FIGURE THIS! Estimated Energy Requirements
RDI? EER? NRVs?... Leanne Cooper demystifies some dietary acronyms and reveals how energy requirements are determined.
So you can rattle off dietary acronyms with the best of them; ‘Oh yes, well his EER was clearly too high for his BMI so I consulted the NRVs and low and behold he was exceeding his RDI’. But do you really understand these terms and how they are arrived at?
Performing calculations is an everyday task for most fitness and health care professionals. However, technology means we aren’t required to actually work them out for ourselves, so the reasons behind formulas can become forgotten or misunderstood. The following may serve as a reminder of how to calculate estimated energy requirements (EER) – and even if you aren’t required to provide these calculations, it is useful to familiarise yourself with the jargon for occasions when clients present their ‘stats’ to you.
Understanding nutritional terms can also assist you in your discussions with other health care professionals. For example, if you are working with a client who is under the care of a dietitian, knowing what an EER is and why a person has been prescribed a certain level of energy intake can be invaluable for both you and your client.
To work out the energy needs of an individual we need:
- To know details about the individual
- A guide to compile this information into a potential figure or range of figures relating to energy requirements. Luckily, there is a very useful document that does this called the Nutrient Reference Values – or NRVs for those of us into acronyms.
What are the NRVs?
The NRVs are set out by the National Health and Medical Research Council (NHMRC), which describes the purpose of the values as being to ‘outline the levels of intake of essential nutrients considered, on the basis of available scientific knowledge, to be adequate to meet the known nutritional needs of practically all healthy people for prevention of deficiency states.’ It is important to note that they are based on healthy people and those outside of this definition, such as pre-term infants, those with illness and conditions, and people with specific genetic profiles, may require different levels of nutrients.
Where we once used only RDIs (Recommended Dietary Intakes), the improved data collation and nutritional analysis of the newer NRVs has yielded other figures such as the estimated average requirement (EAR), adequate intake figures (AI) and upper limits (UL). The NRVs also provide tables for the calculation of EER for infants through to adults and for pregnant and lactating women.
|Sourcing your copy of the NRVs|
The National Health and Medical Research Council (NHMRC) website has a full set of NRVs that are free to download and very useful to have to hand. Alternatively, you can download just the tables without the background data. Go to www.nhmrc.gov.au and type in NRVs in the Search field.
Estimated energy requirements (EER)
EER figures are predictive equations that use age, gender, weight, height and physical activity levels (PAL) to provide figures for a person’s energy requirements. These calculations should provide a reasonable guide for maintaining energy balance (essentially the old ‘what goes in should equal what goes out’, though we know that this falls well short of being the whole story).
Keep in mind that these figures are based on averages: there will always be individuals who sit outside the ‘norm’. For example, you will commonly find that a person doesn’t fit neatly into the expected weight and height references.
How to calculate a person’s EER
So let’s take a look at how you might work out your own or a client’s EER, using the Estimated Energy Requirement table.
Example: ‘Normal’ weight female
Age in yr: 35
PAL: No formal exercise = 1.6
Status: Otherwise well
- Review the Estimated Energy Requirements table (click below to download).
- Select appropriate age group from left hand column: 31-50
- Select the row with the closest height for this person: In this case we will use 1.6
- Select the row with the closest weight for this person: Given this person’s weight is closest to 56.3 this is the one we will use.
- Consider the person’s level of activity and select a PAL (physical activity level) from the columns under the ‘Female’ heading: In this case this person does no formal activity and given a PAL of 1.7 equates the ideal level of activity, we will take the next level down. There are charts that you can use to estimate this by recording a person’s activity over a day.
- Find the point where the relevant column and row intersect and this will be the EER for this person: 8.8 (M/Jday) or 8800 kJ/d
This is a nice straightforward example, but in reality most people cannot be as neatly categorised. You may find that a client comes to you with an EER range that spans the height and weight figures they are closest to on the NRVs. In this case a range can be helpful in providing achievable targets for weight loss as well as ensuring nutritional sufficiency.
Things to keep in mind
Although gathering key figures from clients is very useful, it doesn’t always tell the full story. Don’t overlook the person in front of you: all sorts of variables can alter what a person needs to eat, including stress, illness, unaccounted intake or energy expenditure and genetic body shape.
Reviewing a diet and programming for change requires an integration of a number of dietary and lifestyle factors, rather than any single factor. Often individuals can become overly concerned with figures such as grams of fat in food, caloric measurements or body measures. There can be times when this is simply a diversion, and others where it acts as an obstacle to real change. A holistic approach that encompasses a healthy view of food, eating and activity will be motivating, realistic, and more likely to result in success.
Leanne Cooper, Grad Cert Human Nutrition, BA Pysch/Ed, Dip Nutr
Leanne holds tertiary qualifications in nutrition, psychology and education, and consults to a number of national teams and elite athletes. The founder of Cadence Health and Nutrition Courses, Leanne has grown the company into a popular stop for personal trainers to access relevant, informative, accredited distance education courses. To enrol into the 5 CEC-accredited Dietary Assessment Methods course, visit www.cadencehealth.com.au