Intermittent Fasting: Everything you need to know about losing weight and staying healthy

Weight loss is defined as the decrease of our total body mass through loss of fluid, body fat or lean mass – namely bone mineral deposits, muscle, tendon and connective tissue. It can occur unintentionally due to malnourishment and disease, or it may be intentional to improve actual overweight or obese state. Intentional weight loss is usually called slimming.

Losing weight is no easy task. As many people want to lose weight naturally and quickly, they often try fad diets and other weight loss programmes that promise quick results. What these people don’t know is that if they lose weight gradually and steadily, they are more likely to be successful at maintaining their ideal weight. Healthy weight is not only about diet rather it’s about an ongoing lifestyle that includes long-term changes in daily eating and exercise habits.

Intermittent Fasting: What is it and how does it work

Intermittent Fasting (IF) is currently gaining popularity in the health and fitness industry. Many are using it to lose weight and improve their health and lifestyle. Several studies[1] have also suggested that it has a powerful effect on our body and brain’s vitality but what is intermittent fasting and how does it actually work?

Contrary to what most people think, intermittent fasting is not a diet rather it is an eating pattern that is divided between two periods – fasting and eating. It doesn’t provide specific foods that you can eat or types of food to avoid, rather it dictates to you the time when you should eat and when you need to fast. With intermittent fasting, you are only allowed to eat for a limited time and fast for a certain number of hours each day which in turn is supposed to help your body burn excess fat.

How intermittent fasting works in your body

When we eat, the insulin levels rises, thus storing the excess energy in two ways. First, carbohydrates are broken down into glucose and stored in the liver or muscle. With limited storage space for carbohydrates, the liver starts to turn excess glucose into fat which is the second way of storing excess energy in our body. Some of these newly created fats are stored in our liver but most of them are exported to other fat deposits in our body and with no limit.

However, during intermittent fasting, the process goes in reverse when we do not eat. Our insulin levels drop creating an SOS in our body to start burning stored energy because of the absence of food. Usually, glycogen is broken down first into glucose molecules to provide energy for our body since it is the most accessible energy source. After 24-36 hours of fasting, our body will then start breaking down our fats for energy.

In intermittent fasting, our body only has two states – the fed state and the fasted state. This means we are only either storing food energy or we are burning stored energy. If these two states are balanced, there will be no net change in our weight.

Benefits of intermittent fasting

It helps to lose weight and belly fat. Studies showed that intermittent fasting can cause weight loss of 3-8% over 3-24 weeks.

It lowers your risk for type 2 diabetes. Intermittent fasting has been shown to reduce insulin resistance, thus, leading to an impressive reduction in blood sugar levels.

It has proven beneficial effect to your heart. Most studies suggest that intermittent fasting has been shown to improve blood pressure, total and LDL cholesterol and blood triglycerides.

It aids in your brain health. Interestingly, intermittent fasting has been suggested to help prevent Alzheimer’s Disease. Studies conducted in rats have shown an increased growth of new nerve cells which suggest that intermittent fasting may have a good effect on our brain health.

So, are you ready to lose the weight with intermittent fasting?

Types of Intermittent Fasting

Below are the 4 most common types of intermittent fasting that might work for you.

1. The 5:2 twice-a-week method – 5:2

The 5:2 ratio refers to breaking the 7 days of the week down to 5 non-fasting days and 2 fasting days. For this method the idea is to limit your calorie intake to just 500 calories for 2 days a week and on the remaining 5 days, you maintain a healthy and normal diet (general recommended daily calorie intake for men is 2500 calories and for women is 2000 calories). On your fasting days (500 calories), it is recommended that you eat high-fiber and high-protein foods (vegetable, eggs, oats, cheese, milk, brocolli, quinoa etc) to help fill you up, but to also keep calories low when fasting.

It is important when you choose your two fasting days to make sure that there is a non-fasting day between them, say for example, you can select Tuesday and Thursday as your fasting days and ensure that on Wednesday you eat normally.

2. Alternate day fasting

This type of method involves “modified” fasting every other day. Using this method, you should limit your calories on fasting days from 0 to about 25% of your normal intake. On non-fasting days, you can resume your regular, healthy diet.

Example: If you want a more extreme alternate day fasting and decided not to take in any calorie, you could start fasting on Friday at 10 pm and eat your next meal on Saturday at 10 pm. Ideally, this type of fasting should allow you to eat at least one meal a day.

Or if you opt for the 25% of your normal intake, for instance, you’ve calculated that 1,500 calories a day is the amount you need to eat in order to lose weight. On a fasting day, you’d eat no more than 375 calories. On non-fasting days, you’d eat 1,500 calories.

3. Time-restricted eating

In this method, you have a fasting time and eating window. For instance, you fast for 16 hours and eat only eight hours per day. Since most people fast while they sleep, this method is very popular and convenient. Some of the most common patterns are:

• 16/8 method: Fasting for 16 hours and eating for 8 hours per day.
• 14/10 method: Fasting for 14 hours and eating for 10 hours per day.

