Iron Deficiency Is Associated with Elevated Parathormone Levels, Low Vitamin D Status, and Risk of Bone Loss in Omnivores and Plant-Based Diet Consumers.

A cross-sectional study was performed in healthy adults (mean age 28 y, 67% women) whose habitual diet was an omnivore, lacto-ovo vegetarian, or vegan diet. The total sample (n = 297) was divided into two groups according to the parathormone (PTH) cut-off value of 65 pg/mL of either normal-PTH (n = 228) or high-PTH (n = 69). Vitamin D status (25-hydroxycholecalciferol, 25-OHD), PTH, and bone formation (bone alkaline phosphatase, BAP) and bone resorption (N-telopeptides of type I collagen, NTx) markers were determined. Hematocrit, erythrocytes, hemoglobin, platelets, serum iron, serum transferrin, transferrin saturation, and serum ferritin were also measured. In the total sample, 25-OHD and PTH were negatively correlated, and all subjects with high PTH presented vitamin D insufficiency (25-OHD < 75 nmol/L). High bone remodeling was observed in the high-PTH group, with significantly higher NTx and marginally higher BAP compared to the normal-PTH group. Hematocrit and ferritin were significantly lower in the high-PTH compared to the normal-PTH group. However, serum iron was higher in the high-PTH group, which was only observed for the lacto-ovo vegetarian and vegan subjects. It is concluded that both low vitamin D and low iron status are associated with elevated PTH and bone resorption, more in vegetarians than omnivores, which is in line with the hypothesis that chronic iron deficiency in adulthood mainly predisposes to osteoporosis in postmenopausal women and the elderly.

Changes in fatty acid levels after consumption of a novel docosahexaenoic supplement from algae: a crossover randomized controlled trial in omnivorous, lacto-ovo vegetarians and vegans.

PURPOSE: To determine serum fatty acids of lacto-ovo vegetarian (LOV), vegan (VEG) and omnivorous (OMN) adults, and to analyse the effects of consuming a docosahexaenoic acid (DHA) supplement of vegetable origin on fatty acid profile. METHODS: A randomized, double-blind, placebo-controlled crossover design was conducted in healthy adults. Volunteers (n = 116) were randomly assigned to a DHA-supplement (dose 250 mg/day), made from the microalgae Schizochytrium sp., or a placebo during 5-week periods separated by a 5-week washout interim period. Compliance and dietary intake were estimated and serum fatty acids were determined by gas chromatography. Results were analysed by mixed linear models. RESULTS: Percentage of linoleic acid (C18:2n6) in serum was the highest among the fatty acids in the three diet groups, followed by oleic (C18:1n9) and palmitic (C16:0) acids. Linoleic (C18:2n6) and alpha-linolenic (C18:3n3) acids were higher in VEG compared to OMN (p < 0.001), while in LOV, their levels were intermediate between the other groups. Women presented higher DHA (C22:6n3) than men (p < 0.001). The DHA-supplement increased serum DHA compared to placebo in the three diet groups (p < 0.001), and a higher increase was observed in VEG followed by LOV (p < 0.001). The ratio serum n-6/n-3 improved by the supplementation but remained higher in LOV and VEG than in OMN. In contrast, the DHA-supplement decreased docosapentaenoic (C22:5n3) and docosatetraenoic (C22:4n6) acids in all diet groups (p < 0.001) and increased the eicosapentaenoic to alpha-linolenic fatty acids ratio (p = 0.016). CONCLUSION: The DHA-supplement at dose of 250 mg/day was effective in increasing serum DHA either in omnivorous, lacto-ovo vegetarian and vegan adults. CLINICAL TRIAL REGISTRATION: Registered at Clinicaltrials.gov ( www. CLINICALTRIALS: gov ), NCT04278482.

Methylmalonic Acid Levels and their Relation with Cobalamin Supplementation in Spanish Vegetarians.

