The up-to-date FAO and WHO definition of a healthy diet emphasizes moderation

The two UN bodies, FAO and WHO, have released a new document detailing all aspects of a diet plan that promotes human health, growth and an active lifestyle while presenting nutrient deficiencies and excesses. The report emphasizes the importance of diet in mitigating communicable and noncommunicable diseases, foodborne diseases and overall well-being.

The organizations highlight that the core principles of healthy diets remain the same: adequacy, balance, moderation and a diversity of nutrients.

The report states: “With such prominence in the scientific literature and public media has come a range of definitions and perspectives about what constitutes healthy diets, and how these can be achieved, while protecting the environment.”

“Heads have turned to the agri-food system and the ways in which it can and must be transformed to contribute to the commitments of ending hunger and all forms of malnutrition, elevating levels of human health and protecting and restoring the environment. But

lack of consensus of what constitutes healthy diets can undermine progress and continuity of efforts to achieve them.”

FAO and WHO aim to address this issue with their new guidelines on healthy diets. The document sets out principles recognized by the scientific literature and previous guidelines and norms developed by the FAO and WHO.

“Multiple dietary patterns that meet these principles, and in which foods are safe, can therefore be defined as healthy dietary patterns.”

Principles of a healthy diet

The document outlines that while many diet patterns can be defined as healthy.

For food intake to meet all nutritional needs, it has to be adequate. This means that it should provide a sufficient amount of all essential nutrients to prevent deficiencies and promote health without excess. 

Foods, nutrients and other compounds can lead to detrimental effects if consumed without moderation.A healthy diet should also be balanced in terms of energy intake and sources. Consuming the right amount of fats, carbohydrates and proteins is essential to ensuring healthy weight and growth and to preventing diseases. 

Moderation is also highlighted as a key principle of a healthy diet. Foods, nutrients and other compounds can lead to detrimental effects if consumed without moderation. 

Diets should be diverse as well, because a wide variety of nutritious foods within and across food groups is vital to nutrient adequacy and the intake of “health promoting substances.”

FAO and WHO also highlight the importance of ensuring that all food and beverages are safe for human consumption to prevent foodborne diseases. 

Personalized and infant nutrition

Further addressing how to ensure adequacy, the document highlights the importance of age, gender, body composition, physical activity levels, physiology and disease in determining the optimal nutrient requirements.

“Meeting nutrient requirements for children aged zero to 23 months is particularly important given growth and development and the small total quantity of foods consumed. For infants zero to six months of age, nutrient needs should be met through exclusive breastfeeding,” the authors detail. 

“As of six months of age, animal-source foods are a good source of high-quality protein and bioavailable key vitamins and minerals. Therefore, WHO recommends, in addition to continued breastfeeding, the daily consumption of animal source foods, including unprocessed meat, fish or eggs, for children in this age group.”

Meeting nutrient requirements for children aged zero to 23 months is particularly important given growth and development.The FAO and WHO have already established dietary requirements for energy, proteins and amino acids, fats and fatty acids, vitamins and minerals. Many countries have established their recommendations for their populations. 

Nutrient balance

Healthy diets should be appropriately balanced across the three primary macronutrient groups and energy sources: protein, fats and carbohydrates. “Absolute requirements for the amount of protein, fat and carbohydrates in the diet vary with total energy intake, and thus are expressed as a proportion of energy intake from each.”

The recommended amount of protein intake for both adults and children (defined as those between two and 19 years of age) is 15–30% of the total daily energy intake. 

“Proteins provide the building blocks for much of the structural elements of the body, such as muscle, as well as functional molecules such as hormones and enzymes. Consuming excessive amounts of protein however can place a metabolic burden on the body, particularly the kidneys.”

The report asserts that both animal and plant sources of protein can be appropriate depending on the context. For children, the digestibility and quality of protein sources should be considered. 

Macronutrient sources

For adults, the report recommends switching to more plant-based sources of protein to decrease the risk of cardiometabolic diseases, if appropriate for the context. For many, the consumption of animal-source foods remains important to improving nutrient intake.

Fat should make up 15–30% of energy intake, but 15–35% for children. Both age groups should aim to consume 10% or less saturated fat of their total energy consumption, 1% or less of trans fat, 6–10% of polyunsaturated and a varied amount of monounsaturated fat. 

Switching to more plant-based sources of protein may decrease the risk of cardiometabolic diseases.“Fat is an essential nutrient for proper functioning of cells in the body, and two fatty acids — linoleic acid and α-linolenic acid — can only be obtained from the diet,” explain the authors. 

“High intakes of fat may lead to excess energy intake and limiting intake to 30% or less may help to reduce the risk of unhealthy weight gain. 

Carbohydrates should represent at least 45% of the total daily caloric consumption of an adult or a child and a maximum of 75%. Of these, 10% or less can be sugars. 

“Carbohydrates provide the primary energy source for the body. The amount of carbohydrate in the diet can vary and should represent the remainder of the diet after taking protein and fat into account.”

“Carbohydrates should come primarily from whole grains, vegetables, fruits and pulses. Adults should aim for at least 400 g of fruits and vegetables and 25 g or more of naturally occurring dietary fiber from foods every day,” the report highlights.