Key Topics Covered

protein powders and scoops scattered on a table

This is another podcast episode loosely inspired by a recently published “questions and misconceptions” paper by the ISSN. We have gone with this because it allows us to cover a range of topics. So that way you may get value from one answer or the following question.

Myth: Protein Is Harmful to Your Kidneys

The research consistently finds that high protein diets are not detrimental to kidneys in those who have healthy kidney function at the baseline. 

  • There have been many studies in the 2-3g/kg range of protein per day with long durations showing no issues with kidney function. 
  • Higher protein intake vs lower protein intake, within reason, has not been linked with different rates of kidney decline. 
  • PLUS there isn’t much reason to go higher than 3g/kg.
    • Although, the highest protein intake studied was 4.4g/kg for 8 weeks, but while no issues with kidney function were noted, they didn’t track markers as closely as other research, it is also a fairly short study duration.
  • If you do NOT have healthy kidneys at the baseline, it’s a bit more complex.
    • The authors of this “questions and misconceptions” study highlighted how research on protein restriction for chronic kidney disease has found inconclusive results. This makes it more complicated.
    • But for those cases I think a personalised approach with your medical team is necessary, particularly the further progressed it is.
  • There is a clinical practice guide for chronic kidney disease that we refer to that lays things out in an evidence-based manner based on individual situations. In there, they build a case for reducing protein intake in very specific cases.

Myth: You Need to Consume Protein ≤ 1 Hour Post-workout for Muscle Growth

Total protein intake matters far more. But if you want to absolutely maximise muscle growth, it is worth having protein within a few hours around the time of your workout (before, after or both).

Do You Need Protein Supplements to Meet the Daily Requirements if You Lift Weights?

  • A typical range often recommended for lifters is to aim for 1.6-2.2g/kg for protein. 
  • This can be met without protein supplements. 
  • But in some cases it is more convenient to include them.

Can Dietary Protein Have a Harmful Effect on Bone Health?

Woman lunging with weights on the beach showing muscle and bone

  • This misconception is typically associated with the acid-ash hypothesis, but it is easy to unpack. 
  • Research consistently finds that those with higher protein intakes tend to have BETTER average bone mineral density.

Is There a Limit to How Much Protein You Can Consume in a Single Meal?

  • There is no specific limit. 
  • Total protein intake is clearly the main priority. 
  • At minimum, distributing your protein intake helps you consume sufficient total intake and ensures that timing is taken care of without much thought.
  • But if  you are undercutting your total protein intake to avoid going over a certain gram amount per meal, you are missing the forest for the trees.

Does Consuming “Excess” Protein Increase Fat Mass?

A calorie surplus causes an increase in fat mass. Protein contributes to calorie intake, but it doesn’t directly cause fat gain without the surplus being present.

Myth: You Should Have Casein Before Bed and Whey Post-workout.

The moment you mix whey or casein with anything (e.g. milk or alongside food), the digestion rate slows down to similar rates, defeating the slow-release argument. Research looking at casein post-workout has found similar muscle growth as whey too.

Can Plant-Based Protein Supplements Work as Well as Whey Protein?

  • Yes. Some plant-based protein powders are low in relevant amino acids, while others aren’t. 
  • Some might also have lower digestibility. But if your total protein intake is high enough and you have abundant amino acids, this is not an issue.
  • It is all about choosing a good quality option.
    • Soy protein isolate has been shown to have a similar anabolic effect and effect on MPS as whey protein. 
    • Pea and rice blends are also particularly good options. 
    • Leucine content >2g per serve.

Summary

Hopefully, the answers provided to some of the most popular questions and misconceptions based on protein supplementation are clear and provide you with a better understanding around the science of protein supplementation.

Relevant Links/Resources

Blog posts:

Research: