Friday, July 10, 2009
If there is one topic that gets people in the sports nutrition arena hot under the collar, is the age old " vegetarian versus meat eater" debate. In particu- lar, the debate is focused on whether or not vegetarian diets are adequate and equivalent to diets that include meat when it comes to adding muscle mass. Outlining the entire debate of both sides of the fence is beyond the scope of this discussion. I am going to stick to the debate regarding how a veg- gie diet vs. a meat-containing diet in uences muscle mass, rather than the larger picture of whether or not vegetarian diets are inherently healthier than diets that contain meat and vice versa.
In a nutshell, strict vegetarians (vegans) maintain that meat is not essential
for building muscle and a diet that mixes complimentary foods such as
beans and rice is adequate.
Lacto-ovo vegetarians ( vegetarians that include milk products and eggs)
further maintain that the inclusion of milk and eggs, as highly bioavailable
complete proteins, is more than adequate for athletes trying to build mus-
cle and maintain peak performance.
Omnivores (omnivore meaning people who eat a wide variety of foods in-
cluding meat) argue that meats such as chicken, beef and others are by
nature more anabolic for a variety of reasons.
So who's right?
This debate has not been adequately looked at in the research but we do
have some data that supports the omnivore's position. For example, sev-
eral studies have found that meat-containing diets are superior for testos-
terone production than strict vegetarian diets.
As most people know, testosterone is an essential hormone for increasing
and maintaining muscle mass while keeping body fat low. It's also essential
for libido and mood in both sexes, but particularly important for men.
One study called,"E ects of an omnivorous diet compared with a lacto-ovo
vegetarian diet on resistance-training-induced changes in body composi-
tion and skeletal muscle in older men” looked directly at this debate.
The researchers wanted to nd out if an omnivorous (meat-containing)
diet was superior to a lacto-ovo vegetarian diet on the retention of muscle
mass of older men put on a weight training routine.
Nineteen men aged 51 - 69 years old were enrolled in the study that ran
12 weeks. Nine men ate their normal meat containing (omnivorous) diet,
providing 50 percent of total dietary protein from meat sources such as
pork, chicken, sh and beef. Another 10 men followed a lacto-ovo type
vegetarian diet for the duration of the study, with both groups following a
weight training schedule.
Although the strength increases between groups were roughly the same,
the study found that the whole-body changes in skeletal muscle size dif-
fered signi cantly between groups. Whole-body muscle mass increased in
the omnivorous group, while it actually decreased in the lacto-ovo group.
Apparently, the meat eaters gained muscle over the 12 weeks while the
lacto-ovo eaters lost muscle mass. Ouch!
The authors concluded:
“...consumption of a meat-containing diet contributed to greater gains in fat-
free mass and skeletal muscle mass with resistance training in older men than
did an a lacto-ovo diet.”
Is this a slam dunk against the vegetarian diet as it relates to the claim that
it is just as good as a meat-containing diet for increasing muscle mass? No,
but it does lend some support to the idea that omnivorous diets have an
edge for producing optimal levels of anabolic (muscle building) hormones
and increases in muscle mass. More research is clearly needed to con rm
There is still some debate over which of the two diets is healthier, however,
and that has to be factored into peoples’ choices as to which diet is best
suited for them.
One area in which vegetarian diets are de cient vs. omnivorous diets is
in muscle creatine stores. In the absence of supplementation, vegetar-
ians have been found to have lower total muscle creatine - which could
limit lean mass gains in response to training. The good news is that a re-
cent study con rmed that vegetarians on a resistance training program
responded well to creatine supplementation: their relative gains in work
performance, total creatine/phosphocreatine levels, and lean tissue mass
were even greater than the response for omnivores taking creatine, due to
lower starting creatine levels. The researchers concluded:
“...subjects with initially low levels of intramuscular Cr ( vegetarians) are more
responsive to supplementation.”
Other areas of concern for vegetarians are: iron status (the iron in plant
foods is less bioavailable than the iron in animal foods), zinc, vitamin B12
(cyanocobalamin), vitamin D (cholecalciferol) and calcium. The very high
ber intake associated with vegetarian diets may also, ironically, limit the
number of calories a vegetarian athlete can consume. This is the basis for
the Ornish Diet, which recommends a vegetarian or near- vegetarian diet
for weight loss, on the grounds that eating high ber plant foods automati-
cally limits calorie intake.
The take-home lesson is that vegetarians wanting to increase lean body
mass should make sure that important nutrients normally supplied by
meat and other animal protein sources are included using a combination
of appropriate foods and supplements.
It is not impossible to gain a signi cant amount of lean body mass on a
vegetarian diet: legendary bodybuilder Bill Pearl is perhaps the best known
example. Truth be known though, my bet would be in favor of the omnivo-
rous diet if optimal muscle mass is the goal.