Nowadays, more people become health aware and are a bit more conscious about their weight. Numerous people are searching for the best and fastest ways to improve their eating habits and slimming down at the same time. However, when it comes to weight loss, shedding pounds fast isn’t the healthiest way possible. Since your health is one of the most important things, it is necessary to choose the safest weight loss method. Choosing the diet that would work for you may turn out to be very difficult since different weight loss methods have varied effects on different people. One diet that people are raving about is called a 2-day fast weight loss diet. In this article, you will find out whether or not this 2-day fast for weight loss is really effective.
What Is Fasting?
Fasting has been around for a long time. It is an eating approach that is based on the principle of time-restricted food consumption, which may eventually lead to ketosis. Ketosis is a process that occurs when your body runs out of glucose, which is the main source of energy for our body, and starts using fat storage as fuel. A lot of people fast for health, religious, or cultural reasons (15).
This nutritional pattern has gained popularity among those whose goal is to lose weight. Many people who fast to shed pounds follow the rules of intermittent fasting, which requires you to entirely or partially refrain from eating for a certain period, before returning to your regular eating habits. Studies suggest that this eating approach may provide you with benefits such as fat loss, increased longevity, and overall better health. A lot of people find this weight loss method easier to stick to since it doesn’t limit any particular type of food rather than the time when you can consume it.
There are a lot of types of intermittent fasting, which vary depending on the time they restrict and the calorie allowances.
Here are the most popular types of intermittent fasting (12):
Fast for 12 hours a day
This type of intermittent fasting is the simplest of all the existing. It allows you to eat during a 12-hour window and bans the consumption of any food during the rest of 12 hours a day. Research shows that fasting for 10-16 hours can lead to ketosis, making your body use your fat storage as the primary energy source (8), which promotes weight loss. This type of intermittent fasting is recommended for beginners because the fasting window is relatively short, and you can spend the majority of fasting time sleeping overnight.
Fasting for 16 hours (16:8 intermittent fasting)
Another popular type of fasting, 16:8 intermittent fasting, is based on the idea of eating during an 8-hour window and fasting for the rest of 16 hours. It is believed that such an eating approach is effective because it follows your internal clock. Those who stick to the 16:8 intermittent fasting usually refrain from eating at night, and partially morning and evening, and consume all their calories during the day (2).
Alternate day fasting
This type of fasting is a bit more advanced, so the beginners may find it difficult to stick to its requirements. It is based on the principle of eating a regular diet for a day and then fasting for the next day. Some people choose to refrain from eating any solid foods on the days of fasting, while others restrict their consumption of calories to 500 per day. On the non-fasting days, you are technically allowed to eat whatever you want in whatever quantities, but for better results, you are recommended to stick to a healthy diet. Alternate day fasting is one of the strictest types of intermittent fasting, and you may find it hard to stick to it for a long time (5).
A weekly 24-hour fast
A relatively strict type of intermittent fasting, a weekly 24-hour fast, requires you to avoid any type of food for 24 hours a week. Your fast can last from breakfast to breakfast or from lunch to lunch. During the 24 hours of fast, you can drink water, unsweetened tea, and other calorie-free drinks. During the non-fasting days, you can stick to your regular diet, but if you want to reach better results, you are encouraged to follow an overall healthy diet. This type of fasting doesn’t restrict any type of food or number of consumed calories during the eating days. Fasting for one day a week can be effective at helping you lose weight since it reduces your weekly energy intake (12).
Fasting for 2 days a week (5:2 diet)
This type of intermittent fasting is also considered to be quite strict since it requires you to fast for 2 days a week. As it becomes clear from its name, the 5:2 diet is based on eating a regular diet for 5 days a week and fasting for the rest of 2 days. During these 2 days, you are to consume a restricted number of daily calories, approximately 500 for women and 600 for men. The number of required calories may vary depending on your age, gender, and level of physical activity. It is recommended that one fasting day should not be followed by the other fasting day, but they should be separated by a couple of days of normal eating. The 5:2 fasting, like any other type of fasting, encourages a well-balanced diet both during the 5 days of following a regular diet and 2 days of fasting. Make sure that on fasting days, your menu includes plenty of fruits, vegetables, lean protein, healthy fats, and complex carbs (17).
2 day fast
Unlike 5:2 intermittent fasting, a 2-day fast is based on fasting for 48 hours straight. This type of fasting requires you to give up on any type of food for 2 days, and are only allowed to drink calorie-free fluids. This kind of intermittent fasting is being raved about, but does it really deliver your desired weight loss?