Cobalamin deficiency represents a health issue for vegetarians, especially vegans, if supplements are not consumed. Vitamin B12 serum levels, traditionally used to assess the vitamin B12 status, can be normal under functional deficiency conditions. In this regard, methylmalonic acid (MMA) has proven to be a more specific marker to detect subclinical vitamin B12 deficiency. In this study, we present for the first time the cobalamin status of Spanish vegetarians using both vitamin B12 and MMA markers, and the effects of the plant-based diet and the intake of vitamin B12 supplements. Healthy adults were recruited (n = 103, 52% vegans). Dietary preferences and use of supplements were assessed by questionnaires and serum samples were collected and stored. Vitamin B12 was measured by chemiluminiscence and MMA by liquid chromatography tandem mass spectrometry (LC-MS/MS) using solid phase extraction for sample preparation. Obtained values, median (IQR), were: vitamin B12, 278.9 (160.2) pmol/l and MMA, 140.2 (78.9) nmol/l. No significant differences between lacto-ovo vegetarians and vegans were observed. Considering these two markers, 10% of the participants were mild vitamin B12 deficient. Supplementation (75% of the participants) was associated with higher vitamin B12 (p < 0.001) and lower MMA (p = 0.012). In conclusion, Spanish vegetarians have low risk of vitamin B12 deficiency due to vitamin B12 supplementation and the MMA determination is useful to detect mild deficiency.

A microalgae docosahexaenoic acid supplement does not modify the influence of sex and diet on iron status in Spanish vegetarians or omnivores: A randomized placebo-controlled crossover study.

OBJECTIVE: Plant-based diets are accepted as healthy, provided that are well-planned and include supplements. In this context, iron deficiency is a threat, and data from Spanish vegetarians are scarce. The aim of this study was to determine if a microalgae ω-3 supplement rich in docosahexaenoic acid (DHA) affected iron status in this population. METHODS: Iron biomarkers and nutrient intake (72-h dietary records) were analyzed in 204 usual consumers of lacto-ovo vegetarian (LOV), vegan (VEG), or omnivorous (OMN) diets. A randomized double-blind, placebo-controlled crossover trial was performed in a subgroup (n = 98) to test if a microalgae DHA supplement (250 mg/d for 5 wk) changed iron status. RESULTS: Iron intake was higher in vegetarians than omnivores (P= 0.002), fiber intake was highest in vegans followed by lacto-ovo vegetarians and omnivores, whereas calcium intake was lower in vegans than both lacto-ovo vegetarians and omnivores (all P < 0.001). Women, regardless of diet type, showed lower iron status than men. Erythrocytes, hemoglobin, hematocrit, and serum ferritin were lower in lacto-ovo vegetarians and vegans than omnivores. The prevalence of iron deficiency anemia was low (<10%), but iron depletion (ferritin <15 ng/mL) was higher in lacto-ovo vegetarians than omnivores (P = 0.003). Iron biomarkers were similar in lacto-ovo vegetarians and vegans. The DHA supplementation did not change iron status compared with placebo. CONCLUSIONS: Spanish vegetarians had lower iron status than omnivores. Consumption of eggs and dairy products increased the risk for iron deficiency, but a microalgae DHA supplement had no effect. Dietary strategies to increase iron bioavailability in vegetarians, particularly in lacto-ovo vegetarians and women, are recommended.

Bone Remodelling, Vitamin D Status, and Lifestyle Factors in Spanish Vegans, Lacto-Ovo Vegetarians, and Omnivores.

Sustainable healthy diets are promoted, and consequently vegetarian diets are currently increasing. However, scientific information on their effects on bone health is scarce. A cross-sectional study was performed in adults (66% women) classified into three groups: omnivores (n = 93), lacto-ovo vegetarians (n = 96), and vegans (n = 112). Nutrient intake, body composition, physical activity, vitamin D status (25-hydroxycholecalciferol, 25-OHD), parathormone (PTH), and bone formation (bone alkaline phosphatase, BAP) and resorption (N-telopeptides of type I collagen, NTx) markers were determined. Lacto-ovo vegetarians and especially vegans showed lower protein, fat, calcium, phosphorous, vitamin D, retinol, iodine, and zinc intakes, and higher carbohydrate, fibre, carotenes, magnesium, and vitamin K intakes compared to omnivores. Body composition was similar in the three groups that performed vigorous physical activity regularly. Body bone mass and muscle mass were positively correlated with BAP, and time performing physical activity with 25-OHD. The prevalence of vitamin D deficiency or insufficiency (25-OHD < 75 nmol/L) was 93.7% in the studied population, and vitamin D deficiency (25-OHD < 25 nmol/L) was significantly higher in vegans. Vegetarians of both groups had increased PTH and NTx with vegans showing significantly higher PTH and NTx than omnivores. Conclusion: Adult vegetarians, especially vegans, should reduce the risk of bone loss by appropriate diet planning and vitamin D supplementation.

