Lecture_1_week_2_food_diaries_and_bias
Applied Nutrition Lecture by Dr. Orla Flannery
Contact: o.Flannery@mmu.ac.uk
Aim of the Lecture
The lecture aims to explore dietary assessment and its significance, introducing food diaries and their applications, as well as discussing dietary quantification to understand nutrient intake.
Importance of Measuring Dietary Intake
Measuring dietary intake is critical to assess the nutritional intake of individuals, understand their food patterns, and classify consumption into categories, including specific foods and broader dietary patterns.
Major Categories in Nutritional Assessment
The major categories of nutritional assessment include Dietary Categories, Anthropometric Status, Biochemical Status, and Functional and Clinical Status as defined by Gibson in 1990.
Aims of Nutritional Assessment
The primary aims of nutritional assessment involve geographic mapping to identify the distribution of nutritional disorders, identifying high-risk groups vulnerable to deficiencies, analyzing epidemiological factors contributing to these deficiencies, proposing recommendations for intervention, developing budgetary plans for food provision at a national strategy, and informing athletes about their nutritional needs to enhance performance.
Dietary Assessment Methods
Methods for dietary assessment typically focus on measuring food and nutrient intake. This involves compiling reports of all foods consumed, identifying food using standard tables, quantifying portion sizes, assessing the frequency of consumption, and ultimately calculating nutrient intake based on portion size (g) multiplied by frequency and nutrient content.
Levels of Food Assessment
Dietary assessments can be conducted at various levels, including within families or schools, local communities, national demographics, and global populations.
Types of Dietary Assessment Methods
There are two key types of dietary assessment methods: Subjective and Objective. Subjective methods include Food Records/Diaries, Food Frequency Questionnaires, Diet Histories, and 24-Hour Dietary Recalls, while Objective methods include evaluating Nutritional Biomarkers and Doubly Labeled Water (DLW).
Prospective and Retrospective Assessment Methods
Subjective retrospective assessments involve Food Frequency Questionnaires, 24-Hour Recalls, and Diet Histories, while subjective prospective assessments focus on Food Records/Diaries. Self-reported dietary assessment methods can include both open-ended and closed-ended questions, each having its strengths and limitations.
Food Record Methodology
The Food Record methodology involves participants recording everything consumed over time, with a recommended recording period of 3-7 days, ensuring to include at least one weekend day.
Food Diaries Overview
Methodological variability exists based on respondent training and the quality of data collection. Effective assessment considerations include the number of days recorded, the corrective nature of dietary intake, and any variability in the data collected.
Strengths and Limitations of Food Records
Strengths of Food Records include the accurate quantification of intake and providing rich data about nutrition, cooking practices, and meal frequency. Limitations may include potential bias in dietary reporting, literacy requirements, compromised quality controls, respondent burden, and variability in completion rates affecting accuracy.
Practical Considerations in Data Collection
Researchers must recognize burdens faced by participants and themselves and address biases impacting data collection, including the representativeness of individual and group intakes.
Validation of Food Records
Methods of validation can involve observation, 24-hour recall, and biomarker correlation, noting that there is often underreporting of energy intake, particularly in overweight populations, with a reported 20% underestimation compared to DLW.
Uses of Food Records
Food Records are effective for analyzing eating patterns, assessing adherence to nutritional interventions, and conducting institutional assessments, such as in hospitals.
Objectives in Dietary Quantification
The objectives of dietary quantification focus on evaluating various food quantification methods and comprehending recall bias and its effects.
Bias in Dietary Reporting
Bias in dietary reporting can arise from measurement errors, both random and systematic; thus, methods to quantify intake may include weighing intakes, using household measures, or estimating through photographs or food models, each with its own biases.
Food Portion Variations
It is essential to recognize changes in portion sizes over the last 20 years and their implications for dietary assessments.
Cognitive Processing in Dietary Recall
A child's cognitive processing involves perceiving, attending, and remembering food information, which is critical in dietary recall.
Reporting Biases in Dietary Assessment
Types of reporting biases discussed include recall bias and interviewer bias.
References for Further Reading
For further reading, refer to Gibson's work on dietary assessment in "Essentials of Human Nutrition" (2nd Edition) and Conway et al., which provides details on dietary assessment methods in clinical nutrition journals, as well as studies validating dietary assessment instruments against biomarkers of habitual energy intake.
