Posted by kathryn in A Balanced Diet and Q & A Thursday

Next on Q & A Thursday we move on to portion sizes. A reader has asked:

There’s lots of information around about how many portions of fruit & veg, protein, grains & carbs and fats we should be eating each day; and there’s a reasonable amount of info about how big a ‘portion’ is. My problem is this – when I set out to eat the recommended daily amounts of everything, it’s too much food for me. I manage to maintain the ratio of the different food groups to each other, but the physical amount of each food is smaller. Am I short-changing myself on nutrients?

This is a great question and has made me realise how little I’ve written on portion sizes. Definitely a topic for the future. However to answer this specific question . . .

Dietary guidelines

Here in Australia the definitive dietary guidelines are put together by the NHMRC. They release publications both to the industry and also to the general public, providing information on what people should be eating. You can download their current guidelines here.

In interpreting this information, nutritionists and health bodies invariably simplify the rules. And this leads to guidelines on what and how much to eat. These rules are based on average intakes and kilojoule requirement. And the problem is, so few of us are actually average.

Dietary Intakes

Take the Dietary Intake (DI) information now listed on some food labels. These specify how much of certain nutrients a particular food contains, and the percentage of the average daily intake that forms.

The average daily intake has been calculated as 8,700kJ. But if you’re female this is too much, unless you’re very tall or very active. If you’re a male that’s overweight this is too much. But if you’re male and over 1.8 metres, it’s nowhere near enough.

In this case the average only applies to a small portion of the community.

General dietary advice

Many health bodies split their guidelines between male and female, old and young. However, even with that differentiation there’s still a variety between what we all need.

I’m 1.60 metres and moderately active, but one of my closest friends is 1.8 metres, also moderately active. Our difference in height means we have differing food needs. However, in the dietary guidelines we are lumped together as female adults – needing the same food portions.

Stick with the ratios

It’s basically impossible to put together meaningful dietary information, that’s easily accessible, but also captures all the nuances of peoples’ needs. Therefore the dietary guidelines are exactly that, guidelines.

They’re not hard and fast rules and you have to tweak them to suit your own personal food needs.

One of the best ways is to look at the ratio of different foods and adapt that to your own diet. If you look at the quantity of vegetables to fats to wholegrains in the guidelines, you can then adjust the portion sizes to suit your own needs. And in this way you’ll be getting the right amount of nutrients for your body.

Healthy Eating Pyramid

One of the best tools for this in my opinion is the Harvard School of Public Health’s food pyramid – as shown above. Unlike the old fashioned food pyramid, which has debatable value, this is a better reflection of how to eat well.

This food pyramid gives equal emphasis to fruit and vegetables, and whole grain cereals, as the foundations of your diet. It promotes the consumption of nuts, seeds, legumes and low fat meats, rather than lumping all “proteins” together in one category. Plus it differentiates between the quality of the fats we consume.

It provides a visual guide to how much of each food to include in your diet. And is, in my opinion, a better reflection of how we should be eating for maximum health.

What is Q & A Thursday?

This post is part of Q & A Thursday – a monthly burst of blogging, where you get to dictate the subject matter. Q & A Thursday is all about simple, practical answers to food and diet dilemmas sent in by readers.

If you have a question you’d like answered send me an email. For more information you can take a look at the Q & A Thursday archives.

05 June, 2008