During the last 50 years, a variety of methods have been developed to estimate Ca absorption in man. Mass balances were initially used, but these were unable to accurately measure fractional Ca absorption because they cannot distinguish unabsorbed dietary Ca from endogenous faecal Ca excretion (excretion of previously absorbed Ca back into the gut). A number of isotopic methods have been developed that can measure true fractional Ca absorption, employing radioisotopes, stable isotopes, or both. Different methods involve collection of urine, faecal or plasma samples. Of the currently available methods, the dual isotope tracer method with a timed urine collection is probably the most precise and reliable. It is also relatively straightforward to carry out and avoids the need for a faecal collection. The purpose of the present paper is to discuss the general advantages and disadvantages of the different methods of Ca absorption. In addition, the limitations the different methods have in examining the possible effects of non-digestible oligosaccharides on Ca absorption will be discussed.

A computer-based dietary assessment tool, the meal-based intake assessment tool (MBIAT), is described. In the current study, dietary intakes of Fe and Zn fractions (total Fe, non-haem Fe, haem Fe, meat Fe, total Zn) and dietary components that influence Fe and Zn absorption (vitamin C, phytate, Ca, grams of meat/fish/poultry, black tea equivalents, phytate:Zn molar ratio) were assessed. The relative validity of the MBIAT was determined in forty-eight UK men aged 40 years and over by comparing its results with those from weighed diet records collected over 12 d. There was good agreement between the MBIAT and the weighed diet records for median intakes of total, non-haem, haem and meat Fe, Zn, vitamin C, phytate, grams of meat/fish/poultry and phytate:Zn molar ratio. Correlations between the two methods ranged from 0·32 (for Ca) to 0·80 (for haem Fe), with 0·76 for total Fe and 0·75 for Zn. The percentage of participants classified by the MBIAT into the same/opposite weighed diet record quartiles ranged from 56/0 for Fe and 60/0 for Zn to 33/10 for Ca. The questionnaire also showed an acceptable level of agreement between repeat administrations (e.g. a correlation for total Fe of 0·74). In conclusion, the MBIAT is appropriate for assessing group dietary intakes of total Fe and Zn and their absorption modifiers in UK men aged 40 years and over.

The validity of fruit and vegetable intake estimated by 14 d weighed records, a twenty-seven-item food frequency questionnaire (FFQ) and a 180-item FFQ was investigated using serum carotenoids as the validity criterion. In addition, the method of triads was used to assess the validity of fruit and vegetable intake estimated from the FFQ and serum carotenoids. One hundred Norwegian men completed 14 d weighed records and the 180-item FFQ. Eighty-six of them also completed the twenty-seven item FFQ. The partial correlation coefficients between serum carotenoids and fruit and vegetable intake were slightly higher for the 14 d weighed records than for the two FFQ, but no difference was observed between the 180- and the twenty-seven item FFQ. The strongest correlations were observed between vegetable intake and serum α-carotene. The highest validity coefficients (VC) were observed for vegetable intake estimated from weighed records, the 180-item FFQ, the twenty-seven item FFQ and by the biomarker serum α-carotene, with VC of 0·77, 0·58, 0·51 and 0·67, respectively. In conclusion, the short FFQ gave as valid estimates for fruit and vegetable intake as the long FFQ. Both the estimated partial correlation coefficients and VC suggest that serum α-carotene is the best biomarker for intake of vegetable alone and total intake of fruit and vegetables in this population of Norwegian men, but the biomarkers did not perform any better than the FFQ.

This paper deals with BMI and morbidity in relation to body-fat mass (BFM) and fat-free mass (FFM). The analysis was based on cross-sectional data concerning the age, household income, anthropometry and morbidity of 575 males aged 18–59 years from a rural community in North-East India. Data on morbidity were based on the self-reported morbidity (SRM) of the subjects during the last 4 weeks before the survey, whereas data on BMI and body composition were estimated from anthropometry. It was found that SRM was significantly associated with age and income. However, the relationship between BMI and SRM was not significant after adjusting for age and income. Separating the BMI into body-fat mass index (BFMI being BFM in kg divided by height squared in metres) and fat-free mass index (FFMI being FFM in kg divided by height squared in metres), it was found that BFMI was significantly associated with SRM after adjusting for age, income and FFMI. The subjects with a low (<2·9 kg/m2) BFMI were about 4·7 times (odds ratio 4·7, 95 % CI 2·6, 8·6) more likely to become sick than those with a normal (2·9–5·0 kg/m2) BFMI. In addition, the risk of becoming sick was higher in the subjects with a high (>5·0 kg/m2) BFMI than in those with a normal BFMI (odds ratio 3·9, 95 % CI 1·3, 9·8). However, the relationship between FFMI and morbidity was not clearly perceptible. It is therefore speculated that BMI may not always provide accurate information about the variation in body fat and body composition that is associated with morbidity.

