Changes in intake of key nutrients over 17 years during adult life of a British birth cohort.

An investigation was carried out to determine whether there were significant changes in nutrient intake over 17 years of adult life. The Medical Research Council National Survey of Health and Development is a longitudinal study of a nationally representative cohort of singleton births in the UK in 1946. Of this cohort, 1253 survey members provided information on diet recorded in a 5 d diary at age 36 years in 1982, 43 years in 1989 and 53 years in 1999. The outcome measures were mean intakes of energy, macronutrients, minerals and vitamins. There were significant changes in the intake of most nutrients in 1999 compared with previous years. Intakes of fat, Na, Fe and Cu have fallen, but there was a rising trend in the intakes of Ca, P, carotene, thiamin, pyridoxine, folic acid and vitamins C, D and E in both men and women. Additionally, intakes of K, Mg and vitamin K1 have risen in women. There were significant gender differences, women showing a higher percentage rise in the intakes of carotene, riboflavin, folic acid, vitamin C and vitamin E. These changes were related to changes in the consumption of certain key foods, such as the increased consumption of fruit and vegetables and a shift away from whole milk, butter and red meat. Most of these trends are in line with accepted nutritional guidelines. How far these changes are due to consumer choice and real changes in food composition or are due to artefacts inherent in the methodology is discussed.