Lecture_1_week_2_food_diaries_and_bias
Applied Nutrition Lecture by Dr. Orla Flannery
Contact: o.Flannery@mmu.ac.uk
Aim of the Lecture
The lecture aims to explore dietary assessment and its significance, introducing food diaries and their applications, as well as discussing dietary quantification to understand nutrient intake.
Importance of Measuring Dietary Intake
Measuring dietary intake is critical to assess the nutritional intake of individuals, understand their food patterns, and classify consumption into categories, including specific foods and broader dietary patterns.
Major Categories in Nutritional Assessment
The major categories of nutritional assessment include Dietary Categories, Anthropometric Status, Biochemical Status, and Functional and Clinical Status as defined by Gibson in 1990.
Aims of Nutritional Assessment
The primary aims of nutritional assessment involve geographic mapping to identify the distribution of nutritional disorders, identifying high-risk groups vulnerable to deficiencies, analyzing epidemiological factors contributing to these deficiencies, proposing recommendations for intervention, developing budgetary plans for food provision at a national strategy, and informing athletes about their nutritional needs to enhance performance.
Dietary Assessment Methods
Methods for dietary assessment typically focus on measuring food and nutrient intake. This involves compiling reports of all foods consumed, identifying food using standard tables, quantifying portion sizes, assessing the frequency of consumption, and ultimately calculating nutrient intake based on portion size (g) multiplied by frequency and nutrient content.
Levels of Food Assessment
Dietary assessments can be conducted at various levels, including within families or schools, local communities, national demographics, and global populations.
Types of Dietary Assessment Methods
There are two key types of dietary assessment methods: Subjective and Objective. Subjective methods include Food Records/Diaries, Food Frequency Questionnaires, Diet Histories, and 24-Hour Dietary Recalls, while Objective methods include evaluating Nutritional Biomarkers and Doubly Labeled Water (DLW).
Prospective and Retrospective Assessment Methods
Subjective retrospective assessments involve Food Frequency Questionnaires, 24-Hour Recalls, and Diet Histories, while subjective prospective assessments focus on Food Records/Diaries. Self-reported dietary assessment methods can include both open-ended and closed-ended questions, each having its strengths and limitations.
Food Record Methodology
The Food Record methodology involves participants recording everything consumed over time, with a recommended recording period of 3-7 days, ensuring to include at least one weekend day.
Food Diaries Overview
Methodological variability exists based on respondent training and the quality of data collection. Effective assessment considerations include the number of days recorded, the corrective nature of dietary intake, and any variability in the data collected.
Strengths and Limitations of Food Records
Strengths of Food Records include the accurate quantification of intake and providing rich data about nutrition, cooking practices, and meal frequency. Limitations may include potential bias in dietary reporting, literacy requirements, compromised quality controls, respondent burden, and variability in completion rates affecting accuracy.
Practical Considerations in Data Collection
Researchers must recognize burdens faced by participants and themselves and address biases impacting data collection, including the representativeness of individual and group intakes.
Validation of Food Records
Methods of validation can involve observation, 24-hour recall, and biomarker correlation, noting that there is often underreporting of energy intake, particularly in overweight populations, with a reported 20% underestimation compared to DLW.
Uses of Food Records
Food Records are effective for analyzing eating patterns, assessing adherence to nutritional interventions, and conducting institutional assessments, such as in hospitals.
Objectives in Dietary Quantification
The objectives of dietary quantification focus on evaluating various food quantification methods and comprehending recall bias and its effects.
Bias in Dietary Reporting
Bias in dietary reporting can arise from measurement errors, both random and systematic; thus, methods to quantify intake may include weighing intakes, using household measures, or estimating through photographs or food models, each with its own biases.
Food Portion Variations
It is essential to recognize changes in portion sizes over the last 20 years and their implications for dietary assessments.
Cognitive Processing in Dietary Recall
A child's cognitive processing involves perceiving, attending, and remembering food information, which is critical in dietary recall.
Reporting Biases in Dietary Assessment
Types of reporting biases discussed include recall bias and interviewer bias.
References for Further Reading
For further reading, refer to Gibson's work on dietary assessment in "Essentials of Human Nutrition" (2nd Edition) and Conway et al., which provides details on dietary assessment methods in clinical nutrition journals, as well as studies validating dietary assessment instruments against biomarkers of habitual energy intake.
