tiểu luận kinh tế lượng EFECTS OF EATING HABIT AND DOING EXCERCISES ON THE BMI

Research objective The main purposes of this study is to provide thorough understanding ofBMI index, and analyze fundamental elements contributing to fluctuation of BMIranging from nut

FOREIGN TRADE UNIVERSITY

FACULTY OF INTERNATIONAL ECONOMICS

Lecturer: MSc Quynh Thuy Nguyen

Hanoi, 26th September 2019

FOREIGN TRADE UNIVERSITY

FACULTY OF INTERNATIONAL ECONOMICS

Lecturer: MSc Quynh Thuy Nguyen

Hanoi, 26th September 2019

TABLE OF CONTENTS

ABSTRACT 5

INTRODUCTION 6

1 Research objective 6

2 Rationale of study 6

3 Object and scope of study 7

4 Structure of scope 7

SECTION I: OVERVIEW OF THE TOPIC 8

1 General definitions and economic theories 8

1.1 General definitions 8

1.2 Economic theories related to the research 9

2 Literature view 12

2.1 Related published researches 12

2.2 Research hypotheses 12

2.3 BMR 13

2.4 Calorie Expenditure of Exercise 13

2.5 Calories expenditure of Common Foods 14

SECTION II: MODEL SPECIFICATION 16

1 Methodology 16

1.1 Method you use to derive the model 16

2 Theoretical model specification 17

2.1 Specification of the model 17

2.3 Describe the data 21

SECTION III: ESTIMATED MODEL AND STATISTICAL INFERENCES 24

1 Estimated model: 24

1.1Estimation result: 24

1.3 Explain the meanings of estimated coefficients 25

1.4 The coefficient of determination 26

2 Hypothesis Testing 26

2.1 Testing the significance of an individual regression coefficient β j 26

2.2 The confidence interval approach 27

2.3 The T-distribution approach 27

3 The P-value approach 28

4 Testing the overall significance 28

4.1 The F-test of significance approach 28

4.2 The P-value approach 29

CONCLUSION: 30

In the last a few decades, BMI index has been becoming one of the growingconcerns all over the world, especially to the health conscious as well as healthpublic researchers BMI is a measurement of a person's leanness or corpulencebased on their height and weight, and is intended to quantify tissue mass It iswidely used as a general indicator of whether a person has a healthy body weightfor their height Specifically, the value obtained from the calculation of BMI isused to categorize whether a person is underweight, normal weight, overweight, orobese depending on what range the value falls between This is the World HealthOrganization's (WHO) recommended body weight based on BMI values for adults

It is used for both men and women, age 18 or older

This provides the answer to our question why BMI is one of the most reliableindex reflecting the recent health situation BMI plays a crucial role in analyzingthe status of well-being, measuring the risk of hazardous diseases resulting fromoverweight like obesity, cardiovascular diseases, high blood pressure or fromunderweight like malnutrition, vitamin deficiencies, etc However, in reality, toachieve an ideal BMI index, we have to pay more attention to a number of factorsdirectly affecting it, namely nutritious intake in each portion, daily eating habit,average workout hours, sex, age, etc So in this study we will gain deeper insightinto the primary factors affecting BMI index and shed light on the optimalapproaches to reach standardized BMI, improve the general public well-being

We would like to give our appreciation to your useful lectures of this courseand instruction to fulfill this report Throughout process of making this report, ourteam did try our best to gather data, conduct researches and utilize availablematerials to analyze the result However, mistakes are inevitable Therefore, pleaselet us know if there are some ones that must be fixed to achieve more accurateresult

1 Research objective

The main purposes of this study is to provide thorough understanding ofBMI index, and analyze fundamental elements contributing to fluctuation of BMIranging from nutritious regime, eating habit to workout routine To be morespecific, it also supplies data about every single substance in daily diets, frequencyand the typical amount of calorie burned in exercising, the number and rationaldistribution of daily meals This study also enables people to foresee the positive ornegative trend of BMI in the future, gives recommendations for them to proposelong-term plan for the sustainable development of public health

2 Rationale of study

There are a few motivations prompting us to do this research:

- The lifestyle in the modern societies pose various threats to our health,particularly for youngster The consumption of junk food has been considerablyincreasing year by year Besides, the rate of children as well as adults becomingobese is so alarming, which has been linked to a lack of physical exercises On thecontrary, in the most remote areas, many families have to struggle to feedthemselves so malnutrition is a very common tendency The underweight andoverweight is associated with a plenty of dangerous diseases for health:

- Being overweight increases the risk of a number of serious diseases andhealth conditions Below is a list of said risks, according to the Centers for DiseaseControl and Prevention (CDC):

 High blood pressure

 Higher levels of LDL cholesterol, which is widely considered "badcholesterol," lower levels of HDL cholesterol, considered to be goodcholesterol in moderation, and high levels of triglycerides