Metabolic and nutritional biomarkers in adults consuming lacto-ovo vegetarian, vegan and omnivorous diets in Spain. A cross-sectional study.

Knowledge on the characteristics of consumers who choose plant-based diets and the relationship with nutritional status and disease risk is needed. In the present study, 207 Spanish adults participated in a cross-sectional study, and were classified in three groups: lacto-ovo vegetarian (LOV), vegan (VEG), and omnivore (OMN). Dietary intake, anthropometry, body composition, haematology, and metabolic markers were evaluated. Body composition and body weight did not vary among groups. The majority of these adults performed moderate-vigorous physical activity, and LOV performed more moderate activity than OMN. Total energy intake (En) was similar in the three groups. However, cholesterol and fat intakes (%En) were higher in the order OMN, LOV, VEG, fibre and carbohydrate intakes showed the opposite trend, and protein intake (%En) was higher in OMN than both LOV and VEG (all p < 0.001). Systolic blood pressure (p = 0.04), erythrocytes (p < 0.001), and haematocrit (p < 0.001) were lower in LOV and VEG than OMN, and lymphocyte count was lower in LOV than OMN (p < 0.01). There were marked differences between groups in serum total-cholesterol and LDL-cholesterol that were lower in LOV and VEG than OMN (both p < 0.001). However, glucose, insulin and insulin resistance did not show group differences. Leptin and adiponectin were related with gender and body fat but not with diet. The inflammation marker interleukin-1ß was lower in LOV than OMN but TNF-α did not show differences. All levels were within normal ranges. Conclusion: consumption of plant-based diets compared to omnivorous diets in combination with moderate-high physical activity appears to protect similarly from cardiometabolic diseases in Spanish adults.

Changes in cardiometabolic risk factors, appetite-controlling hormones and cytokines after a treatment program in overweight adolescents: preliminary findings from the EVASYON study.

OBJECTIVE: We investigated the effects of the EVASYON program on body fatness, cardiometabolic risk factors, gut appetite-controlling hormones and serum levels of cytokines in adolescents with overweight or obesity (OW/OB). METHODS: This study comprised 13 boys (10 obese) and 12 girls (8 obese), aged 13-16 years, from a Madrid Hospital. The EVASYON program was based on a calorie-restricted diet (10-40%), increased physical activity (at least 60 min/day 5 days a week), psychological therapy and nutritional education for 13 months. Anthropometric and blood pressure measurements were measured before and after intervention. Serum glucose, total cholesterol, high-density lipoprotein cholesterol, triglycerides, leptin, total peptide YY and insulin levels were determined before and after intervention. Serum levels of cytokines IL-1ß, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, and TNF-α were also assessed before and after intervention. RESULTS: A decrease in body mass index (BMI), BMI z-score, skinfolds (triceps, biceps, subscapular, thigh, and calf), sum of six skinfolds and body circumferences (arm relaxed and flexed, waist, hip, and proximal thigh) values were observed after the intervention program (all p < 0.05). In addition, diastolic blood pressure also decreased (p < 0.05). A decrease in serum leptin levels (-48.4%, p < 0.001) was observed after intervention without changes in total peptide YY and insulin levels. Levels of IL-8, IL-10, and TNF-α also decreased (all p < 0.05) after the intervention program. CONCLUSIONS: These preliminary results evidence that the EVASYON program may improve body fat, leptin, and some pro-inflammatory cytokines in adolescents with OW/OB.

