How Much Protein Should You Really Be Eating?

How much protein should you really be eating?

Earlier this month, I went to a talk on muscle building and longevity where my friend Max Lugavere, a well-known podcaster, interviewed Dr. Gabrielle Lyon, a functional medicine doctor whose focus is on bodybuilding and longevity. The talk was about how much protein we need to build muscle and the benefits of building and maintaining muscle as we age. Both are proponents of eating a lot more protein than today’s RDA (recommended daily allowance) from the FDA.

A few people came up to me after the talk. Are they right? How much protein should I really eat? And practically speaking, how on earth do you eat that much protein in a day even if you want to?

The power of protein

Lately it seems like everyone is talking about muscle building and protein intake, which I love, because it means we are taking the longevity movement past the hypothetical and into the practical.

For me, at 42, I know it’s time to get serious about building up some muscle. I’ve lost a lot of the muscle layer I naturally had from playing sports growing up and in college, and that loss has accelerated in the past decade from having three kids and running a startup (Zoom jockey over here).

If anything has fallen off my list when it comes to my health, it’s exercise, which I hate to admit. I eat well, supplement optimally, manage stress proactively, and my labs look great, but when it comes to exercise, I get a B- at best.

I know that exercise is nature’s number one longevity drug, and it turns out that one of the primary ways in which exercise increases both lifespan and healthspan—the number of years you live healthy—is by building lean muscle mass.

What follows is the science of how much protein to eat if you need or want to build muscle. But if you want to skip to the end to how I’m getting in optimal protein each day, go for it.

The research says:

I see a lot of patients in their 30s, 40s, and 50s who are treating a specific condition (like an autoimmune disease or a hormone disorder) and simultaneously looking to optimize their health for the long term.

One of the top things I emphasize when it comes to longevity is building and maintaining muscle and strength.

The link between muscle and lifespan

People who maintain muscle mass as they age live longer. But it’s not just about mass—muscle strength matters as much if not more than muscle mass when it comes to longevity.

Protein matters for both of these measures. A meta-analysis published in the British Medical Journal in 2020 showed a dose-dependent relationship between protein consumption and longevity, particularly when it came to plant-based proteins.  

Our ability to build muscle depends on our dietary protein intake

Protein is made of amino acids, which are required to build muscle. Eaten in the right quantities, eating protein also acts as a stimulus to our bodies to build muscle. It takes about 25-30 grams of protein intake to stimulate muscle building, so the amount matters—i.e. eating an egg alone (about 6 grams of protein) won’t do it.

The current RDA of protein is .8 grams per kilo or .36 grams per pound for adults under 60. (The reason these recommendations only apply to those under 60 years old is because of a lack of research, not because people over 60 don’t benefit from protein intake—muscle mass, and the protein that supports it, is even more important as we age.) For a 150 pound person, this translates to 54 g/day. But context is important when it comes to how RDAs are set. RDAs are the amount we need to avoid a deficiency, not the amount we need to optimize health or longevity.

So for anyone looking to RDAs for their nutritional guidelines, I suggest reframing that guidance as what you need to literally just stay alive, not what you need to thrive.

How much protein do you really need?

Ignore the RDA—the optimal amount of protein we should eat daily to build muscle (vs maintain muscle) is higher.

Research shows that to build muscle mass we need to intake between 1.6 to 2.2 grams of protein per kilogram of bodyweight per day. (This equates to about a gram per pound of body weight per day.) A meta-analysis of randomized control trials published in 2022 found that consuming 1.6 g/kg of protein per day, combined with resistance training, resulted in increased lean muscle mass for adults under 65. Other studies have found there’s no increased benefit for building lean muscle mass beyond 1.6 g/kg, so we should consider this a good target.

Now if you want to maintain muscle as opposed to build it, the amount of protein advised is lower, but ideally still higher than the RDA. To maintain muscle you should consume at least 0.8 g/kg of body weight, but ideally closer to 1 g/kg.

