Eating well goes beyond just personal choice; it’s a pathway to long-term health, disease prevention, and even environmental sustainability. In a new collaborative report, the Food and Agriculture Organisation (FAO) and the World Health Organisation (WHO) outline a universal framework for defining healthy diets, emphasising their role in supporting development, preventing diseases, and promoting sustainable food systems. Here’s a closer look at the four foundational principles they advocate and how these can be adapted to diverse dietary patterns around the world.
1. Adequate: Meeting Essential Nutritional Needs
A healthy diet must fulfil all essential nutritional needs without excess. This means providing sufficient energy and nutrients, including vitamins, minerals, essential amino acids, and fatty acids that the body cannot produce on its own. The FAO and WHO stress that adequacy in a diet varies based on factors like age, sex, physical activity level, and physiological conditions (such as pregnancy). Nutrient adequacy is especially crucial for infants and young children due to their rapid growth and small food intake volumes.
For children under two years, the WHO recommends exclusive breastfeeding for the first six months, followed by nutrient-dense complementary foods rich in essential nutrients, like high-quality animal proteins. In this stage, balanced protein, fat, and micronutrient intake is vital for cognitive and physical development. Meeting adequacy for older age groups involves a range of foods that cover the recommended dietary allowances for essential nutrients, aiming to prevent both deficiency syndromes and the health issues associated with nutrient excesses.
2. Balanced: Proportioning Macronutrients for Health
The concept of balance in a diet involves maintaining appropriate ratios of macronutrients—carbohydrates, fats, and proteins. This balance is essential for stable energy levels, healthy metabolism, and weight management. According to the FAO and WHO:
- Proteins should constitute about 10-15% of total daily energy intake. Protein sources, both plant- and animal-based, are vital for building and repairing tissues and for producing enzymes and hormones. WHO suggests that in certain stages, like adolescence or for athletes, slightly higher protein intake may be beneficial.
- Fats should account for 15-30% of daily energy, prioritizing unsaturated fats from plant sources. Unsaturated fats, including essential fatty acids like omega-3 and omega-6, support cardiovascular health, cellular function, and brain health. Saturated fat intake should remain below 10% to reduce risks of chronic diseases, while trans fats should make up less than 1% of daily calories.
- Carbohydrates should cover 45-75% of daily energy requirements, with a focus on complex carbohydrates from whole grains, fruits, vegetables, and legumes/pulses. These foods provide sustained energy and are rich in dietary fibre, which aids in digestion and supports cardiovascular health. Adults are advised to consume at least 400 grams of vegetables and fruits daily, alongside 25 grams of fibre.
3. Moderate: Limiting Risky Nutrients and Compounds
Moderation is the balance between essential nutrients that support health and those that can harm it when consumed in excess. Some nutrients, like sodium, sugars, and certain types of fats, are associated with health risks, such as hypertension, obesity, and cardiovascular disease. WHO provides guidelines to help manage these elements within a healthy diet:
- Sodium should be limited to 2 grams per day (approximately 5 grams of table salt) to support cardiovascular health. High sodium intake can increase blood pressure, a risk factor for stroke and heart disease.
- Free Sugars—like those added to foods or naturally present in honey and syrups—should constitute less than 10% of daily energy, ideally below 5%. High sugar intake is associated with weight gain, metabolic issues, and dental problems.
- Saturated and Trans Fats should also be limited. Saturated fats, primarily found in animal products, should make up no more than 10% of daily calories, while trans fats—typically from industrial sources—should be restricted to under 1%. WHO recommends avoiding artificial trans fats due to their links with increased risk of heart disease.
The FAO and WHO also highlight concerns with ultra-processed foods (UPFs), which are often high in fats, sugars, sodium, and artificial additives. UPFs have been associated with a range of negative health outcomes, including obesity, type 2 diabetes, and cardiovascular issues. Limiting these foods and focusing on whole, minimally processed ingredients can lead to improved health outcomes.
4. Diverse: Embracing Variety for Comprehensive Nutrition
Dietary diversity is the inclusion of a wide array of foods across and within food groups to ensure comprehensive nutrient intake. Diverse diets make it easier to achieve nutrient adequacy, as each food group and food item provides a unique set of essential vitamins, minerals, and bioactive compounds. This variety not only supports individual health but also allows for cultural and regional adaptability in diets.
FAO and WHO emphasise that a diverse diet contributes to reduced risks of nutrient deficiencies and diet-related noncommunicable diseases (NCDs), such as heart disease and diabetes. They recommend daily inclusion of various food types, including whole grains, fruits, vegetables, lean proteins, and healthy fats, and they encourage increased dietary diversity in children’s diets to build healthy eating habits from a young age.
Adapting the Core Principles Across Cultures and Contexts
While these principles are universally applicable, the FAO and WHO acknowledge that dietary patterns—the specific combinations of foods and drinks consumed regularly—are influenced by cultural, social, economic, and environmental factors. For example, plant-based diets in regions with limited access to animal protein may rely on local legumes and grains, while some regions may incorporate more seafood or dairy depending on availability. Recognising these cultural variations allows diets to be both healthy and contextually appropriate.
Additionally, dietary patterns are tied to sustainable food systems. Balanced diets that include a variety of plant-based foods often have a lower environmental impact, reducing demands on resources and helping to mitigate biodiversity loss, deforestation, and greenhouse gas emissions. Shifts towards sustainable dietary patterns are essential in creating resilient food systems that support both human and planetary health.
Celebrating Healthy Dietary Patterns and Promoting Food Safety
Healthy diets must also prioritise food safety at every stage of the food chain, ensuring foods are free from contaminants that could cause illness. According to FAO and WHO standards, food safety practices should be in place from production to consumption, as unsafe foods disproportionately affect vulnerable populations, including children and the elderly.
Food-based dietary guidelines are a practical tool many countries use to translate these principles into actionable recommendations. These guidelines offer local dietary models that support balanced nutrition and encourage sustainable practices. FAO and WHO encourage nations to adopt food guidelines that reflect these principles while considering local food production practices and cultural preferences.
Moving Forward with the FAO and WHO Guidelines
FAO and WHO urge consistency in framing of healthy diets based on the four core principles outlined here, and comprised of safe foods and water. They also encourage recognition and celebration of healthy dietary patterns and the sustainable agri-food systems that can promote and protect human and planetary health.
Adopting a healthy diet is a key step towards long-term health, well-being, and a sustainable food system. By promoting adequacy, balance, moderation, and diversity in diets, the FAO and WHO hope to inspire food policies and consumer behaviours that enhance global health outcomes. For governments, policymakers, and communities, these principles offer a roadmap to foster accessible, nutritious, and culturally respectful diets, empowering individuals and societies alike to make choices that benefit both human and planetary health.
Reference: What are healthy diets? Joint statement by the Food and Agriculture Organization of the United Nations and the World Health Organization. Geneva: World Health Organization and Food and Agriculture Organization of the United Nations; 2024. https://doi.org/10.4060/cd2223en.
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