IGF-1

IGF-1 (insulin-like growth factor 1) is a hormone produced mainly by the liver in response to growth hormone. It plays a central role in growth during childhood and continues in adulthood to influence tissue repair, muscle and bone maintenance, and metabolism. Because its level closely mirrors growth hormone activity, IGF-1 is often measured to assess the growth-hormone system, and it is also studied in the context of ageing and longevity. Levels naturally change with age, so results are interpreted against age-appropriate expectations and your wider clinical picture.

IGF-1 rises and falls chiefly with growth hormone activity, which is highest in childhood and adolescence and gradually declines with age. Nutrition, adequate protein and energy intake, sleep, and physical activity all influence levels. Higher values can reflect increased growth hormone activity, while lower values may relate to reduced growth hormone output, ageing, undernutrition, or certain liver and chronic conditions. Because many factors feed into a single value, IGF-1 is interpreted alongside age, symptoms, and sometimes additional hormone testing.

IGF-1 itself does not cause symptoms; it is a measure of hormonal activity rather than a condition you would feel directly. Any symptoms come from the underlying state of the growth-hormone system. Very high activity over long periods can be associated with changes in bone and tissue growth, while low activity may relate to fatigue, reduced muscle mass, or altered body composition. These pictures are non-specific, so an abnormal IGF-1 is a prompt for your healthcare provider to look further rather than a diagnosis in itself.

No single food sets your IGF-1 level, but overall nutrition strongly supports the growth-hormone system. Adequate protein from meat, fish, eggs, legumes, and dairy such as milk and yoghurt provides amino acids the body uses for tissue maintenance. Sufficient total energy and a balanced intake of wholegrains, vegetables, and healthy fats support normal hormonal signalling. Good sleep and regular physical activity work alongside diet to keep this system functioning well.

There is no specific food that needs strict limiting to manage IGF-1 for most people. Chronic under-eating or very low protein intake can lower IGF-1 by depriving the system of building blocks, so extreme restriction is best avoided unless medically guided. At the other end, patterns of persistent overeating and excess weight can disturb hormonal and metabolic balance more broadly. Aim for a balanced, adequate diet rather than manipulating IGF-1 directly, and raise any concerns with your healthcare provider.