By Carla Gerryts — Registered Dietitian (RD SA)
Nutrition strategies to build building health and immunity from childhood to older age
When we think about health, it is easy to only focus on the present: what to eat today, how to feel better this week, or how to manage a current condition. However, nutrition is not just about the now. Each bite is an investment in your long-term health. From the first days of life through to older age, what we eat not only plays a powerful role in shaping our health, but even our ability to fight off illness.
In the context of preventive healthcare, highlighted each year by World Health Day, nutrition remains one of the most accessible and impactful tools we have to make a difference in the day-to-day experience of our bodies.
But, let’s start at the very beginning – always a very good place to start.
Infancy and early childhood: building the foundation
The first 1,000 days of life, from conception to around two years of age, are often described as a critical window for development. During this time, nutrition literally lays the foundation for future health.
Breastfeeding, where possible, provides optimal nutrition and immune protection, providing antibodies and bioactive compounds that help protect infants against infections. As complementary foods are introduced, the focus should shift to nutrient dense options, including iron-rich foods, healthy fats, and a variety of fruits and vegetables. Infant-led feeding can guide the parent to read hunger and satiety cues.
At this stage, nutrition is not only about physical growth, but also about immune programming. A well-nourished child is better equipped to respond to infections and develop a robust immune system. Some of the first introductory foods are for sensory integration and “just for fun”, gaining meaning as the emphasis moves towards nutrient density.
The most important message I have for parents: monkey see, monkey do.
School-age children: we are supporting growth, learning, and immunity
As children grow, their nutritional needs expand along with their curiosity, activity levels, and cognitive development. School years are often busy, and, in many households, meals can become rushed or inconsistent. It can be hard for a schoolboy to eat at break when there is so much fun to be had!
A balanced diet that includes whole grains, lean proteins, dairy or alternatives, fruits and vegetables is essential for sustained energy and concentration. Key nutrients such as iron, zinc, vitamin A, and vitamin C play an important role in immune support. Did you know that guavas are one of fruits rich in vitamin C?
This stage also presents an opportunity to reinforce healthy relationships with food. Encouraging regular meals, including children in food preparation, and modelling balanced eating behaviours can have lasting effects well into adolescence and adulthood.
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Adolescence: addressing growth and changing needs
Adolescence is a period of rapid physical growth, hormonal changes, and increased independence. Nutritional requirements increase, but this is also a time when eating habits may become erratic.
Iron becomes particularly important, especially for adolescent girls, while calcium and vitamin D are critical for bone development. Adequate protein intake supports growth and muscle development, and a balanced intake of carbohydrates and fats provides the energy needed for both physical activity and academic demands.
Immune health remains relevant here as well. Busy schedules and increased stress levels can compromise both nutritional intake and immune resilience. Supporting adolescents with practical, realistic strategies, such as quick and balanced meals and snacks, can make a meaningful difference.
Adulthood: maintenance, prevention and lifestyle balance
In adulthood, the focus often shifts from growth to maintenance and prevention. This is the stage where lifestyle-related conditions such as obesity, type 2 diabetes, and cardiovascular disease may begin to emerge, often influenced by long-standing dietary habits.
For many adults, particularly those who balance work, family and other responsibilities, time constraints can be a major barrier to healthy eating. This is where practical strategies become essential, such as meal planning, the preparation of simple meals and choosing convenient but nutritious options.
It is also important to highlight the immunosuppressant effects of alcohol in this phase of life, and if supporting your immune function is a priority to you, it is worth paying attention to your alcohol consumption and if it is supportive towards your overall goals.
Older age: the goal is to preserve strength and function
As we age, nutritional needs shift once again. Appetite may decrease, while the body’s ability to absorb certain nutrients can change. At the same time, maintaining muscle mass, bone health, and immune function becomes increasingly important.
Protein intake plays a crucial role in preserving muscle mass and preventing frailty. Calcium and vitamin D remain essential for bone health, while nutrients such as vitamin B12 may require more attention due to reduced absorption. Hydration is another factor often overlooked in older adults. Even mild dehydration can affect overall health and wellbeing.
Enjoyment of food, maintaining independence, and supporting overall vitality can contribute to the most important outcome: improving quality of life. Smoothies, soups and meal replacement can assist in meeting nutrition targets.
A lifelong approach to health
Although nutritional needs evolve at all stages of life, one principle remains constant: a balanced and varied diet is foundational to good health. There is no single “superfood” or quick fix that can replace the benefits of consistent, nourishing choices over time.
In the context of immune health, particularly highlighted during initiatives such as African Vaccination Week celebrated from the 24th to the 30th of April, we are starting to understand that nutrition plays a supportive role. Although vaccines provide targeted protection against specific diseases, good nutrition helps ensure that the body is well equipped to respond effectively.
In summary: when it comes to health, what we do consistently, over years and across life stages, matters much more than what we do occasionally.