Hidden Hunger

Hidden hunger means a shortage of essential vitamins and minerals even when a person consumes enough or too many calories. It is a form of micronutrient deficiency: food may supply sufficient energy without supplying the nutrients needed for normal growth, immunity and bodily functions. It can therefore coexist with overweight or obesity and may not produce obvious hunger or visible wasting.

Why adequate calories may not mean adequate nutrition

Energy adequacy and nutrient adequacy are different. Calories measure the energy supplied by food, not whether the diet provides enough of every essential nutrient.

• A monotonous diet dominated by staples, or one containing many energy-dense but nutrient-poor foods, can meet calorie needs while leaving micronutrient requirements unmet.
• Low dietary diversity, including inadequate consumption of vegetables, fruits, pulses and other nutrient-rich foods, increases the risk of deficiencies.
• Poor absorption, infections and increased requirements during growth or pregnancy can also contribute to micronutrient deficiencies.

Major deficiencies and their consequences

The consequences depend on the nutrient involved, the severity of deficiency and the person's stage of life. Children, adolescents and pregnant women require particular attention because of their nutritional needs.

• Iron deficiency can cause anaemia, reducing physical work capacity and impairing attention; however, not all anaemia is caused by iron deficiency.
• Iodine deficiency can impair thyroid function and, during fetal development, harm brain development.
• Vitamin A deficiency can cause night blindness and increase vulnerability to infections.
• Zinc deficiency can impair growth and immune function.

How hidden hunger can be prevented

Prevention must improve diet quality, rather than merely increase the quantity of food or calories supplied.

• Dietary diversification should provide a balanced mix of food groups and nutrient-rich foods suited to local availability.
• Food fortification adds specified micronutrients to commonly consumed foods; iodised salt is an important example.
• Targeted supplementation can address specific needs, such as iron and folic acid supplementation for identified population groups.
• Nutrition education, balanced school meals, sanitation and appropriate healthcare can support better nutrient intake and utilisation.
• Assessment should consider dietary quality and relevant clinical or laboratory indicators, because body weight alone cannot rule out micronutrient deficiency.