Rebecca Toutant, MA, RD, CSSD, LDN, CEDS, CDCES, cPT

All about macros (part 2/3) Protein

Last post I explained the definition of macros and explored the complicated chemistry of carbohydrates

This post I’ll talk about everyone’s favorite macro – protein. Why is it so valuable? Where does it come from? How much do you need? What’s the best source?

Remember from the first post in this series that everything in nutrition is about categories and chemistry.

Proteins are complex molecules made up of chains of amino acids (A.A.). Those amino acids are the building blocks of life and are used to: 

  • Form DNA
  • Create hemoglobin (the part of your red blood cells that carries oxygen)
  • Build and repair muscle
  • Create hormones
  • Makes chemical reactions happen
  • Form antibodies (the basis of the immune system)
 
There are 20 amino acids (the building blocks of protein) that get split into 2 categories – essential and non essential. Non-essential amino acids can be created by the body. However, essential amino acids must be obtained from food. 
 
Essential A.A.
(must eat!)
phenylalanine, valine, threonine, tryptophan, methionine, leucine, isoleucine, lysine, and histidine
Non Essential A.A.
(body can make)
alanine, arginine, aspartic acid, asparagine, cysteine, glutamic acid, glutamine, glycine serine, proline, and tyrosine
 
The food groups that contain protein are not exclusively protein / A.A. Most contain another macronutrient such as carbohydrate or fat in addition to water. 

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How much protein do I need?

Like many macronutrients, protein needs are largely indicated by total energy needs and physical activity. They can range anywhere from .8g/kg at the bare minimum and upwards of 2 g/kg for someone with a high focus on muscle protein synthesis.
 
Protein intake beyond this has not shown to be beneficial for health or muscle development / muscle protein synthesis. 

 

Plant vs Animal Protein 

Protein is found in both plant and animal based foods. However, there are some differences
  • Plant proteins have lower “bioavailability”
  • Most plant protein do not contain all of the essential A.A.
  • The other micronutrients we need from protein rich foods (iron, b12) can also have different forms or be absent.

 

That doesn’t mean we “can’t” do plant based lifestyles – we just have to be more thoughtful about food to ensure we’re getting what we need.

In order to create a “complete” protein and get all of the A.A. that you need, you pair…

grain (eg, rice, oats, wheat)
nut (eg, almonds, peanuts, cashews), or
seed (eg, sunflower, pumpkin, sesame)

bean (eg, chickpea, soy beans, black beans)
lentil, or
pea

 
The pairing can be done at the same time, or as a balance over time.  

A.A.’s aren’t the only consideration when deciding whether or not to go animal or vegetable for your protein source. Calcium, iron, b12, and vitamin D are also nutrients to consider.

Animal based foods also contain a more biologically available source of iron compared to plant based foods. In order to better absorb the iron in plants, pair greens and beans with a food rich in vitamin C (most fruits / vegetables).

Blood sugar management is also a consideration for those deciding whether or not go to more plant based with their protein sources. Most plant sources of protein also contain a healthy dose of carbohydrate – which we learned in the 1st part of this series is converted to blood sugar. 
 
Deciding whether to go with animal vs plant protein is a personal decision based upon your personal values and  health circumstances. But regardless of which way you go, don’t just eat a plate of rice or pasta and call it sufficient. 
 

Is there such a thing as too much protein? 

Excessive protein displaces other foods in the diet which can negatively impact health and performance. Protein cannot do the job of carbohydrate or lipid. If what your body needs is carb, but you give it protein, it doesn’t feel great. I’ve had endurance athlete often make this mistake – over fixating on protein instead of carbohydrate. They often find they’re uncomfortable full / nauseous, but still hungry.

Moreover, when people increase their protein intake, they do it in the form of meat or protein shakes which edges out plant based foods and associated nutrients.

Plants are amazing at disease prevention due to their high levels of fiber, antioxidants, as well as vitamins and minerals. Additionally animal based protein also tends to increase the amount of saturated fat (and often sodium) in the diet which is not awesome for our cardiovascular health. 

What about protein supplements?

While protein supplements (shakes / bars) provide amino acids, they often lack of the other nutrients we need that come from protein rich foods. If protein supplements are the “only” way you can hit your protein needs, it’s worth reevaluating the diet and the target. 

Sometime athletes feel like they “need” a protein supplement – but in reality, you don’t. The “benefit” of protein supplements are that they are convenient and sometimes taste good. But they are not superior to whole food sources. 

Protein itself is not a magic bullet – by itself, it does not “create” muscle. What makes you gain muscle is physical activity – namely, lifting heavy things. 

Protein (with carbohydrate) after workouts can improve recovery and adaptation to training. But eating protein without challenging your muscles may not result in change. There’s also a limit to how much protein your body can use in the repair process. More protein does not mean more muscle. 

The moral of the story…

We do need protein but it’s not what make a food “healthy.” Animal protein tends to have more protein per serving BUT plants are 100% capable of providing our bodies with everything we need along with the added benefit of high levels of disease prevention. Our bodies thrive when they’re fed a balanced diet based upon our physical and emotional needs. If you’re trying to figure out how to make it work for you, connect with a dietitian!