Teenagers nowadays consume fewer calories, especially from fat. They also eat less fresh fruit and healthy vegetables and are more likely to load up on junk food. To summarize:

• The total calories consumed by teenagers decreased from 1965 to 1996, as did the proportion of energy from total fat (39% to 32%) and saturated fat (15% to 12%).

• There were significant increases in the consumption of soft drinks, as well as higher fat carbohydrates such as potatoes, pizza, and macaroni and cheese.

• Lower fat milk replaced higher fat milk but total milk consumption decreased by 36%.

• Researchers used information from four USDA surveys conducted between 1965 and 1996, including 12,498 boys and girls aged 11 to 18 years.

• Iron, folate and calcium intakes continue to be below the recommendations for girls.

• Authors identify several potential nutritional problems including inadequate fiber consumption, and decreasing raw fruit and non-potato vegetable consumption.

"Thus, not only are adolescents at risk of chronic diseases because of low fibre intake but also because of low antioxidant and non-nutrient sources of plant foods, which may serve as protective factors for certain cancers," researchers state. While teens in the 1990s consumed more vegetables than those in the 1960s overall, they did so by increasing consumption of less-healthy potatoes, to the detriment of green and orange vegetables.

An increase in soft drink consumption coupled with overall low consumption of green and orange vegetables may possibly lead to an increase in phosphorous excretion, "which subsequently may compromise bone building and maintenance," according to the researchers.

"In conclusion, these results show food consumption trends that are compromising the nutritional and health status of US adolescents and may contribute to important increases in nutrition related chronic diseases," the researchers conclude.

Archives of Disease in Childhood July, 2000;83:18-24.