 Type II diabetes

 Coronary heart disease

 Stroke

 Gallbladder disease

 Osteoarthritis, a type of joint disease caused by breakdown of joint cartilage

 Sleep apnea and breathing problems

 Certain cancers (endometrial, breast, colon, kidney, gallbladder, liver)

 Low quality of life

 Mental illnesses such as clinical depression, anxiety, and others

 Body pains and difficulty with certain physical functions

 Generally, an increased risk of mortality compared to those with a healthyBMI

- Being underweight has its own associated risks, listed below:

 Malnutrition, vitamin deficiencies, anemia (lowered ability to carry bloodvessels)

 Osteoporosis, a disease that causes bone weakness, increasing the risk ofbreaking a bone

 A decrease in immune function

 Growth and development issues, particularly in children and teenagers

 Possible reproductive issues for women due to hormonal imbalances that candisrupt the menstrual cycle Underweight women also have a higher chance

of miscarriage in the first trimester

 Potential complications as a result of surgery

 Generally, an increased risk of mortality compared to those with a healthyBMI

Therefore, more attention should be placed on and more investigation should beconducted on a regular basis to get deep understanding of primary elements havinginfluences on BMI index From those data and results of this paper, a specific plancan be set up to regulate the amount of nutrition intake, time for exercise andoutdoors activities, which can help control weight, height and lead a healthierlifestyle

3 Object and scope of study

In this study, we will concentrate on young people at ages ranging from 18 to

22 both female and male These are the most adequate and ideal ages to get

variables directly affecting BMI as well as the most accurate consequences A

range of research methodologies was used to investigate current practice and tocapture data about the scope and fundamental contributors in BMI index Using asoftware Stata used for statistical analysis; descriptive statistics and summarymethods to analyze the information from the survey

4 Structure of scope

The report has been structured to reflect the different research goals for theproject This report is organized as follows: Sections I will overview definitions.Section II will explore methodology of study: Factors that affect BMI index andanalyze dependent and independent variables in the OLS model Section III willexplain result we get from the Stata and test initial hypotheses Finally, give somerecommendations and effective way to positively alter daily diets and workoutroutine, improving the state of well-being and reaching an ideal BMI

SECTION I: OVERVIEW OF THE TOPIC

1 General definitions and economic theories

- Body mass index is a measure of body fat and is commonly used within thehealth industry to determine whether your weight is healthy BMI applies toboth adult men and women and is the calculation of body weight in relation

to height This article delves into the BMI formula and demonstrates howyou can use it to calculate your own BMI

b Formula of BMI

The first formula we've listed is the metric BMI formula, using kilograms and meters The second one is the imperial BMI formula, which uses units of

pounds and inches

 Metric BMI Formula: BMI = weight(kg)

Less than 15 Very severely underweightBetween 15 and 16 Severely underweightBetween 16 and 18.5 UnderweightBetween 18.5 and 25 Normal (healthy weight)Between 25 and 30 Overweight

Between 30 and 35 Moderately obeseBetween 35 and 40 Severely obeseOver 40 Very severely obese

Table 1 1.1.3 Current problems around BMI

It is a common argument that the results the BMI formula provides are toogeneral and do not consider the gender, build, age or ethnicity of a person Forexample, professional athletes are often considered overweight or obese whenusing BMI measurements due to their muscle content, which weighs more than fat

Similarly, as people age their bone density decreases So, although they mayseem to have a weight within the normal BMI range, their measurement actuallyneeds to be scaled-down to reflect this In a study published in the Journal ofEconomics in 2008, John Cawley, professor at Cornell University, was able todemonstrate that, relative to percent body fat, BMI appears to misclassifysubstantial fractions of individuals as obese or non-obese

1.2 Economic theories related to the research

a The three-variable model

 Population regression function:

E (YX2i, X3i) = β1 + β2X2i + β3X3i

 Stochastic form

Yi = β1 + β2X2i + β3X3i + ui

Where: Y: dependent variable

X2, X3: independent variables

β 1: intercept term

β 2, β 3: partial regression coefficients

ui: disturbance

 The meaning of partial regression coefficients

- β 2 measures the change in the conditional mean value of Y, E(YX2i,

X3i), per unit change in X2, holding the value of X3 constant

b Coefficient of determination R2 and the adjusted R2

 The multiple coefficient of determination R2

The extent to which all the independent variables jointly (i.e., the model)explain the variation in the dependent variable

- If there are too many predictors, it will result in over-fitting the model: misleading high R2 and a lessened ability to make predictions

- k is the number of parameters in the model

- “Adjusted”: adjusted for the degree of freedom associated with the sums

´R2 penalizes models with a larger number of parameters to be estimated

- ´R2 can be less than zero

- ´R2is used for the following purposes:

