Posted: December 7th, 2022

DT/NU5053 Scientific Report

DT/NU5053 Scientific Report

An Evaluation of Two Methods for the Assessment of Dietary Intake

Guide

Background

This coursework is designed to give you some practical experience of assessing dietary intake. This will be achieved through performing two different dietary assessment methodologies. The two methods are the 24-hour recall and the 7-day weighed record. These will be used to collect dietary intake data. You will also develop a better understanding of the errors and bias associated with dietary assessment methodologies and how this may influence data quality. In addition, you will extend your knowledge and ability to analyse dietary intake data and further develop your skills in scientific report writing.

Aim

The overall aim of the coursework is to compare the two methodologies and discuss the strengths, limitations and errors contained within them. This will be achieved by recording and analysing your own personal dietary intake for energy, protein, fat, carbohydrate, fibre, iron, calcium and vitamin C, using the 24-hour recall method and the 7-day weighed record method. For the 24-hour recall method you will require someone to carry out the assessment of your dietary intake and you will analyse your own dietary data collected from both methods.

Learning Outcomes

LO1: Demonstrate an understanding of the use and application of different dietary assessment methodologies and an ability to appraise their strengths and limitations.
LO2: Use dietary analysis software and food composition data to analyse dietary intake and evaluate the data gained.

Description of the Assessment

For the 7-day weighted record, you need to measure all the food and drink that you consume over 7 days and record the information in a food diary. This allows you to experience what it is like for study participants to carry out this procedure and also gives personal insight into the issues associated with this method.

For the 24-hour recall, you will need to find a partner. Your partner needs to ask you to recall your diet over the past 24 hours and record it and then you do the same for them. This allows you to experience both giving and taking a 24-hour recall and will give you a better understanding of the issues associated with the method. The 24-hour recall should not be taken on a day when recording the 7-day weight intake.
Nutrient Composition Analysis

Once you have completed the dietary assessment, you are expected to analyse your personal dietary intake in the following way:

• Electronically using Nutritics (dietary analysis software)

Both sets of intake must be analysed for energy, protein, fat, carbohydrate, fibre, iron, calcium and vitamin C.

In order to analyse the 24-hour recall dietary data correctly it is important that you can understand what your partner has written. It is advisable that you spend some time at the end clarifying the written data.

You will have an opportunity to familiarise yourselves further with Nutritics during the practical in week 5 and will start to analyse your own diet at this time. The software is available online and you will be expected to finish analysing your diets in a self-directed manner.

PLEASE NOTE:

You are advised to keep a copy of all the data collection sheets – for the submitted report you will be expected to include in the appendix a summary of the average intakes as provided by the analysis software and the original data.

Food Scales

You will need electronic food scales accurate to 1-2g for part of your course work.

Methods for Collecting Dietary Intake Data

Multiple-pass 24-hour dietary recall

Principle

The purpose of a 24-hour recall is to obtain precise information on an individual’s exact food intake during the previous 24-hour period. A multiple-pass recall is a type of 24-hour recall that is conducted in four stages using a standardised protocol. Using this staged approach reduces underreporting.

In stage one, a complete list of all foods and beverages consumed during the previous 24-hour period is obtained. In stage two, detailed descriptions of all foods and drinks consumed, including cooking methods, brand names (if possible), are recorded along with time and place of consumption. In stage three, estimates of the amounts of foods and drinks consumed are obtained. Finally, in stage four, the recall is reviewed to ensure all items have been recorded properly.

The manner and technical skills of the interviewer are important, as is the environment in which the interview is conducted. The interviewer should adopt an open and pleasant manner with the aim of being friendly, diplomatic and determined, as appropriate. A rapport should be established with the respondent at the start of the interview. Respondents should not be given advanced notification of when the 24-hour recall will be conducted as they may change their eating habits. Avoid asking questions about specific meals e.g. breakfast, lunch or dinner. The interviewer should be non-judgemental at all times and avoid showing signs of disapproval or surprise regarding the respondents eating habits.

You cannot perform a 24-hour recall on yourself. You will need to find a colleague in class to do this for you, and you in turn will complete a recall for them. Remember it needs to be completed on one of the days when you are not doing the 7-day weighed record.