We investigated the effects of consuming an isoflavone aglycone-enriched soya milk containing viable bifidobacteria on urinary isoflavone excretion and percentage recovery. Sixteen postmenopausal women were randomly divided into two groups to consume either fermented or non-fermented soya milk. Each group participated in a double-blind, crossover study with three 14 d supplementation periods, separated by a 14 d washout. Subjects ingested three daily dosages of isoflavone via the soya milk and collected four 24 h pooled urine specimens per supplementation period. Soya milks were prepared with soya protein isolate and soya germ, followed by fermentation with bifidobacteria. Isoflavone levels were quantified using HPLC. Non-fermented soya milks at 20, 40 and 80 mg isoflavone/200 ml contained 10 %, 9 % and 7 % aglycone, respectively, with their fermented counterparts containing 69 %, 57 % and 36 % aglycone (P<0·001). A trend to a greater percentage urinary recovery of daidzein and glycitein was observed among women consuming fermented soya milk at a dosage of 40 mg isoflavone (P=0·13). A distinct linear dose response for the fermented soya milk group (R2=0·9993) compared with the non-fermented group (R2=0·8865) suggested less interindividual variation in isoflavone absorption. However, total urinary isoflavone excretion was similar for both groups (P>0·05), with urinary isoflavone recovery at approximately 31 %. Increasing the isoflavone dosage correlated positively with its urinary excretion, but urinary percentage recovery of isoflavone was inversely related to dosage level. Hence, a modest dosage ranging from 20 to 30 mg/d may provide the most bioavailable source of isoflavone, regardless of whether it is via an aglycone-rich fermented soya milk or a glucoside-rich soya milk.

Our aim was to determine whether meal fatty acids influence insulin and glucose responses to mixed meals and whether these effects can be explained by variations in postprandial NEFA and Apo, which regulate the metabolism of triacylglycerol-rich lipoproteins (Apo C and E). A single-blind crossover study examined the effects of single meals enriched in saturated fatty acids SFA), n-6 PUFA and MUFA on plasma metabolite and insulin responses. The triacylglycerol response following the PUFA meal showed a lower net incremental area under the curve than following the SFA and MUFA meals (P<0·007). Compared with the SFA meal, the PUFA meal showed a lower net incremental area under the curve for the NEFA response from initial suppression to the end of the postprandial period (180–480 min; P<0·02), and both PUFA and MUFA showed a lower net incremental glucose response (P<0·02), although insulin concentrations were similar between meals. The pattern of the Apo E response was also different following the SFA meal (P<0·02). There was a significant association between the net incremental NEFA (180–480 min) and glucose response (rs=0·409, P=0·025), and in multiple regression analysis the NEFA response accounted for 24 % of the variation in glucose response. Meal SFA have adverse effects on the postprandial glucose response that may be due to greater elevations in NEFA arising from differences in the metabolism of SFA- v. PUFA- and MUFA-rich lipoproteins. Elevated Apo E responses to high-SFA meals may have important implications for the hepatic metabolism of triacylglycerol-rich lipoproteins.

The aim of the present study was to assess the respective contributions of regional and socio-economic factors to dietary pattern. We used the data from the final MONICA (MONItoring of trends and determinants in Cardiovascular disease) population survey conducted in the three French centres in 1995–7 among a representative sample of 976 men aged 45–64 years. Dietary intake was assessed using a 3-d record method. Dietary patterns were identified by a factor analysis, based on fifteen food items. An analysis of variance was then used to study their relationship with regional and socio-economic determinants. Two major dietary patterns were identified: a ‘Western diet’, characterized by high intakes of sugar and sweets, grains, butter, added fats, eggs, potatoes and cheese; a ‘prudent diet’, mainly distinguished by high intakes of fruit, vegetables, olive oil and fish and low intakes of alcohol, high-fat meat and potatoes. Strong associations were mostly observed with the ‘prudent diet’ pattern, with a significant relationship with region, educational and income-tax levels, leisure-time physical activity and smoking status. There was also a statistically significant interaction between region and educational level (P=0·05), and between region and income-tax level (P=0·03), indicating that the influence of socio-economic factors is different among regions. In conclusion, these results indicate large regional and socio-economic differences in the dietary patterns of this French male population. When considering the ‘prudent diet’ pattern, they also suggest that traditional regional influences may now be overcome by socio-economic determinants.