2 Day Fast Benefits
As was mentioned before, a 48-hour fast is a type of intermittent fasting that involves taking a 2-day pause on eating while drinking only calorie-free fluids. The 2-day fast is one of the longest-lasting fasts, with shorter fasting periods being more common. Just like other diet plan, 48-hour fasting has its benefits as well.
The following are the benefits that you can expect when you do the 2-day fast:
Blood Sugar Regulation
Fasting for a longer period has a greater effect on blood sugar reduction than short-time fasting. When a person fasts for longer than 24 hours, their body begins to use glycogen, thus reducing insulin levels. So, fasting for 2 days can bring such impressive results, as boosted insulin sensitivity and a 20% reduction in blood sugar levels (1).
Autophagy (Slow aging)
The intermittent fasting supporters claim that this nutritional pattern can promote autophagy. Autophagy, simply put, is a process during which your body disposes of damaged cells that fail to function the way they are supposed to. This allows your body to regenerate and maintain the proper work of its whole system. It is believed that intermittent fasting can lead to autophagy because, during long-term fasting, your energy stores get depleted, and it activates certain pathways that trigger autophagy. These claims were backed up by the 2018 research review, which showed that fasting and calorie restriction effectively promote autophagy (16).
A 48-hour fast creates a great calorie deficit, which can aid long-term weight loss in some people. However, a person should not perform 48-hour fasts regularly.
A 2017 review, found that overweight and obese people who stick to the rules of intermittent fasting reach the same short-term weight loss results as those who use traditional calorie-restricting methods (10). So, intermittent fasting can be as effective at weight loss as various nutritional plans that create a calorie deficit.
2 Day Fast For Weight Loss: How to Do It?
The best way to start is to stop eating at dinner on a given day and start eating with dinner as the first meal two days later. For example, if you decide to start your 2-day fast on a Wednesday, you should stop eating in the evening on that day. You would then start eating again in the evening on Friday. Through this, you will give your body time to digest your last meal on Wednesday before you sleep. By the time you wake up on Thursday, about 10–12 hours of your fast will have already passed.
During your fasting period, you can only drink calorie-free fluids, such as water, which is why people also call this method the 2-day water fast weight loss. Besides water, you can drink calorie-free unsweetened herbal tea and black coffee as well.
When Friday evening comes, you should have a light, simple dinner. From Saturday onward, you can gradually return to your regular diet (19).
It is necessary to stay hydrated while fasting. Try to drink plenty of fluids to prevent dehydration, which is one of the major potential complications of longer fasts (6).
2 day Juice Fast Weight Loss
Aside from water and other calorie-free fluids, another popular 2-day fast is what they call the “juice cleanse”. It is a type of restrictive diet that involves consuming only juices from vegetables and fruits in an attempt to lose weight and “detoxify” the body. As these cleanses are restrictive in terms of food groups and calories, many people are skeptical about their possible benefits.
Like any other diet, the 2-day juice fast for weight loss has its pros and cons too.
Benefits of the juice fast (18):
Offers plenty of micronutrients
Various vegetables and fruits are filled to the brim with a great plethora of essential vitamins and minerals. Therefore, drinking juices can provide you with different micronutrients, thus promoting overall health.
- Boosts your immunity
Juices are packed with anti-inflammatory compounds that are known to improve your immunity and boost your energy.
Regular consumption of juices may provide you with healthy enzymes that improve the work of your digestive system, thus boosting all the digestive processes.
Risks of the juice fast (18):
Not recommended for people with kidney disorders
If you suffer from kidney disorders, then juice fast is not for you. Certain types of juice contain oxalate, which is an acid that may increase the risk of kidney stones and other kidney disorders. That is why drinking a lot of juices may be harmful to patients with kidney problems.
Provides a short-term result
Since juices are overall low in calories, sticking to a 2-day juice fast will help you slim down, but your weight loss results are likely to only last for a short time.
Increased risk of illness
Consuming juices that were not pasteurized and haven’t undergone any other type of bacteria-removing procedure can increase the risk of an illness. Particularly, people who are most susceptible to developing illnesses like children and older people, as well as those who have a weakened immune system.
May lead to dehydration and electrolyte imbalance
Drinking a lot of juice that contains laxatives or any other methods of bowel stimulation may lead to the significant loss of nutrients with the stool, which in turn causes dehydration and electrolyte imbalance.
Lack of energy
As you already know, juices are low in calories. Juice fast may create an extreme calorie deficit, failing to provide you with enough energy and leading to such unpleasant symptoms as fainting, weakness, mood swings, dehydration, hunger, and headaches.
