food intake and nutrient composition and
reported that most of their daily energy and
nutrients come from corn, beans and squash.
About 94% of their daily protein intake is from
vegetable sources and only 6% from animal
sources. Since most of the fat in their diet (9–12%)
was derived from corn, beans and squash, their
diets are rich in linoleic acid and plant sterols.
The Tarahumara diet is extremely low in choles-
terol (71 mg · day–1) since their primary source of
cholesterol is eggs, of which they consume about
two or three per week. Other sources of fat and
cholesterol in the Tarahumara diet come from
small, infrequent servings of meat, fish, poultry
and dairy products and lard. Even though the
diet of the Tarahumara Indians is a simple one
consisting mainly of plant foods, it is of high
nutritional quality and is nutritionally sound,
resulting in little chronic deficiencies and no
widespread undernutrition (Cerqueira et al.
1979).
Hanneet al.(1986) investigated various fitness
parameters of vegetarian athletes and compared
them with non-vegetarians. Forty-nine athletes
(29 men and 20 women) who had been either
lacto-ovo- or lactovegetarian for at least 2 years
were compared with 49 controls (29 men and 20
women). Subject ages ranged from 17 to 60 years
of age, with the majority of the subjects in the
age range of 17–35 years. Fitness parameters
included anthropometric measurements, pul-
monary function, aerobic and anaerobic capacity
and blood chemistries. The authors found no sig-
nificant differences in body mass between the
two groups, although the female vegetarians had
a significantly (P>0.01) high percentage body
fat than their non-vegetarian counterparts. No
differences were found in pulmonary function,
heart rate, blood pressure or in the electrocardio-
gram. No differences were found between the
two groups of subjects in aerobic capacity or
anaerobic capacity as determined from a sub-
maximal test and a Wingate test, respectively.
Results from the blood examination found that
non-vegetarian controls had lower uric acid
levels than the vegetarian males, but the non-
vegetarian group were within the normal range.
444 special considerations
Vegetarian women had lower haematocrit values
than controls, but haemoglobin, total protein,
and glucose were similar in both groups. While
no differences were found between the two
groups, it is always difficult to find significant
differences, because vegetarianism does not
embrace a single, well-defined diet, and the
influence of other lifestyle factors, including
habitual physical activity levels, may obscure
possible effects of the diet itself. Herein may lie
part of the problem, as past research on vegetari-
anism and athletic performance did not clearly
define the type of diet being followed by groups
of individuals studied. Many athletes may call
themselves vegetarian when in fact they simply
eliminate from their diet a food group or a certain
class of foods. Information on the diet of vegetar-
ian athletes would be helpful in defining limiting
or beneficial factors.Classifications of vegetarian diets
Vegetarian diets range from the vegan diet,
which excludes all animal proteins, to the semi-
vegetarian diet, which may include some animal
proteins (Table 33.1).
Whatever the term an individual uses, it
appears that vegetarianism is a continuum of
eating styles, which range from the sole con-
sumption of plant foods to a diet restric-
ting certain kinds of animal proteins or limiting
the frequency of animal protein consumption
(Ratzin 1995). Because of the variety of vegetar-
ian eating styles among practitioners, it is diffi-
cult to define the variables that will influence
human performance, but relationships have been
found between vegetarianism and a reduction in
specific health risks.Health implications of
vegetarian diets
There is increasing tendency among researchers
to conclude that the reduced disease risk
observed among vegetarians is not explained so
much by the absence of meat from the diet, but
by the fact that they eat more plant foods. Results