The information below provides details on the multiple-pass method for carrying out a 24 hour recall.

Method

Stage 1: Recall of foods and drinks consumed

The recall should begin with the first food and/or drink consumed in the morning. The interviewer should use neutral questions such as:

“I would like you to tell me what you had to eat or drink after you woke up yesterday morning. What did you have next and when was that?”

Proceed through the day, repeating these questions as necessary, and record each food or drink consumed in the appropriate column of the 24-hour recall form (photocopy the form on page 14).

Stage 2: Description of foods and drinks consumed

During this stage, the interviewer should go over each of the responses made by the respondent, probing for more specific descriptions of all the food and drink consumed, including cooking methods and (if possible) brand names. These details are recorded in the third and fourth columns of the form. Information on the place and time of eating should also be obtained and recorded in the first two columns. For homemade composite dishes, the amount of each raw ingredient used in the recipe should be recorded, the number of serving sizes for the recipe, and the amount of the composite dish consumed by the subject.

Guidelines for appropriate prompts for specific food items are given below:
Meat:
– kind of meat
– description of cut
– raw or cooked weight
– method of cooking
– lean or lean + fat
– bone in or not (waste factor) Bread/rolls
– type of grain (e.g. rye)
– homemade/bought
– size: standard or unusual
– thickness of bread – thin/med/thick
– toasted or not
– topping/condiments
Fish/sea food:
– kind of fish/sea food
– raw or cooked weight
– method of cooking
– bones/skin/shell (waste factor) Cereals/pasta/rice:
– type of grain
– brand name
– raw or cooked weight
Poultry:
– kind of poultry
– parts or pieces eaten (e.g. thigh)
– raw or cooked weight
– method of cooking
– meat+ skin or meat only
– bones (waste factor) Baked goods:
– type of product
– whether iced or not
– homemade or commercial
– type of filling
Soups:
– diluting (milk/water) Cheese:
– type (e.g. edam, Swiss)
– percentage fat (if possible)
Milk products:
– kind of diary product
– brand name (if possible)
– percentage fat Fats:
– kind of fat
– brand name
Vegetables:
– fresh/frozen/canned
– peeled/unpeeled
– method of cooking
– topping (e.g. butter) Fruits:
– fresh/frozen/canned
– peeled/unpeeled
– type of liquid (syrup/natural juice)
Beverages/soup:
– size of can or bottle
– fresh/frozen/canned/bottled
– juice: sweetened/unsweetened
– soup: homemade/canned Take-away foods:
– restaurant name
– food/beverage name
– size of portion
– condiments added
Coffee:
– brewed, instant, decaffeinated, regular Sweets:
– brand name
– size or amount
Stage 3: Estimation of amounts

• Use household measures to assist the respondent in estimating amounts.
• Quantities can be recorded by the interviewer as volumes – millilitres, pints, cups, glasses etc.; or as weighs – grams, pounds, ounces etc.
• Use counts for eggs and slices of bread.

Stage 4: Review of interview data

At the end of the interview, it is important that the interviewer reviews the recall to ensure that all the items have been recorded correctly. This can be accomplished using a statement such as the following:

“I will read back to you what I have recorded to make sure that I have not made any mistakes.”

Finally the respondent should be asked about the use of vitamin and mineral supplements, protein or diet drinks and also asked in a non-threatening manner about any alcohol consumed e.g.

“Did you have any alcoholic drinks during the day?”

Enquire about anything consumed in the middle of the night. As a final check, the interviewer should scan the recall in case any food groups have been omitted and should politely enquire about any missing items (e.g. meat or milk). The interviewer should then ask the subject whether the day of the recall represented a ‘normal’ day. At the end of the interview, the interviewer should thank the respondent for his or her time and cooperation (Adapted from Gibson, 1993).

Data Processing and Analysis

For this coursework you will process and analyse the dietary intake data for your own 24-hour recall taken by a partner. Obviously, in real-life this would not happen; it would be the interviewer or trained personnel that would carry out the analysis. When you swap over the recalls spend a little time with your partner clarifying difficult to decipher words or numbers, as it is likely that your partner will not be around when you are analysing the data.