Since long-term weight maintenance (WM) is a major problem, interventions to improve WM are needed. The aim of the study was to investigate whether the addition of protein to the diet might limit weight regain after a weight loss of 5–10 % in overweight subjects. In a randomised parallel study design, 113 overweight subjects (BMI 29·3 (SD 2·5) kg/m2); age 45·1 (SD 10·4) years) followed a very-low-energy diet for 4 weeks, after which there was a 6-month period of WM. During WM, subjects were randomised into either a protein group or a control group. The protein group received 30 g/d protein in addition to their own usual diet. During the very-low-energy diet, no differences were observed between the groups. During WM, the protein group showed a higher protein intake (18 % v. 15 %; P<0·05), a lower weight regain (0·8 v. 3·0 kg; P<0·05), a decreased waist circumference (−1·2 (SD 0·7) v. 0·5 (SD 0·5 ) cm; P<0·05) and a smaller increase in respiratory quotient (0·03 (SD 0·01) v. 0·07 0·01; (SD/)P <0·05) compared with the control group. Weight regain in the protein group consisted of only fat-free mass, whereas the control group gained fat mass as well. Satiety in the fasted state before breakfast increased significantly more in the protein group than in the control group. After 6 months follow-up, body weight showed a significant group × time interaction. A protein intake of 18 % compared with 15 % resulted in improved WM in overweight subjects after a weight loss of 7·5 %. This improved WM implied several factors, i.e. improved body composition, fat distribution, substrate oxidation and satiety.

The dietary intake of certain fatty acids might contribute to the development of allergic diseases such as hay fever and asthma. We investigated the association between the concentrations of fifteen fatty acids in serum phospholipids, as a marker of dietary intake and metabolism, and hay fever, allergic sensitisation and total IgE in adults. Data from a population-based cross-sectional study on respiratory health, including the measurement of fatty acids in the serum phospholipids of 740 adults between 20 and 64 years of age, were analysed. Positive associations were found between hay fever and arachidonic acid, and allergic sensitisation and oleic acid. No other fatty acids showed any association with hay fever or allergic sensitisation. Elevated levels of total IgE were not related to fatty acids. Concentrations of long-chain n-3 fatty acids, trans fatty acids or saturated fatty acids in serum phospholipids were not associated with allergic diseases in adults in this study. The present result on the association between hay fever and arachidonic acid is consistent with current hypotheses but warrants further research.

If the primary role of diet is to provide sufficient nutrients to meet the metabolic requirements of an individual, there is an emerging rationale to support the hypothesis that, by modulating specific target functions in the body, it can help achieve optimal health. Regarding osteoporosis prevention, since Ca is most likely to be inadequate in terms of dietary intake, every strategy targeting an improvement in Ca absorption is very interesting. Actually, this process may be susceptible to manipulation by fermentable substrates. In this light, inulin-type fructans are very interesting, even if we need to gather more data targeting bone metabolism before health professionals can actively advocate their consumption to prevent senile osteoporosis. Besides targeting the prevention of postmenopausal osteoporosis, inulin-type fructans still remain a source for putative innovative dietary health intervention. Indeed, given in combination with isoflavones, they may have a potential for maintaining or improving the bone mass of human subjects, by modulating the bioavailability of phyto-oestrogens.