This is why you need to put your critical thinking cap on when you read articles like this one that says “Americans are eating way too much protein!” The authors based this headline on the RDA, and Americans on average do get more protein than the RDA. But as we just covered, the RDA is the bare minimum, not the optimal.

Plant vs animal protein

The research on protein for building muscle has largely been done using animal protein sources, not plant-based protein. In addition there are some known downsides of plant-based protein sources.

  1. They are less bioavailable—you absorb 10-20% less protein from plant sources vs protein from animal sources.
  2. Many plant-based proteins are not complete proteins, meaning they don’t have the full array of amino acids (particularly the branch-chain amino acid leucine) which are required for muscle building. The best plant-based protein powders are a pea-rice blend with added leucine (such as Parsley Health’s Rebuild Clean Protein Powder).
  3. You have to eat a high volume of plant-based protein to get the same amount of protein as you would from an animal source. For example, you would have to eat two and a half cups of quinoa to get about the same amount of protein as three ounces of beef. That’s a lot of quinoa.
  4. You’ve probably seen articles that say eating animal protein increases cancer rates. This data is also problematic. When you look at people who eat low-sugar, high-fiber, and high-quality animal protein diets, the association falls away. (The link is mostly attributed to processed meats, animal proteins high in fat, and meat cooking methods like smoking and grilling.) Big Macs and fries are not the same as a lean steak and a salad, it turns out.

What about animal welfare and ethical issues?

Personally, I don’t eat pigs or birds because it’s very difficult to source ethically and sustainably raised pork and poultry in the US. I find it much easier to find ethically and sustainably raised beef and seafood, so I eat both, but try to find pasture-raised grass-fed beef and sustainably fished wild and farmed seafood sources.

If you’re fully vegetarian or vegan, it is very hard to get enough protein to build muscle without a lot of dairy consumption or processed protein supplements. You have to be very diligent. I offer a few plant-based options below.

How to actually eat enough protein

Eating the optimal amount of protein a day, while staying within a 1,600-2,000 calorie a day diet (and not feeling so full you can’t stuff in another mouthful), is hard for some people—including me.

I haven’t been in a phase where I’m trying to build muscle, I’ve been mainly in maintenance mode, so I currently get closer to 0.6 grams of protein per pound of body weight a day—if I focus on my protein intake and I’m diligent about it.  

My mindset is changing, however. At 42, with a goal of maximizing longevity and health span (the number of years I am active and healthy), I know that after having three children and a pretty sedentary job, I need to start building muscle to maintain my metabolic and cognitive function.

That means I need to both increase my protein intake AND increase my weight training. There is no point in eating a gram of protein per pound of body weight a day just to sit and stare at a screen for 10 hours a day. I’ve started adding weights to the equation with a once-a-week reformer-based pilates session. Next up, I’m investigating getting a trainer and adding two days per week of weight training to my regimen.

Once I do that, I’ll try to increase my protein intake by about 30-40 grams per day so that I can build vs just maintain muscle.

In the meantime, I am getting my 80 or so maintenance grams by eating fish, meat, and eggs, and supplementing with optimized protein powders like Parsley’s Rebuild.

Here’s what a typical day’s protein intake looks like for me:

  • 3 egg omelet – 18 grams
  • 1 Rebuild Protein smoothie – 26 grams
  • 1 6 oz portion of salmon – 36 grams

Total protein intake: 80 grams

To up that by 30+ grams to build muscle, I’ll need to add options like:

  • 1 ounce of parmesan cheese – 10 grams
  • Plant-based protein bar snack – 20 grams
  • 1 cup whole fat, no sugar added Greek yogurt – 18 grams
  • 1 cup tofu – 20 grams
  • 3 oz beef – 22 grams
  • 3 oz shrimp – 21 grams

The takeaway

Eating more protein is good for building muscle. And building muscle, both volume and strength, is good for longevity. You can get enough protein as a vegetarian but it’s hard—eating some form of animal protein makes it a lot more doable.

If you’re looking to work with a doctor who understands nutrition and longevity and will adapt these recommendations to a personalized nutrition and fitness regimen, work with us at Parsley Health. Learn more with a free call.