The way we feel can be an indication of whether our diet contains the right nutrients. Take a look at what you need to meet your daily nutrition targets and how to top up.
How do we know if we’re meeting our daily targets for nutrients? Short of visually dissecting everything you eat and drink and asking a dietitian to analyse it for you, it can be hit and miss. Guidelines for nutrients exist for good reasons, as insufficient levels, over time, can lead to health complications. Our guide makes it easy to see key nutrient requirements for different population groups, and ways to get them. First, here’s what the terms mean:
Recommended dietary intake (RDI) is the average daily dietary intake level sufficient to meet the nutrient requirements of nearly all (97-98 per cent) healthy individuals in a particular life stage and gender group.
Adequate intake (AI) is the average daily nutrient intake level, based on observed or experimentally determined approximations or estimates of nutrient intake, by a group (or groups) of apparently healthy people, that is assumed to be adequate. The AI is used where there is not enough information to determine an RDI.
Suggested dietary target (SDT) is a daily average intake from food and beverages for certain nutrients that may help in prevention of chronic disease. These have been set for a small number of nutrients including sodium, fibre and vitamin C.
Upper limit (UL) is the highest average daily nutrient intake level likely to pose no adverse health effects to most people. As intake increases above the UL, the potential risk of adverse effects increases. Remember, more is not always better.
Calcium
What happens if you don’t get enough?
The body tries to maintain normal levels in the blood by taking calcium from our bones instead. Bone density is accrued at the highest rate during teenage years – after the late 20s, you merely to maintain your bone density, and from your 40s you begin to lose it.
Worrying stats
Around 60 per cent of us don’t get the recommended amount and, in the crucial 15 to 18-year-old age group, it’s estimated 88 per cent of females and 58 per cent of males have inadequate intakes.
Why it’s essential
A lack of calcium can cause bone deformation in children and weak bones and osteoporosis in later life. It’s also crucial for heart health, muscle contraction and blood clotting.
How to get it
Dairy foods are important sources so, if choosing non-dairy alternatives, it’s crucial they’re fortified with calcium. Soy beans, tofu and nuts (especially almonds) and green veges, such as broccoli and cabbage, also provide it, but it’s not absorbed as readily as calcium in dairy.
Surprising fact
Pregnant women absorb calcium more efficiently to meet the needs of the foetus.
Easy ways to boost calcium
1 cup trim milk = 330mg
105g can sardines = 250mg
20g cheddar cheese = 170mg
small handful almonds (30g) = 80mg
The figures you need to know (RDI)
nine to 13-year-olds 1000-1300mg
14 to 18-year-olds 1300mg
women aged 19-50 and men aged 19-70 1000mg
women over 50 and men over 70 1300mg
Vitamin C
What happens if you don’t get enough?
Deficiency can lead to scurvy, compromising new connective tissue formation. Expect weakness, bleeding gums and poor wound healing.
Worrying stats
While almost all Kiwis easily achieve the RDI, our average intake is 108mg, considerably lower than the SDT.
Why it’s essential
Vitamin C is needed to produce collagen for healthy skin, teeth, bones and tendons. It’s also a powerful antioxidant that helps protect cells and enhance immunity.
How to get it
Vegetables and fruit are the main sources of vitamin C, with other foods containing little.
Surprising fact
There’s not a specific upper limit, although having more than 1000mg a day may cause gut problems.
Easy ways to boost vitamin C
1 orange = 75mg
1 kiwifruit = 65mg
¼ red capsicum = 60mg
1 cup cooked kumara = 40mg
The figures you need to know
nine to 18-year-olds 40mg (RDI)
over 19-year-olds 45mg (RDI) and for SDT, 190mg for women, 220mg for men
Iron
What happens if you don’t get enough?
Over time, it can affect energy levels and immunity
Worrying stats
Thirty-four per cent of females aged 15-18 may have inadequate iron intake.
Why it’s essential
We need iron to make haemoglobin, a protein that transports oxygen from our lungs to every cell in our body. Too little iron means less oxygen and a subsequent risk of extreme tiredness and poor concentration. Your immune system can also suffer, making you more open to picking up infections. Iron deficiency anaemia needs to be diagnosed and treated by your doctor.
How to get it
‘Haem’ iron (from an animal source) is more easily absorbed by the body than ‘non-haem’ iron (from plants). Lean red meat and mussels are great sources of haem iron. Pulses, such as baked beans and lentils, dark green veges, such as broccoli, kale and watercress, grainy breads and iron-fortified breakfast cereals give us non-haem iron.
Tea, coffee and dairy products hinder absorption, so avoid having these at the same time. Vitamin C helps non-haem iron absorption and helps overcome the effects of iron inhibitors.
Surprising fact
Six mussels contain more iron than a lean steak.
