Serum fibroblast growth factor 23 (FGF23) is a novel phosphaturic factor and important for the regulation of inorganic phosphate (Pi) homeostasis. In this study, we examined an acute effect of oral Pi loading on serum FGF23 levels to clarify the role in rapid adjustment of serum Pi level. We performed a randomized, double-blind, crossover study in eight healthy male volunteers. The subjects were alternately served one of three test meals containing different Pi amounts (400 mg (P400), 800 mg (P800), and 1200 mg (P1200)) as lunch at noon. The postprandial changes in serum levels of Pi, Ca, 1,25-dihydroxyvitamin D, intact-parathyroid hormone (iPTH), intact-FGF23 (iFGF23), and urinary excretion of Pi and Ca until 8 h after Pi loading were estimated. Serum Pi levels and urinary Pi excretion significantly increased within 1 h after P400 and P800 intake. Serum iPTH levels at 1-2 and 4-6 h after P1200 intake was significantly higher than those of P400 intake. Serum iFGF23 levels slightly decreased up to 8 h after P400 intake and up to 6 h after P800 intake, but not changed in P1200 intake. Significant increase of iFGF23 was observed at 8 h after P1200 intake compared with both P400 and P800 intake. Additionally, negative association was detected between iFGF23 and serum Pi, whereas positive association was observed between iPTH and serum Pi during the short period. We conclude that oral Pi loading cannot rapidly increase serum FGF23 level. FGF23 may be not associated with rapid adaptation of Pi homeostasis.

We previously suggested that the consumption of natto and viscous vegetables as part of a Japanese-style meal based on white rice (WR) reduced postprandial glucose and insulin levels in healthy subjects. The aim of the present study was to assess whether a single breakfast of natto and viscous vegetables or the same breakfast consumed for 2 weeks could improve glucose control, insulin sensitivity, lipid metabolism and oxidative stress in overweight subjects with impaired glucose tolerance (IGT). A total of eleven free-living subjects with IGT followed a randomised, crossover breakfast intervention for 2 weeks. The test meal included boiled WR with natto (viscous fermented soyabeans), Japanese yam and okra. The control meal included WR with non-viscous boiled soyabeans, potatoes and broccoli. Both meals contained comparable amounts of carbohydrate, fat, protein and fibre. The test meal reduced acute glucose and insulin responses compared to the control meal in the study participants. Insulin sensitivity was assessed using the composite insulin sensitivity index (CISI) after both the test and control meal periods. The test meal resulted in improvements in CISI compared to the baseline, whereas no significant changes were observed after the control meal period. Serum levels of both total and LDL-cholesterol were assessed before and after the test meal period and found to decrease significantly. There was also a tendency towards reduced serum malondialdehyde-modified LDL and N 1 -carboxymethyllysine. No differences were observed in the measures of chronic glycaemic control. Thus, we conclude that a breakfast of natto and viscous vegetables consumed for 2 weeks improves insulin sensitivity, serum lipid and oxidative stress.Key words: Natto and viscous vegetable: Postprandial hyperglycaemia: Insulin sensitivity: Lipid metabolism: Oxidative stress Glycaemic index (GI) is an approach to classify carbohydrate foods by comparing the glycaemic effect of carbohydrate weight in individual foods (1) . In a meta-analysis of randomised controlled trials, diets with a lower GI were associated with a modest improvement in HbA1c in individuals with diabetes (2) .Postprandial hyperglycaemia is not only associated with impaired glucose tolerance (IGT) but also with hyperlipidaemia and oxidative stress, both of which increase the risk of CVD (3,4) . There is, however, considerable debate regarding the optimum and specific diet composition for preventing postprandial hyperglycaemia (5) .In Japan, many naturally viscous foods such as some types of potatoes, vegetables, mushrooms and seaweeds are cooked and eaten. They contain viscous polysaccharides such as mannan, pectin, alginic acid and galactan. Natto, a traditional and popular Japanese food made by fermenting boiled soyabeans with Bacillus natto (6) , has viscous properties. We have previously demonstrated that the consumption of natto and viscous vegetables combined with white rice (WR) suppressed postprandial hyperglycaemia and hyperinsulinaemia in healthy young subjects...

Hyperphosphatemia and hyperparathyroidism, frequently observed in patients with endstage renal disease, are associated with renal osteodystrophy, organ calcification, cardiovascular disease and sudden death. Restriction of dietary protein and phosphorus is beneficial in slowing the progression of renal failure. Dietary phosphorus restriction must be prescribed at all stages of renal failure in adults. It may be achieved by decreasing protein intake and avoiding foods rich in phosphorus. An average of 60-80% of the phosphorus intake is absorbed in the gut in dialysis patients. If phosphate binders are employed, the phosphorus absorbed from the diet may be reduced to 40%. Conventional hemodialysis with a high-flux, high-efficiency dialyzer removes approximately 30 mmol (900 mg) phosphorus during each dialysis performed three times weekly. Therefore, 750 mg of phosphorus intake should be the critical value above which a positive balance of phosphorus may occur. This value corresponds to a protein diet of 45-50 g/day or 0.8 g/kg body weight/day for a 60 kg patient. Target levels should become 9.2-9.6 mg/dl for calcium, 2.5-5.5 mg/dl for phosphorus, <55 mg2/dl2 for the calcium-phosphorus product, and 100-200 pg/ml for intact parathyroid hormone.

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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 lycopenecontaining 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.