Dry Fast vs. Water Fast


Dry fasting or water fasting? Do you know the difference between the two? Both forms of fasting provide their own health benefits and drawbacks. Today, we will go over the differences between a water fast and a dry fast and the advantages and disadvantages of both. 

Comparing Dry And Water Fasting

Fasting has been around for thousands of years. Only recently has it been turned into a popular dietary trend. With its increase in popularity, we have seen many different forms of fasting become popular. Whether you’re practicing intermittent fasting, alternate-day fasting, eat-stop-eat, or periodic fasting, you will have to determine whether you’re embarking on a water fast vs a dry fast.

The main - and only difference - between a dry fast and a water fast is in the names themselves; A dry fast restricts both food and liquid - including water. On a water fast, the only thing you’re allowed to take into your body is liquids - typically low caloric liquids such as water or certain teas. 

Is Dry Fasting More Effective for Fat Loss?

One of the main reasons why people start fasting is to lose weight. Some believe you can maximize the results of a fast by practicing dry fasting instead of water fasting. Before going any further, we should note that research regarding fasting - and dry fasting in particular - is in its infancy. 

With that being said, certain studies point towards benefits of dry fasting vs water fasting when it comes to weight loss. Researchers are unsure as to whether or not this is due to dry fasting or fasting in general. In summary, we just don’t know. There’s not enough research to definitively say whether or not you lose more weight when practicing a dry fast. 

Does Water Fasting Provide Healing Benefits for Kidneys?

There is research that points towards fasting helping with kidneys. Some in favor of dry fasting would argue that dry fasting is the best way to focus on your kidney health. The argument is that dry fasting gives your kidneys the break that they so desperately need. However, dehydration can be very harmful to your kidneys. 

The reality is, your body is made of around 60% of water, and water is critical to ensure all of your organs are functioning correctly. This includes your kidneys. Your kidneys need water to help remove the waste products from your body. There are other ways to stay hydrated, but drinking water should be your main one. 

What Effects Does Fasting Have On The Body Each Hour?

Being more in tune with your body can help you better understand what’s going on with your body. Knowing what to expect each hour when fasting can make the process more successful. Let’s go over what happens when you fast hour-by-hour:

  • 4-8 hours - All the food you ate before the fast has left the stomach, and blood sugars fall
  • 12-hours - Food consumed before the fast has been burned, your digestive system goes to sleep, and your body begins the healing process
  • 14-hours - Your body is now burning fat for energy instead of sugar
  • 16-hours - Fat burning increases
  • 18-hours - Natural human growth hormone increases dramatically
  • 24-hours - The autophagy process begins, and ketones are released into the bloodstream
  • 36-hours - The autophagy process sees a 300% increase
  • 48-hours - The autophagy process sees a 30% increase, and the immune system begins to reset and regenerate
  • 72-hours - Autophagy maxes out

Signs That It Is Time to End Your Water Fast

The benefits of fasting are widely known. However, there are some drawbacks. It can be dangerous to fast, and understanding when it’s time to stop a fast is very important. Below are some of the signs to stop water fasting and eat a snack:

  • Dehydration - Even if you’re practicing water fast, you can become dehydrated. This is because 20-30% of your daily water intake comes from food
  • Dizziness - It’s not uncommon to feel lightheaded when practicing a fast. However, if you feel as though you’re about to pass out, you should eat a snack
  • Feeling unwell - You may feel tired and irritable when practicing a fast. This is normal. However, you should never feel ill. If you begin to feel sick, stop the fast immediately and seek medical help

It’s important to talk with your doctor before starting a fast. A fast may not be healthy depending on your health and lifestyle. 

Safe Ways to End A Dry Fast

Breaking a dry fast isn’t as easy as simply eating food and drinking water normally. You should take steps to ensure you break a fast safely. For example, you should drink a glass of water after a dry fast, but you must sip slowly, so the body is not overwhelmed with the sudden inflow. 

After your first glass of water, you should not have any liquid for the next hour or two. Take small sips to prevent bloating. You will start to feel your energy levels rise the more water you drink. When it comes to food, it’s important to eat healthy and nutritious foods. Breaking your fast with a massive meal from your favorite pizza joint isn’t healthy. 

What Foods Are Best For Breaking a Water Fast?

We get it; you’re tempted to break your fast with a huge meal. However, research shows you should break your fast with a smaller, gentle meal. This will help your body break down food more effortlessly and not get too overwhelmed. Some of the foods we recommend include:

  • Smoothies
  • Dried fruits
  • Soups
  • Vegetables
  • Fermented foods
  • Healthy fats

By eating healthy foods, you can help your body replenish the important nutrients it missed out on during the fast. 

How Supplements Can Benefit You

A healthy lifestyle extends beyond your diet and fasting. Pairing your healthy lifestyle with exercise and a regular supplement regimen can help enhance the positive effects of dieting and fasting. Spermidine supplementation can help your body induce both ketosis and autophagy. Furthermore, autophagy provides many of the same benefits of fasting without the need for caloric restriction.


  • Don Moxley - Director of Applied Science

    Don Moxley is the Director of Applied Science at Longevity Labs. Moxley draws upon his career as an athlete, a sports scientist, and an instructor to lead and educate on the science of autophagy and longevity.