The Intricate Relationship between Chronic Undernutrition, Impaired Linear Growth and Delayed Puberty: Is ‘catch-up’ growth possible during adolescence?

Chronic undernutrition is characterized by long-term exposure to food of insufficient quality and inadequate quantity, including restricted intake of energy, protein, fat, micronutrients, essential amino acids, vitamins and minerals. Physiologically, in a state of chronic food insufficiency, the human body conserves energy by prioritizing essential metabolic processes resulting in impaired linear growth and delayed reproductive maturation. Consequently, height can theoretically be considered a measure of an individual’s cumulative health and nutrition. Therefore, a deviation from the ‘normal’ height relative to one’s age represents a deviation from one’s optimal growth and, potentially, the presence of other issues. Similarly, the delayed onset of puberty is another common physiological response to food insufficiency, often accompanying impaired linear growth. Chronic undernutrition can arise from chronic disease, congenital abnormalities and insufficient food intake. In this review, we will explore the hypothesis of CUG during adolescence, given the relationship between impaired linear growth and the delayed onset of puberty in children suffering from chronic undernutrition due to a lack of sufficient quality and quantity of food.