What is protein, and why is it so important in our diet? The building blocks of proteins are called amino acids. When amino acids are bound together, they form peptides that fold into different protein shapes with a unique biochemical function. The body uses 20 amino acids and 9 are “essential”, meaning the body cannot make them and must therefore come from our diet.
Protein has many unique functions in our bodies:
- Hormone Production
- Immune Response (i.e., antibodies)
- Transport Proteins of Water, Vitamins/Minerals, Fatty Acids etc.
- Cellular Communication
- Gene Expression
- Cellular Structure & Metabolism
- Fluid & Electrolyte Balance
- Wound Healing
- Acid-Base (pH) Balance
- Muscle Hypertrophy
BODY’S RESPONSE TO LACK OR EXCESS PROTEIN
What are indicators of a protein deficiency? You may experience poor immunity and lack of recovery. Keratin is a protein found in hair, skin, and nails. These may be brittle or cracking. Energy levels may be decreased and your ability to regulate your body temperature may be affected. Proteins are crucial in our basic metabolic and energy processes.
While deficiencies have negative effects on the body, excess protein can cause gout from increased protein breakdown products (i.e., ammonia) that overwhelm the kidney’s ability to eliminate it. You may also experience weight gain if the training stimulus doesn’t match your protein intake. Protein can be converted back into glucose by liver through a process called gluconeogenesis. Protein toxicity, however, would be exceedingly rare in the presence of normal kidney function.
How much protein should I eat? It depends on your goals, your activity level, your age and gender. The recommended daily protein intake in based upon a general average to maintain basic functions of metabolism and sustain life. This will not fuel a CrossFit athlete’s recovery and increase muscle production. This recommendation varies by institution but falls within the range of 0.3 0.9 grams of protein per pound of body weight. For example: A 140lb female would need 42g-126g of protein per day.
There is obviously room for individualization. What would increase our protein requirements?
- Intense Training Regimen
- Increased Age
- Body Composition Goal (i.e., increase muscle and decrease body fat)
Currently, recommendations for optimal protein intake range for building and maintaining muscle range from 1.6-2.2 g/kg (0.73-1.0 g/lb) per day, though some suggest that people losing body fat while maintaining lean mass should shoot for 2.3-3.3 g/kg (1.04-1.5 g/lb) per day (Precision Nutrition). The table below provides recommendations based upon activity level and overall goal.
PROTEIN FOOD SOURCES
What are the best sources of protein from our diet? There are animal and plant-based options to include lean meats (i.e., turkey, chicken, fish), eggs and beans/legumes (lentils, chickpeas, blackbeans), Greek yogurt or cottage cheese and tofu. It is helpful to think of protein and food in general on a continuum of things I should eat more of and things I should eat less of rather than moralizing food as “good” or “bad.” The image below gives an example of this thought process.
Trifecta Nutrition (https://www.trifectanutrition.com/blog/high-protein-foods-to-help-you-hit-your-macros) also has a helpful article on protein sources that are pure protein, protein + fat, or protein + carbs. This is helpful in understanding the macronutrient breakdown.
Hopefully, this will give you the knowledge necessary to understand why protein is so important to our health and performance, how much you need for your individual goals and what dietary sources are the most nutritionally advantageous. If you have any questions or want to let others know how you meet your protein requirements, post on our Facebook page or Instagram!
Lindsey G. Johnson
North Durham Fitness