Intermittent Fasting and Loose Skin (Does It Tighten Sagging Skin?)

Frustrated with loose skin and want to know if and how intermittent fasting can help tighten it up?

Intermittent fasting is well known to be effective for weight loss, but it can tighten loose skin too. Those looking to avoid skin tightening surgery and loose skin from weight loss should consider intermittent fasting.

One of the problems with weight loss is the saggy skin that can come with it. And many are worried about losing weight if it means they’ll continue to get loose and saggy skin in areas like their stomach, neck, lower belly and inner thighs.

The good news is you can use intermittent fasting to tighten up loose skin since it promotes autophagy. Excess skin can be prevented and even reversed when you’re doing intermittent fasting for the right amount of time.

Keep reading to discover how intermittent fasting can promote autophagy and tighten and prevent loose skin.

Does Intermittent Fasting Get Rid of Loose Skin?

sagging flabby skin on a woman's arm

To know if intermittent fasting can help to get rid of loose skin, you first need to know what causes it in the first place. As you gain weight, your skin stretches out and sometimes cannot contract back once you lose that weight.

Loose skin is also caused by the natural aging process, chronic inflammation, UV light from sun exposure, environment, stress, genetics, diet, and exercise.1,2,3 Then when some lose weight, their skin has been stretched out so much that they’re left with saggy and loose skin.4

The worry and frustration are if the loose skin will ever shrink back down. While the damage is too significant for some, skin removal surgery is the only option. But if the loose skin isn’t too bad, then there are some ways to reverse it and avoid it in the first place.

Some factors that impact your skin’s ability to shrink back down include:

  • genetics
  • hormones
  • age
  • weight to lose
  • gender
  • body fat composition

While reducing calories is a big part of the weight loss process, it also isn’t optimal for preventing loose skin. For example, with weight loss from calorie reduction, your body will also lose muscle mass, reducing skin stiffness and causing a “deflating” effect.5

Intermittent fasting has been found to help to prevent muscle loss with weight loss due to its hormonal response. Growth hormone is increased, which helps to promote muscle growth and fat loss.6

What Happens to Your Skin When You Do Intermittent Fasting

fasting loose skin before and after

The big benefit of intermittent fasting and tightening loose skin is its autophagy effect. Autophagy is your body’s way of cleaning out damaged cells and regenerating new ones.7,7.1

Your skin needs autophagy to stay looking young, smooth, and firm, as this helps to create healthy new cells for your skin that can help with tightness and elasticity.8 Reducing calories alone isn’t enough, but you need the autophagy from intermittent fasting to prevent muscle loss and loose sagging skin.

Autophagy improves cell performance, including the fibroblasts that create collagen.9 Collagen is essential for skin elasticity since it is “the support structure for your skin.”

With age, collagen production is reduced.10 You’ll notice it with worsening skin issues such as wrinkles, sagging loose skin, dark spots, etc. So by increasing your body’s natural collagen production, you can increase skin elasticity and thus create tighter skin.

This is why supplementing with collagen is also an excellent idea to improve your results. For example, studies have found collagen peptide supplementation works fast for improving skin elasticity and reducing visible signs of aging.11

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The truth is fasting can help tighten loose skin if you don’t have a significant amount of weight to lose. For example, 10, 30, and 50+ pounds of weight loss is more than doable to tighten up loose and sagging skin.

But if you need to lose 100-200+ pounds, there’s a good chance you can have too much excess skin that will need surgery to remove. Fasting can help reduce some of it, but those only needing to lose 50 pounds or less will usually have the best results.

How to Use Intermittent Fasting to Tighten Skin

intermittent fasting and skin tightening

Those who’ve had the greatest success fasting to prevent loose skin have done extended water fasts. Pure water fasting is when you drink nothing but water during your fasting window.

Extended water fasts of at least 24 hours, but 48-72 hours promote the greatest autophagy for skin tightening.12 Ideally, you’ll use fasting while in the weight loss process and not once you’re at your goal weight. This will help to tighten up your skin as you lose weight too.

