Alternate Day Fasting: Everything Beginners Need To Know

Interest in fasting, Alternate-Day Fasting, or going without food for short periods has been growing in popularity. Alternative-day fasting (ADF) is a popular form of Intermittent Fasting.

I created this overview of ADF to explore popular and scientific findings on how ADF affects overall health, weight loss, cardiovascular blood markers, and metabolic health. I will provide everything you need to know to implement ADF safely, including tips and tricks.

What Is Alternate Day Fasting?

Alternate-day fasting is exactly what it sounds like: One day, you fast, and the next day, you can eat. You restrict caloric intake on Alternate days. You are allowed to feast on the days you are allowed to eat, and you are limited to fasting on the days you are not.

How you fast is up to you. There are almost infinite ways to fast. There is a strict type of fast in which you do not eat anything, and there is a liquid fast in which you limit your intake to water or certain fluids.

The most popular method of the Alternate-Day Fast is to restrict one’s intake to 500 to 800 calories, or 25% of one’s daily energy requirements.

There are many different types of Intermittent Fasting. Here, we will cover everything you need about alternate-day fasting, including the potential benefits and risks.

Alternate Day Fasting Beginners Guide    

To succeed at alternate-day fasting, you must get used to not eating at your regular intervals and feeling hungry.

Your body will experience chemical responses, and your mind will experience mental changes. About one-tenth of the time, it’s just a change in habit, not real, and you should keep going.

Ensure you do everything possible to remain healthy: Exercise, sleep, and eat well.

Studies show that Alternate-Day Fasting is surprisingly easy to follow. I believe the sacrifice reward feature is there, and it is only a day away, making it attractive. If I were successful during the fast, I would dream of what I could eat less than 24 hours away.

I would rarely eat what I dreamed of, but it was nice to know I could if I wanted to without guilt.

When fasting on alternate days, you should either stop eating or reduce your calorie intake to below 500-800k cal on fasting days. On non-fasting days, you can then eat whatever you want.

On fasting days, food can be eaten all at once or as small meals throughout the day. When doing a modified fast, foods high in protein and fiber will help you feel less hungry, and soups can fill you up without adding many calories. 

Alternate Day Fasting What To Eat and Drink

The great thing about Alternate Day Fasting is you decide what to eat or not. More importantly, it’s about when you choose to eat.

If you are not Dry Fasting, it’s best to drink low-calorie drinks on fasting days. I like drinking water the most, but coffee and tea are also delicious.

I am a fan of eating one big meal during the day, but many people prefer a few small meals during the time window when eating is allowed.

You are more likely to choose healthier meals when limited to one (or a few) daily. As you can imagine, a meal with vegetables, low calories, and high protein is preferred.

These meals lack empty calories and make you feel more satisfied and fulfilled.

Soups are also a good choice, but you must be careful with the ingredients. Soups can be deceiving. Salads and fruits are always a great choice because what you see is what you get.

Is Alternate Day Fasting Safe?

Fasting can sometimes be confused with starvation, but they are different. Fasting is something you choose to do voluntarily, with a positive goal in mind, while starvation can be due to one or more unfortunate situations that may or may not be out of your control. 

Never look on the bright side of things, consider the glass half full, and treat starvation as fasting. Please seek the appropriate help to solve the problem of starvation.

I want to stress that alternate-day fasting appears to be safe as a short—and long-term way of life as long as you aren’t malnourished, underweight, or otherwise unhealthy. 

Symptoms like extreme hunger, irritability, constipation, dizziness, weakness, and even bad breath can be considered common side effects of fasting. These symptoms should be mild and disappear in a few weeks but use common sense. 

Alternate-day fasting is not appropriate for people with a history of eating disorders, such as anorexia, children, and pregnant or lactating women. Studies have shown that alternate-day fasting is safe for most people. Anyone not in optimal health, prescribed medication for blood pressure, diabetes, and the like, should ALWAYS seek medical professional advice before participating in any fasting regimen.

Almost everything in life affects men and women differently, and Fasting is no different. It’s widely believed that women can be more sensitive to Fasting due to their Menstrual Cycle and Hormone fluctuations.

Women are also believed to be more sensitive to the higher stress response brought on by the body’s response to Fasting.

It’s also widely believed that the health benefits of fasting outweigh these possible adverse effects in otherwise healthy people.  

As with any dietary change, seeking medical supervision is a good idea if you start alternate-day fasting.

Alternate Day Fasting Health Benefits

Fasting has numerous health benefits, possibly due to ancestral eating patterns. Early Hunter-Gatherer humans would go longer without eating than we do today. The body might have used these periods to ‘clean’ itself of toxins and potentially dangerous mutated cells.

