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Effects of a High Carbohydrate Diet on Run Times
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Abstract
The paper focuses on the problem of the impact of carbohydrate
diet and its effects on human body. The major assumption of
the research is the premise that the high carbohydrate diet
contributes consistently to the development of the obesity
or, at any rate, increases the risk of the development of
obesity. In stark contrast, low carbohydrate diet can have
the opposite effect and can prevent or minimize the risk of
the development of obesity. This research is particularly
important in the context of the current significance of the
problem of obesity. In fact, obesity evolves into epidemic,
which affects a large part of the population. In this respect,
the problem of the healthy nutrition is of the utmost importance.
Therefore, the research of the impact of carbohydrates on
human body is particularly important. At the same time, this
research allows specialists interested in the problem of obesity
and healthy nutrition to continue studies and develop effective
diets which could decrease the risk of the development of
obesity consistently through the low consumption of carbohydrates
and the increasing consumption of elements which contribute
to the faster and effective digestion of fats by human body,
such as omega 4 fatty acids. In order to prove the negative
effects of a high carbohydrate diet and a positive impact
of a low carbohydrate diet, two researches were discussed,
which led to the conclusion that the decrease of the consumption
of carbohydrates is an effective tool which may be used to
decrease the risk of the development of obesity.
Introduction
Today, the problem of obesity is one of the major challenges
to the national health. In this respect, it is important to
underline that obesity is a relatively new problem and the
research of its causes and development are essential for the
understanding of effective tools which can be used to stop
the epidemic of obesity nationwide. Many people suffering
from obesity are unaware of the potential danger of this health
problem and, what is more, they are often helpless in its
solution because they do not really know what exactly provokes
the development of obesity and what they should do to avoid
obesity.
On the other hand, there is no definite answer what is the
main cause of obesity. In fact, specialists (Diamond, 1990)
name several reasons explaining the development of obesity.
First of all, it is worth mentioning the changed lifestyle
of modern people. Today, people lead a sedative lifestyle
and their physical activities are insufficient to maintain
their good physical shape. As a result, the low physical activity
of people, both at home and at work, contributes to the increasing
weight which eventually results in obesity.
However, the nutrition and the food culture at large are not
less important factors which cause obesity. At this point,
it is necessary to lay emphasis on the fact that the quality
of food, ingredients used in the modern food and the way of
the consumption of food are crucial factors leading to the
development of obesity not only among adults but also among
adolescents and even children. What is meant here is the growing
consumption of food containing trans fat and other elements
which contribute to the stocking of fat in human body. In
addition, people often eat irregularly and, instead of healthy
food they are forced to choose fast food which is rich in
fats and carbohydrates. As a result, people consume unhealthy
food and increase their weight.
At the same time, the consumption of carbohydrate may produce
a significant impact on the health of people, at large, and
the development of obesity, in particular. Today, low carbohydrate
diet is considered to be a very effective tool, which can
help to decrease wait in a relatively short period of time
(Eaton et al., 1985). In actuality, this diet is grounded
on the idea that the consumption of food with a high amount
of carbohydrate produces a negative impact on the health of
people and increases their weight. In stark contrast, the
low carbohydrate diet implies that the low amount of carbohydrate
prevents obesity and increasing weight.
Obviously, in the contemporary world, the prospect of the
decreasing weight and prevention of obesity by means of the
reduction of the consumption of carbohydrates is very attracting
for people, who are disenchanted with other diets. However,
it is necessary to remember about the fact that the low carbohydrate
diet as well as any other diet aiming at the decreasing of
body weight cannot work effectively if it is not accompanied
by physical exercises. In other words, people should lead
an active lifestyle, work out, do jogging, etc. in order to
balance calories consumed during a day by the energy wasted
on physical activities. In addition, they should balance their
nutrition since the high carbohydrate food is not the only
cause of obesity. This means that people need to change their
food culture and lifestyle.
Moreover, the low carbohydrate diet naturally evokes the question
concerning its effect on human health, since some specialists
(Diamond, 1990) warn that, even though high carbohydrate diet
increases the risk of obesity, people cannot refuse from carbohydrates
and minimize radically their consumption. In fact, such a
change of the diet can undermine their health and positive
effects of under-consumption of carbohydrates minimizing the
risk of obesity do not necessarily outweigh its negative effects.
Nevertheless, specialists (Cassidy, 1980) agree that the high
carbohydrate food should be avoided in order to prevent the
development of obesity.
Methods and Materials
On analyzing the impact of carbohydrate on obesity, it is
necessary to focus on the research of the influence of low
carbohydrate diet on people. In this respect, it is possible
to refer to the study conducted by Gary D. Foster et al. (2003),
where the researchers studied the impact of the low carbohydrate
diet on obesity. The base-line characteristic of subjects
is presented in the Table 1 (see below).
Table 1. Base-Line Characteristics of the Subjects.
In fact, researchers attempted to select subjects representing
different sex and racial group in order to obtain possibly
more objective results. This is very important because, in
the contemporary society, the problem of obesity affects practically
all layers of society, regardless of gender and race. Therefore,
it is necessary to understand possible impact of the low carbohydrate
diet on representative of different groups of population.
