Wpływ diety i aktywności fizycznej na poprawę parametrów biochemicznych i fizjologicznych u otyłych chłopców (ang.).pdf

ACTA Acta Sci. Pol., Technol. Aliment. 9(1) 2010, 95-104

ISSN 1644-0730 (print) ISSN 1889-9594 (online)

EFFECT OF DIET AND PHYSICAL ACTIVITY

ON PHYSIOLOGICAL AND BIOCHEMICAL

PARAMETERS OF OBESE ADOLESCENTS

Zbigniew Kasprzak, Łucja Pilaczyńska-Szcześniak

University of Physical Education in Poznań

Background. The main cause of the excessive deposition of fat is the destruction of the

mechanisms controlling the expenditure of energy. Pathological increase of adipose tissue

leads to disorders of the body, and lipid – carbohydrate parameters, promotes the devel-

opment of vascular diseases and increases the risk of morbidity and mortality. The aim of

the study is to demonstrate the impact of diet and physical activity changes in the parame-

ters lipid-carbohydrate of adolescents.

Material and methods. The study included obese boys (n = 35), undergoing weight re-

duction. A low-energy diet and regular physical activity were applied. At the beginning

and after four weeks were performed anthropometric measurements and indicators of the

composition of venous blood was determined. In the venous blood was determined total

cholesterol, HDL-cholesterol, triacylglycerols (TG), glucose and insulin. LDL-cholesterol

was calculated.

Results. It was found that the applied treatment improved the lipid profile of blood. Only

for triglyceride change was not statistically significant. Statistically significant was the re-

duction of the concentration of glucose.

Conclusions. Reduction of body mass resulted in positive changes in blood lipidogramme

and reduction of waist hip ratio, which can reduce the risk of cardiovascular disease in the

future. Reduction in serum insulin and glucose demonstrates improved carbohydrate me-

tabolism and indicates a reduced risk for type II diabetes.

Key words: obesity, diet, physical activity, blood lipidograme

INTRODUCTION

The increase of body mass, caused mainly by an accumulation of visceral fat,

is common especially in Europe and North America. In these areas, the consumption of

Corresponding author – Adres do korespondencji: Dr Zbigniew Kasprzak, Department of Hy-

giene of University of Physical Education in Poznań, Królowej Jadwigi 27/39, 61-871 Poznań,

Poland, e-mail: kasprzak@awf.poznan.pl

Z. Kasprzak, Ł. Pilaczyńska-Szcześniak

fat and caloric content of a daily food ration has increased in recent years. There are at

least 300 million obese people and the number has been multiplied three times over the

last 25 years [Ball 2005]. This problem affects not only adults, but also children and

adolescents. The main cause of excessive deposition of fat is destruction of the mecha-

nisms controlling the expenditure of energy [Lenart-Domka and Kwolek 2007]. Accord-

ing to the law of conservation of energy, the mass depends on the quantity supplied with

food and consumed. If the balance is knocked down by excessive energy, the excess

is stored as fat. Disorders of energy balance can be caused both by metabolic factors

(genetic, some endokrynopathies). The second group is described as the causes of regu-

latory problems (environmental impacts, cultural, organic and functional disorders of

the nervous system, emotional factors). Ingestion becomes more and more a form

of leisure, which in combination with sedentary lifestyle leads to overweight.

Excess body fat is not just a matter of weight and aesthetics. From the standpoint of

health consequences of the organism important is not only its quantity in the body, but

its location. Pathological increase in body fat leads to an increase in the incidence of

many diseases associated with it, and their occurrence at a much younger age [Goran

et al. 2003]. Increasing the amount of body fat contributes to the endocrine lipid-carbo-

hydrate disorder and consequently encourages the development of vascular diseases.

The aim of this work is to demonstrate the impact of diet and physical activity

changes in the parameters lipid – carbohydrate among adolescents.

MATERIAL AND METHODS

The study was performed on the group of young boys at the age of 15.6 ±1.40 years

with a substantial obesity (n = 35), subjected to reduce the excessive body mass.

The degree of obesity was determined on the basis of the values of the body mass index

(BMI). During the rehabilitation period (4 weeks) low-calorie diet and intense physical

activity were applied. The diet delivered approximately 1300 kcal per day (Table 1).

