Bariatric Surgery FAQ

Fatigue After Gastric Bypass

Fatigue After Gastric Bypass - Bariatric Fusion

Gastric bypass surgery results in some major changes to the body, as well as changes to lifestyle and diet. Adjusting to a restricted dietary intake can present with an initial tired and weak feeling. In fact, fatigue initially after gastric bypass surgery is one of the common gastric bypass side effects.

It can be frustrating to feel the benefits of weight loss post-surgery, but have no energy to enjoy them. That is why we are going to look at some of the reasons for fatigue after gastric bypass surgery and provide some easy solutions to the problem.

What This Article Covers:

Fatigue After Gastric Bypass

Why Do People Feel Fatigued After Gastric Bypass Surgery?

There are many reasons for feeling a bit tired after gastric bypass surgery. Let’s look at the most common ones below.


Dehydration after bariatric surgery is one of the most common problems after gastric bypass surgery.

Remember, after surgery, the new stomach pouch has a limitation on the amount of fluid it can accommodate.

In addition, there is a limit on when and how much liquid you may consume.

A good rule of thumb is that a post-surgery patient must aim to ingest 64 ounces of non-caloric fluids per day.

It is also recommended that patients avoid coffee, alcohol, and carbonation. Some of these beverages can promote dehydration or even decrease your ability to consume an adequate amount of fluid and protein required daily following surgery.

Vitamin Deficiency

There is a high risk of vitamin deficiencies after gastric bypass surgery. The alterations made to the body affects the ability to absorb nutrients and restricts dietary intake.

The most common vitamin and mineral deficiencies are vitamin B12, iron, Vitamin D, calcium and thiamine.

These deficiencies can lead to many other complications, including malnutrition and hair loss after bariatric surgery.

The easiest way to prevent vitamin and mineral deficiencies is to ensure that you stick to your prescribed diet plan and take the recommended vitamins after bariatric surgery.

Based on the procedure performed, there may be different supplements required. For example, after duodenal switch surgery, it is common to take a multivitamin high in the vitamins A, D, E, and K, found in Bariatric Fusion adek multivitamin.

Most physicians will prescribe a bariatric chewable multivitamin with iron for gastric bypass patients. This will not only keep your energy levels up, but also ensure proper recovery.

fatigue after bariatric surgery


Not getting enough sleep is probably one of the more obvious reasons why patients may struggle with fatigue after surgery.

However, in some cases, getting too much sleep can also be a problem. The average adult needs approximately 8 hours of sleep a night.

This is easier said than done, especially when you have to sleep through the possible pain and side effects of surgery.

Luckily, there are some things you can do to assist with better sleep.

For example, you can document your sleeping patterns to track habits and make adjustments as needed.

It is also recommended that you go to bed and wake up at the same time every day in order to ensure that you don’t have trouble falling asleep or getting up in the morning.

Lack of Protein

Many of the complications after gastric bypass surgery can also be a result of protein deficiency.

At least you can take comfort in the fact that this is not one of the gastric bypass long-term side effects. Rather, it’s a short-term side effect that is usually ascribed to the new diet and lifestyle changes that patients accommodate to post-surgery.

It can be very difficult to ensure adequate protein intake when most protein-rich foods, such as meat, are not included in the bariatric diet for the first few weeks post-surgery.

In addition, even after meat is allowed, it often leads to getting food stuck after gastric bypass surgery because it does not easily enter through the newly narrowed opening in the stomach pouch.

A good way to ensure you are meeting daily dietary protein needs is to incorporate a bariatric high protein meal replacement.

Many doctors recommend this as it makes protein intake easy and accessible.

As a bonus, a meal replacement shake can offer more nutrition than just high protein. They are formulated to mimic a small meal with a variety of vitamins and minerals, fiber, and low-fat content.


Bariatric surgery carries a lot of pressure to lose weight and commitment to extreme lifestyle changes.

While depression is not a surgical risk or nutritional risk, it can be just as serious.

Depression after bariatric surgery is more common than you would think. If you are experiencing feelings of hopelessness and fatigue, you might need to consult someone you trust and reach out for help.

There are also many weight loss surgery support groups, where post-surgery patients support one another on their healing journey.

Calorie Deficiency & Over Exercising

It can be difficult to get the required amount of calories during a post-bariatric diet. This is mostly because it is difficult to eat and the portions are very small.

However, if you follow your prescribed diet closely you should reach about 500-1000 calories the first 6 months after surgery.

People often exercise more than their calorie intake allows, which leaves them feeling fatigued afterward. Typically, you will be recommended to refrain from any kind of strenuous activity for about 6 weeks. This can vary based on the individual.

Food provides energy for the body, so a bariatric diet tailored to your exercise routine and lifestyle will help you from feeling tired after exercise.

Another complication that can surface from extreme exercise and low calorie intake is anorexia after gastric bypass. Anorexia is a common eating disorder that is associated with abnormally low body weight followed by the fear of gaining weight. Be sure to follow a guided diet and exercise plan to prevent overexertion and malnutrition from occurring.


The most important reason why you might be feeling fatigued after surgery is that your body is still healing.

The body takes time to process the effects of surgery and to heal properly.

Gastric bypass surgery is often a shock to the body and it takes time to adjust to the new lifestyle.

This is why fatigue is such a common symptom, especially for the first 8 weeks following surgery.

To aid the healing process, make sure that you follow your healthcare providers orders and get enough sleep and nutrients.

Final Remarks

There are many reasons for feeling tired following bariatric surgery. The most important thing to remember is that feeling tired is completely normal and that there are many ways to boost energy levels while also ensuring a speedy recovery.

If you are feeling fatigued following gastric bypass surgery, take it easy on yourself. Remember, you just had major surgery and you deserve some rest too.

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This blog is for information and education purposes only. This information is not intended to substitute professional medical advice, diagnosis, or treatment. Please consult with your physician or another qualified health provider with any questions in regards to a medical condition. A qualified healthcare professional can best assist you in deciding whether a dietary supplement is suitable based on your individual needs.

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