Nutrition Research Methodologies –
HNH24306
,Table of Contents
Week 1 Introduction...........................................................................................................3
Week 2 Dietary intake........................................................................................................3
Week 2 Video.............................................................................................................................12
Week 2 Book..............................................................................................................................15
Chapter 4 Methods to determine dietary intake.........................................................................................15
Week 3 Body composition................................................................................................21
Week 3 College...........................................................................................................................25
Week 4 Energy expenditure & physical activity................................................................37
Week 4 Reading..........................................................................................................................41
Week 4 Clips...............................................................................................................................46
Week 5 Biomarkers and tracers to assess nutrient intake, status and metabolism............51
Week 5 Reading..........................................................................................................................57
Assignment......................................................................................................................69
,Week 1 Introduction
State of the art methods is important because:
The chosen methods determine the strenght of the results
Better methods in research paper = better chance of publication
Better methods in proposal = easier to get through medical ethical review process = easier to
get funding
For policy makers: how strong is the evidence from observational and clinical studies
For health professionals: how convinced am i that treatment works
For marketeers: can i substantiate claims for my product?
For grant providers: is my money well spent?
Week 2 Dietary intake
Learning objectives
1. Know what the implications of assessing dietary intake are for different study purposes.
2. Identify the principles of different dietary assessments methods.
3. Able to choose the most optimal assessment method for various diet studies
4. Able to explain what types of error are to be expected for commonly used dietary assessment
methods and know how to identify them.
5. Able to compare intake data with dietary reference values in individuals and populations.
With measurement error they are mixed up in quintile. Assesment of dietary intake is essential in
nutrition research. Awareness of errors allow improvement, correction, better interpretation. For
dieticians it is important to learn about application in research. Awareness of characteristics of new
technologies is another reason it is important.
1. Aims of dietary assessment
Research
Experimental and clinical studies
Surveillance and monitoring
Epidemiological studies
Patient care
Dietary advice
Complex to measure, some of the problems are
Preparation
Novel foods and supplements
Age groups
Characteristics will influence the results, under report their intake
Assessment of dietary intake
By different dietary assessment methodes
To indentify types of foods consumed
To define the amounts
, Sometimes: times, location
Using a food composition table or chemical analysis to convert this into intake of energy and
nutrients
Essentials for each dietary assessment method
Reference period: previous month, today
Portion sizes: weighing foods, household measures
Food composition: local tables, recent, specific components available or from chemical
analysis.
2. Available methods
Self-reports: 4 different methods
1. 24 hour dietary recall
Principle: recall of past 24-hours, interview and telephone/face-to-face
Application: monitoring studies, easy for the respondent, comparison between cultues
Disadvantages: Day to-day variation, respons errors
2. Food record or food diary: observation and duplicate portion (aks people to take from everything
they eat an extra portion and put it in a basket)
Principle: record current intake, amount, and time eaten
Application: experiments, small studies and awareness of intake
Disadvantages: change of intake (i have to report it so i won't eat it), burdensome (weighing)
3. Food frequency questionnaire: comprehensive and screeners (can be short)
Principle: frequency of habitual consumption; few nutrients or comprehensive list
Application: easy, in large epi trials
Disadvantages: culturally-based (each country has its own), difficult to recall past intake, no
information on single foods.
Short food frequency questionnaire is a screener
Tailored for qualitative assessment of diet (fruits and vegetables, energy-% from fat, dietary
patterns
Needed when very limited room for questions on diet
Useful in situations that do not require assessment of total diet
Estimates of intake are not as accurate as those from more detailed methods
4. Diet history: research, clinical practice
Principle: interview, habitual intake, meal-based and much detail
Different applications: more or less extended and research or dietary advice
Disadvantage: burdensome, experiened interviewers needed
HNH24306
,Table of Contents
Week 1 Introduction...........................................................................................................3
Week 2 Dietary intake........................................................................................................3
Week 2 Video.............................................................................................................................12
Week 2 Book..............................................................................................................................15
Chapter 4 Methods to determine dietary intake.........................................................................................15
Week 3 Body composition................................................................................................21
Week 3 College...........................................................................................................................25
Week 4 Energy expenditure & physical activity................................................................37
Week 4 Reading..........................................................................................................................41
Week 4 Clips...............................................................................................................................46
Week 5 Biomarkers and tracers to assess nutrient intake, status and metabolism............51
Week 5 Reading..........................................................................................................................57
Assignment......................................................................................................................69
,Week 1 Introduction
State of the art methods is important because:
The chosen methods determine the strenght of the results
Better methods in research paper = better chance of publication
Better methods in proposal = easier to get through medical ethical review process = easier to
get funding
For policy makers: how strong is the evidence from observational and clinical studies
For health professionals: how convinced am i that treatment works
For marketeers: can i substantiate claims for my product?
For grant providers: is my money well spent?
Week 2 Dietary intake
Learning objectives
1. Know what the implications of assessing dietary intake are for different study purposes.
2. Identify the principles of different dietary assessments methods.
3. Able to choose the most optimal assessment method for various diet studies
4. Able to explain what types of error are to be expected for commonly used dietary assessment
methods and know how to identify them.
5. Able to compare intake data with dietary reference values in individuals and populations.
With measurement error they are mixed up in quintile. Assesment of dietary intake is essential in
nutrition research. Awareness of errors allow improvement, correction, better interpretation. For
dieticians it is important to learn about application in research. Awareness of characteristics of new
technologies is another reason it is important.
1. Aims of dietary assessment
Research
Experimental and clinical studies
Surveillance and monitoring
Epidemiological studies
Patient care
Dietary advice
Complex to measure, some of the problems are
Preparation
Novel foods and supplements
Age groups
Characteristics will influence the results, under report their intake
Assessment of dietary intake
By different dietary assessment methodes
To indentify types of foods consumed
To define the amounts
, Sometimes: times, location
Using a food composition table or chemical analysis to convert this into intake of energy and
nutrients
Essentials for each dietary assessment method
Reference period: previous month, today
Portion sizes: weighing foods, household measures
Food composition: local tables, recent, specific components available or from chemical
analysis.
2. Available methods
Self-reports: 4 different methods
1. 24 hour dietary recall
Principle: recall of past 24-hours, interview and telephone/face-to-face
Application: monitoring studies, easy for the respondent, comparison between cultues
Disadvantages: Day to-day variation, respons errors
2. Food record or food diary: observation and duplicate portion (aks people to take from everything
they eat an extra portion and put it in a basket)
Principle: record current intake, amount, and time eaten
Application: experiments, small studies and awareness of intake
Disadvantages: change of intake (i have to report it so i won't eat it), burdensome (weighing)
3. Food frequency questionnaire: comprehensive and screeners (can be short)
Principle: frequency of habitual consumption; few nutrients or comprehensive list
Application: easy, in large epi trials
Disadvantages: culturally-based (each country has its own), difficult to recall past intake, no
information on single foods.
Short food frequency questionnaire is a screener
Tailored for qualitative assessment of diet (fruits and vegetables, energy-% from fat, dietary
patterns
Needed when very limited room for questions on diet
Useful in situations that do not require assessment of total diet
Estimates of intake are not as accurate as those from more detailed methods
4. Diet history: research, clinical practice
Principle: interview, habitual intake, meal-based and much detail
Different applications: more or less extended and research or dietary advice
Disadvantage: burdensome, experiened interviewers needed