Behavioural correlates of active commuting to school in Spanish adolescents: the AFINOS (Physical Activity as a Preventive Measure Against Overweight, Obesity, Infections, Allergies, and Cardiovascular Disease Risk Factors in Adolescents) study.

OBJECTIVE: To examine the associations between lifestyle factors and active commuting to school in Spanish adolescents. DESIGN: Cross-sectional study. Lifestyle factors (overall/extracurricular physical activity, television viewing, reading as a hobby, sleep duration, breakfast/fruit intake, smoking and alcohol intake) as well as mode and duration of commuting to school were self-reported. Active commuters were defined as those adolescents who walked or cycled to school. SETTING: Secondary schools in Madrid, Spain. SUBJECTS: Adolescents (n 2029) aged 13 to 17 years. RESULTS: Similar percentages of adolescent boys (57·6 %) and girls (56·1 %) were classified as active commuters to school (P = 0·491). The analysis showed that only adequate sleep duration (OR = 1·35, 95 % CI 1·11, 1·66; P = 0·003) and breakfast consumption (OR = 0·66, 95 % CI 0·49, 0·87; P = 0·004) were independently associated with active commuting to school. CONCLUSIONS: Only those behaviours that occur immediately before commuting to school (sleep and breakfast) are associated with active commuting in Spanish adolescents.

Relationship between iron status markers and insulin resistance: an exploratory study in subjects with excess body weight.

BACKGROUND: Controversy exists on the relationship between iron metabolism and cardiometabolic risk. The aim of this study was to determine if there is a link between dysmetabolic iron and cardiometabolic markers in subjects with excess body weight. METHODS: Cross-sectional study with fifty participants presenting overweight or obesity and at least another metabolic syndrome factor. Determinations: anthropometry, body composition, blood pressure, lipids, glucose, insulin, leptin, areas under the curve (AUC) for glucose and insulin after an oral glucose tolerance test, hs-C reactive protein (hs-CRP), blood count, ferritin, transferrin, transferrin saturation (TSAT), soluble transferrin receptor (sTfR). Gender-adjusted linear correlations and two independent samples t tests were used. RESULTS: Ferritin was positively correlated with insulin-AUC (r = 0.547, p = 0.008) and TSAT was negatively correlated with waist-hip ratio (r =  - 0.385, p = 0.008), insulin (r =  - 0.551, p < 0.001), and insulin resistance (HOMA-IR, r =  - 0.586, p < 0.001). Subjects with TSAT ≤ 20% had higher insulin (p = 0.012) and HOMA-IR (p = 0.003) compared to those with TSAT > 20%. In conclusion, the observed results suggest that iron transport and storage are altered in subjects with overweight/obesity, at the same time that they exhibit the characteristic features of insulin resistance. Nevertheless, this occurs without iron overload or deficiency. These results should be validated in wider cohorts since they suggest that iron transport and storage should be assessed when performing the clinical evaluation of subjects with excess body weight.

Physiological and Dietary Determinants of Iron Status in Spanish Vegetarians.

Vegetarian diets may compromise iron status, as they provide non-haem iron which has low bioavailability. Spanish lacto-ovo vegetarians (n = 49) and vegans (n = 55) were recruited and haematological and biochemical iron parameters were analysed. Food and supplements consumption, body composition, physical activity, menstrual blood losses and hormonal contraceptive use were assessed. Four groups were studied: Iron deficiency anaemia (IDA), iron depletion (ferritin <15 ng/mL), iron deficiency (ferritin ≥15 to ≤30 ng/mL), and iron sufficiency (ferritin >30 ng/mL). IDA was uncommon (n = 5, 4.8%), 27.9% of participants were iron-depleted, and 30.8% were iron-deficient. Serum ferritin was lower in women than men (p < 0.001) and IDA and iron depleted individuals were all women. There were no differences attributed to diet type, time being vegetarian or physical activity. The menstrual period length was negatively associated with transferrin saturation ( = -0.364, p = 0.001) and hormonal contraceptive use ( = -0.276, p = 0.014). Iron supplements were consumed most frequently by IDA and iron-deficient subjects (p = 0.031). Conclusions: Iron status did not vary between lacto-ovo vegetarians and vegans and there was not an influence of the time following a vegetarian diet. Although men were iron-sufficient, iron deficiency was frequent in women, who should apply strategies to increase iron bioavailability, especially if they experience intense menstrual blood losses.

