Eating and exercise after surgery

This blog provides free general information for anyone who is seeking to understand more about dieting and exercise after surgery, not intended as a medical consult. Please seek appropriate medical and allied health advice for individual assessment and management.

The crucial learning points are:

  • Recognizing that long term success of bariatric surgery depends on the patient’s compliance to dietary advice and mainitaining a regular exercise program.
  • The aim is permanent lifestyle change via behavioural modification starting with learning good eating habits.
  • Seeking help from a dietician and an exercise physiologist should be regarded as part of the weight loss program provided by the multidisciplinary team.

Please refer to the section on “Diet after surgery” for further information on nutrition.

Please ask you General Practitioner to refer you to a bariatric dietician and exercise physiologist.



Beth van der Waal is an accredited exercise physiologist also works at Pacific Private Clinic.

Please call 0432 075 992 or email for any enquiries or to make an appointment to schedule an assessment and training session.


The success to losing weight

The main aim of bariatric surgery is to affect permanent lifestyle change and behavioural modification to result in excess weight loss and more importantly sustained long term weight loss. This is not possible with dieting and exercise alone in the morbidly obese (BMI>40) population.

It is necessary to understand more about healthy eating behaviour and having good quality food in proper controlled portions. Compliance with post op diet and exercise advice is essential to achieving a successful body weight and body fat loss, is the key to durable long-term results and prevention of weight regain (recidivism).

When patients assume personal responsibility to develop a better diet and lifestyle change, the time and effort spent having undergone bariatric surgery makes it all worthwhile. On the contrary with a return to poor diet, poor eating habits and sedentary behaviour, weight regain (months to years after surgery) and return of medical co-morbidities is inevitable, despite good initial results.

Once again to re-iterate, successful long-term weight loss and health improvements is the combined results from effective bariatric surgery, good food portion control, good food choices, good eating habits plus regular exercise. Patient education and motivation is important, with the valuable assistance of a dietician, exercise physiologist and psychologist/counsellor at various point in time when necessary during their weight loss journey, all contribute to a successful, satisfactory outcome and improved quality of life.





Recommended eating behaviour

After surgery there needs to be a gradual transition from liquid to puree to solid meals over the 2-4 weeks period, to reduce the abdominal discomfort, nausea and vomiting as well as to reduce the risk of pouch dilatation.

Thus the following recommendations are advised:

Eat regularly and avoid skipping meals

  • Going for long periods without food may result in calorie /nutrient deficiency and dehydration or result in hunger sensation later, which leads to compensatory overeating.

Consume small meal portions

  • Stop eating when feeling full, the compulsive and binge eating behaviour is gradually unlearnt.

Cut food into smaller pieces

  • This aids in chewing, makes solid food easier to swallow, prevent food bolus obstruction (food getting stuck above the gastric restriction).

Chew food carefully

  • Again this prevents food bolus obstruction as well as teaching the patient to enjoy their food and diminish binge eating habits.

Eat slowly

  • Usually it takes over 40 minutes to finish a meal, especially after a sleeve gastrectomy. This allows the patient to change their eating behaviour (as mentioned above), reduce pain, reflux, nausea and vomiting.

Avoid distractions when eating (such as watching television)

  • This may lead to overconsumption of food/snacks and poor appreciation for quality food. Sedentary behaviour also reduces metabolic rate and hinders weight loss.

Avoid eating and drinking at the same time

  • This allows more solid food and nutrients to be consumed during meal times without filling the stomach with fluids simultaneously. This will reduce the discomfort (fullness sensation) and the risk of dumping.

Proper eating behaviour is important during the recovery phase to avoid discomfort, reflux or vomiting. Vomiting often leads to fluid and electrolyte depletion as well as low thiamine levels, which is detrimental to normal neurological function.

Patients are strongly advised to avoid snacking or grazing poor quality food. Instead ensure adequate protein consumption (on average up to 60g a day is recommended), have low GI (glycemic index) food and less carbs (carbohydrates) in the diet. Refined and processed sugar based foods and drink is discouraged. The daily fluid requirement is 1-1.5 litres of water and 25-30g of fiber a day.



A dietician

Improvement in the quality of food consumed, not just the quantity, is important after surgery. The role of an accredited practising dietician with expertise in bariatric patient management, is invaluable to educate, to facilitate change in the type of food consumed and ultimately the consequential weight loss results are better.

