Accuracy in the estimation of food servings against the portions in food photographs.

OBJECTIVE: In diet surveys, quantitative underestimation of food consumption may be due to intentional misreporting or false portion-size reporting. Perception of food photographs used as aids for assessing the actual amounts may have an effect. This study was carried out to assess the validity of food photographs. DESIGN: A real-time test protocol where 52 presented food servings were compared against photographed portions with similar food items. SUBJECTS: Volunteers from the Rehabilitation Company Petrea (in Turku) were recruited, 161 adults participated, and for 146 subjects, complete data were collected. METHODS: The proportions of correct estimations and reporting errors, in weights and percentages, are presented by gender and food group. Food descriptors, portion-size options and subject characteristics were studied as potential determinants of accuracy in portion-size estimation. RESULTS: The total proportion of exactly correct estimations was 51% in men and 49% in women. The overall reporting error was -10 g in men and +1 g in women for the 52 food servings. Underreporting was typical for bread, spread and cold cuts and dishes in both genders. Over-reporting was typical for cereals in both genders and for snacks, vegetables and fruit in women. The estimation error was associated with the portion-size options but not associated with the energy density of food items, education or body mass index. CONCLUSIONS: Food portions in photographs seem to be a useful aid for the quantification of most food items. However, validation studies are needed to test the applicability of photographs for estimating current portions and for searching better tools in dietary surveys.

Sodium in the Finnish diet: II trends in dietary sodium intake and comparison between intake and 24-h excretion of sodium.

OBJECTIVE: To estimate cross-sectional and long-term dietary sodium intakes and sources in Finland, and to evaluate the validity of 48-h recall to assess sodium intake. DESIGN: Cross-sectional dietary surveys and food availability data (Food Balance Sheets). SETTING: Dietary surveys were carried out in Finland in 1992, 1997 and 2002. Food availability data were collected from 1980 to 1999. SUBJECTS: A stratified random sample was drawn from the population register. The total number of participants in the three dietary surveys was 6730. In the subsample for urine collection, the number of participants was 879. INTERVENTIONS: Nutrient intakes were estimated on the basis of a 3-day food diary in 1992, a 24-h recall in 1997 and a 48-h recall in 2002. The 24-h urinary excretion of sodium was used to validate sodium intake. In addition, salt intake was estimated based on Food Balance Sheets. RESULTS: Sodium intake has slowly decreased since the early 1980s. Reported daily sodium intake correlated significantly with sodium excretion. CONCLUSIONS: Sodium intake has decreased during the last two decades, but is still higher than the recommended daily intake. Sodium intake estimation based on dietary surveys and food availability data is a valid method provided that the food composition database is up to date and of good quality. SPONSORSHIP: All surveys were funded by the National Public Health Institute in Finland and the Ministry of Social Affairs and Health.

Sodium in the Finnish diet: 20-year trends in urinary sodium excretion among the adult population.

OBJECTIVE: High sodium intake increases the risk of cardiovascular diseases and may also be associated with higher rates of stomach cancer, asthma disorders and infections. In Finland, cross-sectional population surveys to monitor cardiovascular risk factors have been carried out since the 1970s. The main aim of this paper is to present trends in urinary sodium and potassium excretion from 1979 to 2002. DESIGN: Cross-sectional population surveys on cardiovascular risk factors. SETTING: Surveys were carried out in Finland in 1979, 1982, 1987 and 2002 in four geographical areas: North Karelia, the Kuopio area, Southwestern Finland and the Helsinki area. SUBJECTS: For each survey a random sample stratified by age and sex was drawn from the population register. In this analysis, participants of urine collection subsamples aged 25-64 years (n = 4648) were included. INTERVENTIONS: A 24-h urinary collection was carried out in subsamples (n = 2218-2487) in connection with population risk factor surveys. Urinary sodium and potassium concentrations were analyzed in the same laboratory throughout, using a flame photometer in 1979, 1982 and 1987 and an ion-selective electrode in 2002. RESULTS: Between 1979 and 2002 urinary sodium excretion in Finland decreased from over 220 to less than 170 mmol/day among men and from nearly 180 to less than 130 mmol/day among women. Although potassium excretion decreased somewhat as well, the decrease in sodium-potassium molar ratio was also significant. CONCLUSIONS: The 24-h urinary sodium excretion in Finland has decreased significantly during the last 20 years. However, excretion levels are still considerably higher than recommendations. A further decrease in sodium intake remains a goal for the Finnish food industry and consumers. SPONSORSHIP: All surveys were funded by the National Public Health Institute in Finland.

Snacks as an element of energy intake and food consumption.

BACKGROUND: An increasing frequency of snacks has been observed in meal pattern studies. Snacks can alter the diet because of their high-energy density and low-nutrient content or on the contrary. OBJECTIVE: The prominence of snacks in energy intake and food consumption was assessed. DESIGN: Dietary data were collected for 2007 adults by using a computer-assisted 48-h dietary recall in the national FINDIET 2002 survey. Energy intakes and food consumption were aggregated for snacks and for main meals. RESULTS: Daily energy was mostly derived from main meals comprising traditional mixed dishes, milk and bread. However, a snack-dominating meal pattern was observed in 19% of men and 24% of women. This meal pattern was associated with urbanization in both genders and with physical work in men. Higher sucrose intake and lower intake of micronutrients were typical of the snack-dominating meal pattern compared to the others. CONCLUSIONS: As snacks appear to have a higher energy density and a lower content of micronutrients than main meals, a snack-dominating meal pattern is inadvisable. However, further studies are needed to examine the association between meal pattern and health status.