Undernutrition contributes to poor clinical outcomes in hospitalised elderly patients but the potential impact of oral nutritional supplements may be reduced by suppressing subsequent food intake. We investigated this possibility in elderly female patients recovering mainly from hip fracture by studying the effect of oral supplements on subsequent food intake during an ad libitum buffet luncheon meal. We tested the effect in seven women by giving the supplement 90 min before the meal and compared energy and macronutrient intake with a control water pre-load condition. A similar study was carried out in another seven women with the supplement or water drink given 30 min beforehand. Both self-rated appetite and energy intake were low in these women. The nutritional supplement did not alter ratings of hunger, fullness or prospective consumption or subsequent energy and macronutrient consumption whether given 90 or 30 min before the meal. There were significant independent correlations between the lack of adequate compensation of energy intake at meals and chronic undernutrition (as assessed by skinfold thickness) and energy intake during the control meal. We conclude that elderly women during the recovery phase after major fractures have low appetites and energy intakes and markedly impaired adjustment of energy intake following liquid oral nutritional supplements. The reasons for this are unknown but are related to anorexia and undernutrition. The consumption of liquid oral supplements given up to 30 min before a meal does not suppress subsequent energy intake from meals.

The present study investigated the effects of mixed high-carbohydrate (CHO) meals (breakfast and lunch) with different glycaemic indices (GI) on substrate metabolism during rest throughout the postprandial periods and during subsequent exercise. Nine recreationally active males completed two trials, high glycaemic index (HGI) and low glycaemic index (LGI), separated by 7 d in a randomised crossover design. In each trial, participants consumed breakfast and lunch, both of which were followed by a 3 h resting postprandial period. Following this, participants completed a 60 min run at 70 % of V˙O2max. The plasma glucose and serum insulin concentrations following both meals were significantly higher in the HGI trial than in the LGI trial (P<0·05). Serum insulin concentrations remained higher throughout the postprandial period following lunch in the HGI trial compared with the LGI trial (P<0·05). The total amount of fat oxidised was higher during the 3 h rest following lunch in the LGI trial than in the HGI trial (P<0·01) and subsequently CHO oxidation was lower (P<0·005). No significant differences in substrate utilisation were observed throughout the subsequent run. At 45 and 60 min, plasma glucose concentrations were higher in the LGI trial v. the HGI trial (P<0·05). The results of the present study provide further support that the GI concept can be successfully applied to mixed meals. The results also suggest that meals composed of LGI CHO may be more beneficial for maintaining a favourable metabolic milieu during the postprandial periods. Furthermore, during subsequent exercise, plasma glucose concentrations were better maintained following the LGI CHO meals.

The relative contents of the fatty acids 14: 0, 15: 0 and 17: 0 in serum and adipose tissue may be used as biological markers of dairy fat intake. However, the determinants of these fatty acids are not fully understood. This study investigates the relationship between these fatty acids and the intake of macronutrients and physical activity in a cross-sectional study of 301 healthy men aged 61–64 years. Dietary intake was assessed using a pre-coded 7 d food record, and physical activity during the previous year was recorded in an interview. Under-reporters of energy intake were identified by the Goldberg cut-off. Fatty acid composition was determined in serum phospholipids (PL) and subcutaneous adipose tissue (AT) from the upper buttock. The relative content of each of 14: 0, 15: 0 and 17: 0 in PL and AT was positively associated with the intake of dairy fat. In addition, all three fatty acids were inversely correlated with alcohol intake, R ranging from −0·28 to −0·53 (P<0·001). The results were not markedly affected when under-reporters (n 88) were excluded from the analyses. In both PL and AT, the relative content of the fatty acids was approximately 5% higher in a group of high physical activity compared with a group of low physical activity, although significant trends were only seen for 14: 0 in PL and 17: 0 in AT. The findings suggest that adjustments should be made for alcohol intake when the fatty acids 14: 0, 15: 0 and 17: 0 are applied as markers for dairy fat intake.

The inulin-type fructans are non-digestible oligosaccharides that are fermented in the gastrointestinal tract of farm animals and pets. This review focuses on the various effects of inulin-type fructans in pigs, poultry, calves and companion animals. Effects of the inulin-type fructans on gut microflora, digestion and availability of nutrients, gut morphology, fermentation characteristics and animal performance are discussed. Inulin-type fructans can support animal performance and health by affecting nutrient digestion, gut microflora and gut morphology, although results vary depending on composition of the basal diet, inclusion level, type of fructan, adaptation period and experimental hygienic conditions.