When the body goes into fasting mode, it switches from using food as fuel to ketones, which it makes by metabolizing fat stores. We can still trigger these responses through fasting for results such as weight loss.

Most people are attracted to ADF for weight loss and to improve health. Studies show that ADF reduces insulin resistance, especially in people with high levels of insulin resistance.

Research shows ADF is more effective than caloric restriction at improving metabolic disease markers in people at most risk of developing diabetes. Metabolic disease markers are used to identify overweight people who are insulin-resistant. 

However, in metabolically healthy individuals similarly overweight, there was no difference found in metabolic disease markers in people doing ADF as opposed to simple caloric restriction.

This would lead one to believe ADF is more effective in people with significant metabolic dysfunction at improving health.

Studies report that alternate-day fasting decreases total cholesterol, low-density lipoprotein cholesterol (LDL-C), triglycerides, and systolic and diastolic blood pressure.

Researchers have also found positive impacts on LDL-C particle size. People who exercised while following an ADF diet and People who did a simple diet alone had increased LDL particle size after 12 weeks.

This is important because larger LDL particles are associated with a lower risk of coronary heart disease than smaller particles.

The most common effect of ADF is stimulating autophagy. Autophagy is the body cleaning out damaged cells to regenerate newer, healthier cells. It prevents cancer, neurodegeneration, heart disease, and infections.

Animal research has consistently shown that fasting increases autophagy and is linked to delayed aging and a reduced risk of tumors. It has also been shown to increase lifespan in these subjects.

Human studies also support this, showing that ADF diets reduce oxidative damage and promote changes that may be linked to longer life. Still, the effects of ADF on autophagy and longevity need to be studied more. 

Alternate Day Fasting Hunger and Weight Loss

Many people find Alternate-day Fasting easier to commit to than most other diets. For me, it’s the promise of being able to eat the next day. Stick it out for one day and feast the next.

Unfortunately, most studies have found that to be false. The success and failure rate is on par with most other diets. People tend to start and stop at the same rate.

My mind thinks digitally, 1s and 0s, on and off. For this reason, weight loss is a matter of math for me. To lose weight, the body needs to consume fewer calories than it takes in.

To lose weight, all you need to do is eat less. It’s simple, right? People who take this approach tend to fail because the body will stimulate hunger pains and cravings in response to Fasting.

This is why people who engage in caloric restriction tend to fail. There was a time when food was not as readily available for as many people as it is today, and our bodies remind us to nourish it.

ADF may be a way to reduce calorie intake while lowering the body’s hunger pains and response to food cravings. This may be a simple solution for losing weight and improving health while eating the foods you like and avoiding expensive supplements.

I love that I can eat anything I like on the days I am allowed to—anything within reason. I mean, you still have to try and create that caloric deficit to maintain a healthy body weight.

Studies show that if you can maintain a caloric intake deficit combined with a low carbohydrate diet for 6 to 12 weeks, you will see a 4 to 8 percent reduction in body weight with ADF.

This rate of weight loss is similar to any diet, and the primary catalyst to weight loss is the caloric deficit, not the diet name. Similar caloric deficits will produce similar weight loss outcomes.

Also, the types of food you consume and the amount of physical exercise can accelerate the weight loss and health benefits of ADF.

As we can see, weight loss is often the easy part. What constantly proves to be the more difficult part is keeping it off.

Dieters participating in ADF are more likely to keep body fat lower and retain muscle to help maintain a healthy body weight. Lean muscle helps maintain a resting metabolic rate by burning more energy at rest than body fat.

Overweight ADF dieters tend to lose body fat and inflammatory markers in the belly area, where dangerous internal fat competes for space with their organs. While more healthy, lean individuals lose more lean tissue than body fat.

All of that research concludes that although ADF can help promote weight loss, it is not significantly more effective than any other traditional daily caloric restriction diet.

Research shows that modified ADF with 500 calories on fasting days is much more tolerable than many other diets. Some studies show that hunger ultimately goes down on fasting days, while others state that hunger remains unchanged.

Animal studies have shown that modified ADF resulted in decreased hunger hormones and increased satiety hormones compared to other diets.

Conclusion

Alternate-day fasting has proven very effective and offers a great alternative way to lose weight, improve metabolic health, and positively affect cardiovascular blood markers. However, it’s not recommended for young children, pregnant or lactating women, or people with eating disorders.

ADF may have many benefits over traditional calorie-restricted diets and offers significant improvements in many health markers.

For many people, the best part is it’s surprisingly easy to stick to and maintain than most other diets. One day on and the other day off can be so satisfying.