Hi! I am María, a medical student! I take JimmyJoy for breakfast and often lunch. I saw this post and I got interested in the matter. I am not an expert in nutrition, but I have been taught the basics and I have access to medical resources that normally need payment.
UpToDate is a paid service that recopiles information about EVERYTHING health-related, and it updates frequently. A lot of teachers recommend us this webpage whenever we face a problem we don’t know about, since it summarizes all relevant and novel info. Being a student, I can access for free. UpToDate says the following about protein intake in healthy individuals:
- Protein intake should make 10-35% of caloric intake, as recommended by the United States Dietary Guidelines (1)
- The recommend consumption of between 1.6 and 2.2 g per kg of bodyweight per day of dietary protein for those participating in strength training programs . Contrary to widely held assumptions, this level of protein intake does not harm the healthy kidney. They cite studies (2), (3) and (4). Access the link at the end of this post for references.
Plenny Shake (not active) actually has a protein intake of 20%, which is in the recommended range. As for active people, if they want to build up muscle, it is recommended to take between 1.6 and 2.2 per kg, which is safe. This data is up to date as of June 2020 (last review), and it was last modified on December 2019. This is just evidence supporting that, in fact, there is no risk in an increased protein intake. We can still question if >2.2 is risky or not, and what is the best protein ratio per kg.
PubMed recopiles studies from all around the world as long as they have been published in a magazine. In PubMed, I found the following:
- USA investigators refuting the American RDA for protein intake, which is 0’83g per kg. In short, they found that people with an increased protein intake were less likely to suffer from bone fractures in their old age. So they conclude that it should be recommended to increase this minimum limit. To what value you may ask… More research to find out. Link (5).
- USA investigators again!! This time, it is muscle mass and old age. Again, 0’83 is less than sufficient. Link (6).
- USA. A protein intake of 20-35% of the total caloric intake is safe for renal health.
- Australia. 1’0-1’3 g/kg/day in old people can reduce muscle mass loss. 0’83, again, insufficient for a determined age group.
- USA. An study shows that the majority of American surpass the RDA for protein.
Additionally, I found two reviews that discuss what is the optimal protein intake. They argue that the current 0’83 is based on certain parameters that don’t actually reflect the reality of protein metabolism in the human body. It was a good aproach when it was decided (in 2004 I think?) but now we know more about metabolism and there are better parameters to determine other better reference value. Links (7) and (8).
A review by Spanish investigators ( 9) concludes the following:
“High-protein diets may be appropriate for some individuals, but not for others; hence, specific individual needs, as well as potential negative consequences, must be considered cautiously before such a diet is adopted. The protein content of a diet may be measured using several methods; however, because of the great individual variability in caloric requirements, measuring intake based on the proportion of proteins in total energy intake seems to be the most realistic method. A moderate intake of 1.5 g/(kg ⋅ d) may be easily included in the acceptable protein intake range (AMDR 10–35%) for most individuals. However, currently, no objective standard for protein consumption >0.8 g/(kg ⋅ d) exists. It is important to distinguish between the amount of protein that is required to optimize bone and muscle health and the amount necessary to prevent a deficiency. It is also important to note that high-protein diets are harmful to CKD patients; however, for healthy kidney patients, in view of the findings of several studies, the consumption of a high-protein diet appears to be more advantageous than deleterious. In addition, dietary protein seems to play an important role in other metabolic processes, such as satiety, cellular signaling, and thermogenic and glycemic regulation in the body. However, this effect becomes important only when consumption is above the RDI; thus, it seems likely that protein intake above the RDI could be advantageous in many situations. Long-term clinical intervention trials in which dietary protein is increased in healthy individuals should be carried out to determine the efficacy and potential negative consequences of a high-protein diet.”
Please notice that 1’5 is considered a moderate intake and fitting for the majority.
Conclusion: If you were to ask me if Plenny Shake is healthy, I would say it is for the majority of individuals. It contains 20% of protein intake, which is a middle value in the 10-35% range, and it is considered safe for health in most of the recent articles and guidelines. Of course, Plenny Shake is made for “normal” people, so anyone with lower or higher calory intakes than those considered normal for your age and physical activity will be affected somehow.
I would like to point out a little misconception about proteins. We have talking about quantity as if it was the only parameter that matters. If someone reads the articles (7) and (8), you will notice that the quality is far more important, just less discussed. The difference between eating a good quantity of proteins in a plate of pasta and in a Plenny Shake is that you are not getting all high-quality proteins with pasta. The issue with proteins in health is not only a matter of too little or too much (which can also get you sick) but what proteins?. You can eat a lot but that won’t mean you are getting enough. Appart from needing certain proteins to multiply or rechange cells, the proteins that we eat affect our gut and microbiote, which in turn send signals to our brain. Same can be said about other macronutrients. Brain-intestine axis is a novelty even for scientists, but it has been proposed to have a role in pathology.
PD: I am sorry this is long and probably not that interesting. Please have in mind English is not my first language. And if you know more, please share and comment!! Does someone knows where 1’8 has been recommended? Or other reference values? Or papers.