Easy ways to boost iron
150g lean scotch fillet steak = 3.1mg
2 Weet-Bix = 3mg
½ cup cooked lentils = 2.4mg
200g baked beans = 2.4mg
The figures you need to know (RDI)
boys and girls aged 9-13 8mg
females aged 14-18 15mg
males aged 14-18 11mg
women aged 19-50 18mg
women aged 50+ and men aged 19+ 8mg
Selenium
What happens if you don’t get enough?
Over time, it may affect fertility in men and our ability to fight infections.
Worrying stats
Nearly 60 per cent of women and over 30 per cent of men 15 years and over don’t get the recommended amount of selenium in their diet.
Why it’s essential
Selenium produces vital antioxidant enzymes that protect cells and tissue. It also helps with reproduction, the immune system and brain function.
How to get it
Brazil nuts are by far the richest source, but selenium is also found in fish and other seafood, eggs, meat and cashew nuts.
Surprising fact
Too much of this mineral can cause selenosis, triggering hair loss and damage to nails and skin. The maximum safe intake (UL) from all sources is 280mcg for nine to 13-year-olds and 400mcg a day for people aged 14 and over.
Easy ways to boost selenium
2 Brazil nuts (8g) = 95mcg
1 cup prawns = 65mcg
95g canned tuna = 65mcg
The figures you need to know (RDI)
boys and girls aged 9-13 50mcg
girls and women 14 and over 60mcg
boys and men 14 and over 70mcg
Iodine
What happens if you don’t get enough?
It may cause thyroid problems, which affect metabolism.
Worrying stats
Since compulsory fortification of bread in 2009, average iodine levels in over 15-year-olds have almost doubled, crossing into the ‘adequate’ range. But Kiwi women over 30 still don’t get enough.
Why it’s essential
Iodine is crucial to production of thyroid hormones, which help to control the speed we burn energy (kilojoules) and chemical reactions in our bodies. A minimum 40mcg daily is needed to avoid goitre, where the thyroid gland grows as it struggles to produce thyroxine, and metabolism slows.
How to get it
Fish and shellfish are by far the best sources, but it can also be found in milk and bread.
Surprising fact
Getting too much iodine can change the way your thyroid gland works over time and can lead to weight gain. Seek advice from your GP or a dietitian before supplementing.
Easy ways to boost iodine
6 mussels = 130mcg
120g tarakihi = 60mcg
2 poached eggs = 50mcg
1 cup plain low-fat yoghurt = 25mcg
The figures you need to know (RDI)
nine to 13-year-olds 120mcg
over 14 150mcg
Fibre
What happens if you don’t get enough?
Constipation and an increased risk of bowel cancer.
Worrying stats
Many of us don’t get enough fibre, with the average intake for women 18g and men 23g.
Why it’s essential
Fibre is vital for our gut to work normally and it’s related to reduced risk of several diseases, from bowel cancer and type 2 diabetes to heart disease. It’s important to drink enough fluids throughout the day to allow the fibre to create soft stools in your colon.
How to get it
Wholegrain breakfast cereals, bread, pasta and rice, veges, fruit, nuts and seeds all provide fibre.
Useful fact
It’s important to increase your fibre intake gradually, and drink plenty of water, or you may experience gas and bloating.
Easy ways to boost fibre
1 cup cooked broccoli = 5.6g
½ cup (raw) wholemeal spirals or penne pasta = 5.3g
2 toast slices grainy bread = 4.5-6g
1 apple = 3.5g
2 teaspoons chia seeds = 3g
30g mixed nuts = 2.3g
The figures you need to know
girls aged 9-13 20g (AI)
boys aged 9-13 24g (AI)
girls aged 14-18 22g (AI)
boys aged 14-18 28g (AI)
women aged 19+25g (AI) and 28g (SDT)
men aged 19+ 30g (AI) and 38g (SDT)
Potassium
What happens if you don’t get enough?
A low intake, coupled with too much salt, can contribute to high blood pressure, increasing the risk of stroke and heart attacks. But people with kidney problems need to limit potassium and should check with their GP.
Worrying stats
While, on average, women meet the RDI (2817mg) and men are not too far off theirs (3535mg), most of us are miles away from the SDT.
Why it’s essential
We need potassium to balance fluids and for heart electrical signals to function properly.
How to get it
Vegetables, fruit, nuts, seeds, fish, shellfish, beef and chicken are all sources.
Surprising fact
The more potassium you eat (to a point), the more sodium you lose through urine. Potassium also helps to ease tension in the blood vessel walls. These two effects combined can have a positive effect on blood pressure.
Easy ways to boost potassium
½ 400g can tomatoes = 680mg
1 small baked potato = 600mg
1 cooked kumara = 490mg
¾ cup sliced courgette = 400mg
¼ avocado = 230mg
Zinc
What happens if you don’t get enough?
