The Protein Equation: How to Balance Quantity and Quality

November 3, 2024

by Cathe Friedrich

If you exercise, you know how important it is to get adequate protein. While you need protein for a variety of functions, these long strings of amino acids are what your muscles use to repair damage and build new muscle tissues.

While you might think all protein sources stack up equally, that’s far from the truth. Quality matters. Just like all the foods you buy at the grocery store aren’t equal in nutrition, proteins differ in quality. Let’s take a closer look at various food sources of protein and how their quality differs, so you can make smarter choices.

Essential Amino Acids

As mentioned, proteins are strings of amino acids hooked together by peptide bonds. The most important amino acids, from a dietary standpoint, are essential amino acids, ones your body needs but can’t make. There are 9 essential amino acids that you must get through diet. Foods that contain all 9 essential amino acids are called complete proteins.

Protein Quality: Complete vs. Incomplete

Most animal-based proteins contain all 9 essential amino acids, making them complete proteins. These include meat, poultry, fish, eggs, and dairy products. Still, consuming large quantities of animal proteins can still have downsides. Meat, eggs, and dairy are high in saturated fat, a type of fat linked with cardiovascular disease. That doesn’t mean you shouldn’t eat them, but it’s best to do so in moderation. Fish, by comparison, is low in saturated fat. Plus, fatty fish, like ocean-caught salmon, contain a heart-healthy type of fatty acid called omega-3s.

While fish might sound like the perfect protein source, it has shortcomings too. Oceans are becoming more polluted and many of its marine inhabitants are absorbing toxins, including heavy metals, and even microplastics. When you eat fish, you also consume these toxins.

Plant-based protein sources often lack one or more essential amino acids or have them in low quantities. So, any plant protein sources are incomplete proteins. An example is grains, which are low in the amino acid lysine. Legumes, like beans and lentils are low in methionine. But if you consume diverse types of plant protein, you should get all the essential amino acids your body needs through a plant-based diet. An exception to the incomplete protein rule is soy. It contains all 9 essential amino acids. Quinoa, buckwheat, and hemp seeds are also complete, plant-based proteins.

Animal vs. Plant Protein Sources

There are advantages to getting some of your protein from plant-based sources. When you do, you’re getting fiber and a diversity of nutrients that will round out your diet. Animal-based protein sources lack the phytonutrients that plants have. Phytonutrients have antioxidant and anti-inflammatory activity that offer benefits beyond their nutritional benefits.

But as with animal protein, there are downsides to building a diet totally around plant protein sources. They often have less total protein than animal sources and lack or have low levels of essential amino acids. So, it takes more planning to get enough essential amino acids, especially if you do intense exercise, where your protein needs are greater.

So, the best approach is to eat a diet that contains more plant-based protein for health, but some animal-based protein sources to make it easier to meet your body’s protein requirements. Diversity is beneficial for your gut microbiome too.

Daily Protein Requirements

Sometimes bodybuilders and athletes get carried away and think they must eat large quantities of protein to optimize their body composition and performance. Some athletes and bodybuilders get caught up in the “more is better” mentality. Yet your body can only use so much protein at once. According to studies, consuming more than 30 grams of protein at a time may not offer additional benefits. It’s best to consume small amounts throughout the day. Recent studies suggest consuming protein at each meal optimizes muscle synthesis and recovery.

The amount of protein you need daily will depend on your activity level, protein status, and age. If you’re over the age of 60, you should consume higher quantities of protein than someone younger. But be sure to talk to your doctor first.

Based on the search results, here are the key points about daily protein requirements for sedentary people and athletes:

For sedentary adults:

The Recommended Dietary Allowance (RDA) is 0.8 grams of protein per kilogram of body weight per day (0.36 g/lb).
Some more recent analyses suggest slightly higher needs of 1.0-1.2 g/kg/day (0.45-0.55 g/lb.) for sedentary adults.

For athletes:

Endurance athletes need about 1.2 to 1.4 g/kg/day (0.55-0.64 g/lb).
Strength training athletes need about 1.4 to 2.0 g/kg/day (0.64-0.91 g/lb.).
Higher intakes of 2.3-3.1 g/kg/day may be beneficial during periods of intense training or caloric restriction. However, talk to your doctor before consuming this amount.
Protein intakes above 1.6-1.8 g/kg/day generally do not provide additional benefits for muscle gain in most athletes.

To sum it up, sedentary people need around 0.8-1.2 g/kg/day. Athletes need more, around 1.2-2.0 g/kg/day depending on their sport and training intensity. The upper range for what athletes’ need is about 2-3 times higher.

Beyond Protein: The Supporting Cast of Nutrients

Beyond protein, don’t forget about the supporting cast, the vitamins, and minerals in protein foods. If you eat a plant-based diet, you’ll need to supplement with vitamin B12, as plants like this B-vitamin. Plant-based diets can also be low in iron, zinc, and omega-3 fatty acids.

The Final Cut: Your Protein Masterpiece

Whether you’re casting animal proteins as your leads or creating an ensemble piece with plant-based sources, eat a variety of high-quality, nutrient dense protein sources. Don’t be afraid to experiment with different protein sources and combinations to find what makes you feel your best. For example, add lentils to your salads or pair quinoa with grilled vegetables for a complete protein meal. After all, you’re the star of your own health journey – make it Oscar-worthy!

References:

Adhikari S, Schop M, de Boer IJM, Huppertz T. Protein Quality in Perspective: A Review of Protein Quality Metrics and Their Applications. Nutrients. 2022 Feb 23;14(5):947. doi: 10.3390/nu14050947. PMID: 35267922; PMCID: PMC8912699.
Katz DL, Doughty KN, Geagan K, Jenkins DA, Gardner CD. Perspective: The Public Health Case for Modernizing the Definition of Protein Quality. Advances in Nutrition. 2019;10(5):755-764. doi:https://doi.org/10.1093/advances/nmz023,
Bauer J, Biolo G, Cederholm T, Cesari M, Cruz-Jentoft AJ, Morley JE, Phillips S, Sieber C, Stehle P, Teta D, Visvanathan R, Volpi E, Boirie Y. Evidence-based recommendations for optimal dietary protein intake in older people: a position paper from the PROT-AGE Study Group. J Am Med Dir Assoc. 2013 Aug;14(8):542-59. doi: 10.1016/j.jamda.2013.05.021. Epub 2013 Jul 16. PMID: 23867520.
Antonio J, Evans C, Ferrando AA, Stout JR, Antonio B, Cinteo H, Harty P, Arent SM, Candow DG, Forbes SC, Kerksick CM, Pereira F, Gonzalez D, Kreider RB. Common questions and misconceptions about protein supplementation: what does the scientific evidence really show? J Int Soc Sports Nutr. 2024 Dec;21(1):2341903. doi: 10.1080/15502783.2024.2341903. Epub 2024 Apr 16. PMID: 38626029; PMCID: PMC11022925.
“Dietary protein recommendations to support healthy muscle ageing in the ….” 11 Oct. 2023, https://www.cambridge.org/core/journals/proceedings-of-the-nutrition-society/article/dietary-protein-recommendations-to-support-healthy-muscle-ageing-in-the-21st-century-and-beyond-considerations-and-future-directions/A60A684B6FA52A6C5BFC315A98BF8146.