Sport & Performance Dietetics
Lecture 1: Course introduction, Energy Balance,
Assessment of dietary intake & Introduction assignment
1
Chapter 2 – Measuring Nutritional Status of Athletes: Clinical and
Research Perspectives
Introduction
- The purpose of nutrition assessment is to identify athletes at risk of diet-
related problems and their probable causes.
- The goals of nutrition assessments are to
o Identify athletes who require nutritional support to restore or
maintain nutritional status
o Provide appropriate nutrition therapy
o Monitor the progress and efficacy of dietary therapy
- The purpose of a nutrition-focused examination is to uncover any medical
condition or physiological factors that interfere with food intake, digestion
and metabolism
Dietary assessment
In clinical practice, dietary assessment involves collecting information on dietary
intakes and then interpreting food or nutrient intakes against reference
measures.
Why measure dietary intake?
Use Application
Determining nutritional status Calculating average nutrient intakes in population groups
of athletes
Comparing apparent adequacy of group nutrient intake
with population nutrient standards
Combining dietary intake assessment with other
parameters (e.g. biochemical, anthropometric and
medical) to assess nutritional status of individuals and
groups
Assessing the links with Comparing and contrasting indices of nutritional status
performance, diet and health status with the incidence and prevalence of health problems or
performance measures in groups
Evaluating nutrition education and Providing feedback on the efficacy of dietary intervention
intervention programs in individuals or groups of athletes
Assessing the effect of different Determining potential ergogenic effects of diets,
dietary regimens on performance components of diets or supplements
measures or metabolic responses
Assessing the effect of different Determining the turnover of nutrient requirements at
training periods or intensities on different training intensities and duration in combination
dietary intake with other parameters
Research applications
- The main method used to assess dietary/food/nutrient intakes of athletes
has been food records using household measures, which are best suited to
small samples
- FFQs (food frequency questionnaires) are more suitable than food records
for larger samples, but are not validated for all populations.
,Methods for measuring dietary intakes
Table 2.2 Comparison of dietary assessment methods for measuring dietary intakes in groups and individuals
Diet FFQ 24-hour Paper Digital food Image-
history recall food record based food
record record
Overview Respondent Respondent Respondent Responden Respondent Respondent
recalls the recalls, over a recalls all t records keeps a takes before
frequency set time food and foods and digital log of or
of period, the beverages in beverages all foods and before/after
consumptio frequency of the previous consumed beverages images of all
n of core consumption 24 hours. after eight consumed foods and
food over 7 of foods and Conducted weighing with an app beverages
days with beverages in-person or or that consumed
3, 6 of 12m from a set list. by telephone estimating provides with an app
cross-check Some FFQ with an with household using an
plus a 24- incorporate interviewer household measures or embedded
hour recall portion sizes or web-base; measures; weights for camera or a
for can be done usually portion camera;
foods/beverag for more done for 3- sizes; usually for
es than 1 day 7 days usually done 3–7 days
for 3-7 days
Application/ Provides Provides an Used mainly Assesses Assesses Assesses
purpose assessment estimate of as a food and food and food and
of usual total intake population beverages beverages beverages
intakes of over a specific survey consumed consumed in consumed in
individuals time period method at the time real-time real time
in dietetic Used to rank A single 24- of eating Can be used Can be used
clinical individuals by hour recall Can be to estimate to estimate
practice their can be used used to nutrients, nutrients,
Details of consumption to provide estimate foods, food foods, food
meal of nutrients, population nutrients, groups or groups or
preparation foods, food average of foods, food dietary dietary
and meal groups or nutrients, groups, or patterns for patterns for
patterns dietary foods, food dietary populations populations
can be patterns groups or patterns or or
obtained dietary for individuals individuals
patterns population Images can
Multiple days s or provide
required for individuals additional
individual contextual
estimates information
Training Interviewer Can be self- Interviewer Responden Respondent Respondent
required training administered training t needs to needs to be needs to be
required without required for be instructed on instructed
training or can the instructed how to use on how to
be interviewer structured on how to the app to use the app
administrated interview record record foods and capture
with specific foods and and amounts a usable
probes (e.g. amounts and the level image and
multi-pass and the of detail place a
method) level of required fiducial
Respondent detail marker (if
training required used)
recommende
d for web-
based
administratio
n
Respondent Low (20-40 Low (15- Low to High for High – Moderate –
burden minutes to 30minutes to moderate hand requires requires
complete) complete (30-60 recording selection of image