Vitamin B12 and folate status in Spanish lacto-ovo vegetarians and vegans.

Studies on the nutritional status of vegetarians in Spain are lacking. Prevention of vitamin B12 deficiency is the main concern, as dietary sources are of animal origin. The present study aimed to evaluate vitamin B12 and folate status of Spanish vegetarians using classical markers and functional markers. Participants were adult and healthy lacto-ovo vegetarians (forty-nine subjects) and vegans (fifty-four subjects) who underwent blood analyses and completed a FFQ. Serum vitamin B12, homocysteine (Hcy), methylmalonic acid (MMA), erythrocyte folate and haematological parameters were determined. The effects of the type of plant-based diet, and the intake of supplements and foods were studied by a FFQ. Mean erythrocyte folate was 1704 (sd 609) nmol/l. Clinical or subclinical vitamin B12 deficiency was detected in 11 % of the subjects (MMA>271 nmol/l) and 33 % of the participants showed hyperhomocysteinaemia (Hcy>15 µmol/l). Regarding plant-based diet type, significantly higher Hcy was observed in lacto-ovo vegetarians compared with vegans (P = 0·019). Moreover, use of vitamin B12 supplements involved an improvement of vitamin B12 status but further increase in erythrocyte folate (P = 0·024). Consumption of yoghurts was weakly associated with serum vitamin B12 adequacy (P = 0·049) and that of eggs with lower Hcy (P = 0·030). In conclusion, Spanish vegetarians present high folate status but vitamin B12 subclinical deficiency was demonstrated using functional markers. The lack of influence of dietary sources on functional markers and the strong effect of vitamin B12 supplement intake emphasise the need of cobalamin supplementation in both lacto-ovo vegetarians and vegans.

Fatty Acid Profile and Cardiometabolic Markers in Relation with Diet Type and Omega-3 Supplementation in Spanish Vegetarians.

Plant-based diets are becoming increasingly popular, and scientific information concerning the nutritional status in this population is needed. This study determined the fatty acid profile of Spanish lacto-ovo vegetarians (LO-vegetarians) and vegans. Participants were 104 healthy adults, LO-vegetarians (n = 49) and vegans (n = 55). Lifestyle habits and consumption of food and omega-3 supplements were estimated by questionnaires. BMI, blood pressure, and abdominal and body fat were determined. Serum was collected to analyze fatty acids, glucose, lipids, homocysteine, insulin, and leptin. Volunteers were classified according to serum omega-6 to omega-3 (n-6/n-3) ratio into three groups: n-6/n-3 < 10, n-6/n-3 ≥ 10 to 20, and n-6/n-3 > 20. Results showed low cardiovascular risk and high insulin sensitivity with negligible differences between diet types. Linoleic acid (C18:2n-6) was the major serum fatty acid, followed by oleic (C18:1n-9) and palmitic (C16:0) acids. In contrast, serum eicosapentaenoic acid (EPA, C20:5n-3) and docosahexaenoic acid (DHA, C22:6n-3) were (median, interquartile range) 0.27, 0.18% and 1.59, and 0.93%, respectively. Users of n-3 supplements (<10% of total vegetarians) had significantly higher EPA than non-users, while frequent consumption of flax-seeds was associated with increased α-linolenic acid (C18:3n-3). However, neither n-3 supplementation nor food consumption affected DHA levels in this vegetarian population.

A 6-week supplementation with grape pomace to subjects at cardiometabolic risk ameliorates insulin sensitivity, without affecting other metabolic syndrome markers.

