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Pros & Cons Of Intermittent Fasting

Intermittent Fasting

Intermittent fasting is when you go for extended times without eating. This is followed by periods of eating normally. Your ancestors would have eaten like this, not because of choice but because of food availability. They would have only eaten when they could find food.

Intermittent fasting has become a popular trend with people who are trying to lose weight. There are a variety of ways that you can incorporate this type of diet trend, some recommend 16:8, which means for 16 hours of the day you are not consuming anything, and then all of your meals and calories are consumed in the 8 hour window. Some suggest 5:2, which requires that you fast and eat roughly 500 calories for two consecutive days and then eat what you want on the remaining five days of the week. Other forms of this process recommend taking a complete 36 hour fast once a week.

There are a few different options that may be suitable to you but like with anything there are pros and cons. Please find these below:


Can help you to lose weight and visceral fat – Intermittent fasting helps you eat fewer calories while boosting metabolism slightly, allowing you to lose weight more easily. 

Can reduce insulin resistance, lowering your risk of type 2 diabetes – Intermittent fasting has been shown to have major benefits for insulin resistance and can lead to an impressive reduction in blood sugar levels. 

Can reduce oxidative stress and inflammation in the body – Oxidative stress is one of the steps towards aging and many chronic diseases. Several studies show that intermittent fasting may enhance the body’s resistance to oxidative stress.

May be beneficial for heart health – Studies have shown that intermittent fasting can improve numerous risk factors for heart disease, such as blood pressure, cholesterol levels, triglycerides and inflammatory markers. 

Changes the function of hormone cells and genes – When you don’t eat for a while, several things happen to your body. For example, your body changes hormone levels to make stored fat more accessible and initiates important cellular repair processes.


● Hunger and Cravings – When you reduce your calorie intake or go long periods of time without taking in calories, it is likely that you will experience hunger.

Headaches and lightheadedness – Headaches are a common side effect of intermittent fasting. They typically occur during the first few days of fasting.

Digestive issues – Constipation, nausea and bloating are common symptoms that you might experience if you start intermittent fasting. 

Irritability and other mood changes – Some people may feel irritable, as when your blood sugar is low it may cause you to feel annoyed. 

Fatigue and low energy – Low blood sugar related to intermittent fasting can cause you to feel tired and weak. 

Bad breath – Bad breath is a side effect that can occur in some people during intermittent fasting. This is caused by lack of salivary flow and the rise of acetone in the breath.

Although intermittent fasting may be a smart choice for some, it is not appropriate or safe for others. Healthcare professionals generally advise that the following people avoid intermittent fasting:

● Women that are pregnant or breastfeeding

● Young children and teens

● Older adults who experience weakness

● People with immunodeficiency

● People with current or past eating disorders

● People with dementia

● Those with a history of traumatic injury or post concussive syndrome

This list is not exhaustive and there are exceptions. For example, healthcare professionals have used fasting to treat epilepsy in children. 

To find out more about the pros and cons of intermittent fasting, please do not hesitate to contact us today at David Jones Personal Training.