Requires an depending on minutes to all foods individual capture of
interview the length of complete) and food and food and
by a questionnaire) depending beverages beverages in beverages
dietitian on type (e.g. in every every eating in every
interview eating occasion and eating
versus web) occasion, their occasion
additional correspondin
burden for g amounts
weighing
foods and
moderate
for
, estimating
amounts
Data collection High – Low – High- trained High – Low – if data Low – if
burden trained particularly if staff needed trained are available automatic
staff instrument is for collection staff from app analyses
needed for scannable or and data needed for and linked to and linked
collection administered entry resolutions food to food
and data via the web Low for web- and data composition compensati
entry based entry data base on database
High – if data Moderate –
are if trained
unavailable, analysts are
need to be used to link
reconstructe to food
d and linked composition
to database data based
Strengths and limitations for the clinician or researcher
Strengths Literacy is Suitable for When Does not Provides less Literacy is
not large conducted as rely on burden on not required
required populations an interview memory if researcher/ Provides
due to the low literacy is recorded clinician for real-time
respondent not required at time of analysis if dietary
burden Low burden eating linked to assessment
Relatively on the Potential to food that
inexpensive to respondent provide composition includes
administer and detailed database metadata on
process accurate Provides the time of
informatio metadata on eating and
n on food the time of additional
and eating if contextual
beverages completed information
consumed correctly Has
potential for
more
accurate
automated
estimation
of food
volume
Limitations Methodolog Potential for Subject to Potential Potential for Potential for
y needs to measurement recall bias for reactivity yet reactivity
be error is high Previous day reactivity to be fully yet to be
standardize Subject to may not be high tested fully tested
d for recall bias representativ High Automation
suitability Estimation of e burden, of food and
for portion size Multiple days especially volume
research difficult for needed to for recognition
respondents to capture respondent not fully
quantify ‘usual’ intake s recording developed
Episodically Episodically high
consumed consumed energy
foods may not foods may intakes
be captured if not be Verification
not on food list captured of time of
recording
not
possible
(e.g. if
recorded
after
eating)
Dietary intakes in the present (diet record methods)
In research
- A weighed record is the gold standard, but for representativeness they
need to be conducted over several days repeated several times over
different seasons
- Disadvantage take long time to complete and require a literate and
cooperative respondent and a trained interviewer
- Weighed food records are more accurate than household measures
, Use of innovative technologies as an alternative to diet records
- Innovative technology provide opportunities for real-time recording, which
reduces respondent burden of written recording
Diet records are useful to
- Raise awareness of eating habits
- Provide a benchmark for evaluating diet and follow-up counseling
- Provide a self-monitoring tool
- Avoid the problems of memory bias inherent in recall methods
- Assess diet where an individual has an erratic or inconsistent food intake
and the usual recall methods used in practice are inapplicable
Dietary intakes in the past (recall methods)
24-hour recall
- Remember and describe quantities of food and beverage consumed in the
past 24 hours
- In clinical practice a 24-hour recall is useful and forms the basis for
pursuing a broader or more detailed assessment of usual intake using a
diet history
Food frequency questionnaires
- FFQs contain a predetermined food list, with or without portion sizes, plus
a frequency response option to report how often each food was eaten
- In research FFQs have been designed and validated in different
population groups to retrospectively assess intakes of nutrients, specific
foods or selected food groups consumed in the recent or distant past.
- In clinical practice
o As a rapid screening tool or rapid assessment method for selected
nutrients
o To evaluate the impact of dietary intervention counseling or
intervention programs
o As an education resource, for self-help intervention
o To monitor compliance with diet intervention
o For a variety of clinical situations (such as recent large loss/gain of
body mass) where there is a need to gather dietary information over
a short period of time
o To generate inexpensive and rapid behavioral feedback to an
individual on dietary intake
Diet history
- Involves a combination of a 24-hour recall and a FFQ
- In research limited use in research because of time-consuming,
dependent on a skilled interviewer and relies on memory and cooperation
of respondent
- In clinical practice modification of original diet history is mostly used
Sources of error in dietary measurement
Recognizing and reducing error when collecting and analyzing dietary intake data
is crucial in both research and clinical practice
Sources of error common to all methods of dietary intake data collection
- The largest source of error in collecting dietary intake data is respondent
inaccuracy in either recalling or reporting actual food intake.