Daily nourishing ration was divided into 5 meals. The meals contained vegetables and

fruits, the main source of vitamins, mineral salts and fiber. The proteins in the diet was

derived from milk, dairy products, poultry and fish. The total amount of cholesterol

in daily ration was not more than 300 mg. Essential fatty acid were derived mainly from

vegetable oils.

Table 1. The average caloric diet and participation of proteins, fats and carbohydrates

Protein

Fat

Carbohydrate

Fiber

Kcal

% energy

1 291.3

21.1

66.5

24.0

33.3

54.9

176.9

31.18

Each day subjects were performing 2-hours walks and 1-hour sport activities (game

sports, swimming) and three days a week they were performing 30-minutes exercise on

a cycloergometer, each at an individually matched load, adequate to 70% of V O2 max, at

frequency of 60 per minute.

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Effect of diet and physical activity on physiological and biochemical parameters ...

The physiological and biochemical tests were made twice – at the beginning (I term)

and 4 weeks later (II term). The tests encompassed the measure of anthropometrical

indices (BMI, WHR, body mass, height). The body content was determined (fatty mass

– FM, fatty – free mass – FFM, total body water – TBW) by using the electrical bioim-

pedance method (Body Impedance Analyser – Akern, BIA-101), the results were calcu-

lated as the absolute values of mass (kg). The maximal oxygen absorption (V O2 max ) was

measured with an indirect method, by using the Ästrand-Rhyming nomogram [Ästrand

and Rhyming 1954].

The parameters determined in a fraction of the venous blood serum, taken in the

morning, using the tests by Cormay: total cholesterol, HDL-cholesterol fraction, triacy-

loglycerol concentration (TG), glucose concentration. Insulin concentration, measured

by radioimmunological method, using special sets produced by the Research and De-

velopment Radioisotope Center in Świerk, Poland. The concentration of LDL-

cholesterol was calculated from the Friedewald’s formula [Bobilewicz 1961]: LDL-

cholesterol = total cholesterol – HDL-cholesterol – (TG/5).

The young boys were qualified to participate in the research by a doctor. The study

was conducted with the consent of subjects and their parents as well as in agreement

with Local Committee of Ethics in Scientific Research of the Karol Marcinkowski Uni-

versity School of Medical Sciences in Poznań, Poland.

STATIC ANALYSIS

The results of the study were prepared using the program STATISTICA (StatSoft).

The Wilcoxon signed rank test was applied to make the comparison of the groups.

RESULTS AND DISCUSSION

The time and effect of body mass reduction among subjects with overweight and

obesity depend on their energy balance. The augmentation of the energy expenditure

during the process of reduction of the body mass is associated with more intense con-

version of the nutritional substrates stored in adipose tissue, what is the effect of physi-

cal activity or smaller daily ration, or both. Therefore, the most important thing in the

process of reduction of the body mass is still the appropriate daily ration and modifica-

tion of the lifestyle.

The most successful results can be obtained by mixing the low-calorie diet and

physical activity [Miller et al. 1990, Nazar and Kaciuba-Uściłko 1995, Kasprzak et al.

1995]. We can observe that obese people at all ages are less physically active and lead

more sedentary lifestyle [Hardman 1999, Westerterp 1999] what mainly influences the

increase of body mass. The method heading up to reduce body mass applied in this

study relies on low-calorie diet with lower content of fatty acids (about 1300 kcal) and

systematic, moderate aerobic physical activity. The result of this method is statistically

important and significant decrease of body mass from 107.7 ±21.43 at the beginning to

98.9 ±19.62 at the end of the treatment (p ≤ 0.01). The reduction of the body mass of

8.8 kg was the effect of the decrease of quantity of adipose tissue (average 7.6 kg) that

influenced also beneficial changes in visceral adipose tissue, proved by decrease of

Acta Scientiarum Polonorum, Technologia Alimentaria 9(1) 2010

Z. Kasprzak, Ł. Pilaczyńska-Szcześniak

120

Term I

Term II

100

107.7

98.9

65.8

64.6

48.4

47.6

41.9

34.3

35.0

32.1

0.92 0.87

Wight, kg

Water, kg

Free fat mass, kg Fat mass, kg

BMI, kg/m 2

WHR

Fig. 1. Weight and body composition and BMI and WHR boys undergoing weight reduction

in both periods of research at rest

WHR coefficient and also it minimizes the risk of threat to one’s health (Fig. 1) [Cybul-

ska and Szostak 1995, Gibney 1999].