Grape polyphenols have shown a promising role in the modulation of metabolic syndrome (MetS), mostly in animal models. However, clinical studies are scarce and they usually only consider a fraction of polyphenols, ignoring the non-extractable polyphenols (high molecular weight compounds or associated with macromolecules such as dietary fibre). This study aimed at evaluating the effect of grape pomace, rich in both extractable and non-extractable polyphenols, on markers of MetS. Fifty subjects (22 women) aged 20-65 with at least two MetS factors were randomly assigned to the product (daily dose of 8 g of dried grape pomace) or to the control group in a 6 week crossover design with a 4 week wash-out. Samples were collected at the beginning and at the end of both periods; half of the participants were subjected to an oral glucose tolerance test at the beginning and the end of the supplementation period. Grape pomace supplementation significantly improved fasting insulinaemia (p < 0.01), without affecting other cardiometabolic risk parameters. A tendency towards an improvement in postprandial insulinaemia was observed, particularly in those subjects with higher fasting insulin levels. Therefore, supplementation with grape pomace may be a strategy for improving insulin sensitivity in subjects at high cardiometabolic risk.

Immunonutrition: methodology and applications.

Immunonutrition is an emergent and interdisciplinary subject, since it comprises several aspects related to Nutrition, Immunity, Infection, Inflammation, and Injury or tissue damage, what is known as Nutrition and 4 "Is". Within these interactions the endocrine, nervous and immune systems are involved, microbiota being a part of the last one. Nowadays, gut microbiota has been shown to play an essential role, not only in the gastrointestinal tract but also into the nervous system, because of its bilateral connection. There are several methods to study Immunonutrition, which allow measuring different immunological biomarkers to provide information about the nutritional status. However, it should be taken into account that there is not a single gold standard parameter to evaluate the cause- effect relationship between nutrition and the immune system. On the contrary, a combination of biomarkers have to be assessed depending on the different nutritional situations. Since Immunonutrition is a multidisciplinary matter as mentioned above, the study on the interactions between nutrition and the immune system has not been exclusively focused as such, but bearing in mind other systems of the organisms as well as a wide range of confounding factors and determinants coming from idiosyncratic features, genes and lifestyle of each individual. Therefore, Immunonutrition allows to study the following research fields: 1) Evaluation of nutritional status in presumably healthy people with risk of malnutrition (children, adolescents, adults, pregnant women, elderly, and sportspeople); 2) Assessment of the evolution and progress of patients with nutrition and immune-related diseases, such as food allergies, eating and metabolic disorders; 3) Evaluation of the effects of nutrients, bioactive compounds and both conventional and functional foods on the immune system; 4) Evaluation of impact of lifestyle determinants on the immune system, such as diet, food behaviour, physical activity, sedentariness, sleep quality and quantity, and as a key factor, stress.

Immunonutrition is an emergent and interdisciplinary subject, since it comprises several aspects related to Nutrition, Immunity, Infection, Inflammation, and Injury or tissue damage, what is known as Nutrition and 4 "Is". Within these interactions the endocrine, nervous and immune systems are involved, microbiota being a part of the last one. Nowadays, gut microbiota has been shown to play an essential role, not only in the gastrointestinal tract but also into the nervous system, because of its bilateral connection. There are several methods to study Immunonutrition, which allow measuring different immunological biomarkers to provide information about the nutritional status. However, it should be taken into account that there is not a single gold standard parameter to evaluate the cause- effect relationship between nutrition and the immune system. On the contrary, a combination of biomarkers have to be assessed depending on the different nutritional situations. Since Immunonutrition is a multidisciplinary matter as mentioned above, the study on the interactions between nutrition and the immune system has not been exclusively focused as such, but bearing in mind other systems of the organisms as well as a wide range of confounding factors and determinants coming from idiosyncratic features, genes and lifestyle of each individual. Therefore, Immunonutrition allows to study the following research fields: 1) Evaluation of nutritional status in presumably healthy people with risk of malnutrition (children, adolescents, adults, pregnant women, elderly, and sportspeople); 2) Assessment of the evolution and progress of patients with nutrition and immune-related diseases, such as food allergies, eating and metabolic disorders; 3) Evaluation of the effects of nutrients, bioactive compounds and both conventional and functional foods on the immune system; 4) Evaluation of impact of lifestyle determinants on the immune system, such as diet, food behaviour, physical activity, sedentariness, sleep quality and quantity, and as a key factor, stress.

