Pre and Post Surgical Nutrition – Harriet Smith Registered Dietitian & Nutritionist

Any form of surgical procedure causes the body physio­logical stress, the extent of which depends on the extent of the surgery. Orthopaedic surgical procedures can have a profound effect on nutritional status and this article describes the part that nutrition can play pre- and post- spinal fusion surgery.

Healthy and balanced diet

In general, there’s no specific diet that needs to be followed before spinal fusion surgery. We should all be aiming to eat more fruits and vegetables, wholegrains, and oily fish, keeping the Government Eatwell Guide in mind (see figure 1). In the UK, it’s recommended that we consume two portions of fish a week, with at least one portion from oily fish (eg, salmon, makeral, sardines, or herrings). Choose lean meats and low-fat dairy as well as heart healthy fats such as olive oil and rapeseed oil. Restrict the amount of saturated fat, alcohol, and caffeine consumed in your diet.

Most young and middle-aged people in the UK consume above the recommended daily amount of protein; however, if you follow a vegan or vegetarian diet, make sure you are consuming adequate amounts of protein from plant-based sources (eg, lentils, chickpeas, peanuts, tofu, and edamame beans). Elderly people and those with chronic illnesses often do  not have enough protein in their diet, leading to muscle loss and sarcopenia (loss of skeletal muscle mass and strength). The optimum amount of protein in our diet is controversal and recent reports point to beneficial effects of protein intake – particularly if it is plant-based.

It’s also important to make sure you are drinking enough water in the lead up to surgery to avoid dehydration, because dehydration can lead to post-operative complications. A good way to check your hydration status is to check the colour of your urine. Aim for a pale straw yellow colour and if it is dark, drink more fluids!


Nutritional supplements

Whilst there are no specific clinical guidelines for vitamin and mineral supplementation before to spinal surgery, your surgeon may advise you to take a supplement (eg, vitamin D) before surgery. The UK government recommends that people older than age 1 should take vitamin D supplement, particularly during autumn and winter, because of the reduced exposure to sunlight (the main source of vitamin D in the UK in those months). Vitamin D is an important component in musculoskeletal development and deficiency is thought to have widespread consequences for bone healing. It is important that you inform your surgeon of any supplements or herbal remedies that you are taking  before, because they may interact with some medications he will prescribe.


Optimising your nutritional status before surgery

Studies have shown that being malnourished before orthopaedic surgery is associated with a significantly higher risk of post-operative complications such as increased risk of infection at the surgical site. A person is classified as malnourished if they meet a set of criteria which includes a low body mass index (BMI less than 20 kg/m2), unintentional weight loss over the past 3 to 6 months, and being acutely unwell with little or no nutritional intake for five or more days. Guidelines recommend delaying elective surgery in patients with malnutrition until their nutritional status has improved. Although obesity is no longer regarded as a risk factor for post-operative complications, it can increase the operating time.

Nutritional screening is recommended in National Institute for Health and Care Excellence (NICE) guidelines for all inpatient admissions in the UK. You will probably have your height and weight measured during your pre-op assessment and at regular intervals after your operation. It is important to consult a healthcare professional if you are concerned about your weight because they will be able to do nutritional screening (using the Malnutrition Universal Screening tool) and can refer you to a dietitian if necessary.



Before surgery, you will be required to fast (usually overnight) to reduce your risk of complications during the general anaesthetic. Most hospitals have their own fasting policies, and your hospital will inform you of the fasting guidelines before your operation. If you have diabetes, make sure you discuss this with your medical team before fasting because medication (particularly insulin) needs to be reduced to prevent severe hypoglycemia.


Post-operative nutrition

Wound healing and bone fusion

After surgery, there’s an increase in the amount of energy used by the body and proteins are mobilised, which is thought to be mediated by signalling proteins called cytokines. Bone fusion can take up to 12-18 months to grow and become solid.

There are three phases involved with wound healing: inflammation, proliferation and maturation, and remodelling. The inflammatory phase occurs within the first few days after surgery during which time the wound area attempts to restore homoeostasis (internal balance in an organisim to compenstate for environmental changes) by constricting blood vessels to prevent bleeding.

The proliferative stages lasts 3 or more weeks and involve the formation of collagen (the main structural protein in connective tissue) to fill the wound and new blood vessel formation. The maturation and remodelling stage may last up to 2 years, during which time new collagen is made and eventually scar tissue forms. During wound healing, there is increased cellular activity, which raises the metabolic demand for nutrients.


Nutritional requirements

Nutritional requirements are higher in the presence of a chronic wound. If you don’t eat enough food to meet your energy requirements, this can have a significant effect on wound healing. It is important to re-introduce oral food as soon as possible after surgery to prevent weight loss and subsequent malnutrition.

Energy demands are thought to rise by 10% after even minor surgery and up to 60-70% in major trauma. As a rule of thumb, a patient probably requires at least 30-35 calories per kilogram of body weight each day during the wound healing process post-surgery, which for a 60kg person, would equate to 1800-2100 kcal/day. However, lots of other factors could increase your nutritional requirements such as having an infection or a temperature.

