I’ll admit: before digging into Sports Nutrition for Health Professionals (2nd. Ed.), I didn’t think it was possible to eat too much protein.
I figured whatever protein my body didn’t absorb would be excreted.
It turns out that I was only partially correct.
In studying for my ACE Fitness Nutrition Specialist Certification, I learned a lot more about protein needs for the general public, endurance athletes, and strength athletes.Becoming a Fitness Nutrition Specialist will help you develop expertise in all areas of nutrition education and promotion that are within the scope of practice for health and fitness professionals.
In Chapter 2, we look at two hypothetical case studies about protein ingestion, as well as my own protein recommendations and intake.
The book does not include the correct answers for these case studies, but my answers are based on guidelines in the text.
Please use these articles as reference points, but they may not be appropriate for your specific situation.
Case 1: Kate, The Marathon Runner
Kate is an experienced 22-year-old marathon runner who is trying to qualify for the Boston Marathon. She is 5’6” and 126 pounds. To qualify, she needs to shave off 20 minutes from her personal record (PR). She would like to develop a nutrition program that will help her achieve her goal. The marathon is in one month.
The American College of Sports Medicine and the Academy of Nutrition and Dietetics recommend that endurance athletes consume 1.2 to 1.4 g/kg (0.5 to 0.6 g/lb) of protein per day.
1. Based on this recommendation, about how many grams of protein should Kate eat per day?
At 126 pounds, Kate’s daily protein intake should fall in the following range:
- 0.5 g/lb = 63 grams or 252 calories
- 0.6 g/lb = 76 grams or 302 calories
Protein Timing and Exercise
2. As an endurance athlete, what are general recommendations for protein consumption before, during, and after a prolonged endurance workout?
- Before a workout – The authors recommend eating 6-20 grams of protein with 30-40 grams of carbs (approximately a 3:1 ratio) within 3 hours prior to and after exercise.
- During a workout – Endurance athletes, in particular, can benefit from consuming branched chain amino acids to combat fatigue. The authors recommend a 2:1:1 ratio of leucine, isoleucine, and valine in that order.
- After a workout – It’s recommended to consume protein within 15-30 minutes following exercise to help with the repair and synthesis of muscle proteins.
Special Considerations: Vegetarianism
Kate shares that she is considering adopting a vegetarian diet.
1. What is a nutritional concern in terms of adequate protein intake for vegetarian athletes?
Vegetarian diets are plant-based and do not include meat and poultry.
A concern is that plant proteins aren’t as readily digestible as animal proteins.
2. How much protein will Kate need per day if she becomes a strict vegetarian? Translate this increased need into a vegetarian food item or food items.
Because plant proteins aren’t as readily digestible as animal proteins, vegetarian athletes should add about 10% more in protein to their diet.
If Kate were eating 3,000 calories a day with 20% of those calories coming from protein, she would consume approximately 600 calories a day (150 grams) from protein. Kate would need to consume an additional 60 calories (15 grams) per day in protein for a total of 660 calories or 165 grams of protein.
3. What are five possible protein combinations to ensure that she consumes all of the essential amino acids?
First, what’s an essential amino acid? It’s one that must be consumed in the diet because it is not produced by the body.
Kate could combine incomplete plant proteins to form a complementary protein to achieve high-quality protein. Some combinations include:
- Grains & legumes (rice and beans)
- Grains & dairy (pasta and cheese)
- Legumes and seeds (falafel)
Soy and quinoa are also considered complete plant-based proteins.
Case 2: Eric, The Recreational Bodybuilder
Eric is a thirty-one-year-old competitive bodybuilder. He participates in bodybuilding competitions in the fall and trains the rest of the year. He is 5’11” and weighs 184 pounds. He is currently in summer training. He is reviewing his current exercise and nutrition plan to see if he can identify any areas for improvement.
The American College of Sports Medicine and the Academy of Nutrition and Dietetics recommend that endurance athletes consume 1.6 to 1.7 g/kg (0.7 to 0.9 g/lb) of protein per day.
1. Based on this recommendation, about how many grams of protein should Eric eat per day?
Eric should eat protein that falls within this range:
- 129 grams (516 calories)
- 166 (622 calories)
Protein Timing and Exercise
The timing of protein intake likely plays an important role in determining the extent of strength gains around the time of exercise.