Water fasting for extended periods should be done infrequently because it can be strenuous. You may want to consider Alternate Day Fasting or OMAD (one meal a day) fasting the rest of the time.13

It’s also best to work out during your fasting window to further promote autophagy and skin tightening. Studies have found exercise boosts autophagy naturally.14

With fasting and exercise, your body will gradually turn to your fat stores and possible excess loose skin for fuel. Your body burns glycogen first, but with fasting and a low-carb diet, your glycogen stores will deplete. Then your body will use fat stores and proteins (possibly those in your skin) for fuel.15

Dry fasts are dangerous when you don’t drink or eat anything (even water), and I wouldn’t recommend them. Dirty fasting isn’t the greatest for promoting autophagy, and pure water fasting will work best.

How long does it take for the skin to tighten with fasting?

Water fasting will be sufficient to promote autophagy but will take time. Patience is needed, and it could take months or even possibly years before you get the results you’re looking for.

Suppose you have great genetics, are still youthful, and don’t have much weight to lose. In that case, you can definitely tighten up your skin quicker by fasting.

Will You Have More Loose Skin if You Lose Weight Fast?

slow vs fast weight loss loose skin

It’s best to lose a lot of weight more slowly and gradually than rapid weight loss. Fast weight loss can cause more loose skin since the skin doesn’t have time to tighten up too.

Extreme fast weight loss usually produces muscle mass loss too. As you lose muscle, you’ll lose the toning and stiffness in the area that fills out the skin. Instead, it would be best to lose weight slower, focusing on fat loss and preventing lean muscle mass loss.

What pace of weight loss is best to prevent loose skin?

Slower weight loss at 10 pounds or less a month is best. This will also depend on how much excess weight you have to lose in the first place. For example, if you only have 10-30 pounds of weight to lose, you could lose it faster without getting loose skin than someone with 50+ pounds to lose.

Staying hydrated and drinking a lot of water during weight loss is best. Your skin is the largest organ in your body, and it’s made up of 64% water. Dehydration reduces skin elasticity and reduces cell turnover.16

Studies have found drinking enough water every day improves skin elasticity, density, and thickness.17 A general rule of thumb is to drink about half your body weight in fluid ounces daily. So if you weigh 160 pounds, it’s best to drink at least 80 fluid ounces of water.

Best Fasting Methods to Avoid Loose Skin

16 hours fasting autophagy

Extended water fasts of 48-72 hours will work best for maximizing autophagy to tighten up loose skin. But these shouldn’t be done too frequently because they are hard and taxing on the body.

16 hours of fasting daily can be good for your skin, but it’s not ideal for promoting autophagy. So I’d go with 18 hours of fasting daily as the minimum before autophagy starts to kick in.

You may even want to follow a 20/4 fasting schedule once you build up to it. This will give you a couple of extra hours of autophagy during the day for better results. Alternate Day fasting, when you fast for the entire day (except for a small, less than 500-calorie meal), will also work well.

If you’ve never done intermittent fasting before, working up to it gradually is a good idea. Start with 12-14 hours of fasting, then move up to 16-18 hours, and finally, 20-23 hours of daily fasting. Then add the less frequent extended water fasts to kick up the autophagy.

To help kickstart ketosis when fasting then try adding C8 MCTs to your morning coffee. They’re converted into ketones via your liver which can help to trigger the burning of your fat stores. They also curb hunger, boost energy, enhance mental clarity.

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Make sure you’re consuming enough protein during your feeding window time. Protein is needed to prevent muscle mass loss from losing weight. Your skin is also made up of mostly protein, so it’ll help promote skin tightening.


In conclusion, fasting is a great way to help tighten loose skin due to weight loss or other factors. Water fasting and alternate-day fasting will best induce autophagy and prevent excessive loose skin.

Stubborn loose skin will be easier to get rid of if you don’t have a lot of weight to lose. Those who only need to lose 50 pounds or less will have an easier time avoiding and reversing sagging skin. Slow and healthy weight loss is also best to prevent loose skin.

The key is to find the right balance between promoting autophagy and avoiding extreme calorie restriction, which could lead to muscle loss. Also, make sure you drink enough water daily and consume adequate amounts of protein during your feeding window time for better results.

With patience and consistency, it’s possible to reduce the appearance of saggy skin with these methods. So if you’re looking for an alternative option besides surgery, consider trying some of these techniques.