Nutrition Through Life: How Dietary Needs Change With Age

Federica Amati, a nutrition expert at Imperial College London, explains that the high energy demands of children necessitate diets rich in nutrients.

“Food plays a fundamental role in building the body and brain during childhood,” she says. Beyond healthy calories, children need essential nutrients like iron, iodine, and a range of vitamins to support their immune systems, brain development, and muscle growth.

This means prioritizing a diet abundant in fruits, vegetables, whole grains, legumes like beans and lentils, and healthy fats including nuts and seeds, while limiting ultra-processed foods as much as possible.

Amati adds that during pregnancy and the first 1,000 days of a child’s life, a foundation for most of their future bone mass is laid. Calcium and vitamin D are therefore priority nutrients during this period, maximizing bone health and reducing the risk of osteoporosis and fractures later in life.

Practically, this means providing regular sources of calcium, such as milk, yogurt, and cheese, or calcium-fortified tofu and plant-based drinks, alongside sufficient vitamin D through sunlight exposure and foods like fish and eggs.

Supporting this, a 2023 study analyzed children’s dietary patterns and compared them to their health outcomes in childhood and early adulthood. The study found that children who met three or more recommendations from the British “Eatwell” guide had lower risks of heart disease at age 24 compared to those who didn’t meet the recommendations.

While childhood is crucial, dietary patterns during adolescence and the 20s play a vital role in establishing long-term health. This is a period of completing bone and muscle development, alongside increased daily demands from study, work, and social activity, raising the body’s nutritional needs.

“Adolescence and early adulthood offer another significant opportunity for positive dietary intervention,” Amati says. “Although growth slows in the 20s, these years remain critical for establishing dietary habits that protect heart and brain health in the long term. Evidence suggests that many of the foundations of heart disease begin to form during this period, even if symptoms don’t appear for decades.”

The body needs higher amounts of certain nutrients during adolescence compared to later adulthood, including calcium, vitamin D, and iron, which is particularly important for girls during menstruation. Proteins and vitamin B are also essential during this stage, according to Amati.

Dietarily, Amati recommends that teenagers and young adults prioritize a plant-based diet, avoiding ultra-processed foods, and including plenty of fruits, vegetables, whole grains, legumes, nuts, seeds, and lentils, ensuring adequate protein intake with each meal, whether from plant or animal sources.

Studies show that adhering to this dietary pattern benefits not only physical health but also mental well-being.

“Increasing evidence suggests that dietary patterns during adolescence can influence the development of mental health disorders,” Amati says. “Diets high in ultra-processed foods and low-nutrient plant-based foods are linked to higher rates of depression and anxiety, while dietary patterns similar to the Mediterranean diet appear to have a protective effect.”

The Mediterranean diet is characterized by a high intake of vegetables, legumes, nuts, olive oil, moderate consumption of fish and dairy, and poultry.

This dietary approach can offer additional benefits for men and women entering their marriage years, typically in their 20s, 30s, or 40s. Studies show that the Mediterranean diet may support fertility, while the Western diet, high in saturated fats, meats, and refined carbohydrates, is associated with increased infertility rates in both sexes.

For women, evidence suggests that diets rich in folic acid may support fertility treatments. Dietary sources of folic acid include dark leafy greens, sprouts, broccoli, and chickpeas.

Elizabeth Williams, a professor of human nutrition at the University of Sheffield in the UK, explains that in midlife, it becomes necessary to adapt and improve your diet to maintain health in later life. This is a crucial step for women approaching menopause, as Williams explains that “in this period, there is an acceleration in the loss of bone density, along with sarcopenia (age-related muscle loss), and an increased risk of osteoporosis.”

In addition to osteoporosis, menopause is associated with an increased risk of obesity, heart disease, and type 2 diabetes. Before reproductive age, estrogen plays an important role in the central nervous system in reducing appetite, and also enhances muscle sensitivity to insulin and glucose absorption. However, declining estrogen levels during menopause lead to changes in metabolism, resulting in weight gain and the accumulation of visceral fat.

