Key Topics Covered

Let’s unpack the question, “Are there downsides to eating too much protein?” Protein is essential for muscle growth, recovery, and overall health, but is there such a thing as too much? While many people are focused on maximising protein intake, there’s a point where consuming extra doesn’t lead to greater muscle gains. But whilst there may not be benefits to going higher than the general protein recommendations for muscle growth, are there potential downsides?

Missing Out on Other Macronutrients

  • Takes away from the ability to eat more carbohydrates and fats.
  • From a fat perspective, if you consume too little, this could have hormonal implications.
  • We also know there are health benefits from certain types of fats, for example, we consistently see things like extra virgin olive oil, nuts, salmon and avocado being linked with health benefits.
  • It reduces how much room you have for carbohydrates.
  • We know carbohydrates are the best fuel source for exercise.
  • But it also reduces the room you have for high-fibre carbohydrate sources. This has implications for gut health.
  • Many micronutrient-rich carbohydrate sources would be displaced by this approach.

It Still Contributes Calories

  • Stating the obvious, protein still contributes calories (4kcal/g)
  • We don’t need to focus on this too much, but it is another factor to consider.

Satiety

  • Protein is the most satiating macronutrient per calorie.
  • If somebody struggled to get enough calories in, it might make sense to avoid going much higher protein than needed 

Taste & Dietary Flexibility

  • I can only name a few people who have claimed that protein is their favourite macronutrient from a taste perspective.
  • Honestly, I don’t believe that. Those people have all been bodybuilders with a warped perception of food.
  • If you forgot everything you knew about nutrition, you would never try to make that claim.
  • By avoiding going significantly higher protein than needed to maximise muscle growth, you can be much more flexible with food.

Gut health

  • There’s research indicating that high protein diets are linked with poorer gut health.
  • But honestly, I’m not overly concerned by that since it seems like having a high fibre intake coming from a variety of sources offsets that completely.
  • Consuming high protein also likely reduces the odds of you achieving a good protein-to-fibre ratio.

Longevity

  • There’s a lot of evidence that consuming sufficient protein late into life has a tonne of benefits.
  • But if we look at clear trends, populations of people who live long lives on average don’t tend to be consuming super high protein diets. 
  • I’m not using that as an argument for low-protein diets. I’m just saying that common themes occur when studying the diets of people who average longer lifespans. 
  • Many mechanisms can explain this, and the source of protein influences this a lot as well.

Environmental Impact

  • Without going into too much detail, there is an environmental impact of trying to consume high amounts of protein when it comes from animal sources.

Cost

  • Protein is typically the most expensive macronutrient, too.
  • Having significantly more protein than required is also more expensive than necessary.
  • This may or may not be a relevant factor for you.

Summary

It is “fine” to go well above the necessary amount of protein to optimise muscle growth. In many cases, we like to go a bit above what is required since it will help ensure people consistently hit their needs every day. However, we typically would not recommend going a lot over this target because then you may start running into these other problems discussed.

Relevant Blogs/Research

Relevant studies:

Relevant Blogs:

The Complete Guide to Protein for Athletes | Ideal Nutrition