Intermittent Fasting for Weight Loss

Intermittent fasting has become quite popular these days for losing weight, improving health, and embracing the idea of living longer. We are here to understand what it entails, its history, methods, beneficial results, and any possible side effects.

What Is Intermittent Fasting (IF)?

intermittent fasting question
Courtesy: Photo by Tim Wildsmith

At first glance, Intermittent Fasting (IF) might seem like a diet, but it’s not. It involves periods of either eating very little or not eating at all for a specific duration. Unlike typical dieting, it doesn’t restrict what you can eat. Fasting is an ancient tradition practiced by many cultures and religions over centuries, including Buddhism, Hinduism, Islam, Judaism, and Christianity. However, therapeutic intermittent fasting for treating obesity was first investigated as early as 1915 and regained interest in the medical community in the 1960s after the publication of an ‘enthusiastic report’ by Blood and his colleagues. A type of periodic fasting known as the 5:2 diet was introduced by Michelle Harvie and Mark Mattson, popularized in the UK and Australia around 2012 by Michael Mosley. By 2019, Intermittent Fasting had become a significant phenomenon, attracting celebrity endorsements and global public interest.

Benefits of Intermittent Fasting:

More people are joining the Intermittent Fasting trend due to its weight loss results. Saying that, IF has numerous other benefits which are listed below based on research findings:

Give our body a break: Going into fasting mode gives our vital organs, hormones, and certain hormones a ‘break’.

Cellular repair: While fasting, our body goes into cellular repair mode, such as removing waste material from cells and rejuvenating the tissues.

Gene expression: Beneficial changes take place among several genes and molecules, which protect against certain ailments and diseases in the long run.

Boost Human Growth Hormone: The blood levels of human growth hormone (HGH) spike dramatically, which helps in gaining new muscle tissues and burning body fat.

Insulin balance: Insulin levels drop, which improves insulin sensitivity. Excessive insulin secretion leads to the development of metabolic disorders, kickstarting prediabetes, so IF lowers the risk of developing type 2 diabetes.

Lowers oxidative stress and inflammation throughout the body. We know inflammation is the root cause of many chronic diseases.

Good for cardiac health: Due to its beneficial impact on blood sugar, blood pressure, and triglyceride levels in the blood, while reducing inflammation, it contributes to a synergistic effect on improving heart health.

Brain health: Proper insulin metabolism and other factors like less oxidative stress and inflammation with Intermittent Fasting help memory along with overall brain health.

Longevity: Studies in rodents have shown intermittent fasting extends lifespan by around 13%. Meta-analysis on human studies is still pending to look into this area.

May help prevent Alzheimer’s disease and the development of cancers.

How Intermittent Helps in Weight Loss?

To understand how Intermittent Fasting helps us lose weight, we need to understand the four transition states that our body goes through when we fast:

1. Absorptive stage: After a meal, our body’s fat storage becomes active for about four hours, during which the primary source of fuel is glucose to carry out bodily functions.

2. Post-absorptive stage: Glycogen (glucose reserves in the liver) is released as a fuel source during this state, which can last up to 18 hours.

3. The fasted stage: Continued fasting, lasting from 12 to 20 hours, transitions the body to use other fuel reserves like fat, lactic acid, and alanine as a fuel source, as glycogen reserves in the liver begin to deplete.

4. Metabolic Switch: This is the final stage when fat storage and lipid synthesis mobilize into free fatty acid-derived ketones to supply energy, transforming our body into a fat-burning furnace.

In addition to the production of abundant ketone bodies (KB) from free fatty acids, higher levels of HGH, lower insulin levels, and an increased amount of the noradrenaline hormone create a domino effect, rapidly breaking down body fats with overall increased energy.

In addition to burning excess body fats, fasting helps detoxify our vital organs, enabling our systems to work better and more efficiently, aiding in weight loss while minimizing health risks and improving our life expectancy.

Read More: The Hidden Dangers of Excess Belly Fat You Should Know

Types of Intermittent Fasting:

There are mainly three types of intermittent fasting:

1. Time-restricted fasting: This involves fasting for a certain number of hours each day, along with a consistent pattern of caloric intake. The fasting hours can last 8, 12, 16, or even 20 hours, with the remaining time window for feeding. For example, it can be a 16:8 diet, which consists of 16 hours of fasting followed by 8 hours of non-fasting.

2. Alternate-day fasting: In this method, you fast for one day (24 hours) and consume minimal food, amounting to 1/4th of the usual energy requirement. This is followed by a non-fasting day (24 hours).

3. Periodic fasting: This method involves consecutive fasting periods of more than 24 hours. For example, the 5:2 diet consists of eating normally for five days per week without caloric restrictions, and on the remaining two days, reducing calorie intake to 25% of daily needs, which is approximately 500 to 700 calories.

So, which one is the most popular method? The 16/8 method of intermittent fasting is the most popular, as many people find it to be the simplest and easiest to stick to. With this method, you fast for 16 hours each day, consuming only plain water, tea, or coffee, and then have an 8-hour window for snacks and meals. Typically, one starts fasting at night by skipping dinner, then skips breakfast, and breaks the fast around mid-day. Many people have experienced significant weight loss with this method while ensuring they consume only sugar-free or low-sugar beverages during the fasting phase.

For example, Reddit user “Suesiesunshine” provided comments about the 16/8 fasting method. At the time of writing this review, she was 49 years old.

‘’I’ve been doing that for several months and I believe that it’s helped reset my relationship with food to a much more healthy perspective. I was so food obsessed before! You think I was about to starve to death even though I need to lose a few pounds.

In the morning I have a cup of tea with a scoop of powdered MCT oil for energy and that keeps me full. I generally get hungry around 11 AM or noon and then break my fast and eat until seven or 8 PM. I find that it has made it much easier for me to eat the right amount of calories without feeling deprived. I do a “lazy keto” type diet with a target of 20 to 30 net carbs per day.

I’ve had several people ask about whether I have enough energy to work out, and I absolutely do! You just need to get through a couple of days to get all of the carbs out of your system and get your body into using ketones for energy. It’s worked great for me and it was an effortless way to lose about 20 to 30 pounds.’’

As you can see the above review is quite encouraging and you shall find more comments about 16:8 fasting method here:

The 16/8 method is the most popular because you can easily include your sleeping time in the 16-hour fasting phase, avoiding the hassle of preparing breakfast in the morning while getting ready for work.

Research Findings:

Most studies on humans have observed weight loss ranging between 2.5 to 9.9%.

For time-restricted eating, such as 16/8 or 20/4 IF, the ratio of weight loss is 3:1 for body fat loss to lean mass loss. (source)

Alternate-day fasting may be better suited for individuals concerned about losing lean mass, as it has been shown not to significantly affect body mass.

Additionally, this fasting method is particularly beneficial for overweight people with metabolic syndrome, as it improves metabolism and cardiac health. (source)

Are There Any Side Effects of Intermittent Fasting You Need to Be Aware Of?

Short-term effects may include continuous feelings of hunger, dizziness, irritability, poor concentration, and headaches during the first several days. These symptoms typically subside as your body becomes accustomed to intermittent fasting.

Intermittent fasting is not recommended for individuals with eating disorders, pregnant or breastfeeding mothers, the elderly, or vulnerable individuals.