Intermittent fasting is an eating pattern where you cycle between periods of eating and fasting.
It does not say anything about which foods to eat, but rather when you should eat them.
There are several different intermittent fasting methods, all of which split the day or week into eating periods and fasting periods.
Most people already “fast” every day, while they sleep. Intermittent fasting can be as simple as extending that fast a little longer.
You can do this by skipping breakfast, eating your first meal at noon and your last meal at 8 pm.
Then you’re technically fasting for 16 hours every day, and restricting your eating to an 8-hour eating window. This is the most popular form of intermittent fasting, known as the 16/8 method.
Despite what you may think, intermittent fasting is actually fairly easy to do. Many people report feeling better and having more energy during a fast.
Hunger is usually not that big of an issue, although it can be a problem in the beginning, while your body is getting used to not eating for extended periods of time.
No food is allowed during the fasting period, but you can drink water, coffee, tea and other non-caloric beverages.
Some forms of intermittent fasting allow small amounts of low-calorie foods during the fasting period.
TYPES OF INTERMITTENT FASTING
Intermittent Fasting is seen as an umbrella term, because there are a variety of types of fasting. This also makes it difficult to study Intermittent Fasting because it’s harder to compare diets when they are executed in different ways.
- The most popular Intermittent Fasting are alternate day fasting, whole day fasting and overnight fasting. Let’s take a look at.
Alternate Day Fasting
A type of intermittent fasting that calls for eating nothing one day, and then whatever a person wants the next, can be done safely for several months and comes with a number of health benefits, a study has found.
Alternate day fasting improved cardiovascular markers, reducing blood pressure and heart rate after four weeks, researchers reported in Cell Metabolism on Tuesday. People who followed the plan for six months also had lower levels of LDL “bad” cholesterol and triglycerides compared to those who ate normally.
2. Whole-Day Fasting
Compared to alternate-day fasting, this kind of fasting may seem “more extreme”. 1 to 2 days per week, you need to either severely restrict your calories or completely abstain from food. This is also called the “5:2 diet”. The 5 represents the number of ad libitum days you eat normally. The 2 represents the number of non-consecutive days you have to restrict calorie consumption to 25% (500-600 calories) of your total daily energy expenditure calories.
3. Overnight Fasting
This approach is the simplest of the bunch and involves fasting for a 12-hour period every day. For example: Choose to stop eating after dinner by 7 p.m. and resume eating at 7 a.m. with breakfast the next morning. This is the minimum number of fasting hours . A pro of this method is that it’s easy to implement. Also, you don’t have to skip meals; if anything, all you’re doing is eliminating a bedtime snack (if you ate one to begin with). But this method doesn’t maximize the advantages of fasting. If you’re using fasting for weight loss, a smaller fasting window means more time to eat, and it may not help you decrease the number of calories you consume.
Pros of Intermittent Fasting
Several types of intermittent fasting have been associated with different benefits for their adherents compared to other traditional diets.
Weight Loss
One of the main reasons why people adopt intermittent fasting is to manage or lose weight. Evidence suggests that intermittent fasting can be beneficial as a weight loss tool. Specific research investigating the effects of ADF on weight loss found that within a 2 to 3-week period, there was a 2.5% reduction in weight compared to baseline measurements.
Health Benefits
It has been found that intermittent fasting can have several long-term preventative health benefits. It is well researched that being overweight and obese can increase the likelihood of developing a range of life-threatening diseases such as coronary artery disease (CAD). An intermittent fasting dietary program can thus bring about a reduction in triacylglycerol concentrations, and an increase in high-density lipoprotein cholesterol. These changes lead to an overall reduction in the risk of developing CAD. Further research has also demonstrated that by adopting intermittent fasting, individuals can actually reduce the likelihood of developing age-related diseases such as Alzheimer’s.
It’s easier to follow
Research has found that people find it easier to follow an intermittent fasting diet over a long-term period compared to following a calorie-restricted diet. It is suggested that as individuals only have to reduce their calorie intake every other day on the ADF diet, it is easier to achieve than lowering consumption every day. Even those who follow the amended ADF diet, where they can consume 500 calories on “fast days”, have found that much more achievable than maintaining a constant calorie deficit. Therefore, for those wanting to achieve sustainable weight loss, intermittent fasting might be extremely beneficial.
Cons of Intermittent Fasting
Those who are thinking of adopting intermittent fasting into their routine may want to consider the following negatives.
Side Effects of Intermittent Fasting
Like many diets, intermittent fasting can have several side effects. Research investigating the impact of ADF on weight loss found that participants experienced headaches, constipation and lack of energy. The reported lack of energy may be an issue for those wishing to train or exercise, which is also recommended for adults in order to maintain a healthy lifestyle.
Furthermore, varying psychological effects were reported such as a lack of concentration and bad temper. One major highlight from the research was that people were found to be more preoccupied with food as a result of intermittent fasting. This may cause further issues for those who are predisposed to certain eating disorders.
The Effectiveness of Intermittent Fasting in Weight Loss
There are conflicting research findings on the impact of intermittent fasting on weight loss compared to traditional calorie restricted diets. Some researchers suggest that intermittent fasting is not superior to conventional calorie-restricted diets.
Suitability of Intermittent Fasting
Despite the many health benefits that it offers for individuals who are overweight, obese or of average weight, intermittent fasting is not suitable for everyone. There are specific groups of society for whom this plan is not recommended, such as pregnant women, those with eating disorders and those with certain health issues.
Sources
- Intermittent fasting protects against the deterioration of cognitive function, energy metabolism and dyslipidemia in Alzheimer’s disease-induced estrogen deficient rats: journals.sagepub.com/doi/abs/10.1177/1535370217751610?journalCode=ebmb
- Intermittent fasting dissociates beneficial effects of dietary restriction on glucose metabolism and neuronal resistance to injury from calorie intake: http://www.pnas.org/content/100/10/6216.full
- Practically of Intermittent Fasting in Humans and its Effect on Oxidative Stress and Genes Related to Aging and Metabolism: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4403246/
- Short-term modified alternate-day fasting: a novel dietary strategy for weight loss and cardioprotection in obese adults: https://academic.oup.com/ajcn/article/90/5/1138/4598070
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1859864/
- Intermittent fasting and human metabolic health: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4516560/