Intermittent fasting has become an increasingly popular way to lose weight. Supporters claim it’s an easy way to decrease calorie intake while providing various health benefits. This article explores how much weight you can expect to lose if you fast for 2 days.
What Is Intermittent Fasting?
Intermittent fasting (IF) describes eating patterns that cycle between periods of fasting and eating. Rather than restrict what foods you eat, it controls when you eat them. The two most common approaches are:
- 16/8 method: Fast for 16 hours per day and restrict eating to an 8-hour window.
- 5:2 diet: Fast for 2 non-consecutive days per week, eating normally the other 5 days.
Both types reduce your calorie intake by limiting the number of hours you eat each day or week. Many people find IF a more sustainable approach than traditional, restrictive diets.
Benefits of Intermittent Fasting
Intermittent fasting may provide the following benefits:
- Weight loss — By limiting the number of hours you eat, you reduce your calorie intake, leading to weight loss.
- Lower blood sugar — IF has been shown to help lower blood sugar and improve insulin resistance.
- Brain health — Fasting may help improve memory and prevent neurodegenerative disorders like Alzheimer’s.
- Longevity — Some research shows IF may extend lifespan by slowing aging and protecting cells from damage.
How Intermittent Fasting Leads to Weight Loss
Here’s a look at how intermittent fasting promotes weight loss:
Decreases Calorie Intake
The primary reason IF leads to weight loss is that it decreases your overall calorie intake. By limiting your eating window, you reduce the number of hours you can consume calories.
Depending on your eating window, you may be missing meals like breakfast or dinner each day or fasting 1–2 days per week. This results in an automatic calorie deficit.
Intermittent fasting is shown to reduce levels of the hunger hormone ghrelin while boosting levels of appetite-reducing hormones like peptide YY and glucagon-like peptide-1 (1, 2).
This hormonal modulation may allow you to feel satisfied despite fewer calories, making IF more sustainable than traditional diets.
Some research indicates short-term fasting temporarily boosts metabolism by 3.6–14% (3, 4). This is thought to occur via effects on appetite-regulating hormones like norepinephrine.
One study found metabolism remained elevated by 3.6–6.8% even 15 days after fasting ended (5). Enhanced metabolism may promote weight loss.
How Much Weight Can You Lose Fasting for 2 Days?
The amount of weight you lose fasting for 2 days depends on several factors:
Your Calorie Needs
Your calorie needs are based on your age, sex, height, weight and activity level. The more calories you require each day, the more you stand to lose by fasting.
For example, someone needing 2,500 calories per day will lose more fasting than someone requiring just 1,800 calories.
Your Usual Eating Pattern
If your regular diet is higher in calories, cutting back for 2 days per week will result in greater calorie and weight reduction.
Fasting will produce more significant weight loss for those eating larger vs. smaller portions regularly.
What You Eat on Non-Fasting Days
Weight loss will also vary based on whether you make healthy dietary changes on the days you don’t fast. Fasting for 2 days won’t cancel out 5 days of unhealthy eating.
To maximize weight loss, follow a sensible diet with appropriate portion sizes even when you aren’t fasting.
Use of Exercise
Incorporating aerobic exercise and strength training can increase the calorie deficit produced by fasting. However, working out excessively could make fasting harder.
Aim for 150–300 minutes of moderate exercise per week to enhance weight loss.
Example Weight Loss
Here’s an estimate of expected 2-day fasting weight loss:
|Potential 2-Day Deficit
|Expected Weight Loss
|0.9 lbs (0.4 kg)
|1.1 lbs (0.5 kg)
|1.4 lbs (0.6 kg)
As you can see, fasting just 2 days per week creates a significant calorie deficit and weight loss over time.
Tips for Maximizing Weight Loss
Follow these tips to increase the amount of weight you lose while intermittent fasting:
Gradually Increase Your Fasting Duration
If new to IF, don’t jump straight into a 16-hour fast. Start with 12 hours and work up to 16 hours over several weeks. This allows your body to adapt.
Drink water, unsweetened tea and other zero-calorie beverages while fasting to reduce hunger levels.
Get Plenty of Sleep
Adequate sleep minimizes cravings and controls the hunger hormone ghrelin to enhance weight loss.
Add Apple Cider Vinegar
Some research shows apple cider vinegar may boost metabolism, increase satiety after meals and support weight loss.
Try a Keto or Low-Carb Diet
Following keto or low-carb on your non-fasting days may make fasting more effective for weight loss.
Exercise in the Fasted State
Exercising while fasted may help burn extra fat for energy. Just stay hydrated and listen to your body.
Safety and Side Effects
When done properly, intermittent fasting is safe for most healthy adults. Potential side effects and tips for minimizing issues include:
- Hunger – Drink water or unsweetened teas during the fast.
- Headaches – Caused by dehydration. Be sure to get enough fluids.
- Dizziness – Eat salt to help stabilize blood pressure.
- Difficulty concentrating – Take a break from mentally demanding tasks.
People with medical conditions like diabetes should talk to their doctor before trying intermittent fasting.
How much weight you lose while intermittent fasting for 2 days per week depends on your calorie intake, food choices and lifestyle habits.
Though affected by individual factors, you can expect to lose around 0.5–1.5 lbs (0.2–0.7 kg) per week fasting just 2 days.
For best results, combine fasting with a healthy diet and active lifestyle. Be sure to speak with your healthcare provider, especially if you have any medical conditions.