As we age, we tend to lose muscle mass.  This process, known as sarcopenia, is associated with an increased risk of disability, loss of independence, and a lower quality of life among older adults.  Moreover, it is associated with an increased risk of mortality.

In addition to exercise and resistance training, protein supplementation is often recommended to prevent the loss of muscle mass among older adults; however, it could be counterproductive as protein is also known to suppress appetite, causing us to eat less.  In response, the authors of “The Impact of Protein Supplementation on Appetite and Energy Intake in Healthy Older Adults: A Systematic Review with Meta-Analysis,” published in Advances in Nutrition, sought to determine the effects of protein supplementation on appetite and energy intake in older adults.  Specifically, the authors, Sana Ben-Harchache et al., wanted to know if the positive effects of protein supplementation on building and maintaining muscle mass could be counterbalanced by the negative effects of lowered appetite and energy intake (i.e., eating less).

In order to conduct their research, the authors performed a comprehensive search of the scientific literature, leading them to 22 studies that met their criteria.  Nine of these studies were short-term studies .  The remaining 13 studies were longitudinal studies that tracked older adults’ response to protein supplementation repeatedly over a period of time.  In some instances, the studies looked at the effect of protein supplementation in the form of whole foods such as soy milk or yogurt.  Other studies examined the effect of protein supplementation in the form of protein supplements such as whey protein drinks.

Overall, the authors of this scientific review did find that “protein supplementation may suppress appetite under some conditions in older adults.  However, there is either a positive effect or no effect on energy intake in both acute and longitudinal studies.”  The authors were therefore able to conclude that “protein supplementation may represent an effective solution to increase protein intakes in healthy older adults without compromising energy intake through appetite suppression.”  Interestingly, the authors noted that, in contrast to older adults, studies have found that protein supplementation among younger adults is associated with lowered energy intake.

All forms of protein supplementation, whether protein supplements or foods high in protein, appear to be effective in increasing overall energy intake among healthy older adults.  In particular, the authors pointed to research indicating that protein supplementation an hour or more before a meal may be particularly effective.

In short, the findings of this scientific review suggest that protein supplementation among older adults is unlikely to be counterbalanced by lowered energy intake.  Individual health and nutrition needs, however, vary.  Older adults seeking to prevent muscle loss should consult with their health care provider to see if protein supplementation is appropriate for them.

Reference: Sana Ben-Harchache, Helen M Roche, Clare A Corish, Katy M Horner, The Impact of Protein Supplementation on Appetite and Energy Intake in Healthy Older Adults: A Systematic Review with Meta-Analysis, Advances in Nutrition, nmaa115,

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