Protein powders in rehab - who needs them and when? - Specialist Nutrition Rehab


30 Mar 2022

Protein powders in rehab – who needs them and when?


After a major trauma or injury, many clients ask us whether they need to be taking protein powders as part of the rehabilitation process.

There are two main types of protein powders:

  • “Diet” or “lean” protein powders – these are a concentrated form of protein, because they strip out the fat, carbohydrate, vitamins and minerals that would otherwise be in a high protein food (e.g. milk).
  • “Weight gainer” blends – these tend to have significantly more fat, sugar/oats and calories, in addition to the protein.

While protein powders can be helpful in certain situations (depending on what someone is trying to achieve), protein-rich foods are almost always the best choice because most clients need the extra nutrients that these foods provide.


When might “diet” or “lean” protein powders be helpful?

1. People with a high body weight

Protein requirements are based on weight, which means the heavier someone is, the more protein they often need.   As a general rule, protein requirements are 1.0 – 1.6 grams protein per kg body weight per day, depending on whether someone is trying to maintain or increase their muscle mass.  These calculations will need to be adjusted for clients who are obese and those who have kidney problems.  For a person that weighs 75kg, that means they may require 75 – 120 grams of protein per day.  If you consider that 120 grams of cooked meat provides ~25 grams of protein, a high protein yogurt has 20 grams and 200mL semi-skimmed milk has 7 grams, you can see why someone may struggle to meet their requirements if they have a small appetite, have difficulty chewing/swallowing meat or if the bulk of their diet consists of high carbohydrate foods like bread, pasta and potatoes.

It’s important to note that the body can only absorb about 20-40 grams of protein at one time.1, 2  This means that protein needs to be spread throughout the day.  Eating a massive amount of protein at the evening meal (which is what most clients want to do) is not going to achieve the desired outcome.  Protein powders can therefore make it easier for someone to meet their protein requirements and/or space this protein throughout the day, if someone is unable to achieve this by changing their typical food intake.


2. People who need under 1500 kcal per day

After the initial “acute” phase of a trauma/injury, many clients end up requiring less than 1500 kcal per day to maintain their weight.  This is because these clients lose large amounts of muscle mass immediately post-injury, due to high levels of inflammation, muscle atrophy from disuse and/or inadequate nutrition while in hospital. Since muscle is what burns the calories, the less muscle mass someone has, the less calories they burn.  The biggest challenge for these clients is when someone has high protein requirements for skin/muscle repair, but they can only consume <1500 kcal per day before gaining weight.  These people need to become very strategic with their food choices, either choosing low-calorie, high protein foods or using protein powders to help meet their requirements. One scoop/serving of “diet” or “lean” protein powder provides ~100-125 calories and 20-30 grams of protein when mixed with water to make a shake, so it’s a low calorie option.


3.  People with a wound or pressure sore

Protein provides one of the essential building blocks necessary to repair damaged skin (along with vitamin C and zinc). Protein requirements for wound healing are set at 1.2 – 1.5 grams per kg body weight per day, depending on the severity of the wound.3  “Diet” or “lean” protein powders can be a helpful way to get extra protein for short periods of time, because they can be easily added or removed as needed.  This is often easier than trying to change someone’s overall diet, as eating more high protein foods can lead to unwanted weight gain if the person isn’t careful. For more details go to Slow Healing Wounds? Consider Nutrition and Nutrition…healing wounds from the inside out.


4.  People doing strength training

People who are into bodybuilding and weight lifting often take protein powders (as shakes) immediately after a workout.  The principle behind this, is that effortful strength training causes microtears in the muscle and protein is needed to repair the damage and make the muscle stronger.  For most novice exercisers, it’s more important to get the strength training program right and ensure they are meeting their daily protein requirements.1  If muscle-building is the goal, 1.6 grams protein per kg body weight needs to be divided over at least four meals (with a 20-40 gram protein “dose” per meal, evenly spaced throughout the day).1, 2. That means a 75kg individual would need 120 grams of protein per day and this would be best divided into either 6 mini-meals containing 20 grams of protein each, or 4 meals containing 30 grams of protein each.

Note that eating extra protein doesn’t magically build muscle all on its own. Protein only boosts the increase in muscle strength and growth caused by resistance training.4

Once total protein needs have been met, further benefit can be seen from focusing on the timing of the protein and taking 20-40 grams of whey protein powder immediately after a strength training workout.  Whey protein is used specifically, because this gets into the system quickly and provides the highest source of the amino acid leucine, which stimulates muscle repair.5  For vegans, soy protein and pea protein are the highest in leucine.  Other food sources of protein can then be consumed at other times of the day.  For other muscle building tips post-injury, go to our article on muscle-targeted nutrition therapy.

5.  People trying to lose weight

While most people set a goal for “losing weight,” what they actually want is to lose fat.  They certainly don’t want to be losing a large amount of vital muscle mass in the process.  Exercise (preferably resistance training), must be combined with eating adequate protein, if someone wants to minimise the amount of muscle mass that is lost when losing weight.6, 7  This is because when the body doesn’t get enough calories, it will either start burning protein for energy (instead of using it for muscle/skin repair) or breaking down the person’s own muscle mass.  The faster the weight loss, the more muscle mass someone will lose, particularly if they are not eating sufficient protein.6, 7. “Diet” and “lean” protein powders can be a low calorie way to help meet someone’s protein requirements.

How to get more protein

  • High protein foods – fish, chicken, eggs, low-fat meat, legumes, nuts and low-fat milk products, are generally the best ways for people to meet their protein needs.  High protein yogurts (with 20 grams of protein per serving) and/or adding dried milk powder to regular milk to make it “fortified” are great, low cost options.  Most clients will need to minimise high-fat, high-calorie protein foods (e.g. high fat meat/milk products) if they want to avoid unintended weight gain.


  • “Diet” or “lean” protein powders – these are usually best immediately after a strength workout (for people doing serious strength training) and/or those who need a lot of protein but very few calories.


  • Oral nutrition supplements (such as Fortisip™ or Ensure™) and “weight gainer” blends – while these are usually high in protein, they are also high in calories and may also have extra vitamins and minerals added to them.  These products are best for people who are underweight and/or struggling to eat enough.


Dietitians can help clients figure out what their protein requirements are, analyse their intake to see if these targets are being achieved and help clients strategise on the best way to meet their protein needs.

To refer a client for specialist dietetic assessment and treatment, please contact us at 0121 384 7087 or

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Specialist Nutrition Rehab
West Midlands
B24 0PL


07787 603 863

0121 384 7087

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