Can you have too much protein?

Protein. We know it, we love it. Can we get too much of it? Believe it or not, yes, we can, especially if you have any underlying kidney disease or dysfunction. But even if kidneys are the picture of health, there are other things to consider here.

I have a lot of clients who have been told to eat their body weight in grams of protein, i.e. if someone weighs 225#, they need to eat 225 g/d protein- that’s a lot of protein y’all.

There are a few things to consider here- first of all, if you are eating that much protein, it is likely that the other macros- fats and carbohydrates- are being left out somewhere and not consumed enough to support training and recovery.

Also, there is a limit on the amount of protein utilized in muscle protein synthesis at one time- somewhere in the range of 30 g of protein at a time.

In the above example, the person would need ~ 7 servings of protein to meet that goal for optimal muscle building. For most of us this means eating protein all day long.

But perhaps the piece of this that gives me the most pause is, what is your fat free mass versus total mass?

One research study I looked at phrased this really well-

“A person’s protein requirement depends on their age, the amount of fat free mass (FFM) extent and type of physical activity, the protein quality and the severity of disease. There are several ways to estimate the individual optimal protein requirement. In dietary practice, it is common to estimate protein requirements based solely on body weight. The recommended daily amount of protein of 0.8 g (g) per kilogram (kg) bodyweight per day in healthy subjects is based on the amount of protein needed to compensate for daily loss of nitrogen and is based on short-term (<2 weeks) nitrogen balance studies.”*

For athletes that number increases to 1.2-1.7 g/kg/d depending on sport (endurance vs strength). To figure out your weight in kilograms, divide your pounds by 2.2. Some of y’all doing the math right now are coming up with numbers much smaller than g/pound of bodyweight.

This is why dietitians like to look at ranges of protein intake, and then adjust needs based on performance, goals, muscle gain/fat loss, recovery, etc. It typically isn't quite so clear cut as eat what you weigh. In athletes, this is a particularly important thing to consider when looking at training and performance goals as well as training schedules, meal and snack intakes, optimizing muscle protein synthesis around training, and recovery.

If you've just been following generic advice and aren't sure where to start, let me know. I'd love to work specifically with YOU and your needs.

Sarah Szejn, RD