Commercial hydrogenation results in the formation of trans fatty acids. An unintended consequence of the hydrogenation process is conversion of phylloquinone (vitamin K1) to dihydrophylloquinone. Plasma dihydrophylloquinone concentrations have yet to be characterized in population-based studies. Dietary determinants of plasma dihydrophylloquinone were estimated using a semi-quantitative food frequency questionnaire in 803 men and 913 women in the Framingham Offspring Study. Geometric mean dihydrophylloquinone intake was 21·3 (95 % CI 20·4, 22·3) μg/d in men and 19·4 (95 % CI 18·5, 20·2) μg/d in women. Detectable (>0·05 nmol/l) plasma dihydrophylloquinone concentrations were measured in 41 % and 30 % of men and women, respectively. The multivariate odds ratio (OR) of detectable plasma dihydrophylloquinone from the lowest to the highest quartile category of dihydrophylloquinone intake were 1 (referent), 1·13 (95 % CI 0·83, 1·53), 1·66 (95 % CI 1·21, 2·26) and 1·84 (95 % CI 1·31, 2·58), P for trend <0·001, adjusted for sex, age, body mass index, triacylglycerols, season and energy intake. Higher trans fatty acid intake was associated with higher multivariate OR for detectable plasma dihydrophylloquinone (OR comparing extreme quartiles 2·41 (95 % CI 1·59, 3·64), P for trend <0·001). There were limitations in the use of plasma dihydrophylloquinone, evident in the high proportion of the population that had non-detectable dihydrophylloquinone concentrations. Despite this caveat, higher plasma dihydrophylloquinone was associated with higher dihydrophylloquinone intake and higher trans fatty acid intake.

The National School Fruit Scheme (NSFS) provides one free piece of fruit each school day to children, aged 4 to 6 years, attending state schools in England. The aims of the present study were to determine if NSFS was associated with a higher fruit consumption in infant school children (4–6 years old), and to assess whether fruit consumption was higher in junior school children (7–8 years old) who had received free fruit as infants compared with those who had not. The present cross-sectional study involved seventeen schools, eight in the NSFS (study schools) and nine not in the NSFS (control schools). Study and control schools were selected in areas of similar levels of deprivation. All schools were on the outskirts of London in Southeast England. A retrospective 24 h food tick list was given to each pupil in Reception to Year 4 to take home for their parents to complete and return. Response rate was 51 %. Median total fruit consumption (excluding fruit juice) in infants receiving free fruit was 117 g/d compared with 67 g/d in infants not receiving free fruit (P<0·001). Median consumption in juniors who had received free fruit at school as infants did not differ from those who had not (83 g/d v. 86 g/d). The NSFS has increased fruit consumption in infant school children. It does not appear to have longer-term effects in junior school children. If the scheme is to affect dietary habits and improve health in the long term, further interventions will be needed.

Dietary patterns are comprehensive variables of dietary intake appropriate to model the complex exposure in nutritional research. The objectives of this study were to identify dietary patterns by applying two statistical methods, principal component analysis (PCA) and reduced rank regression (RRR), and to assess their ability to predict all-cause mortality. Motivated by previous studies we chose percentages of energy from different macronutrients as response variables in the RRR analysis. We used data from 9356 German elderly subject enrolled in the European Prospective Investigation into Cancer and Nutrition study. The first RRR pattern, subjects which explained 30·8 % of variation in energy sources and especially much variation in intake of saturated fat, monounsaturated fat and carbohydrates was a significant predictor of all-cause mortality. The pattern score had high positive loadings in all types of meat, butter, sauces and eggs, and was inversely associated with bread and fruits. After adjustment for other known risk factors, the relative risks from the lowest to highest quintiles of the first RRR pattern score were 1·0, 1·01, 0·96, 1·32, 1·61 (P for trend: 0·0004). In contrast, the first two PCA patterns explaining 19·7 % of food intake variation but only 7·0 % of variation in energy sources were not related to mortality. These results suggest that variation in macronutrients is meaningful for mortality and that the RRR method is more appropriate than the classic PCA method to identify dietary patterns relevant to mortality.