The estimated food and drink amounts need to be converted to grams before analysis. The Food Portion Sizes Booklet (FSA, 1994) should be used to convert estimated amounts to grams (there are a number of copies of this book available in the library). The intake data must be analysed for energy, protein, fat, carbohydrate, fibre, iron, vitamin C and calcium.

24-Hour Recall Form

Day ………… Date ………………… Name ……………………….
Place eaten Time Description of food/drink Brand name Amount

Methods for Collecting Dietary Intake Data

7-day weighed record

Principle

The purpose of a 7-day weighed record is to provide a quantitative assessment of food intake over 7 days. The respondent is instructed to weigh all foods and beverages consumed. Details of the method of food preparation, description of foods, and brand names (if known) should also be recorded. The method of recording is similar to that used for the 24-hour recall method. Often foods that are eaten away from home cannot be measured, so respondents are asked to record the descriptions of the amounts of food eaten using household measure to describe portion size.

If the weight food record method is to be used, respondents must be numerate and literate. They must also be highly motivated because this method is more time consuming than a 24-hour recall, and the respondent burden is higher.

During a 7-day period you will weigh everything you eat and drink and record the information in a diary (photocopy form on page 9). In order to measure food accurately use an electronic weighing scales.

Method

Recording procedure

• All food and beverages consumed throughout the 7-day period must be recorded on the appropriate form. Include all snacks, condiments and spices (e.g. pickles, ketchup, and sauces), alcoholic beverages, sweets etc.
• All snacks, meals, or beverages consumed away from home must also be recorded.
• Begin each new day on a new page of the record form.
• Record the day of the week and the date at the top of each page.
• Record each item of a composite dish on a separate line. For example, a ham sandwich would be recorded as bread, ham, mayonnaise and butter, each on a separate line.
• Record where (e.g. home, restaurant, office) and at what time, each meal, snack, or drink was consumed.
• If vitamins or mineral supplements are used, list the amount taken each day, the brand name, and label information.

How to describe foods and drinks

Use a separate line for each food or food type when recording, and separate out components of composite dishes such as sandwiches, salads, or casseroles. For all foods, include the following details:

• Method of cooking (e.g. roasted, stewed, fried, boiled, and steamed).
• Kind of food (e.g. raw or cooked; peeled or unpeeled; white or whole wheat bread; fresh, canned, frozen, dried; skimmed, semi-skimmed or whole milk).
• Brand names of all processed foods wherever applicable (e.g. Kellogg’s corn flakes, Galaxy chocolate)
• Include all condiments (e.g. pickles, sauces, ketchup, and mustard).
• Provide as much label information as possible and the brand name of any unusual or special foods consumed (e.g. sodium reduced bread).
• If a recipe is used to make composite products record, on the back of the food record sheet, the complete recipe, giving the measured amount of each raw ingredient, the total number of servings for the dish, and the amount of the dish eaten by the respondent.

How to record amounts of foods and drinks

• Record the amounts of all food and beverages in the form they are consumed. For example, do not record the weight or size of a raw pork chop: instead, record the amount of a fried pork chop.
• Record the amount of all leftovers; any remaining bones from meat, apple cores, or the skin from a baked potato, etc. Subtract the amount leftover from the original weight or volume for that food.
• Remove the peel from fruit such as bananas or oranges before recording the weight eaten.

Using dietary scales

• Adjust the scales to zero.
• Place the serving dish or cup on the scale.
• Adjust the scale to zero.
• Place the food or beverage in a serving dish or cup.
• Read and record the weights in grams.
• Repeat this weighing procedure for the next food item.

If some food remains, weigh the leftovers and deduct the weight of these from the initial weight. (Adapted from Gibson 1993)

As mentioned above you need to analyse your 7-day weighed intake. The intake data must be analysed for energy, protein, fat, carbohydrate, fibre, iron, vitamin C and calcium. Ensure that you analyse each day separately so that the range of intake for each nutrient can be calculated.

References

Gibson, R.S. (1993) Nutritional Assessment: A laboratory manual. New York: Oxford University Press.

FSA (1994) Food Portion Sizes (3rd edition). London: TSO

Diet Diary Record Form

Day ………… Date ………………… Name ……………………….
Place eaten Time Description of food/drink Initial weight
(g) Leftover weight
(g) Consumed weight
(g)

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