Non-home prepared foods : contribution to energy and nutrient intake of consumers living in two low-income areas in Nairobi

Objective: To determine the nutritional importance of non-home prepared foods for men, women and schoolchildren living in two low-income residential areas of Nairobi, and the sources of these non-home prepared foods. Design, setting and subjects: A survey was conducted in Korogocho, a slum area, and Dandora, a low-middle-income residential area. Some 241 men, 254 women and 146 children aged 9 to 14 years were included in the study. Food intake was measured using three 24-hour recalls per individual, with special attention on the sources of all foods consumed. Results: The median proportion of daily energy intake of consumers provided by non-home prepared foods ranged from 13% for schoolchildren in Korogocho to 36% for men in Dandora. The median contribution to fat intake was higher than to energy, but the contributions to iron and vitamin A intakes were lower than to energy intake. Men consumed more non-home prepared foods on weekdays than at the weekend. Intakes of energy and most nutrients were below Kenyan Recommended Daily Intakes in all groups, but similar for consumers and non-consumers. In Korogocho, street foods were the main source of non-home prepared foods. In Dandora, both kiosks and street foods were major sources. Conclusions: Non-home prepared foods are an important source of energy and nutients for men, women and schoolchildren in Nairobi. In Korogocho, street foods, and in Dandora, both kiosks and street foods are the main sources of non-home prepared foods. The adequacy of energy and nutrient intakes does not differ between consumers and non-consumers of non-home prepared foods

Acetylsalicylate and salicylates in foods

Acetylsalicylic acid is effective in the prevention of cardiovascular disease. It was suggested that fruits and vegetables provide unknown amounts of acetylsalicylic acid. We could not find any acetylsalicylic acid in 30 foods using HPLC with fluorescence detection (detection limits: 0.02 mg/kg for fresh, and 0.2 mg/kg for dried products). We showed that urinary excretion of salicylates is a valid indicator for intake, and found a median salicylate excretion of 10 mol (1.4 mg) in 24 h urine of 17 volunteers eating a variety of diets. Our data suggest that the content of (acetyl)salicylic acid of diets may be too low to affect disease risk

