Calorie and Protein Requirements

By Joel Fuhrman, M.D. 

Athletes Need More Calories And Protein Than Sedentary Individuals!

A diet for serious or competitive vegan athletes must take into account their additional energy requirements above and beyond those of more moderate activity levels. Because of the low calorie density of many plant-based foods, athletes need to make sure they meet their energy requirements.

The timing of protein intake also is important. During exercise, there is an increase in protein oxidation and breakdown, followed by both enhanced muscle protein synthesis and further protein breakdown during recovery. 33 The rise in circulating amino acids following a protein containing meal stimulates muscle protein synthesis and also slightly suppresses muscle protein breakdown 34 and this effect is more pronounced when the meal occurs immediately following exercise. Ingesting carbohydrate alone fails to induce this increase in muscle protein synthesis. Similarly, benefits to immunity, muscle soreness, and overall health by protein-containing meals compared with carbohydrate-only meals have been suggested in the literature. For these reasons, timing of content of protein in meals may be an important factor in recovery, muscle mass maintenance, and muscle mass gain. High-protein foods should be split between at least two meals in order to provide raw material for muscle growth throughout the day, and one protein containing meal closely following exercise will be advantageous for recovery and muscle mass.

Protein Requirements

Athletes require a greater quantity of protein than sedentary individuals. However, the amount of protein required has been a point of confusion and disagreement among both athletes and the scientific community. Daily protein requirements are based on daily nitrogen losses. Since protein may supply five percent of the energy burned during exercise, a positive nitrogen balance is needed as raw material to replace these losses and/or to build additional muscle mass. Insufficient protein ingestion leads to negative nitrogen balance and insufficient recovery following exercise. Adaptation to training also may result in a decrease in protein requirements over time.

In 2009, the Swiss Forum for Sports Nutrition designed a food pyramid for Swiss athletes based on the Swiss Society for Nutrition’s Basic Food Pyramid for healthy adults, taking athletes’ extra energy requirements into account. They made these recommendations based on estimated calorie expenditure of sitting, moderate intensity training, and maximally sustainable aerobic exercise. 37 Percentage of calories is likely the more favorable way to express athletes’ protein needs, since athletes’ caloric needs are more closely related to training volume than to body mass.

Based on the Swiss Society for Nutrition’s estimates of calorie expenditure 37 shown in the table on page 7, we can estimate the calorie and protein requirements for athletes. In the examples below, the lower number of the protein range represents the 1.7 grams per kilogram of body mass method, and the higher number represents the 13.5 percent of calories method.

An endurance athlete weighing 150 pounds who trains four hours per day needs to consume 3600 calories and about 116–121.5 grams of protein per day. A strength athlete weighing 200 pounds who trains four hours per day needs to consume 4800 calories and about 154–162 grams of protein per day.

It is not difficult to reach these protein requirements with proper dietary planning. An athlete on a totally vegan diet can reach his/her protein and calorie requirements and avoid including micronutrient-poor animal products.



Potential Dangers Of Excess Protein

There is no benefit cited in the literature for an athlete to consume more than two grams of protein per kilogram of body mass per day, and excess protein may negatively affect calcium stores, kidney function, and bone health, and may promote cardiovascular events. 39,40 Athletes regularly consume protein supplements in the form of isolated protein; for vegan athletes, most often these are composed of isolated soy, rice, pea, or hemp protein powders. I recommend using whole food sources of protein (tofu, nuts, sunflower seeds, peanuts, and hempseed meal) blended into shakes and smoothies rather than isolated protein powders. Isolated protein powders are micronutrient- poor compared with whole foods, and their use may pose a health risk. Excess animal protein may promote cancers, potentially via up-regulation of insulin-like growth factor 1 (IGF-1). 41 It is important for vegans to know that isolated protein from plant sources also has been found to elevate IGF-1 levels. 42

Safety Of The Protein Levels Required For Bodybuilding

What exactly defines excess protein for athletes has not yet been clearly defined, as studies on protein safety in athletes are scarce. 43 However, increased consumption of either animal products or maybe even protein isolates in the attempt to maximize growth for sports such as power lifting, bodybuilding, or football is likely not life-span-favorable. There is a difference between maximizing muscle growth and maximizing health.

Clearly, a properly designed vegan diet can meet the nutritional needs of speed and agility athletes in sports such as tennis, skiing, basketball, and soccer. Whether it can meet the growth needs of a football lineman who needs to build and maintain a muscular 300-pound body is another question. Of consideration here is the data that suggest that very large athletes have much shorter life spans and that eating to maximize size is not life-span-favorable. 44Besides promoting excellent health, a carefully designed and intelligently supplemented vegan diet can meet caloric and protein needs without excesses that could be disease-promoting.

As to the question of whether athletes requiring overly large body mass would be capable of meeting their calorie and protein requirements eating only whole plant foods, my experience has been that they would not be able to eat enough protein to maximize growth potential. They would have excellent stamina and improved power and strength per body weight, but they would not become massive enough to be highly competitive in their sports. Excessive eating (not life-span-favorable) and high consumption of animal products and/or plant protein concentrates likely would be required to achieve that degree of unnaturally high body mass. Nevertheless, plant protein concentrates such as maca protein, pea protein, rice protein, and hemp protein powders can be considered options for a strength athlete who desires to remain vegan or who wishes to considerably reduce dependency on animal products.

My Recommendations For Vegan Athletes

To maximize performance, recovery from muscle stress, endurance, and resistance to illness, enhanced intake of beans, greens, seeds, nuts, whole grains, and other colorful vegetables and fruits are recommended. These same suggestions are also important for the non-vegan athlete. Excellent nutrition to maximize long-term performance and the athletic life of the athlete requires much more than just macronutrient adequacy and adequate protein intake; it requires micronutrient density and adequacy as well. Supplemental protein is an option, but it is not necessary for most athletes who carefully construct their diets so as to include the higher protein plant foods. Adding vitamin B12, vitamin D, zinc, DHA, and possibly taurine to the diet is more likely to be of benefit than adding excess isolated proteins.




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