This method of IF can be done as often as you’d like depending upon your personal preference. You just have to find out the right eating and fasting windows which might take a few days to figure out, especially if you’re very active or if you wake up hungry for breakfast. For an effective weight loss results, it should be noted that during your eating window, it is a must to practice eating regular healthy meals. Never binge eat during this hour.

4. The full 24-hour fast method (eat: stop: eat method)

This method involves 24 hours of full fasting. Most people do it once or twice a week. With this method, one may feel fatigue, headaches, irritability, hunger and low energy. If you decide to follow this method, you should return to a normal, healthy diet on your non-fasting days.

A full 24-hour fast means you are not allowed to eat anything with caloric value for 24 hours. For example, you would eat dinner today at 9 pm and then you will not be eating anything until tomorrow 9 pm. In this regimen, you do not actually go a full day without eating. You can usually eat one meal on the ‘fasting’ day. Also, people who want to try this method can have water, tea, and other calorie-free drinks during the fasting period.

After a 24-hour full fasting, most people should be able to return to normal eating patterns on the non-fasting days. However, it is recommended to start with drinking fruit shakes and healthy juices to break the fast. Then, this can be followed by a light meal to avoid stomach discomfort.

The dangers and risks of intermittent fasting

Intermittent fasting may have weight loss and certain health benefits but it is not safe and not recommended for everyone. This includes pregnant women, children, people at risk for hypoglycemia and people with chronic diseases. Also, people at risk of an eating disorder are not advised to attempt any fasting diet since intermittent fasting is known to increase chances of binge eating in some people due to restrictions.

Also, if you are interested in trying intermittent fasting you should be aware that it may cause irritability, low energy, persistent hunger, temperature sensitivity and poor work and activity performance.

It is important to note that the long-term implication of IF are not yet known. There have been few long-term studies done on intermittent fasting that examines how it affects people over time. At this point, it is still unclear if there are any long-term health benefits or risks. As we do know that there are risks involved with certain types of intermittent fasting, it is best to proceed with caution. Moreover, since this type of eating pattern has something to do with calorie restriction for a certain time, one should know that prolonged caloric restriction can lead to malnutrition.

How to begin

If you want to start your IF journey, you may want to consider simple methods such as the 16:8 method. You can also start by skipping meals before formally starting to follow the methods mentioned above. This is to gradually prepare your body as you jump into a new eating pattern – what are simple methods?

Typically, people start with the 16/8 method which is the simplest and most sustainable way of intermittent fasting. If you find this method easy and you are starting to be comfortable in this eating pattern, you can try moving on to more advanced fasts like 24-hour fasts 1–2 times per week (Eat-Stop-Eat) or only eating 500 calories 1–2 days per week (5:2 diet).

As you progress, you can then start to mix and match and find out what type of method works best for you. It is also advisable to speak with your doctor or dietitian before starting this type of eating pattern.

To summarize, intermittent fasting has good health benefits – including weight loss, reduction of blood sugar and bad cholesterol levels – what are the health benefits? when combined with a healthy diet and lifestyle. It can also be a particularly effective approach to weight loss but it is not for everybody.

Remember that to really maintain our healthy weight, having a sustainable healthy lifestyle is the key.

References:

Welton, S., Minty, R., O’Driscoll, T., Willms, H., Poirier, D., Madden, S., & Kelly, L. (2020). Intermittent fasting and weight loss: Systematic review. Canadian family physician Medecin de famille canadien, 66(2), 117–125.

Arguin, H., Dionne, I. J., Sénéchal, M., Bouchard, D. R., Carpentier, A. C., Ardilouze, J. L., Tremblay, A., Leblanc, C., &

Brochu, M. (2012). Short- and long-term effects of continuous versus intermittent restrictive diet approaches on body composition and the metabolic profile in overweight and obese postmenopausal women: a pilot study.

Menopause (New York, N.Y.), 19(8), 870–876. https://doi.org/10.1097/gme.0b013e318250a287

Harvie, M., & Howell, A. (2017). Potential Benefits and Harms of Intermittent Energy Restriction and Intermittent Fasting Amongst Obese, Overweight and Normal Weight Subjects-A Narrative Review of Human and Animal Evidence. Behavioral sciences (Basel, Switzerland), 7(1), 4. https://doi.org/10.3390/bs7010004

Aly S. M. (2014). Role of intermittent fasting on improving health and reducing diseases. International journal of health sciences, 8(3), V–VI. https://doi.org/10.12816/0023985

Barnosky, A. R., Hoddy, K. K., Unterman, T. G., & Varady, K. A. (2014). Intermittent fasting vs daily calorie restriction for type 2 diabetes prevention: a review of human findings. Translational research: the journal of laboratory and clinical medicine, 164(4), 302–311. https://doi.org/10.1016/j.trsl.2014.05.013