Having a balanced meal also helps to minimise vitamin and trace mineral deficiencies, this may have been a pre-existing problem before surgery and the condition must not be allowed to worsen after bariatric surgery. The most common deficiencies after surgery (especially gastric bypass) are vitamin D, calcium, iron, folate and selenium. Thiamine deficiency is also common for those who have been vomiting after bariatric surgery. Needless to say oral, intra-muscular or even intra-venous injections of vitamins or minerals may be needed to correct the specific deficiencies without delay.


Monitoring for micronutrient deficiencies

After diversion or malabsorption surgery (such as the Roux Y gastric bypass), it is recommended that lifelong multivitamin replacements be prescribed and blood test monitoring is necessary at regular intervals.

  • Iron studies should be tested in the first 6 months, then annually.
  • Folic acid levels should be tested in the first 6 months, then annually.
  • Vitamin B12 should be tested in the first 3-6 months, then annually.
  • Vitamin A and D should be tested annually.
  • Thiamine should be tested if the patient has been vomiting.

If there are micronutrient deficiencies detected, replacement doses above daily recommended may be needed and more frequent blood test is mandatory.


An exercise physiologist and personal trainer


Physical activity increases overall energy expenditure, promote weight loss and helps with long term weight stabilization (prevent weight regain).


Physical activity and regular exercise is an important predictor of weight loss outcomes (especially to achieve >50% excess weight loss) and maintenance of weight loss after bariatric surgery. Exercise not only helps to preserve lean muscle mass, improve metabolic rate, helps with body toning (to diminish redundant skin flaps), improve physical endurance and fitness but also enhances mental health and well being.

At least 150 minutes a week of moderate intensity cardiovascular and respiratory exercise is recommended. Some may include 2-3 days a week of resistance training, stretching and flexibility training, once the patients have noticed significant weight loss, usually a few months after the surgery.

Exercise has also been reported to improve glucose uptake in peripheral tissues, improve Type 2 diabetes, increase the good HDL cholesterol, reduce triglyceride and reduce cardiovascular disease. On the other hand lack of physical activity impairs insulin sensitivity and cholesterol turnover, increase the risk for metabolic syndrome, central fat accumulation as well as a chronic lack of energy, leads to more sedentary activities and morbid obesity.

Many barriers to exercise have been identified. Listed amongst them are:

  • Chronic injury and pain or those with pre-existing cardiovascular disease and severe co-morbidities associated with morbid obesity limiting their ability to exercise.
  • Lack of time, motivation or energy levels (especially during the rapid weight loss phase).
  • Variable individual motivation, self esteem, confidence and body image perception, which may discourage some to exercise in public.
  • Exercise is of a lower priority to some, leading to lack of consistency or poor adherence to a regular exercise program.
  • There may be lack of enjoyment or simply being unaware that exercise is necessary after bariatric surgery.

It has been estimated that up to 30% of patients fail to achieve the desired weight loss result (which is >50% excess weight, the standard norm after bariatric surgery) for many reasons.

Hence the role of an exercise physiologist or personal trainers is vital to provide the education, support and individual attention to patients, assisting each one in their weight loss journey in a safe and controlled manner. Weight loss results should not be compromised especially when some the barriers to exercise listed above are avoidable.


Recommended physical activities

Many different types of activities to assist with weight loss have been identified and listed below. The important message is to start with some form of gentle activity and with time, increase the frequency and level of intensity of exercise (when the patient is physically able to do so).

The interest in exercise often increases after a person has got started but it begins with the patient being given the right information and properly educated about the benefits of exercise, becoming aware and encouraged to do the exercises.

Incidental activity

  • Choose to use the stairs instead of elevators or volunteer to do errands for others is the simplest form of free exercise.

Low impact, low risk exercise

  • For many this include walking and swimming with minimal stress on weight bearing joints.

Exercise with others

  • Physical activities amongst friends or other people who also had bariatric surgery tend to provide a safe environment, group support and motivation to exercise.

Moderate intensity exercise

  • This may involve exercise with a personal trainer in a safe and supervised environment where you are monitored closely.

Sedentary activity not only thwart excess weight and body fat loss but may also be associated with fading interest in weight loss maintenance, return to poor diet choices and poor eating habits, in the long term weight regain (recidivism).

Hence it is emphasized that physical activity should be commenced early after surgery, start with low impact aerobic activity (such as walking) and increase gradually with supervision if necessary.


An introduction: Exercise Physiologist

Accredited exercise physiologist are members of the allied health, a university qualified professional group with accreditation with Exercise and Sports Science Australia (ESSA).

They provide supervised exercise program and rebate from Medicare and Private Health Funds may be possible.