The results of the research reveal the fact that the low carbohydrate
diet does contribute to the decrease of the weight of the
subjects compared to the control group, which used a conventional
diet (see table 2).
Table 2.
On the other hand, Figure 1 shows that the research which
was conducted within a year proved a very interesting trend.
Subjects using the low carbohydrate diet has lost consistently
their weight compared to the control group using conventional
diet. However, by the end of the experiment the gap between
weight curves of the group using the low carbohydrate diet
and the group using conventional diet has started to close
(figure 1). In such a way, it is possible to presuppose that
the low carbohydrate diet does not necessarily leads to positive
results in a long-run perspective.
Figure 1. Mean (±SE) Percent Change in Weight among
Subjects on the Low-Carbohydrate Diet and Those on the Conventional
(Low-Calorie, High-Carbohydrate) Diet, According to an Analysis
in Which Base-Line Values Were Carried Forward in the Case
of Missing Values (Panel A) or an Analysis That Included Data
on Subjects Who Completed the Study and Data Obtained at the
Time of the Last Follow-up Visit for Those Who Did Not Complete
the Study (Panel B).
In Panel B, the low-carbohydrate group had 28 subjects at
3 months, 24 subjects at 6 months, and 20 subjects at 12 months
and the conventional-diet group had 21 subjects at 3 months,
18 subjects at 6 months, and 17 subjects at 12 months. Asterisks
indicate a significant difference (P<0.05) between the
groups.
Moreover, the researchers revealed even a more disturbing
fact. The Figure 2 shows that the percentage of subjects with
a positive urinary ketone concentration was consistently higher
among people using the low carbohydrate diet compared to people
using the conventional diet. Therefore, it is possible to
estimate that the low carbohydrate diet can expose people
to a risk of development other health problems but obesity.
Figure 2. Percentage of Subjects with a Positive Urinary Ketone
Concentration, According to Whether They Were on the Low-Carbohydrate
Diet or the Conventional (Low-Calorie, High-Carbohydrate)
Diet.
A positive urinary ketone concentration was defined as 5 to
100 mg per deciliter. Asterisks indicate a significant difference
(P<0.003) between the groups.
The similar trend could be traced in regard to the cholesterol
level among people using the low carbohydrate diet compared
to the group using the conventional diet (see Figure 3).
Figure 3. Mean (±SE) Percent Change in Serum Concentrations
of Triglycerides (Panel A), Total Cholesterol (Panel B), Low-Density
Lipoprotein (LDL) Cholesterol (Panel C), and High-Density
Lipoprotein (HDL) Cholesterol (Panel D) among Subjects on
the Low-Carbohydrate Diet and Those on the Conventional (Low-Calorie,
High-Carbohydrate) Diet.
Data were obtained at the end of the study for subjects who
completed the study and at the time of the last follow-up
visit for those who did not complete the study. The low-carbohydrate
group had 28 subjects at 3 months, 24 subjects at 6 months,
and 20 subjects at 12 months. The conventional-diet group
had 21 subjects at 3 months, 18 subjects at 6 months, and
17 subjects at 12 months. Asterisks indicate a significant
difference (P<0.05) between the groups.
In such a way, the researchers revealed the fact that the
low carbohydrate diet, being able to decrease the body weight,
is necessarily positive for human health at large.
However, the researchers studying the impact of the high carbohydrate
diet (Bierer and Bui, 2004) arrived to the similar results.
Even though the researchers used dogs as the subjects of their
experiment, the results of their study are reliable since
the reaction of dogs on the high carbohydrate diet is similar
to that of humans due to the similarity of their constitution
and effects of carbohydrates on their body. In this respect,
figures 4-6 reveal the negative impact of the high carbohydrate
diet on the health of subjects, especially in regard to the
growing body weight. In other words, the study proved the
fact that the high carbohydrate diet, which used during twelve
weeks, led to the increase of the body weight of the subjects
using the carbohydrate diet.
Figure 4. Mean percent of baseline body weight in dogs fed
diets containing high carbohydrate [control (CON), n = 10],
high carbohydrate + CLA (CLA, n = 10), high protein, low carbohydrate
(HP, n = 9), or high protein, low carbohydrate + CLA (n =
10) for 12 wk at 85% of maintenance calories. An asterisk
(*) indicates a significant change (P < 0.05) as compared
to the change in the CON group.
Figure 5. Mean percent change (± SEM) in fat mass
and lean body mass over 12 wk in dogs fed diets containing
high carbohydrate [control (CON), n = 10], high carbohydrate
+ CLA (CLA, n = 10), high protein, low carbohydrate (HP, n
= 9), or high protein, low carbohydrate + CLA (n = 10) at
85% of maintenance calories. An asterisk (*) indicates a significant
change (P < 0.05) as compared to the change in the CON
group.
Figure 6. Mean serum TG (± SEM) at baseline and 12
wk in dogs fed diets containing high carbohydrate [control
(CON), n = 10], high carbohydrate + CLA (CLA, n = 10), high
protein, low carbohydrate (HP, n = 9), or high protein, low
carbohydrate + CLA (n = 10) at 85% of maintenance calories.