BODY COMPOSITION CHANGES DURING A MULTIDISCIPLINARY TREATMENT PROGRAMME IN OVERWEIGHT ADOLESCENTS: EVASYON STUDY.

INTRODUCTION: the main objectives of weight-loss interventions are to decrease fat mass while maintaining fatfree mass. OBJECTIVE: our aim was to address effectiveness body composition changes in overweight adolescents assessed by different body composition methods following an obesity intervention programme. MATERIAL AND METHODS: the life-style intervention was multi-disciplinary, with 13 months follow-up. Participants were 13-to-16 year-old overweight, or obese, Spanish adolescents. The adolescents (n = 156; 54.8% females) had body composition measured with anthropometry, dual-energy X-ray absorptiometry and air-displacement plethysmography. All measurements were made at baseline, and after 2- and 13-months. Repeated measures analysis of covariance to compare mean anthropometric changes over time and the Bonferroni correction were applied. Imputation of anthropometric measures was performed. RESULTS: a high significant decrease in fat mass index was achieved in males after 2-and 13-months of intervention as measured by anthropometry (1.16 and 1.56 kg / m2, respectively), X-ray absorptiometry (1.51 and 1.91 kg / m2) and plethysmography (2.13 and 2.44 kg/m2). Moreover, a short and long-term maintenance of fat-and fat-free mass index was observed by X-ray absorptiometry in females (0.94 and 0.68 kg/m2). CONCLUSION: our multidisciplinary approach to lifestyle intervention has a favourable impact on body fat mass and fat-free mass index as well as waist-to-height ratio, over 13 months intervention in overweight and obese adolescents.

Introducción: el principal objetivo de las intervenciones de pérdida de peso es disminuir la masa grasa manteniendo la masa libre de grasa. Objetivo: evaluar la efectividad de una intervención multidisciplinar en la composición corporal de adolescentes con sobrepeso, evaluados mediante diferentes métodos de composición corporal. Material y métodos: la intervención fue multidisciplinar sobre el estilo de vida, aplicada durante 13 meses. Los participantes eran adolescentes entre 13 y 16 años con sobrepeso y obesidad. Los adolescentes (n = 156; 54,8% mujeres) fueron evaluados mediante antropometría, absorciometría dual de rayos X y pletismografía por desplazamiento de aire. Todas las mediciones se realizaron al inicio, a los 2 y a los 13 meses. Se aplicaron análisis de la covarianza de medidas repetidas y la corrección de Bonferroni. Se realizó la imputación de las medidas antropométricas. Resultados: se logró una alta disminución significativa en el índice de masa grasa en los hombres después de 2 y 13 meses de intervención, según antropometría (1,16 y 1,56 kg/m2, respectivamente), absorciometría de rayos X (1,51 y 1,91 kg/m2) y pletismografía (2,13 y 2,44 kg/m2). Por otra parte, el mantenimiento a corto y largo plazo de la grasa y libre de grasa en el índice de masa fue observado por absorciometría de rayos X en las mujeres (0,94 y 0,68 kg/m2). Conclusión: la intervención multidisciplinar sobre estilo de vida tiene un impacto favorable en la masa grasa corporal y el índice de masa libre de grasa, así como en la relación cintura-altura, durante 13 meses de intervención en adolescentes con sobrepeso y obesidad.

Physical activity during high school recess in spanish adolescents: the AFINOS study.

BACKGROUND: The morning recess period during school days represents a regular opportunity to accumulate physical activity (PA). However, little is known about the contribution of recess to PA guidelines (60 min/day in moderate-to-vigorous PA [MVPA]) in adolescents. METHODS: This study comprised 1065 Spanish adolescents (52% girls), aged 13 to 16 years. Adolescents completed a validated Recess PA Recall in 2007-2008. Differences in levels of PA during the recess period were analyzed by gender, age group, type of school, school location, immigrant status, weight status, fitness levels and snack eating during recess. RESULTS: Adolescent boys spent more time in MVPA (7.7 vs. 6.4 min in MVPA, P = .009) and were more active (29.6% vs. 24.5% in MVPA, P = .007) than girls during the recess period. Adolescent boys in the youngest age group and with the school located in cities were more active than their peers (all P < .05). There were no differences in levels of PA during recess by all the descriptive characteristics in adolescent girls (all P > .05). CONCLUSIONS: These findings suggest that recess in Spanish high schools may contribute to the daily recommended MVPA for adolescents, but greater efforts must be implemented to increase PA levels among adolescent girls during this school period.