+ ´R2 is used to compare the fitness between models with different number

of explanatory variables

The sample size n and the dependent variable must be the same.+ ´R2 is used to consider adding one more variable into the model Thevariable will be added if:

IncreasesThe coefficient associated with the added variable is statistically different from 0

c K-variable regression model

 Population regression model:

E (YX2,…Xk) = β1 + β2X2i +…+ βkXki

Yi = β1 + β2X2i +…+ βkXki + ui

 Sample regression model:

Yi = ^β1 + ^β2X2i +…+ ^β kXki

Yi = ^β1 + ^β2X2i +…+ ^βkXki + ui

2 Literature view

2.1 Related published researches

Obesity is a world-wide health problem across the lifespan that also affectsthe elderly in developed and emerging countries In these countries, theirpopulations have proportionally greater numbers of older adults living to olderages, and the prevalence of obesity is increasing rapidly even at these oldest ages

In the United States, the prevalence of obesity in the elderly ranges from 42.5% inwomen aged 60–69 years to 19.5% in those aged 80 years or older The prevalence

of obesity is 38.1% in men aged 60–69 years and 9.6% for those men aged 80 years

or older In Europe, the prevalence is slightly lower but it is still a significant healthissue In the United Kingdom for example, 22% of women and 12% of men aged

75 years or older are obese These statistics bode ill as the proportion of world’selderly population continues to increase

Obesity in adulthood is associated with increased mortality, and data fromthe Framingham Heart Study report that obese adults (BMI ≥ 30) at age 40 yearslived 6–7 years less than did their normal-weight counterparts Another study based

on several U.S data sets (US Life Tables (1999), the third National Health andNutrition Examination Survey (NHANES III), NHANES I and II, and theNHANES II Mortality Study) also reported that obesity reduces life expectancy,particularly so in younger adults For example, in obese (BMI ≥ 45) white men andwomen aged 20–30 years, the minimum years of life lost was 13 and 8 years,respectively

The aim of this systematic literature review is to collate, review and criticallyassess current scientific and clinical information on the impact of obesity onmortality in the elderly so as to help clarify and improve our understanding of thecomplex relationship between the increasing health problem of obesity in elderlyadults and the risk of mortality This knowledge can help to reduce the cost ofhealth care and improve the quality of life in this segment of the world’spopulation

2.2 Research hypotheses

H1: Are the factors such as Age, Gender, Eating habit, Average calories

burned per day and Rate of absorbed calories over necessary calories influenced more or less on the BMI of 18-22 years old people? And how does it affect?

2.3 BMR

Calculate your Basal Metabolic Rate (BMR)

Our bodies are like engines that are constantly running They're alwaysburning fuel or calories (even during sleep) BMR is the number of calories youburn each day simply by being alive

Your Basal Metabolic Rate (BMR) can vary based on your age, sex, size,and genetics To get an accurate picture of the amount of calories you burn per day,start by calculating a value for your BMR

Use the following equations to find your BMR by hand:

 Men: (0.1 × weight) + (6.25 × height*100) - (5 × age) +5

 Women: (0.1 × weight) + (6.25 × height*100) - (5 × age) -161

 Doing exercises is an important factor which accelerates the burning process

2.4 Calorie Expenditure of Exercise

 Based on your current weight

 Based on 30 mins duration

2.5 Calories expenditure of Common Foods

Table 3

SECTION II: MODEL SPECIFICATION

1 Methodology

1.1 Method you use to derive the model

The process using in this research is called Multiple Linear Regression.This is a linear approach to modeling the statistical relationship of a dependentvariable on one or more explanatory variables Specifically, in our research, it is thestatistically dependent relationship between eating habit, exercising routine andBMI index

Methods used to collect and analyze the data

- Collect: At first we do many types of research: do survey by passing outanswer sheets, gather a number of related researches on World Bank and manypreference books

- Therefore, we decide to find have another methods to collect our data,which is mail interview It took quite a lot of time to draw up an attractive mailform to send to our subjects of research but one of the most benefit of this method

is that we can send to many people in a very polite way Nevertheless, the responserate is often low, it takes a lot of time to wait for outgoing messages and replies,uncontrolled respondents can reply to the wrong target …

- We also collect the data by telephone interview During the process ofcollecting information by telephone interviewing we were able to better understandtheir personal opinions and the response rate was also very high when call peopledirectly Best of all, we can improve the questionnaire during the interview process(improve the questionnaire, or change the order of the questions) However, theinterview time is limited because the respondent is often not willing to talk for along time on the phone, sometimes people need to ask to refuse to answer or not athome

- Especially, we get a lot of data from Worldbank, which is a very reliableopen data site The searching is very fast because we only need to sort out the dataand search directly on the Worldbank website This is really convenient because we

do not have to spending a lot of time and giving us a high level of confidence in theaccuracy of the numbers