Protein is an incredible essential macronutrient. Fat is plentiful, even when you’re lean, and there are only two absolutely essential fatty acids; the rest we can manufacture from other precursors if required. Carbs we can produce from protein, if we really must, or we can just switch over to ketones and fats for the bulk of the energy that would otherwise come from carbs. Protein cannot be made with the raw material available in our bodies. We have to eat foods containing the range of amino acids that we need.
In other words, protein is incredibly important—which is why today I’m writing a definitive guide on the subject. After today’s post, you’ll have a good handle on the role protein plays in the body, how much protein you need to be eating, which foods are highest in protein, and much more.
What Role Does Protein Play in the Body?
Protein is vital to build and repair body tissue and fight viral and bacterial infections. Immune system powerhouses such as antibodies and immune system cells rely on protein. Too little protein in the diet may lead to symptoms of weakness, fatigue, apathy, and poor immunity.
The proteins we consume as part of our diet are broken down in the gut to amino acids. The body can then use these amino acids in 2 main ways:
- As ‘building blocks’ in the production of ‘new’ proteins needed for growth and repair of tissues, making essential hormones and enzymes and supporting immune function.
- As an energy source.
With regards to slimming down and muscling up, protein can decrease your appetite by improving the satiety of your meals, it is also stimulates your metabolism and kicks your fat burning into high gear by encouraging the secretion of glucagon, a fat burning hormone.
How Much Protein Do I Need?
The RDA [Recommended Dietary Allowance] that’s been established for the average healthy sedentary adult is 0.8-1.2 grams of protein per kilogram of protein per day. However, recommended is not optimal. Many studies show we need more than that if we want to be optimal, especially if you are older or pregnant. The range for this group goes up to 1.2-1.5 grams of protein per kilogram of body weight per day. In order to trigger something called Muscle Protein Synthesis you need to consume approximately 25-30 grams of protein in one sitting, ideally containing 2.5 to 2.8 grams of Leucine in it.
For example, if you weigh 165 pounds you would need 90 to 112 grams of protein per day if you are over the age of 65, if you are wanting to build muscle you should pick foods high in leucine, such as eggs or whey protein..
This recommendation is in line with the recommendations in this paper from The Journal of the American Medical Directors Association.
The exception to this rule is someone with kidney disease. They would need to follow a different recommendation.
What Are the Best Sources of Protein?
I know there can be great debates on this topic but I believe that the best sources of protein for humans are animal foods. Meat, fish, fowl, shellfish, eggs, and dairy all contain the most bioavailable form of protein: animal protein. I am also a firm believer in eating these foods in their whole form to the best of your ability and consuming as much of the animal as you can. For example, don’t eat egg white, eat an egg. Don’t just eat the muscle, eat the organs as well. Don’t skim the fat off your dairy, consume whole fat dairy.
You also want to look at the Biological Value or BV of the protein. Because protein cannot be stored (unlike fat and carbohydrate) it is important you not only look at how much protein you get in a certain food, you also have to consider how much of that protiei your body can actually absorb. The BV shows how much protein is actually absorbed by your body. Egg has one of the highest BVs, coming in a close second to the protein in human milk, meaning it is almost 100% absorbable, whey protein is a close second. Fish and beef follow, with plant proteins being much lower on the list.
Lastly, when thinking about protein sources, you want to think about it as a Protein Package. Not only do you want to look at how many grams of protein a certain food has, you also want to see if it has added benefits or perhaps added anti-nutrients.
For example, a ham steak may have loads of protein but it is usually also loaded with salt. Not a great package. Whereas, 4 ounces of grilled sockeye salmon has about 30 grams of protein, is naturally low in sodium, and contains just over 1 gram of saturated fat. Salmon and other fatty fish are also excellent sources of omega 3 fats, a type of fat that’s especially good for the heart. This is a great package.
Is There a Best Time to Consume Protein?
Not unlike all nutrients, your body can only digest so much at one time and so it is best to spread your protein intake out through the day.
According to the International Society of Sports Nutrition, consuming protein any time up to two hours after your workout is ideal for building muscle mass but for the average person, resistance exercise and consuming sufficient protein are more important than timing protein intake.