- The Vegetarian Athlete
- Flavour of the Month: Cool Mint
- Article of the Month: Physical Fitness and Vegetarian Diets.
- Site of the Month: Animal Alliance of Canada
- Cooking Tips: BBQ Time!
- Vegetarian News
- Recipe Update
- Site Update
- Try to add a bit of extra protein to each meal.
- Top salads with beans or marinated, diced tofu.
- Make smoothies and puddings with silken tofu.
- Choose soynuts over potato chips for a high protein, crunchy snack.
- Eat plenty of whole grains and legumes
July 2000
In this issue:
The
Vegetarian Athlete
(http://www.colba.net/~ajstrong/athlete.htm)
But if they consulted the American Dietetic Association (ADA), they would find that being vegetarian and being an athlete are not mutually exclusive. The ADA 1997 position paper on vegetarian diets expressly states that the needs of competitive athletes can be met through a vegetarian diet. (1) This view is echoed in the ADA and Canadian Dietetic Association position paper on physical fitness and athletic performance which states that “foods of animal origin are not essential to ensure optimal athletic performance”, but still recommends that vegetarian athletes have their diets evaluated to ensure adequate intake required nutrients. (2) Special attention should be given to adolescent vegetarian athletes to ensure that their energy, protein, and iron needs are met. (1)
According to the Canadian Dietetic Association, the ideal dietary distribution of carbohydrate, protein, and fat for athletes is similar to the Canadian Nutrition Recommendations* for the general population. However, because of the increased energy requirements of athletes, which vary according to sport and level of competition, quantitative differences may exist. (2)
Carbohydrates
The role of carbohydrates in the diet is
to provide energy to run the body. Since carbohydrates are the primary
fuel for the body, it makes sense that they should be consumed in the largest
quantities, compared to other nutrients. Canadian nutritional guidelines
for athletes recommend that 60% to 66% of the day’s total energy requirements
come from carbohydrates, compared to 55% for the general population.
For athletes engaged in prolonged aerobic activities, a threshold of 500
to 800g of carbohydrate (2000 to 3200 kcal) may be needed to maintain muscle
glycogen stores, regardless of total daily caloric intake. Glycogen is
the “energy store” in muscles used for aerobic and anaerobic endurance
activities. Maximizing these stores results in better endurance,
delayed fatigue and hence improved performance. (2)
Protein
Ingested protein is broken down into its
component “building blocks” called amino acids. In addition to being involved
in building, maintaining and repairing body tissues, like muscle, these
20 different amino acids are needed to make up the many hormones and enzymes
needed to run our body.
Meeting and defining protein needs is always a hot topic among vegetarians and athletes, independently. So you can imagine the controversy surrounding protein among vegetarian athletes.
The Canadian Recommended Nutrient Intake for protein in the general population is 0.86 g/ per kg of body weight (about 60g for a 70 kg, or 154lb, individual). (2) It is generally considered that vegetarians can easily meet these protein needs if they are meeting their energy requirements and are consuming a healthy variety of foods. Although plant-based foods tend to be lacking in one or more of the essential amino acids (amino acids the body can not manufacture itself), it is not necessary to combine foods in specific combinations in an effort to get a “complete” protein. (1)
Athletes may require increased protein needs due to increased amino acid metabolism. The suggested intake for athletes is therefore 1.0 – 1.5 g per kg of body weight (70 – 105 g for a 70 kg, or 154 lb, individual). (2) Recent studies have suggested that the optimum quantity of dietary protein for those wanting to increase body mass is 1.5 g per kg of body weight, but the limiting factor in muscle mass gains appears to be total caloric intake, not protein intake. Therefore caloric needs should be met first, through the adequate intake of carbohydrates, and then it should be verified that protein needs are being met. For athletes, protein needs are rarely calculated based on percentage of caloric intake since this approach generally results in an exaggeration of protein needs. (2)
Research indicates that the consumption of excessive protein does not result in increased muscle synthesis, increased muscle mass or improved athletic performance. In fact, it may decrease athletic performance and carry health risks. Excess amino acids, whether generated from protein metabolism or provided from amino acid supplementation, are either turned into fat (like all excess calories) or oxidized. Oxidation is an undesirable physiological process since it increases the risk of dehydration in the short term, and causes undue renal (kidney) stress in the long term. (2)
Tips on meeting your protein needs:
Fat
Fat is actually required by the body to
help absorb vitamins, and for energy needs when carbohydrates are not available.