After Care: What to Eat and What Not to Eat After the 2 Day Fast
Fasting can be beneficial for you, but it is extremely important to safely return to your regular diet after you finish it. That is why you need to know what foods to eat and what to avoid after your 2-day fast. Don’t jump into filling your stomach with junk food right after your fast ends, as it will not only cancel your positive results but may even reverse them. It may also trigger the gut, leading to nausea and diarrhea (1). That is why you need to start slowly. Gradually introduce food into your system, start with a light snack, then progress to a whole meal a couple of hours later.
Foods to Eat after the 2 day fast:
Proteins are essential for the proper functioning of your body. That is why your after-fast meal should include a small portion of food that contains this macronutrient. It can be fish, lean meat, poultry, legumes and beans, tofu and eggs since they are packed with protein but don’t provide you with tons of unhealthy saturated fat.
Non-cruciferous, less starchy vegetables
Choose less-starchy, non-cruciferous vegetables cooked in healthy fats. This will add to your after-fast ketosis and make it easier for your body to digest your food. You can also consume avocados since they are filled with fiber and healthy fats.
Bone broth is one of the best meal choices after you finish fasting. It is packed with various micronutrients that promote the proper functioning of your body and especially the gut since it contains plenty of minerals and gelatin, which is super beneficial for your intestinal permeability (7).
Foods to Avoid after the 2 day fast:
Overall unhealthy foods
Foods that provide you with empty calories, highly processed, high glycemic index (GI) foods. Sugary foods and beverages are advised to be avoided at all times, but it is especially important to reduce their consumption right after your 2-day fast. These unhealthy foods provide you with little to no essential components and may even lead to an increased risk of various serious diseases. And since your body may be sensitive to the consumption of carbs after your fast, it may lead to undesired insulin spikes (11).
It is recommended to keep away from such high-lactose dairy products such as milk, yogurt, and ice-cream right after you finish a fast. It is because lactose is overall difficult to digest for some people, and consuming it after a 2-day fast may lead to some problems with digestion (3).
Although they overall have health benefits and can provide you with lots of vital nutrients, cruciferous vegetables (broccoli, cabbage, cauliflower, brussels sprouts) may interfere with your digestion right after the fast, leading to gassiness. This happens because they are packed with fiber and contain a trisaccharide called raffinose, which is difficult to digest (3).
2 Day Fast: Expected Weight Loss
A 2-day fast performed twice a month can reduce your monthly calorie intake by approximately 8000 calories. It may also boost your metabolism, which makes you burn more calories during the non-fasting days (1). Since one pound of fat consists of 3500 calories, you can expect to lose a bit more than 2 pounds a month simply by fasting occasionally.
It is recommended that you do a 2-day fast once or twice per month rather than once or twice per week. Being able to space out your 2-day fasts properly can bring you better results (14).
2 Day Fast For Weight Loss: Risks and Restrictions
As tempting as it is, there are certain risks and restrictions that a 2-day fast for weight loss entails. Before committing to it, you should know whether you can fast or not.
You should refrain from the 2-day fast for weight loss if you (13):
- Suffer from type I diabetes
- Have low blood pressure
- Underweight or have a history of eating disorders
- Are pregnant, breastfeeding, trying to conceive, or have a history of amenorrhea
- Are taking medications such as insulin blood pressure, blood thinners, and nonsteroidal anti-inflammatory drugs (NSAIDS).
- Are under the age of 18
It’s also important to be aware of the downsides of a 2-day fast.
This duration is not suitable for everyone. The longer the fast, the greater the potential for side effects.
Below are the possible side effects that you could encounter when doing the 2-day fast for weight loss.
Hunger and dizziness
Restricting yourself from consuming any calories for the whole 48 hours can be accompanied by severe hunger, although many people claim this side effect to be temporary. That is why instead of getting down to a 2-day fast right away, you first need to gradually work your way up, starting with shorter fasts (9).
Exhaustion and sluggishness
Due to its duration, a 48-hour fast may be harder to stick to than other fasting methods. Exhaustion is a major concern here because this is a long fast. It is one weight loss strategy that is difficult to complete.
Aside from the two major risks or side effects of the 2-day fast for weight-loss method, there are other risks that you should be concerned about before starting this type of fasting (9). Such as:
- Digestive problems
- Mood swings
- Insomnia and troubled sleep
The Bottom Line: Is 2 Day Fast for Weight Loss Effective?
Yes, it is. Considering the details about this kind of fasting presented above, the 2 day fast can indeed help you to lose weight, but the risks are greater. You might want to consider safer and healthier eating habits that don’t bear as many risks as this weight loss method. It is also recommended that you try shorter fasts first to avoid any serious side effects.
If you are considering the 2 day fasting, make sure to discuss it with your doctor or dietitian. Skipping meals and severely limiting calories can be dangerous for people with certain medical conditions.
Remember that a proper diet is not everything you need. Supplement your diet with some exercise to double your results.