Food intake measurements : their validity and reproducibility

This thesis reports on the validity and the reproduciblity of methods assessing food consumption in groups of free-living Dutch adults consuming self-selected diets. The validity of a method, that is the demonstration that a method measures what it is intended to measure, can only be assessed by comparing it with an independent method of indisputable accuracy. There Is no such absolute method because of the nature of the data to be collected. Instead, it may be possible to establish either the relative validity or the concurrent validity. The relative validity evaluates the method in terms of another generally accepted method, designed to measure the same concept. The concurrent validity compares the results of a method with a biological marker. Validity studies refer to information bias and systematic response errors.A method is commonly called reliable or reproducible if it gives the same results when used repeatedly in the same situation. The problem in food consumption surveys is that the situation is never absolutely identical. Reproducibility refer to the biological within- person variation (a true day-to-day variation) as well as to random response errors, because these two sources of variation can hardly be separated.Many objectives can be served in conducting food consumption studies. It is essential to distinguish between food consumption surveys mainly used for national food planning and administration and surveys in which the emphasis is primarily on the relation between nutrition and health. Distinction is necessary because each objective demands a different type of information. In this thesis only methods assessing food consumption used in studies on the relationship between diet and health have been examined.Chapter 2 describes the state of the art of methods assessing food consumption. There are many sources of error in these types of studies as Table 4 in Chapter 2 clearly shows. For epidemiological studies, however, it is not always necessary to produce accurate results for each individual, but methods yielding valid data on groups of individuals would be of great value. To be able to obtain such valid data on a group level it is of the utmost importance to specify beforehand which data the study should supply. In Chapter 2, Table 6, the data required for three purposes have been formulated, viz.:A. Average energy and nutrient intake data of a group, to make group-to- group comparisons. In such a survey a representative sample of the population under study as well as a representative period of observation are required.B. The distribution of usual energy and nutrient intake data within a population, to detect groups of individuals at risk, if the risk is marked by a high or a low intake of a certain nutrient.C. The usual energy and nutrient intake of groups of individuals throughout time to make a correlation and regression analysis relating independent and dependent variables in order to make inferences on an aggregate level.For all three purposes data have to be collected on an individual level, but they are analysed and interpreted on an aggregated level. Chapters 3 to 8 describe the evaluation of methods used for the above-mentioned purposes in groups of Dutch adults. In all methods sizes of portions of the foods most frequently consumed have been checked by weighing by the interviewer. Other portions have been estimated in standard household measurements. The amounts of foods consumed have been converted into energy and nutrients using the national nutrient data base "UCV".In Chapter 3 the seven-day record method has been described assessing the energy and dietary fiber intake of 100 adults (44 men and 56 women). In the analysis the emphasis was on the within-person and the between-person variation in the intake of energy and dietary fiber. Information on these components of variance is desired to determine in study designs the number of persons and the number of records per person required to assess with a certain precision the group mean in the intakes of nutrients. The findings in this study show that the precision for the measurement of dietary fiber intake obtained by using one-day food records from twice the number of individuals is comparable to that obtained from a seven-day food record. For the measurement of energy intake, only 1.5 times the number of individuals is required for the one-day record method to obtain the same precision as with the seven-day record method. However, a one-day record method does not yield information on the usual food consumption of an individual. To be able to distinguish within the study population groups of individuals with a very high or a very low intake of a certain nutrient more food records per person are needed. The number of records required depends on the ratio of the within-person variation to the between-person variation.Chapter 4 describes the validity and the reproducibility of a dietary history method assessing the usual food consumption during one month. Forty-four young adults (aged 19-32 years) participated in this study. The concurrent validity of the method was assessed by means of the 24-hour urine nitrogen excretion. The mean difference between nitrogen intake and nitrogen excretion was 0.0 g with a 95 per cent confidence limit of ±1.1 g. These limits for the mean difference between excretion and intake indicate a valid assessment of the protein intake of this group.The reproducibility was evaluated in the same group through a test- retest design. The intra-class correlation coefficients were high over a weighted average of week-days and for an average workday as regards the intakes of energy and selected nutrients. As to the Saturday and Sunday intakes, the correlation coefficients were lower for the energy intakes and most of the nutrients (except alcohol) indicating a poorer reproducibility for week-end assessments.Chapter 5 describes a dietary history method assessing the food consumption In retrospect. In 1983 the relative validity of the retrospective dietary history method (DH'R) was assessed against a current dietary history taken seven years earlier, in 1976 (DH'76), and a second current dietary history taken in 1983 (DH'83). In total 44 men and 58 women, aged 38-62 years, participated in the study. For the intake of energy and most of the nutrients the relative difference between DH'R and DH'76 was below 15 per cent. The difference between energy and nutrient intake reported contemporaneously and retrospectively appears to be comparable with or slightly more than the reported change in food consumption between 1976 and 1983. Similar results were found for food groups. The results indicate that for group- to-group comparisons past dietary patterns can be ascertained retrospectively with some degree of success. Such data can be useful in case-control studies examining the relationship between diet and cancer.Seasonal variation in the intakes of energy and nutrients may affect the validity as well as the reproducibility of results in studies examining food consumption.In Chapter 6 the effects of the season on the energy balance of 114 young adult women are described. Energy intake and pattern of physical activity were assessed monthly fourteen times with the 24-hour recall method. The day following each interview before breakfast body weight without clothes was measured by the participants themselves. After these 14 months, in the second year the same estimates were made with intervals of 2-3 months to check if the observed seasonal variations were not a casual effect.The study did not demonstrate seasonal variation in the mean energy intake of the group under study. A statistically significant effect of the season was observed in the intake of fat, dietary fiber and mono- and disaccharides. For mono- and disaccharides this seasonal effect could not be confirmed the second year. Small seasonal fluctuations were observed in body weight and time spent in the various physical activity categories. On the one hand these fluctuations are too small to indicate physiological significance, on the other hand the fluctuations are wide enough to be taken into account in many longitudinal studies assessing changes in intakes of nutrients and body weight.Chapter 7 describes the same study as Chapter 6, but reports on the validity of the monthly, fourteen times repeated, 24-hour food recall method. Validity was examined by comparing the mean daily energy intake with fluctuations in body weight over a period of 14 months and by comparing the mean daily protein intake with the protein intake as assessed from the nitrogen excretion in at least 11 collections of 24- hour urine. A hundred and twenty-three women participated in this study. The data confirm earlier findings that the 24-hour recall gives a valid estimate of energy and protein intake on a group level.Categorizing the group in approximately quintiles of the energy intake revealed that subjects reporting a very low energy intake tend to underestimate their energy intake and that subjects reporting a very high energy intake tend to overreport their energy intake. In 20 subjects (16 per cent) the mean difference in daily protein intake as assessed with the fourteen 24-hour recalls and as assessed from the nitrogen excretion in 24-hour urine exceeded 20 grams. Sixteen of these subjects reported either a very high (n = 7) or a very low energy intake (n = 9). The results indicate that it is very difficult to determine within a group under study - solely on the basis of food consumption data - the percentage of subjects with a very high or a very low intake of certain nutrients. This implicates that it is also difficult to determine within such a group the percentage of subjects with a high or a low health risk, if the risk is marked by a high or a low intake of a certain nutrient.Chapter 8 reports on the validity of the fatty acid composition of subcutaneous fat tissue microbiopsies as an estimate of the long-term average fatty acid composition of the diet of separate individuals. Fifty-nine women taking part in the study on seasonal variation (Chapter 6) and whose food consumption data were considered valid (Chapter 7) participated in this study. Three months after the food consumption study had been finished subcutaneous adipose tissue samples were collected during a home visit. Highly significant correlations were found between the linoleic acid content of diet and fat tissue (r = 0.70) and also between the linoleic acid-to-saturated fatty acid ratio (linoleic/S) of fat tissue and diet (r = 0.62). This confirms the hypothesis that on an individual level the fatty acid composition of the adipose tissue is a valid index for the habitual dietary fatty acid composition of free-living individuals.When using one 24-hour recall instead of the average of 19 recalls, the correlation coefficient between the linoleic/S ratio of the diet and that of the adipose tissue was substantially lower. This demonstrates the weakening effect of the wide day-to-day variation in within-person intakes on the correlation between a short-term assessment of the nutrient intake of an individual and a biochemical indicator of a long-term nutritional status.In the final discussion of this thesis (Chapter 9) it is concluded that the methods assessing food consumption described appear to be relatively valid for estimating the mean intakes of energy and of the described nutrients In groups. If only data on food consumption are available, however, it is difficult to categorize unbiased within the study population groups with a low or a high intake of a certain nutrient. This is so even if, based on the precision required, the ratio of the witrhin-person to the between-person variation, enough food records or recalls are obtained per participants in a sample of sufficient size.If energy and nutrient intake data are to be related to health indicators, it is advocated to oversample and to check the intake data with an independent biochemical or physiological indicator of the intake of a nutrient. This makes it possible to discard data that are considered not to be trustworthy. The remaining data, considered valid, and collected within an adequately formulated research design, will be very useful in finding out the relation between nutrition, health and disease

