will give different results to different people. However, one thing is sure. When done properly, intermittent fasting has some benefit or other to offer to every person taking to it.
Difference in Intermittent Fasting in Women and Men
Intermittent fasting affects men and women in different ways. Women should consider the possible risks around reproductive health, bone health and overall well-being while entering into intermittent fasting.
Although you can eat normally during the non-fasting periods, certain forms of intermittent fasting helps lower your calorie intake. With calories, your body gets energy, especially if it is in short supply. Moreover, your body needs to be more focused on survival in comparison to other functions.
Intermittent fasting for women has received lesser research but a few studies on rodents suggest intermittent fasting may lead to changes in estrogen levels. This can negatively impact reproductive functions like menstrual regularity, fertility, pregnancy and lactation.
The hormone levels of male rodents also get affected, but disruptions do not affect their reproductive functions as much as female rodents. One of the reasons for this may be that functions such as pregnancy and breastfeeding need more energy than functions in men.
So, if energy intake is too low, these functions can be negatively affected. However, it is seen that human females get affected in the same way as rodent females.
CONCLUSION
Research suggests that there are various health benefits to intermittent fasting, including possible weight loss, improved insulin sensitivity and heart health. Additionally, every person has a unique response to different foods and fasting timelines. There can be various benefits one can get for different health aspects, such as your weight. A comprehensive nutrition and gut microbiome study in the world shows strong links between specific gut microbes and body composition. Intermittent fasting can help women in getting personalized nutrition for achieving specific health goals.