Although a high intake of fat, particularly SFA, is a well-known risk factor for CVD, fat intake in Japan has attracted relatively little attention from health professionals to date due to the low intake in the Japanese population. However, recent surveys have shown an increase in fat intake in younger Japanese populations. Here, we described the fat intake and dietary sources of SFA in Japanese schoolchildren. Also, we experimentally exchanged a high-SFA food with a low-SFA substitute in the data, and calculated the resulting changes in nutrient intakes.

The study was conducted nationwide under a cross-sectional design. A non-consecutive, three-day diet record was performed on two school days and a non-school day.

Fourteen elementary and thirteen junior high schools.

Elementary-school children (n 629) and junior high-school children (n 281).

Prevalence of excess fat intake was 35·4 % in boys and 45·0 % in girls. Excess SFA intake was suspected in 97·7 % of boys and 99·4 % of girls when the dietary reference intake values for adults were applied. Major dietary sources of SFA were meat (26·4 % of total SFA intake), dairy products (25·7 %) and confectioneries (11·3 %).

Since one-third to nearly one-half of our Japanese schoolchildren consumed excess fat, careful monitoring of fat intake in the Japanese population should be continued. Adoption of low-fat milk and/or lean meat in daily meals might be a suitable means of reducing fat, particularly SFA intake, in schoolchildren.

To examine the association between 24 h urinary water-soluble vitamin levels and their intakes in free-living Japanese schoolchildren.

All foods consumed for four consecutive days were recorded accurately by a weighed food record. A single 24 h urine sample was collected on the fourth day, and the urinary levels of water-soluble vitamins were measured.

An elementary school in Inazawa City, Japan.

A total of 114 healthy, free-living, Japanese elementary-school children aged 10–12 years.

The urinary level of each water-soluble vitamin was correlated positively to its mean intake in the past 2–4 d (vitamin B1: r = 0·42, P < 0·001; vitamin B2: r = 0·43, P < 0·001; vitamin B6: r = 0·49, P < 0·001; niacin: r = 0·32, P < 0·001; niacin equivalents: r = 0·32, P < 0·001; pantothenic acid: r = 0·32, P < 0·001; folic acid: r = 0·27, P < 0·01; vitamin C: r = 0·39, P < 0.001), except for vitamin B12 (r = 0·10, P = NS). Estimated mean intakes of water-soluble vitamins calculated using urinary levels and recovery rates were 97–102 % of their 3 d mean intake, except for vitamin B12 (79 %).

The results show that urinary levels of water-soluble vitamins, except for vitamin B12, reflected their recent intakes in free-living Japanese schoolchildren and could be used as a potential biomarker to estimate mean vitamin intake.