Ask the Expert: How Much Protein Do You Need?
What's with all the obsessing over protein lately? It seems like half the western world thinks too much protein will destroy their kidneys, make them pee ammonia, and rot their insides. The other half shovel down tons of the stuff, believing massive protein consumption is the only path to achieving epic hugeness.There's a thin thread of truth to both of these assumptions, but for the most part they're oversimplifications. Let's set the record straight.
What is protein?
Protein is made up of amino acids, the body's primary building blocks. Muscles, bones, skin, internal organs, and enzymes—and much more—are all made of protein. Protein also regulates fluids and pH.For your body to function at its best, it needs 20 different amino acids, 11 of those your body makes. The other nine—known as "essential amino acids"—come from your diet. (There used to be eight, but it was recently discovered that adults can't synthesize histidine.) Any protein that contains all nine essential amino acids in adequate levels is called a "complete protein."
Complete proteins are important because amino acids work as a team. If you're low on one essential amino acid, the rest of them can't do their jobs at an optimal level.
How do I know if my diet contains all nine essential amino acids?
The easy answer—and some of you aren't going to like it—is to eat animal products. Just like us, animals are made of protein, including the nine essentials. (We're made of them too, technically, but we need to continually replenish them via diet.)Luckily for those of us who aren't into the whole "animal hostility" thing, there are plenty of complete protein sources out there that are plant based. Hemp and soy contain all nine essential amino acids. You can also eat a combination of legumes (beans and peas) and grains to get all the essential amino acids. The classic example of this is rice and beans. (For the record, you don't need to eat them together. Just get them both at some point during the day.)
Of course, there's also the middle road. Eggs and dairy are both good complete protein sources.
But, what's the best source of protein?
From a dietary perspective, any complete protein will get the job done. It's what comes with the protein that you need to consider.Eggs are a perfect example. Egg whites are about the purest source of protein you'll find in nature. No fat and minimal carbs. (Very few vitamins or minerals though, if you're keeping score.) Sometimes, that's pretty useful. You'll find egg whites in the P90X® and INSANITY® Nutrition Plans because we're trying to target exact macronutrient amounts.
The yolk, however, changes the game considerably. There's a little protein in yolks, but they're mostly fat—and they're loaded with micronutrients. So if you're looking for the maximum health benefit, your best bet is to eat the whole egg. But when you do that, it's important to note that you're getting a protein and a fat source.
In fact, most animal products will have a balance of fat and protein—and some of that fat is super-valuable. Fish, particularly salmon, anchovies, and sardines, are loaded with good, essential omega-3 fatty acids.
Plant-based protein tends to go the opposite direction. They're loaded with carbs. That's why a high-protein, vegan diet is almost impossible unless you want to fill up on isolated protein powder the whole day. I don't know about you, but I prefer getting most of my nutrition from real food, as opposed to a bunch of tubs.
Whatever. What proteins should I eat to maximize my workout?
Hold on, tiger, I was getting to that. When you get into sports nutrition, choosing specific sources of protein matters more. In fact, you're generally better off looking to supplements as opposed to whole foods.When considering sports performance, dairy cows don't generally come to mind (unless you're a cowboy or you're just weird), but whey and casein—the two proteins derived from milk—are terrific supplements.
Whey protein is the fastest absorbing, making it great for quickly delivering protein into muscles after a workout so they can begin the recovery process. Before bed, casein is best. Because your muscles absorb casein slowly, it will feed them all night long. While the musclehead theory that the body catabolizes muscle in sleep unless you eat protein before bed is silly, current research shows that a little sleepy time casein can aid recovery.
You might also want to consider branched chain amino acids (BCAAs) if you're an exerciser on a P90X or INSANITY level. BCAAs appear to be the go-to amino acids for energy production in muscles during strenuous exercise. Also, a number of studies show that they inhibit muscle breakdown during intense exercise.1
Rad! So I should consume tons of those proteins all day, right?
Um, no. Unlike carbs and fat, the body has no way of storing protein. We are not protein camels. Excess amino acids are not turned into bonus muscle, nor are they "peed out," so emulating Eric Cartman is not the way to go, even if you want to look like beefcake. If you eat more protein than you need, it's converted into either glucose or adipose tissue (fat). In order to convert protein to glucose, it goes through a process called deamination, which produces ammonia, which is toxic to our cells, so it's converted to a substance called urea and excreted through urine. We don't pee out excess protein, just its stinky byproduct.Dude, you're still not telling me how much I need.
You're right. I'm geeking out. The general scientific consensus is that you can use about 30 grams of protein (for amino acid functions) in one sitting. That's about 4 ounces of meat. Of course, if you're larger than average, that number increases.2Over a day, you need about 0.8 grams of protein per kilogram of body weight. (Plenty of Internet "experts" confuse kilograms with pounds on this one. Pesky metric system. To determine your weight in kilograms, divide your weight in pounds by 2.2.) If you're a heavy exerciser, that number climbs, peaking at 2 grams of protein per kilogram of body weight, according to International Society of Sports Nutrition.3
Odds are, if you exercise regularly, you're somewhere in the middle, somewhere around 1.5 grams. If you're injured, sick, or really broken down, eat more protein. You need raw materials to repair yourself!
Why don't I just pile on the protein just to make sure?
Remember, the body doesn't convert excess protein into giant muscles. And there are other issues that come up with overdoing protein for a prolonged period. This is one of the reasons we typically suggest people don't want Xers to go past six weeks on the Phase 1 Fat Shredder.When you eat a protein-centric diet, you're also eating less carbs and fat, both of which tend to be the primary transports for vitamins, minerals, phytonutrients, and a host of other goodies. Also, going protein crazy can cause metabolic acidosis, when the body's fluids become overly acidic.4 So a brief high-protein phase for weight loss is okay, but don't go too far beyond a month or so. Finally, if you have existing kidney issues, a very high-protein diet can be harmful as the kidneys play a huge role in processing protein.
Protein is neither a magic muscle elixir nor a toxic kidney killer. If you're trying to get huge, realize that those tubs of targeted amino acids will only benefit you if they're part of a balanced diet. If you're trying to lose weight, stop avoiding fruits and veggies because they're "carbs" and eat less junk food (i.e., refined carbs). As is the case with most things, a good diet is all about balance.
Resources:
1. http://www.ncbi.nlm.nih.gov/pubmed/15212752
2. http://www.sciencedaily.com/releases/2011/08/110818132225.htm
3. http://www.jissn.com/content/4/1/8
4. http://www.jissn.com/content/8/1/10