2. How might Eric time his protein intake?
Eric might follow the same recommendations as Kate did in the example above.
Special Considerations: Ergogenic Aids
1. Eric asks you if you recommend whey supplementation. How would you respond?
The Academy of Nutrition and Dietetics advises against supplementation at all, in part because supplements are not closely regulated by the FDA.
It is outside the scope of a nutrition coach to recommend whey supplementation—that should be left to a registered dietician or a physician.
2. Explain how you would respond to an athlete asking your opinion of leucine supplementation.
Leucine is an essential amino acid, meaning it must be consumed in the diet because the body does not produce it. It’s one of the most studied amino acids because it plays perhaps the largest role in muscle protein function.
My opinion of leucine training is to consider whole foods first, but those wanting to consume leucine could read the following studies:
- High Leucine Diets Stimulate Cerebral Branched-Chain Amino Acid Degradation and Modify Serotonin and Ketone Body Concentrations in a Pig Model
- Molecular, Cellular, and Regulatory Aspects of Nutrition During Development
- Leucine: a nutrient ‘trigger’ for muscle anabolism, but what more?
- Leucine supplementation and intensive training
Train Yourself: Protein Needs
1. Based on your weight and physical activity patterns, about how much protein do you need in a day?
I’ll use a few calculations here.
First, the recommended dietary allowance (RDA) for protein is 0.36 grams of protein per pound per day. At 175 pounds, that equates to need a minimum of 63 grams (252 calories) of protein per day.
However, the Academy of Nutrition and Dietetics, Dietitians of Canada, and the American College of Sports Medicine recommends athletes consume 0.5-0.9 grams per day. By that recommendation, I should consume anywhere between these numbers:
- 0.5 g/lb/day = 87.5 grams (350 calories)
- 0.9 g/lb/day = 157.5 grams (630 calories)
That’s a large range! How do I pick?
Well, the Institute of Medicine has set an acceptable macronutrient distribution range from 10-35 percent. Assuming I maintain my weight at 2,500 calories per day, let’s see the numbers in that range.
- 10% of calories from protein = 250 calories, or 63 grams
- 35% of calories from protein = 875 calories, or 219 grams
Wow, that’s not super helpful, either.
Later on in the text (chapter 9), the authors make protein recommendations for athletes in various endurance, strength, and power sports. My activities trend more toward the strength side, so let’s do some calculations based on those recommendations.
The ACSM and AND both advise consuming 1.5-2.0 grams of protein per kilogram of bodyweight per day.
At 175 pounds, I translate to approximately 79 kilograms. My recommended protein intake would then be:
- 1.5 g/kg = 119 grams, or 474 calories (19% of my total caloric intake—within the AMDR)
- 2.0 g/kg = 158 grams, or 632 calories (25% of my total caloric intake—within the AMDR)
2. Think back to all of the food you ate in the past 24 hours. Complete a dietary recall of your intake. Approximately how many grams of protein did you eat? How does this compare to your recommended needs?
As of this writing, I’m still with a nutrition service that I will be eliminating from my budget soon. This service has me at 185 grams of protein.
I’m skeptical of eating this amount of protein. It’s 30% of my total caloric intake, which is in the AMDR, but I’m not sure my body is using all this protein. Excess protein is either excreted or, like carbs, stored in the body as fat.
Plus, the text says that ingesting more than 2.0 g/kg of bodyweight per day is “unlikely to result in further muscle gains because the body has a limited capacity to utilize amino acids to build muscle.”
Protein Timing and Exercise
1. How might you space this daily protein intake during days in which you engage in strenuous aerobic exercise? How about days in which you do heavy lifting?
Even the authors of this text state that “the ideal protein consumption for athletes is still uncertain and the subject of ongoing research and evaluation.”
However, if I were to space the daily protein intake out, I would follow the recommendations listed above for Kate.
1. Are there any special considerations such as diets or vegetarianism you should keep in mind when considering your protein needs? If not, make up a special consideration and describe how it might affect protein needs and protein intake.
I do not have any special considerations when it comes to my diet, but if I were vegetarian or working with a vegetarian, I would rely on the foods listed here, which include:
- Nut butters
- Soy products
- Milk products