Do dietary patterns in older men influence change in homocysteine through folate fortification? The Normative Aging Study

Objective We aimed to describe the difference in B-vitamin intake and in plasma B-vitamin and homocysteine concentrations before and after folic acid fortification, in relation to dietary patterns. Design The Normative Aging Study (NAS) is a longitudinal study on ageing. Between 1961 and 1970, 2280 male volunteers aged 21¿80 years (mean 42 years) were recruited. Dietary intake data have been collected since 1987 and assessment of plasma B vitamins and homocysteine was added in 1993. Setting Boston, Massachusetts, USA. Subjects In the present study, 354 men who had completed at least one FFQ and one measurement of homocysteine, both before and after the fortification period, were included. Results Three dietary patterns were identified by cluster analysis: (i) a prudent pattern, with relatively high intakes of fruit, vegetables, low-fat milk and breakfast cereals; (ii) an unhealthy pattern, with high intakes of baked products, sweets and added fats; and (iii) a low fruit and vegetable but relatively high alcohol intake pattern. Dietary intake and plasma concentrations of folate increased significantly (P <0·05) among all dietary patterns after the fortification period. Homocysteine tended to decrease in supplement non-users and in subjects in the high alcohol, low fruit and vegetable dietary pattern (both P = 0·08). Conclusions After fortification with folic acid, folate intake and plasma folate concentration increased significantly in all dietary patterns. There was a trend towards greatest homocysteine lowering in the high alcohol, low fruit and vegetable grou

