Post-surgery (orthopedic)/injury nutritional guideline; Part 1 (protein, EAAs, energy)

This guideline will be divided into 3 short sections, intended for general informational purposes. Always consult your healthcare team for personalised advice, as individual factors like your medical history and type of surgery/ injury are crucial. There are a few concerns when it comes to some sort of immobilisation or muscle disuse after injury or surgery.

• Muscle atrophy (loss of muscle mass) & loss of strength

• Reduced muscle protein synthesis (MPS)

• Anabolic resistance 

  
  

The amount of muscle loss will vary depending on the type of surgery, the length of immobilisation, reduced functionality, and how well the body heals. Many studies show different amounts of muscle loss ranging from 0.1kg-0.3kg within just 1-7 days post-surgery/disuse. To be completely realistic, some muscle loss is inevitable, however, we want to minimise it as much as possible. The next 2 paragraphs go a bit into muscle physiology, you can skip it if you don't care.

Muscle loss occurs when the synthesis of myofibrillar proteins is insufficient, meaning the body isn't producing enough muscle protein. After surgery or injury, the body particularly relies on the synthesis of collagen and other proteins to heal. Muscle protein balance (NBAL) refers to the difference between muscle protein synthesis (MPS)- how much protein you're building and muscle protein breakdown (MPB)- how much protein is being broken down. This balance is constantly shifting in your body. However, after surgery, MPS typically decreases due to reduced muscle use, leading to a greater negative NBAL and consequently muscle loss.

An important factor contributing to muscle loss is anabolic resistance, which makes it more challenging for muscles to respond to protein intake.The exact mechanisms behind anabolic resistance are multifactorial and not yet fully understood. Possible factors include impaired digestion of protein and absorption of amino acids, altered microvascular perfusion and amino acid uptake into muscle or impaired intracellular molecular anabolic signaling.

To combat this anabolic resistance and reduced MPS, it's essential to incorporate protein-rich foods into your diet during recovery. Leucine, a key amino acid, is particularly important as it stimulates the mTORC1 signaling pathway, which plays a crucial role in muscle growth and repair.

In the early hours after surgery, appetite is often suppressed, and eating solid food can be challenging. A good option during this time is to consume 15g of free-form EAAs (Essential Amino Acids) paired with 30-50g of carbohydrates. Free-form EAAs are quickly absorbed by the body and play a crucial role in supporting wound healing, reducing the risk of post-surgical infection, promoting tissue recovery, and helping with glycemic control—all without putting a heavy load on the stomach. As your appetite begins to recover, you can gradually introduce protein powders and whole food sources of protein into your diet (see below for graphical illustration; screenshot from PMID: 34063333)

Protein intake recommendations during recovery typically range from 1.6g to 3g per kg of body weight per day, with a focus on achieving about 3g of leucine per serving. Whey protein is an excellent option because it is a high-quality, fast-digesting protein that rapidly increases EAA availability in the bloodstream. A typical 30g serving of whey protein contains 2.5 to 3g of leucine. Other great sources of protein include chicken, beef, tuna, milk, fish, greek yogurt, ham, cheese, cottage cheese, eggs, quark etc.

Alright now that we understand the importance of protein intake for recovery, it's essential to determine how much protein and overall calories (calories consist of protein, carbs and fats) you should consume daily, starting approximately 24h post-surgery within reason.

After surgery, your basal metabolic rate (BMR) increases due to higher cellular turnover, potentially rising by 15-50% depending on the type and severity of the surgery (e.g., ACL reconstruction requires more energy for healing). To estimate your energy needs, you can use approximate formulas that take stress factors into account (see below). It's therefore important to avoid an energy deficit after surgery, as this can lead to greater muscle loss and slow down wound healing.

Use this formula (Harris Benedict one) x activity level (if after surgery, you'd be sedentary or lightly active during the first few days- but obviously depending on type of the surgery and if you can walk already, if you're using crutches etc.) x stress factor. Below are two examples of calculations (screenshot from PMID: 32991705)

To finish off this part, it's essential to ensure that your energy intake (calories) is adequately high as soon as possible after surgery along with sufficient protein, carbohydrates and fats intake. Based on your calculations, you'll have a clearer idea of how many grams of each macronutrient to consume, and in the next part, I'll provide you with specific sources (as I did here with protein).

You can focus on consuming high-quality food sources, but if you have some experience in this area, you'll find it easier to navigate your nutritional needs when you use myfitnesspal and log in what you're eating. I often use this analogy: it’s easier to plan a budget when you know exactly how much money you spent, rather than just guessing. But ultimately it's completely up to you. All I can do is provide you with the information and tell you that anecdotally, if I had to have another surgery right now, I would definitely be logging my intake for a few weeks to help me recover as fast as possible.

As mentioned above, in the next parts, I will discuss the optimal sources of fats and carbs, and I will explain which micronutrients are important (along with their sources). I’ll also tell you which supplements I highly recommend you to include.