This study aimed to examine the contribution of school lunch to dietary intake in primary school children, in relation to household income. Students in the fifth grade and their parents were included. The household income of each family was obtained using a questionnaire completed by the parents. Children maintained dietary records for 4 days: 2 school days (weekdays) and 2 non-school days (weekend). Families were assigned to either a low household income group or a non-low income group. The amounts of nutrients and the ratio of nutrient intake from school lunch in relation to household income were assessed using analysis of covariance (ANCOVA). The low-income group consumed fewer nutrients than the other group, especially on non-school days. The protein intake in the low-income group was lower than that in the other group on both school days and non-school days. The percentages of nutrient intake from school lunch did not differ between the groups on school days. However, the percentages of protein, vitamin A, and salt intake from school lunch relative to the total amounts of these nutrients during the 4 days were higher in the low-income group than in the other group.

Lycopene, a major carotenoid in tomato, is one of the strongest natural singlet-oxygen quenchers. Circadian rhythms have been suggested to affect the bioavailability of many nutrients, but no previous studies have investigated such effects on lycopene. Therefore, we investigated the effects of the timing of lycopene ingestion on its bioavailability in both rodents and humans. Rats or healthy human subjects consumed lycopene-containing test food at different times, and their blood lycopene concentrations were then measured. It was found that the increase in blood lycopene level was highest when lycopene was ingested at the beginning of the active period (in rats) or in the morning (in humans) . The result appeared to depend on not only the time slot chosen but also the length of the adjacent fasting period. Our findings suggest that the bioavailability of lycopene is maximal at breakfast because it follows a period of fasting.

Magnesium deficiency is considered to be a risk factor for metabolic disease. Over-nutrition with sucrose and fats is the central feature of the modern dietary lifestyle, and low intake of magnesium is also frequently observed. The present experiment investigated the effect of excess sucrose and fat intake on magnesium bioavailability in rats. Male Wistar rats aged 5 weeks were given a control diet, a magnesium-deficient diet (MD) , a diet rich in fat and sucrose (HFS) , or a magnesium-deficient diet rich in fat and sucrose (HFS ＋ MD) for 4 weeks. The groups given the MD and HFS ＋ MD diets showed inflammation of the ears, one of the typical symptoms of magnesium deficiency, and the HFS ＋ MD group developed such inflammation at any earlier stage than the MD group. The plasma magnesium concentration tended to be lower in the HFS ＋ MD group than in the MD group, and the femoral magnesium concentration was significantly lower in the HFS ＋ MD group. The HFS diet did not affect the magnesium concentration in the plasma or femur, and did not induce ear inflammation. These results indicate that excess sucrose and fat intake does not affect the magnesium nutritional status of rats given sufficient magnesium, but exacerbates it under conditions of magnesium deficiency.