Higher usual dietary intake of phytoestrogens is associated with lower aortic stiffness in postmenopausal women

Objective¿ Phytoestrogens have been postulated to protect against cardiovascular diseases, but few studies have focused on the effect of Western dietary phytoestrogen intake. Methods and Results¿ Four hundred three women with natural menopause either between 1987 and 1989 or between 1969 and 1979 were selected from the baseline data of the PROSPECT study (n=17 395). Isoflavone and lignan intake was calculated from a food-frequency questionnaire. Aortic stiffness was noninvasively assessed by pulse-wave velocity measurement of the aorta. Linear regression analysis was used. After adjustment for age, body mass index, smoking, physical activity, mean arterial pressure, follow-up time, energy intake, dietary fiber intake, glucose, and high density lipoprotein cholesterol, increasing dietary isoflavone intake was associated with decreased aortic stiffness: -0.51 m/s (95% CI -1.00 to -0.03, fourth versus first quartile, P for trend=0.07). Increasing dietary intake of lignans was also associated with decreased aortic pulse-wave velocity: -0.42 m/s (95% CI -0.93 to 0.11, fourth versus first quartile, P for trend=0.06). Results were most pronounced in older women: for isoflavones, -0.94 m/s (95% CI -1.65 to -0.22, P for trend=0.02), and for lignans, -0.80 m/s (95% CI -1.85 to -0.05), fourth versus first quartile. Conclusions¿ The results of our study support the view that phytoestrogens have a protective effect on the risk of atherosclerosis and arterial degeneration through an effect on arterial walls, especially among older wome

Weight loss in head and neck cancer patients little noticed in general practice

INTRODUCTION: In head and neck cancer patients, weight loss increases morbidity and mortality, and decreases treatment tolerance and quality of life. Early nutritional intervention has beneficial effects on these factors. AIM: We observed patients’ weight courses after specialists’ care and surveyed nutrition-related documentation by general practitioners (GPs). METHODS: From a Head and Neck Oncology Centre (HNOC) study, 68 patients were asked to participate in an extended general practice cohort. Twenty-six patients participated in the prospective three-monthly weight measurements during the year after HNOC care. We extracted nutritional information contained in referral letters (n=24) and medical records from the year before referral (n=45) and after HNOC care (n=26). An impaired nutritional status was assigned to weight loss =10% within six months or Body Mass Index (BMI

Flavor enhancement of food improves dietary intake and nutritional status of elderly nursing home residents

Taste and smell losses occur with aging. These changes may decrease the enjoyment of food and may subsequently reduce food consumption and negatively influence the nutritional status of elderly persons, especially those who are frail. The objective of this study was to determine if the addition of flavor enhancers to the cooked meals for elderly residents of a nursing home promotes food consumption and provides nutritional benefits. Methods. We performed a 16-week parallel group intervention consisting of sprinkling flavor enhancers over the cooked meals of the "flavor" group (n = 36) and not over the meals of the control group (n = 31). Measurements of intake of the cooked meals were taken before and after 8 and 16 weeks of intervention. Appetite, daily dietary intake, and anthropometry were assessed before and after the intervention. Results. On average, the body weight of the flavor group increased ( 1.1 ± 1.3 kg; p < .05) compared with that of the control group (-0.3 ± 1.6 kg: p < .05). Daily dietary intake decreased in the control group (-485 ± 1245 kJ; p < .05) but not in the flavor group (-208 ± 1115 kJ; p = .28). Intake of the cooked meal increased in the flavor group (133 ± 367 kJ; p < .05) but not in the control group (85 ± 392 kJ). A similar trend was observed for hunger feelings, which increased only in the flavor group. Conclusion. Adding flavor enhancers to the cooked meals was an effective way to improve dietary intake and body weight in elderly nursing home residents