Age-related macular degeneration (AMD) is a common disorder that causes irreversible loss of central vision. Increased intake of foods containing zeaxanthin may be effective in preventing AMD because the macula accumulates zeaxanthin and lutein, oxygenated carotenoids with antioxidant and blue light-absorbing properties. Lycium barbarum L. is a small red berry known as Fructus lycii and wolfberry in the West, and Kei Tze and Gou Qi Zi in Asia. Wolfberry is rich in zeaxanthin dipalmitate, and is valued in Chinese culture for being good for vision. The aim of this study, which was a single-blinded, placebo-controlled, human intervention trial of parallel design, was to provide data on how fasting plasma zeaxanthin concentration changes as a result of dietary supplementation with whole wolfberries. Fasting blood was collected from healthy, consenting subjects; fourteen subjects took 15 g/d wolfberry (estimated to contain almost 3 mg zeaxanthin) for 28 d. Repeat fasting blood was collected on day 29. Age- and sex-matched controls (n 13) took no wolfberry. Responses in the two groups were compared using the Mann–Whitney test. After supplementation, plasma zeaxanthin increased 2·5-fold: mean values on day 1 and 29 were 0·038 (sem 0·003) and 0·096 (sem 0·009) μmol/l (P<0·01), respectively, for the supplementation group; and 0·038 (sem 0·003) and 0·043 (sem 0·003) μmol/l (P>0·05), respectively, for the control group. This human supplementation trial shows that zeaxanthin in whole wolfberries is bioavailable and that intake of a modest daily amount markedly increases fasting plasma zeaxanthin levels. These new data will support further study of dietary strategies to maintain macular pigment density.

Epidemiological surveys suggest that a higher intake of tea may be associated with a lower risk of CHD. There is accumulating evidence that postprandial lipaemia makes a substantial contribution to the incidence of CHD. Our aim was, therefore, to evaluate the effect of tea catechins (major ingredients in green tea) on postprandial lipid responses in human subjects after the consumption of test meals. In a randomized triple-crossover design, nine male subjects with mild or borderline hypertriacylglycerolaemia consumed 10 (control), 224 (moderate dose) and 674 mg (high dose) of the assigned tea catechins three times each along with a standardized light meal consisting of a piece of bread spread with 20 g butter. Plasma lipids were measured in the fasting state and 1, 2, 3, 4 and 6 h after consuming the light meal. Results showed that, compared with the control, moderate and high doses of tea catechins reduced the incremental area under the plasma triacylglycerol curves by 15·1 and 28·7 %, respectively. Next, the rapid elevation of remnant-like particle cholesterol was significantly inhibited by a high dose of tea catechins 2 h after consuming the light meal (P<0·01). In the range of tea catechin dosages, no significant differences were observed in the postprandial responses for plasma total cholesterol or NEFA at any time point. In conclusion, this trial demonstrated that tea catechins attenuated the postprandial increase in plasma triacylglycerol levels following a fat load. These results may provide evidence for one of the possible mechanisms involved in lowering the incidence of CVD, and may prove useful in further studies on the beneficial health effects of tea drinking.

The aim of the present study was to determine the effect of purified high-dose anthocyanoside oligomer administration on nocturnal visual function and clinical symptoms in low-to-moderate myopia subjects. The study was a randomized, double-blind, placebo-controlled trial and involved sixty subjects with asthenopia and refractive errors between −1·00 and −8·00 diopters in both eyes. Thirty subjects were administered a purified high-dose anthocyanoside oligomer (100 mg tablet comprising 85 % anthocyanoside oligomer), and thirty were given a placebo in tablet form twice daily for 4 weeks. Prior to the treatment, the placebo and anthocyanoside groups were similar in terms of age and contrast sensitivity. Before and after treatment, subjects completed a questionnaire to determine their clinical symptoms and were also assessed for nocturnal visual function using contrast sensitivity testing. Questionnaire data analysis showed that, following treatment, twenty-two (73·3 %) anthocyanoside subjects showed improved symptoms, whereas only one placebo subject showed an improvement (Fisher's exact test, P<0·0001). Contrast sensitivity levels according to each cycle per degree significantly improved in the anthocyanoside group and remained stable in the placebo group. The mean contrast sensitivity change in the anthocyanoside group was 2·41 (SD) 1·91, compared with −0·66 (SD) 2·66 dB for the placebo group (unpaired Student's t test, P<0·0001). At all cycle per degree levels, contrast sensitivity changes in the anthocyanoside group were better than in the placebo group (unpaired Student's t test, P<0·05). The present data show that the administration of anthocyanoside oligomer appears to improve subjective symptoms and objective contrast sensitivity in myopia subjects with asthenopia.