Is Protein Powder Good or Bad for You? A Dietitian Answers Common Questions
Historically protein powder was produced to support the nutritional needs of bodybuilders and athletes. However, protein powder is now used by a much broader audience as a convenient way to increase protein intake (1).
But with increasing talk around processed foods, and the reality that many people in Western countries already consume enough protein, it’s fair to ask: is protein powder necessary, and is it helpful for health?
Let’s break it down.
Is protein powder ‘good’ for you?
Firstly, as a Dietitian, I can’t answer this question without gently challenging the labelling of foods as ‘good’ or ‘bad’. Food is much more complex than its nutritional value, and a healthy relationship with it starts with removing judgment. So, instead, let’s ask: ‘does this food offer benefit?’
Another important point is that protein powder is a supplement. This means it is designed to complement a balanced diet, not replace meals. For the general population, it’s not essential, but it can sometimes be a practical tool in some situations:
When might protein powder be useful?
- Post surgery or injury:
Some medical conditions and injuries increase the body’s protein requirements. For example, recommended protein intakes can be slightly higher for people recovering from severe burns (2), which in clinical settings, Dietitians may use oral nutritional supplements to help meet as part of a wider medical intervention. Some evidence also suggests adequate protein intake following orthopaedic surgery may support muscle maintenance (3).While human research specifically looking at protein powders in these situations is limited, one study using whey protein powder found positive associations in muscle strength and hypertrophy post ACL surgery (4), and animal studies have shown blended protein supplementation (whey and soy) to be potentially beneficial in reducing catabolism and inflammation following burn injury (5). - Older age:
As we age, protein needs can increase to support muscle mass preservation and bone health (6,7). Yet at the same time, appetite can decrease (8, 9). Because protein powder can be easily mixed into foods and drinks, it may help people increase their protein intake without dramatically increasing portion sizes. That said, protein intake is only one piece of the puzzle. Resistance training, alongside adequate Vitamin D and calcium intake, also play vital roles in supporting muscle and bone health (10,11) Emerging research also suggests sufficient leucine intake may be a key contributor to muscle preservation in older adults (12). Leucine can be found in some protein powders, as well as various whole foods including tofu (which can also provide calcium if set in calcium-sulfate – a win-win!) - Active lifestyles:
While many people can meet their protein needs via food alone, those with higher energy or protein requirements may sometimes find protein powder a convenient and relatively low-volume option to help meet daily targets. However, consuming beyond 1.6g protein/kg/day was found to provide no further benefit (13).
Are there any potential downsides to protein powder?
- Sugars & Additives:
Some protein powders contain added sugars, flavourings, and other ingredients designed to improve taste, texture, and shelf life.Consuming these ingredients occasionally is unlikely to be harmful for the general population, and additives must pass safety assessments by The World Health Organisation (WHO) before they are approved for use (14,15). That said, WHO have advised against the consumption of non-sugar sweeteners (16). Plus, free sugars are already overconsumed in many UK diets and associated with dental caries and increased energy intakes (17). If choosing to use protein powder, therefore, consider opting for products with minimal to no added sugars and sweeteners where possible. - Heavy metals:
Heavy metals such as arsenic, cadmium, mercury, and lead occur naturally in soil. These can enter our food chain and trace exposure is difficult to completely avoid (18).Independent analyses have reported the presence of these substances in some protein powders (19,20), and while current evidence suggests exposure from protein powders alone may not necessarily pose a health risk for the general population (21), it can still be sensible to check manufactures follow quality assurance practices. For example, having Certificates of Analysis or independent third-party testing for contaminants (22). - Kidney health:
For people with impaired kidney function, including chronic kidney disease (CKD), recommended protein intakes can vary depending on the stage of disease (23,24). During earlier stages of CKD, if not on dialysis, higher protein intakes may increase strain on the kidneys (25). Therefore, even if physically active, protein powders are not routinely recommended (35). Diet alone is likely to provide all the protein you need (26). Personalised support is vital, however, when it comes to kidney health and protein intake and so advice should always be sought from a qualified healthcare professional before making any dietary changes.
Does protein powder support weight loss or weight gain?
Some research indicates that protein intake – whether from food or supplements – may slow gastric emptying, but has not consistently been shown to suppress appetite or reduce subsequent energy intake in the longer term (27). In some cases, when the calories from the protein supplement itself are included, overall energy intake may be actually higher than without supplementation (28).
For liquid protein supplementation specifically, research remains inconclusive as to whether it could be an effective weight-loss strategy (29, 30). It may be that the absence of chewing needed to consume liquid protein reduces its impact on satiety (31).
Research suggests that it is instead overall energy intake that plays a key role in body fat gain, with one randomised controlled trial showing that when participants were overfed diets containing different levels of protein (but equal energy and other macronutrients), increases in body fat were similar across groups, indicating that excess calories rather than protein intake itself drove fat gain (32).
What this study – and others (33,34) – have suggested, however, is that protein has the potential to support increases in lean body mass, without affecting body fat storage. In other words, it may support with body composition, and particularly when combined with resistance training.
Summary
For most people, protein needs can be met through a balanced diet. When it comes to weight gain or loss, current evidence suggests overall energy intake plays a vital role. More important than protein intake alone.
That said, adequate protein intake may support body composition, and in certain situations – such as during recovery from illness or injury, ageing, or periods of intense training – protein supplementation may offer a convenient way for some individuals to help meet personal protein needs.
If choosing to use protein powder, look for products from reputable manufacturers that carry out quality assurance testing. Look at the ingredient list for added sugars or other ingredients. It can also be useful to discuss with a qualified healthcare professional whether supplementation is appropriate. This is especially important if living with impaired kidney function.
Remember, however, that protein powder should always be used as part of a varied diet. Not a replacement for whole foods.
Not sure which shake is right for you? Protein Works have put together this quiz to help you find the right product for your goals!
Dietitian’s disclaimer
The information in this article has been written by Amber Woodhouse, Registered Dietitian, and is based on current scientific evidence and intended solely for educational and informational purposes for the general adult public. The content should not be used as a substitute for individually tailored medical or dietetic advice. Any product links and promotions do not constitute specific endorsements from me as a healthcare professional. Readers should consult with a qualified healthcare professional before making significant changes to their diet or beginning any supplementation.