Though, it is hard to predict, especially in further future, whether the benefits of

the applied therapeutic procedures will be permanent. As it is written in the contempo-

rary literature reports and from the authors’ research, the “yo-yo” effect may be the

consequence of rapid changes in body mass – alternately losing and gaining weight.

Rapid filling and draining of adipose cells stimulate the progression of new adipose

cells and as the result – increase of body mass [Niemiec et al. 2001].

Although, the possibility of metabolic disorders among young people with obesity is

lower than among adults, it is necessary to reduce body mass concerning the potential

metabolic complications in the grownup life.

Regular physical activity can evoke beneficial changes not only in terms of weight

and body components, but can also lead to improve quality of life associated with better

physical efficiency [Gutin et al. 1999]. The study reveals that systematic physical activ-

ity improves one’s physical efficiency which is reflected in the increase of the relative

Table 2. Mean (±SD) concentrations of the blood serum lipid and lipoproteins

Parameter

mg/dl

Term I

x ̅ ±SD

Term II

x ̅ ±SD

Total cholesterol

172.5 ±17.72

168.31 ±14.79*

LDL-cholesterol

116.14 ±20.70

103.13 ±16.58*

HDL-cholesterol

51.90 ±16.12

57.14 ±16.59*

Triglycerides

79.02 ±16.54

75.03 ±14.83

* p ≤ 0.01.

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Effect of diet and physical activity on physiological and biochemical parameters ...

coefficient of the maximal oxygen absorption and the rate of load. The coefficient

V O2 max depends on the efficiency of the circulatory and respiratory systems and the

metabolic processes occurring in the working muscle cells (Table 3).

Table 3. Biochemical and physiological parameters

Parameter

Term I

x ̅ ±SD

Term II

x ̅ ±SD

Insulin, μIU/ml

11.33 ±8.20

9.37 ±4.17*

Glucose, mg/dl

85.40 ±11.07

80.55 ±6.95

VO 2 max, ml/kg -1 /min -1

28.54 ±4.99

32.81 ±6.25*

Load, W

129.43 ±35.27

142.86 ±36.85*

* p ≤ 0.01.

It is proved that the accumulation of adipose tissue around the visceral organs in-

duces the evolution of insulin resistance and hyperlipidemia [Ferrannini and Camastra

1998]. These processes are a consequence of specific metabolic properties of adipose

tissue. The rising amount of abdominal adipose tissue causes not only an increase of

insulin secretion from pancreatic beta cells, but also diminish the hepatic clearance

[Peiris 1989].

Finally appear consequences – the disorder of homeostasis of the axis of glucose –

insulin and the appearance of glucose intolerance, hyperinsulinemia, insulin resistance

and dyslipidemia [Bray 1995]. The major metabolic outcome of insulin resistance

is hyperglycemia, what is the result of hepatic glucose production and its reduced trans-

port to the destined tissues.

The disorder in glucose – insulin homeostasis is caused by small number of mem-

brane insulin receptors of the visceral adipose tissue [Taylor et al. 1984]. Due to this

small number insulin receptors, adipose tissue is less sensitive to insulin antylipolytic

action. Free fatty acids released in the process of lipolysis diffuse into the blood and

thence to the liver. The increase of free fatty acids concentration in plasma influences

pancreatic beta cell dysfunction. Visceral adipose tissue, therefore, is considered the

main factor responsible for insulin resistance and development of diabetes type II [Ruan

and Lodish 2003].

Obesity diagnosed at the time of adolescence is 3 to 4 times more dangerous because

of higher risk of insulin dependent diabetes mellitus and coronary heart disease in ma-

ture life [Rybakowa 1993]. Hyperinsulinemia together with obesity lead to reduce the

number of insulin receptors, mainly in muscle and lipid cells, both at young and adult

subjects, furthermore, the parameters of visceral tissue of adolescents are correlated

with some parameters of insulin resistance [Reaven 1988].

Physical activity is one of the main factors aimed to reduce hyperinsulinemia and in-

sulin resistance [Rychlewski et al. 1997, Szcześniak et al. 1997]. It is known that body

mass reduction evokes increase of insulin receptor affinity while reducing its secretion

by pancreatic beta cells. This beneficial effect of physical activity to reduce hyperinsu-

linemia and insulin resistance is the result of insulin-independent glucose transport into

muscle tissue, and suppression of its secretion by the increase of concentration of cate-

Acta Scientiarum Polonorum, Technologia Alimentaria 9(1) 2010

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