An asterisk (*) indicates a significant change (P < 0.05)
as compared to the change in the CON group.
Speaking about human diet it is particularly important to
realize that it should be balanced and adequate to human needs.
Nowadays numerous carbohydrate diets become more and more
popular and their developers estimate that they are very effective
and do not threat human health.
However, not all specialists agree with this statement. First
of all, it should be said that the consumption of low amount
of carbohydrate in our everyday diet may have negative consequences.
For instance, low carbohydrate consumption may lead to the
decrease while higher to decrease of so-called glycemic index,
i.e. a qualitative indicator of carbohydrate’s ability
to raise blood glucose level.
Furthermore, another argument against carbohydrate restriction
focuses on the purported health risk of this dietary approach.
Of the three macronutrients, protein, fat and carbohydrate,
it is only carbohydrate that is nonessential to the human
diet. Humans can exist for extraordinarily long periods of
time without carbohydrate consumption as long as essential
protein and fat needs are met. It is thus perplexing why nutritional
dogma ascribes so many risks to the restriction of this non-essential
nutrient.
On analyzing my personal food consumption, and carbohydrates
in particular, I would say that basically the level of carbohydrate
consumption is a bit higher that is obviously not very dramatic
but still disturbing fact. On studying the effect of low/high
carbohydrate consumption, I came to the conclusion that it
should be well balanced and adequate to human needs. IN fact
humans should not consume more or less than they need at the
moment carbohydrates, especially, if we take into consideration
that they should be naturally supported by proportional consumption
of proteins and fats.
Trans fat, which may be also called hydrogenated fat, may
be found in processed food or hydrogenated vegetable oil.
These ingredients certainly contribute to the calorie content
of a food, often making it unsuitable if you’re trying
to lose weight. But worse than this, foods containing these
ingredients also contain trans fats – and these are
thought to be as harmful to heart health as saturated fat
(Eaton et al., 1985).
Ironically, it’s the processing of pure vegetable oils
– a good source of heart-friendly unsaturates –
that creates harmful trans fats. During manufacturing, these
liquid oils have hydrogen bubbled through them in a process
called hydrogenation to improve their texture, flavor and
shelf life. The resulting product is a more solid fat, called
hydrogenated fat or hydrogenated vegetable oil, which goes
on to be used as an ingredient in many processed foods.
Essential Omega-3 Complex is a natural marine lipid concentrate,
formulated with the oil of cold-water fish - sardines, mackerel,
herring, and anchovies - which is the best source for omega-3
fatty acids (Eaton et al., 1985).
Traditionally, Omega 3 fatty acids are recommended to use
as an effective mean of resistance to a negative influence
of trans fats or hydrogenated fats. It is recommended to eat
two servings of fish rich in omega 3 fatty acids each week
in order to optimize heart health. At the same time, instead
of such fish diet it is possible to take fish oil capsules
that could be taken by those who cannot afford eating fish
regularly.
In such a way, it is obvious that diet and food culture are
very important for human health and the consumption of carbohydrates
should be carefully regulated in order to avoid possible negative
effects.
Conclusion
Thus, taking into account all above mentioned, it is possible
to conclude that the problem of obesity disturbs many specialists
(Bierer and Bui, 2004), who work on the problem of the minimization
of the risk of obesity. In this respect, researches dedicated
to the effects of carbohydrates are particularly important
because carbohydrates can provoke the increase of the body
weight and, therefore, they can result in obesity. At the
same time, it is necessary to take into consideration the
fact that along with carbohydrates, it is possible to name
the sedative lifestyle, fast food and unhealthy food culture
as the major causes of obesity. Nevertheless, it is important
to avoid underestimation of negative effects of the consumption
of carbohydrates. In fact, researches aforementioned reveal
the negative impact of the high carbohydrate diet because
it leads to the increase of the body weight. On the other
hand, the low carbohydrate diet can be also dangerous to human
health and evoke different health problems, though it can
decrease the body weight.
In such a situation, it is obvious that the effects of carbohydrates
on obesity should be researched further, but it proves beyond
a doubt that it is necessary to avoid extremes in the consumption
of carbohydrates. What is meant here is the fact that a balanced
diet is needed, which should be supported by the change of
food culture of people and their lifestyle.
References:
Bierer, T.L. and Bui, L.M. (August, 2004). “High-protein
low-carbohydrate diets enhance weight loss in dogs.”
Journal of Nutrition, 134: 2087S-2089S.
Cassidy, C.M. (1980) "Nutrition and health in agriculturalist
and hunter-gathers: a case study of two prehistoric populations."
Food and Evolution. Toward a Theory of Human Food Habits.
pp 117-145. Redgrave Publishing Company.
Diamond, L. (1992) The Third Chimpanzee: The Evolution and
Future of The Human Animal. pp 180-191. Harper Collins.
Eaton, S.B. et al. (1985) "Paleolithic Nutrition, a consideration
of its nature and current implications." N Engl J Med;
312:283-289.
Foster, G.D. et al. (May 22, 2003). “Randomized trial
of a low-carbonate diet for obesity.” The New England
Journal of Medicine, 348(21): 2082-2090.
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