It is important to make sure that you are getting enough carbohydrates and fat in the diet since these are the main sources of energy in the wound healing process. Glucose is the major source of fuel for tissues and prevents depletion of protein, whilst fat has an important role in cell membrane structure and function.

Protein is important in tissue synthesis (formation) and repair. NICE guidelines recommend 0.75g of protein per kg in normal, healthy individuals. However, there not much high quality research into optimum levels of protein in the diet post-surgery. Intakes of more than 1.25g/kg (0.2g nitrogen/kg) are thought to be of little benefit to patients. As a rule of thumb, aim for a slightly higher protein intake than normal.

Micronutrients refer to vitamins and minerals, and these play an important part in wound healing and metabolic functions. For example, vitamins A and C promote collagen synthesis and immune response whilst vitamin K is needed for blood clotting. If you were fit and healthy before the surgery, it is unlikely that you will require anything more than a healthy and balanced diet to provide all the necessary micronutrients.

Fluid is very important for maintaining good blood flow and skin tone, which is critical for prevention of skin breakdown and pressure ulcers. In general, 18-60 year olds should aim for just over 2 litres of fluid a day. You can monitor for signs of dehydration yourself (ie, looking out for dark coloured urine or a dry mouth); however, the nursing staff will be monitoring your fluid status.


What should I eat post-surgery?

You may experience some pain and discomfort during the first few days and weeks after surgery. During this time, nutrition and eating may be the last things on your mind!


Little and often

Don’t be too hard on yourself. The anaesthetic can take time to clear from your system, which may affect your appetite. Try to eat little and often and choose whatever you feel like. You aren’t tied to the meal timings at the hospital. Try a small snack between meals. Most hospital wards should be able to offer you some snacks such as cheese and biscuits, yoghurts, sandwiches, biscuits, and crisps outside meal times. Or you could ask family or friends to bring in snacks. Start small and build up gradually. If you can only manage a few mouthfuls, that’s better than nothing.


Hospital food

All hospital dishes are labelled according to their nutritional content on the menus. Try to order high energy and high protein menu options such as jacket potatoes with beans and cheese, meat curries with rice, fish or meat in creamy sauces and cheesy pasta dishes. However, the most important thing is to order something that you feel like eating.

If you don’t like what’s on the hospital menu, speak to the health care assistants and nursing staff because they are sometimes able to provide you with vouchers to use in the hospital canteen or can order you a meal from one of the alternative menus (ie, the vegetarian or halal menu).


Have a pudding

If you feel like it, choose a dessert after your main meal such as a sponge pudding with custard, a full-fat yoghurt or a slice of cheesecake for extra energy and protein. Avoid low-fat and diet versions of food because these will provide you with very little energy. Keep boiled sweets, cereal bars and chocolate at your bedside for whenever you fancy a sweet hit.


Choose nourishing drinks

During the hospital drinks rounds, opt for milky drinks like hot chocolate or full-fat milk. If your family and friends can bring in drinks, you might like to ask them to bring in cordials, fruit juices, or smoothies and milkshakes.

Although we often talk about limiting high fat and high sugar drinks as part of a healthy diet, whilst you are recovering from surgery you need all the energy you can get. Just try not have drinks before meals because they might fill you up.


Nutrition and symptoms management

Dealing with nausea

If you are feeling nauseous, try to start with dry and plain foods such as plain toast, plain pasta or mashed potato. You might find it useful to avoid greasy, fatty, and spicy foods whilst you are feeling sick. You could also try a smaller plate so that the food doesn’t seem so daunting. If the nausea persists, you could ask the doctors to prescribe you an anti-sickness drug before mealtimes.


Dealing with pain

It is important that you communicate your pain levels to your medical team so that they can help you to manage your pain. Ask your doctor whether you can take your medication just before mealtimes to help you manage during meals.


Dealing with drowsiness

The combined effects of the anaesthetic and pain medications may make you feel drowsy. As tempting as it is to sleep through mealtimes, remember that nutrition is a vital part of your recovery. Try to have a relative or friend on hand at mealtimes so that they can wake you up and encourage you to eat.

If you do miss a meal, try to eat something small as soon as you can after waking. Your sleep cycle might be disturbed for the first few weeks and you might find yourself eating at different times from what you are used to.


Food fortification

During the initial weeks, post-surgery, you might find it hard to eat the amount of food that you are used to. Food fortification is a great way of adding extra energy and protein to foods by adding high calorie ingredients such as double cream, grated cheese, butter, sugar, jam, and full-fat milk. This means you eat the same volume of food but consume more protein and energy. For example, if you are having a jacket potato, you could add a sachet of butter and a portion of grated cheese. Similarly, you could add extra sugar and full-fat milk to you breakfast cereal.

Nutrition can play an important part in helping to facilitate your recovery post spinal fusion surgery. If you have any concerns about your nutritional intake or your weight pre- or post-surgery, speak to a healthcare professional. If appropriate, they may be able to refer you to a registered dietitian.

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