Some fats are also involved in the production of hormones. After
total carbohydrate and protein needs have been calculated for an individual,
fat may be used to supply the remaining energy (caloric) needs, providing
fat supplies no more than 30% of the day’s total calories. (2)
Additional energy needs should be provided with high carbohydrate, low
fat foods. (2) Like the general population, no more
than 10% of the weekly caloric consumption should come from saturated (generally
animal) fats, and 5 - 10% of the daily caloric needs should come from essential
fatty acids, linoleic and alpha-linolenic. (3)
Iron
Iron is found primarily in the red blood
cells where it is involved in binding oxygen so that the oxygen can be
transported and used by the body’s muscles, organs and other tissues.
Iron is also involved in immune system function. Athletes are generally
not considered to have increased iron needs despite exercise associated
factors in iron metabolism. (2) However consuming
adequate iron may be a concern among vegetarians, since iron stores generally
tend to be lower among vegetarians than among non-vegetarians. What
this really means to vegetarian health however, is unclear since iron anemia
deficiency is similar among vegetarians and non-vegetarians. (1)
Low iron stores do not appear to affect physical performance, although
iron anemia deficiency does result in decreased performance. Care
should be taken that the recommended dietary intake of iron is met (10
mg/day for men and 15 mg/day for women) is achieved, and iron stores (serum
ferritin) of vegetarian athletes should be monitored regularly.
Should iron deficiency be found, appropriate nutrition guidance from a
dietician should be sought. (2)
Zinc
Zinc is involved in hundreds of different
metabolic pathways including DNA replication and synthesis, immune system
function, endocrine (hormones) function and energy metabolism. It
is considered to be a nutrient of concern for vegetarians since one of
the main sources of zinc in the diet is meat. And although zinc is
available from plant sources, it is less bioavailable. Since the
plasma zinc status of athletes has generally been found to be low, (4)
vegetarian athletes should probably be conscious of meeting their zinc
requirements (9-12 mg in Canada).
Amenorrhea
Amenorrhea is the absence of a menstrual
period among women of child-bearing age, and is generally associated with
increased risk for cardiovascular disease and osteoporosis. It may
be more common among vegetarian than nonvegetarian athletes, although not
all research supports this finding. Athletes with amenorrhea should
try and regain a normal menstrual cycle by increasing energy and fat intake,
reducing fiber, and reducing strenuous training. (1)
Because of the increased risk for osteoporosis, ammenorrheic women should
be conscious of meeting their daily calcium requirements.
Vegetarian post-workout
recipes:
Melon
and Ginger Shake
Minty
Slushy
Peanut
Butter and Oat Power Bars
* Health and Welfare Canada. Nutrition Recommendations. The Report of the Scientific Review Committee. Ottawa: Supply and Services Canada; 1990.
References:
1. American
Dietetic Association (ADA). Vegetarian Diets – ADA position JAMDIETAssc.1997;97:1317-321
(http://www.eatright.org/adap1197.html)
2. 
The position of ADA and the Canadian Dietetic Association Nutrition on
physical fitness and athletic performance for adults. AMDIETAssc. 1993;93:691-697.
(Date of expiration extended until new position is published in late 2000.)
(http://www.eatright.org/afitperform.html)
3. American Dietetic Association (ADA). Fat replacers - ADA position. JAMDIETAssoc.1998;98:463-468. (http://www.eatright.org/adap0498.html)
4. Singh A, Deuster PA, Moser PB. Zinc and copper status in women by physical activity and menstrual status. J Sports Med Phys Fit 1990. 30:29-36
