Claude Cavadini

US adolescent food intake trends from 1965 to 1996

AIM To examine adolescent food consumption trends in the United States with important chronic disease implications. METHODS Analysis of dietary intake data from four nationally representative United States Department of Agriculture surveys of individuals 11–18 years of age (n = 12 498). RESULTS From 1965 to 1996, a considerable shift in the adolescent diet occurred. Total energy intake decreased as did the proportion of energy from total fat (39% to 32%) and saturated fat (15% to 12%). Concurrent increases occurred in the consumption of higher fat potatoes and mixed dishes (pizza, macaroni cheese). Lower fat milks replaced higher fat milks but total milk consumption decreased by 36%. This decrease was accompanied by an increase in consumption of soft drinks and non-citrus juices. An increase in high fat potato consumption led to an increase in vegetable intake but the number of servings for fruits and vegetables is still below the recommended five per day. Iron, folate, and calcium intakes continue to be below recommendations for girls. CONCLUSIONS These trends, far greater than for US adults, may compromise health of the future US population.

Copper, selenium, and zinc status and balances after major trauma

To investigate the trace elements (TE) losses and status after trauma, 11 severely injured patients (Injury Severity Score: 29 +/- 6), admitted to the ICU were studied from the day of injury (D0) until D25. Balance studies were started within 24 hours after injury, until D7. Serum and urine samples were collected from D1 to D7, then on D10, 15, 20, and 25. Intravenous TE supplementation was initiated upon admission. SERUM: Selenium (Se) and zinc (Zn) levels were decreased until D7 and were normal thereafter. LOSSES: TE urinary excretions were higher than reference ranges until D20 in all patients. Fluid losses through drains contained large amounts of TE. BALANCES: Balances were slightly positive for copper (Cu) and Zn, and negative for Se from D5 to D7 despite supplements. Cu status exhibited minor changes compared to those observed with the Zn and Se status: Serum levels were decreased and losses increased. Considering the importance of Se and Zn in free radical scavenging, anabolism, and immunity, current recommendations for TE supplements in severely traumatized patients ought to be revised.

Malondialdehyde measurement in urine

Malondialdehyde (MDA) is an end product of lipid peroxidation and is a frequently measured index of these processes. The thiobarbituric acid (TBA) test is commonly used to measured MDA, but its specificity is questionable due to the presence of interfering chromogens. Wade and van Rij described in 1988 a method which removes these chromogens by HPLC. However, the sensitivity and the resolution of this method was not adequate for measurements of MDA in urine. We have improved this method by replacing TBA with diethylthiobarbituric acid (DETBA). The less polar MDA-DETBA complexes were isolated on Bakerbond cartridges and quantified by HPLC without interference. MDA was detectable using a fluorescence or ultraviolet detector at picomole levels. This technique was applied to urine samples obtained from ten burns patients on different days following their hospitalization. Urinary MDA in burns patients was very high and reached 18.6 mumol/mmol creatinine in one patient compared with a mean value of 0.23 mumol/mmol creatinine in healthy controls. Maximum MDA levels were attained on the third day for the majority of patients and remained, on average, much higher than normal even after 20 days. Using this method, picomole quantities of MDA can be easily and specifically detected in urine samples. This method is useful for assessing an oxidative stress.

Relations between the selenium status and the low T3 syndrome after major trauma.

ObjectiveThyroxine (T4) is deiodinated to triiodothyronine (T3) by the hepatic type I iodothyronine deiodinase, a selenoprotein that is sensitive to selenium (Se) deficiency. After severe injury, T4 deiodination is decreased, leading to the low T3 syndrome. Injury increases free radical production, which inactivates the iodothyronine deiodinase. The aims were to study the Se status after major trauma and to investigate its relation to the low T3 syndrome.DesignPreliminary prospective descriptive study.SettingIntensive care unit at a university teaching hospital.Patients and methods11 patients aged 41±4 years (mean±SEM), with severe multiple injuries (Injury Severity Score 29±2 points). A balance study was performed from day 1 to day 7. Serum and urine samples were collected from the time of admission until day 7, then on days 10, 15, 20, 25 and 30. Nonparametric tests and Pearsons correlation coefficients were used for analysis.ResultsCumulated Se losses were 0.88±0.1 μmol/24h. Serum Se was decreased from admission to day 7. T3, free T3, and the T3/T4 ratio were low until day 5, being lowest on day 2; T4 and thyroid stimulating hormone were normal. Serum Se was correlated with T3 (r=0.55,p=0.0001), and with free T3 (r=0.35).ConclusionSe status is altered after trauma, with decreased Se serum levels upon admission to the ICU but with no major Se losses. Se is probably redistributed to the tissues. The correlation between Se and T3, along with the parallel decrease in T4 deiodination, indicates that reduced deiodination might be related to the transient decrease in serum Se.

Food and nutrient intakes in a group of 11 to 16 year old Swiss teenagers

Better knowledge of the dietary intake of teenagers is necessary to help health professionals to provide better advice on an individual and data for prevention and health programme. We carried out a dietary survey by 3-day records technique in a group of adolescents living in the Canton of Vaud, Switzerland. Food habits were traditional but rich in refined products and poor in plant food. Mean daily energy intake, which was 8025 kJ for the girls and 9350 kJ for boys, was lower than the recommended dietary allowances, especially for girls. Independently of the gender, breakfast represented 19% of the total daily energy intake, lunch 31% and dinner 29%. Total energy provided by snacks was 23.0% for girls and 20.4% for boys. The percentage of energy supplied by the afternoon snack was 15.8% for the girls and 13.3% for the boys. The source of energy was 14% from protein, 37% from fat and 49% from carbohydrates. A high percentage of adolescents had low micronutrient intakes (vitamins A, E, B1, B6, C, folates and for minerals magnesium, calcium and iron). An increase intake of vegetables and fruit should thus be strongly encouraged; snacking could offer a target vector to improve dietary nutritional quality.

Assessment of Adolescent Food Habits in Switzerland

Several physical, psychological and behavioural changes may affect food habits during adolescence and have long-term consequences on adult health status. Also, as food habits are related to lifestyle and physical activity, all should be assessed together. This paper describes a self-administered food frequency questionnaire (FFQ) designed to assess semi-quantitatively food habits of adolescents, and evaluates its use in a study of lifestyle and physical activity. A FFQ was developed, tested in 20 adolescents and compared with a modified version of the diet history method (a combination of a 3-day dietary record and an interview with a dietitian). This validated semi-quantitative questionnaire was later included in a larger questionnaire on lifestyle and physical activity in a study of 3540 adolescents aged 9-19 years. In the validation study with 20 adolescents, the FFQ showed a good agreement with the modified version of the diet history. During the survey several consumption frequencies were found to be low. In the group of adolescents aged 14-19 years old, dairy products were consumed daily by less than 50% of the sample. About 53% girls but only 33% boys consumed one fruit daily. For one vegetable portion, these proportions were 17 and 8%, respectively. The self-administered food frequency questionnaire correctly describes food consumption in adolescents. Moreover, it was well accepted by the target group, easily understood and completed with very few problems. The results show that a significant proportion of adolescents didn>>t consume milk, fruit and vegetable on a daily basis.