Early signs include poor growth in children and lowered immunity.
Worrying stats
When last measured, 39 per cent of males and 11 per cent of females, aged over 15, had inadequate zinc intakes.
Why it’s essential
It’s important for healthy skin, immunity and helps in wound healing. It helps break down and make use of proteins, fats and carbohydrates.
How to get it
Lean red meat, shellfish, some nuts and seeds, and wheatgerm found in bread and cereals.
Surprising fact
While zinc is essential for good immunity, too much zinc (40 mg a day for adults) can supress your immune system.
Easy ways to boost zinc
100g lean roast beef = 5mg
80g canned sardines = 2.4mg
30g pumpkin seeds = 2.2mg
30g cashew nuts = 1.6mg
100g cooked chicken = 1.4mg
The figures you need to know (RDI)
nine to 13-year-olds 6mggirls aged 14-18 7mg
boys aged 14-18 13mg
women aged 19+ 8mg
men aged 19+ 14mg
Why are veges and fruit so important?
People who eat plenty of veges and fruit have a lower risk of many diseases. They provide a vast array of vitamins, minerals and phytonutrients (beneficial chemicals found only in plants), many of which are powerful antioxidants, and fibre.
‘Five a day’ the minimum
Aim to include fresh, frozen or canned veges and fruit with each meal and snack. The average Kiwi doesn’t manage five a day. Only half our children (aged 2-14 years) meet recommendations for vegetable and fruit intake. And just 39 per cent of adults manage to get three-plus veges and two-plus fruit serves daily.
Surprising fact
Veges and fruit can be categorised by colour (eg, orange beta-carotene in carrots and apricots or purple anthocyanidins in blueberries and eggplants) for potential health benefits, but these pigments don’t correspond with their nutrient content, such as vitamins and minerals.
The figures you need to know
girls aged 9-13 2500mg
boys aged 9-13 3000mg
girls aged 14-18 2600mg
boys aged 14-18 3600mg
women aged 19+ 2800mg (RDI) and 4700mg (SDT)
men aged 19+ 3800mg (RDI) and 4700mg (SDT)
Why is oily fish so important?
People who have a diet rich in long-chain omega-3s, found in oily fish, have been shown to have a lower risk of heart disease
The figures you need to know
The SDT is 0.43g for women and 0.61g for men. Eating oily fish several times a week, fresh or canned, will help meet that target. If you really dislike oily fish or follow a vegetarian diet, consider taking an omega-3 supplement.
Worrying stats
Only 42 per cent of us report eating fish or seafood at least once a week.
And for vegetarians and vegans?
Alongside taking a plant-based omega-3 supplement, vegetarians and vegans can get a different form of omega-3 from some plant foods, such as walnuts, chia or ground linseeds.
Surprising fact
White fish such as tarakihi, snapper, hoki and ling also give us useful amounts of omega-3.
Easy ways to boost omega-3s
100g steamed NZ King salmon = 2.3g
100g can kippers = 1.9g
106g can sardines = 1.3g
105g can red salmon = 1.2g
Article sources and references
- Abbaspour N et al. 2014. Review on iron and its importance for human health. Journal of Research in Medical Sciences 19:164-74https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3999603/
- Kieliszek M & Blazejak S. 2016. Current knowledge on the importance of selenium in food for living organisms: A review. Molecules 21:609-24https://www.ncbi.nlm.nih.gov/pubmed/27171069
- Ministry for Primary Industries. 2016. Mandatory iodine fortification in New Zealand: Supplement to the Australian Institute of Health and Welfare 2016 report – Monitoring the health impacts of mandatory folic acid and iodine fortification. MPI Technical – Paper No: 2016/32https://www.mpi.govt.nz/food-safety/food-safety-and-suitability-research/human-health-surveillance/nutrition-strategy-and-research/
- Ministry of Health. 2017. Annual Data Explorer 2016/17: New Zealand Health Survey [Data File], minhealthnz.shinyapps.io/nz-health-survey-2016-17-annual-update Accessed June 2018https://www.health.govt.nz/publication/annual-update-key-results-2016-17-new-zealand-health-survey
- National Health and Medical Research Council (Australia) & Ministry of Health (New Zealand). 2006. Nutrient Reference Values for Australia and New Zealand including Recommended Dietary Intakes. Canberra: NHMRC, health.govt.nz/publication/nutrient-reference-values-australia-and-new-zealand Accessed June 2018https://www.health.govt.nz/publication/nutrient-reference-values-australia-and-new-zealand
- University of Otago and Ministry of Health. 2011. A focus on nutrition: Key findings of the 2008/09 New Zealand adult nutrition survey. Wellington: Ministry of Healthhttps://www.health.govt.nz/publication/focus-nutrition-key-findings-2008-09-nz-adult-nutrition-survey
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