However, these risks can be significantly reduced by following a balanced and healthy diet. In a recent population study, researchers analyzed the relationship between diet and health status in more than 100,000 men and women in the United States, aged 39 and older.

The results showed that a healthy diet, including fruits, vegetables, whole grains, unsaturated fats, nuts, legumes, and low-fat dairy products, was strongly associated with what researchers defined as “healthy aging” – reaching at least age 70 without chronic diseases, with good cognitive and physical function and sound mental health.

Amati says that in midlife, two dietary priorities emerge: maintaining heart health, and bone and muscle health.

She adds that menopause is associated with a sharp increase in the risk of heart disease, partly due to the effect of declining estrogen on blood lipids, blood vessels, and fat distribution in the body.

Amati notes that omega-3 fatty acids, especially those found in oily fish such as mackerel and salmon, help lower risk factors associated with heart disease and have anti-inflammatory effects.

She also recommends a slight increase in protein intake to compensate for muscle loss, and following a diet similar to the Mediterranean diet to improve heart health, and potentially digestive and mental health.

As people age, body composition changes and energy needs decline, requiring a reduction in calorie intake while ensuring sufficient nutrient intake to maintain bone and muscle strength. This shift in nutritional needs is a key aspect of healthy aging.

Williams explains that the two main nutritional elements to focus on in later life are calcium and vitamin D. Older adults who don’t get enough of these nutrients face an increased risk of osteoporosis and fragility fractures.

Calcium is found in milk, fortified alternatives, hard cheeses, yogurt, sardines, tofu, and spinach, while foods rich in vitamin D include oily fish, egg yolks, and fortified foods.

Jane Murphy, a nutrition expert involved in managing the Centre for Ageing and Dementia Research at Bournemouth University in the UK, says that adequate protein intake and quality are crucial with advancing age.

“As we age, physical structure and function decline, and there is a loss of muscle mass and strength, so protein is essential to prevent sarcopenia,” she says.

She adds that ensuring the body benefits from protein requires it to be part of a balanced diet that includes carbohydrates, healthy fats like unsaturated fats found in olive oil, avocados, nuts, and oily fish, along with vitamins and minerals.

With age, changes occur in the gut microbiome, most notably a decrease in beneficial bacteria like *Firmicutes* and *Bifidobacteria*, with an increase in potentially harmful species like *Clostridium*. This imbalance is linked to a number of health conditions, including Alzheimer’s disease, stroke, and heart disease.

While researchers haven’t yet defined the role of the gut microbiome in all diseases, a study of people who reached 100 years of age sheds important light, according to Mary Ni Lochlainn, a lecturer in geriatric medicine at King’s College London.

“People who live to 100 tend to outperform many of the common hallmarks of aging, and they have a more diverse microbiome than other older people,” Ni Lochlainn says.

Generally, there is no clear definition of healthy or harmful bacteria in the gut. The goal is to achieve a balance between microbes to promote health. However, scientists have identified some bacterial species, such as *Faecalibacterium prausnitzii*, that appear to have a protective effect.

Ni Lochlainn says that healthy centenarians are more likely to have this type of bacteria. Although researchers have proven its positive and protective benefits, its exact mechanism of action is not fully understood.

If you want to promote the presence of *Faecalibacterium prausnitzii* in the gut, a diet rich in fiber and polyphenols (abundant in fruits and vegetables) is the best way to do so.

Maintaining gut health can also help address some of the nutrient deficiencies associated with aging, as older adults’ ability to absorb vitamins from food is lower compared to younger people.

Studies suggest that beneficial bacteria in the gut may produce enough vitamin B12 to meet the body’s needs. Some bacteria can also produce folic acid. Furthermore, the gut microbiome may help prevent muscle loss and sarcopenia in old age.

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