Can I Do Intermittent Fasting after Gastric Sleeve Surgery?

author avatar Dr. Eric Berg 05/15/2024

Gastric sleeve surgery can be a highly effective procedure to help obese individuals lose weight. However, adopting healthier eating habits is critical for maintaining long-term results. 

Intermittent fasting is one potential strategy to support ongoing weight loss after bariatric surgery. 

Explore the risks and benefits of intermittent fasting after gastric sleeve surgery and discover the best strategies for optimal results. 

Post-op gastric sleeve surgery illustration

What is gastric sleeve surgery?

Along with gastric bypass surgery, the gastric sleeve method, also called a laparoscopic sleeve gastrectomy, is one of the most commonly performed bariatric surgeries. 

While both procedures aim to help patients lose weight by reducing stomach size and facilitating the consumption of fewer calories, they differ in their surgical approach.

Gastric bypass surgery involves creating a small stomach pouch by dividing the stomach into two parts and rerouting the intestines to accommodate the two sections.

The small pouch at the top of the stomach is used for food intake, while the larger section continues producing digestive fluids that mix with food in the intestines at the newly created junction.

In contrast, gastric sleeve surgery removes around 80 percent of the stomach, including the fundus, which produces the hunger hormone ghrelin. This results in lowered ghrelin release, which is linked to reduced food intake and suppressed appetite while keeping the intestines intact.

A gastric sleeve can be effective for weight loss and improving obesity-related health conditions such as non-alcoholic fatty liver disease (NAFLD), type 2 diabetes, and high blood pressure.

Evidence published in StatPearls states, "The average excess weight loss after five years in a laparoscopic sleeve gastrectomy is reported to be around 60 percent, and the resolution of comorbidities is excellent."

Intermittent fasting clock on a plate

What is intermittent fasting?

Intermittent fasting is a mealtime schedule that involves cycling between fasting periods and time-restricted eating windows. 

There are several ways to practice intermittent fasting, such as one meal a day (OMAD), alternate-day fasting, and daily time-restricted eating, which are considered the most suitable fasting methods for bariatric surgery patients. 

Daily time-restricted eating includes fasting for a set time window per day and eating within another. The most popular form of intermittent fasting is 16:8, which involves fasting for 16 hours, followed by an eight-hour eating window.

Watch this video to learn how Healthy Keto® and intermittent fasting can help support healthy weight management after bariatric surgery.

Gastric Bypass & Keto and Intermittent Fasting

Benefits of intermittent fasting after a gastric sleeve surgery

Here are three potential benefits of intermittent fasting after gastric sleeve surgery.

1. Supports long-term weight loss

Intermittent fasting can be a highly effective strategy for gastric sleeve patients who have reached a weight loss plateau or are experiencing weight gain. 

Prolonged periods of caloric restriction exhaust the body’s glucose stores. This forces the liver to utilize stored body fat as an energy source, which explains why intermittent fasting is a highly effective weight-loss strategy. 

By establishing normal eating in a regularly scheduled manner that discourages snacking throughout the day, intermittent fasting supports long-term weight management and health-related outcomes.

2. Improves cardiometabolic health

Research published in the Journal of Clinical Medicine found that time-restricted eating can lead to weight loss, improved insulin levels, and reduced inflammation.

These improvements in cardiometabolic health are particularly relevant for individuals with a gastric sleeve as they complement the benefits of bariatric surgery by promoting a healthy body weight. 

3. Triggers autophagy

Prolonged fasting triggers autophagy, a process that removes and recycles old or dysfunctional cellular material and facilitates the regeneration of new cells.

This is a critical process that can help increase longevity and may reduce the progression of metabolic issues often present in individuals who underwent gastric sleeve surgery. 

Women binge eating unhealthy food

Risks associated with intermittent fasting after a gastric sleeve surgery 

While intermittent fasting offers several benefits, gastric sleeve patients must be aware of potential risks and follow medical guidance. 

Blood sugar drops during fasting can be problematic for individuals taking diabetes medications or those with reactive hypoglycemia. For this reason, balanced nutrition and medical guidance are vital to limit adverse effects for bariatric patients.

Especially for those new to intermittent fasting, it’s critical to slowly ease into your chosen fasting schedule by starting with shorter fasting periods. In addition, it’s vital to fuel your body with nutritious meals to reduce the risk of nutritional deficiencies and promote satiety.

Otherwise, bariatric surgery patients may be prone to binge eating, which can lead to serious issues, including nausea, vomiting, rupture or perforation of the stomach lining, or an anastomotic leak.

A spread of healthy keto food

Tips for maintaining your weight and health after gastric sleeve surgery

In addition to intermittent fasting, there are other steps you can take to promote a healthy body after gastric sleeve surgery. 

Here are four other tips to help you meet your weight-loss goals post-surgery.

1. Eat nutrient-dense foods

Following a nutritious diet plan such as Healthy Keto®, which prioritizes nutrient-dense whole foods, can help maximize your nutrient intake while promoting weight loss.

Healthy Keto limits carbs and sugars, the main culprits for weight gain, making this dietary approach an excellent choice for individuals who have had gastric sleeve surgery.

2. Support stomach acid production 

"Taking acidifiers such as apple cider vinegar or betaine hydrochloride (HCl) can promote satiety and overall health by helping your digestive tract to break down and digest proteins, fats, vitamins, and minerals," says Dr. Berg.

3. Take purified bile salts

Gastric sleeve surgery alters the body’s ability to release bile, significantly impacting the absorption of fat-soluble vitamins and fatty acids essential for overall health.

Taking purified bile salts can help your body absorb fats and fat-soluble nutrients, including vitamins A, D, E, and K. 

4. Promote trace mineral intake 

Significantly reducing the size of the stomach can hinder its ability to absorb minerals effectively.

A high-quality trace mineral complex can help promote the body’s nutrient stores. Trace minerals are critical in various physiological functions, including energy-making processes, metabolic balance, and cognitive functions.  

Surgeons performing gastric sleeve surgery

Key takeaways

With medical supervision, intermittent fasting after gastric sleeve surgery can help regulate appetite, support metabolic health, and maintain a healthy weight. 

However, there is some risk associated with intermittent fasting after bariatric surgery. It’s recommended to consult a bariatric professional to create a personalized intermittent fasting plan focused on nutritious whole foods for optimal success.


1. Can I do intermittent fasting after a gastric sleeve surgery?

Yes, intermittent fasting can be an effective strategy to promote a healthy body weight after gastric sleeve surgery.

However, it’s advised to ease into intermittent fasting slowly, consume a nutrient-dense diet, and consider dietary supplements to reduce the risk of nutritional deficiencies. 

2. Can I do the keto diet after gastric sleeve surgery?

Yes, a Healthy Keto® diet can help lose excess body weight by promoting fat-burning after gastric sleeve surgery.

3. Do you go into ketosis after gastric sleeve surgery?

In some cases, mild ketosis may occur due to gastric sleeve surgery as a result of a very low-calorie intake.  

4. Does your metabolism slow down after gastric sleeve surgery?

Yes, your metabolism can slow down after gastric sleeve surgery. This is because the body requires less energy to maintain a lower weight.

Building muscle through resistance exercise can help keep your metabolism up after weight loss surgery.

5. How can I maximize weight loss after gastric sleeve surgery?

Intermittent fasting, in combination with a nutritious low-carb diet such as Healthy Keto, is an excellent strategy to prevent food cravings and maximize weight loss after surgery.




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