Aoife Hearne: The connections between teenagers' diet and iron deficiency

It is well accepted that eating and other health-related habits developed during teenage years tend to stick into adulthood. For this reason, supporting a healthy relationship with food is essential not only for the teenage years but for life.

Adolescence is a time of increased energy needs due to physical activity and the energy required for growth and maturation. However, it is not unusual for this age group, particularly females, to reduce energy intake to keep their weight under control. Skipping meals in favour of snacking, for example, can negatively impact total energy intake and, more importantly, lead to micronutrient deficiencies. When snacking replaces meals, essential nutrients such as protein, fibre, calcium, and folate can be decreased.

Research by the Irish Universities Nutrition Alliance (IUNA) on dietary intakes and patterns in teenagers found a noticeable deficit in vegetable and fruit consumption. Teenagers in Ireland currently consume three servings of vegetables and fruit daily, a far cry from the five to seven recommended portions. While virtually all teenagers eat meat, there is a noticeable increase in the consumption of processed meats instead of fresh meat. This change also impacts the nutrient profile and can increase the risk of deficiencies.

Iron is a mineral found mostly in animal products, such as fresh meat. It is essential for growth and development. Iron also makes the protein haemoglobin in red blood cells, which carries oxygen around the body. This explains why it plays a vital role in reducing tiredness and fatigue.

Iron requirements increase during the teenage years. Teenagers are recommended to aim for 7-13mg a day. Due to a heavy menstrual cycle and low iron intake, it is not uncommon for teenage girls to develop low iron levels or iron deficiency anaemia. While only 9% of adolescent girls had inadequate iron intake, according to the National Teens’ Food Survey II, the nutrient needs to be prioritised. 

Two main types of iron are available in food: haem iron and no haem iron. Haem iron is mainly found in animal products and is easily absorbed by the body. Though non-haem iron is less well absorbed, foods rich in this nutrient are also important.

Non-haem iron is mainly found in plants and wholegrain — for example, leafy vegetables, pulses and fortified foods such as cereal. Combining acid foods (foods containing vitamin C), such as fruit juices, berries, and tomato-based sauces, will also help increase non-haem iron absorption.

Consuming adequate energy by having regular meals and snacks is a good starting point to help with energy levels during the menstrual cycle. As always, we aim to focus on whole foods such as vegetables, fruits, whole grains, and lean protein sources that will help ensure that the micronutrients essential for energy are not missed.

It would be advisable to discuss these issues with your GP and work with a CORU-registered dietitian to ensure your daughter meets her energy and micronutrient needs to optimise her growth, development and quality of life.

If you have a question for dietitian Aoife Hearne, please send it to parenting@examiner.ie