Patterns of sedentary behavior and compliance with public health recommendations in Spanish adolescents: the AFINOS study.

The aims of the present study were: (i) describe patterns of sedentary behavior in Spanish adolescents; and (ii) determine the proportion of adolescents that do not meet the public health recommendations for sedentary behavior. This study comprised 1,724 Spanish adolescents (882 girls), aged 13 to 16 years. Patterns of sedentary behavior (TV viewing, use of computer games, console games and surfing the Internet) were assessed using the HELENA sedentary behavior questionnaire. The total proportion of adolescents watching TV, using computer and console games, and surfing the internet for more than two hours daily was 24%, 9%, 7%, and 17%, respectively, on weekdays, and 50%, 22%, 16%, and 35%, respectively, on weekends. Over 63% of the adolescents from the study did not meet the recommendation for sedentary behavior (< 2 hours daily screen time) on weekdays and 87% did not comply with this recommendation on weekends. Since sedentary behavior plays a key role in adolescent health, public health interventions in Spain that take these factors into consideration are needed.

Association between excessive body fat and eating-disorder risk in adolescents: the AFINOS Study.

BACKGROUND AND OBJECTIVE: Overweight and obesity, together with eating disorders, are important public health concerns in adolescence. The aim of this study was to assess the association between excessive body fat and the risk of eating disorders. SUBJECTS AND METHOD: The sample consisted of 195 adolescents (97 girls) aged 13 to 18 years. Eating-disorder risk was evaluated by applying the SCOFF questionnaire. Body mass index, sum of 6 skinfolds, waist and hip circumferences and waist-hip and waist-height ratios were used to assess body fat. RESULTS: 24.7% of girls and 17.3% of boys were at risk of eating disorders, and 31.6% of boys and 21.6% of girls presented overweight (including obesity) according to Cole's cut-off points. Those adolescents classified above the 85th percentile on all the anthropometric measurements, as well as overweight adolescents, were at increased risk of developing an eating disorder (OR: 2.8-4.30, all p < 0.01). CONCLUSION: Regardless of the anthropometric measurements used, adolescents with excessive body fat showed a higher risk of having eating disorders than those with normal weight.

Sleep duration and emerging cardiometabolic risk markers in adolescents. The AFINOS study.

OBJECTIVE: To examine the associations between sleep duration and emerging inflammatory and endothelial function risk factors in adolescents. METHODS: This study included a total of 183 (88 girls) adolescents, aged 13-17 years, without diagnosed sleep-related disorders. White blood cell counts, C-reactive protein (CRP), complement factors 3 and 4, interleukin-6, adiponectin, leptin, inter-cellular adhesion molecule 1, vascular cell adhesion molecule-1, E-selectin, l-selectin, and plasminogen activator inhibitor-1 were measured. Sleep duration and sleep-related disorders were obtained by self-report and moderate-to-vigorous physical activity (MVPA) was objectively measured by accelerometer. Body mass index (BMI) was calculated from measured height and weight. RESULTS: A significant inverse association between sleep duration and CRP (ß=-0.17, P=0.024) existed only after controlling for sex, age, and pubertal status. The results did not change when MVPA was included into the model. However, the association of sleep duration with CRP was slightly attenuated when BMI was included in the model, though it remained significant (ß=-0.15, P=0.044). CONCLUSION: Short sleep duration during adolescence might play an important and independent role in cardiovascular and metabolic diseases through CRP.

[Validity of four questionnaires to assess physical activity in Spanish adolescents]. / Validez de cuatro cuestionarios para valorar la actividad física en adolescentes españoles.

OBJECTIVES: The physical activity (PA) levels of Spanish adolescents must be determined to assess how the lack of PA may affect the increasing prevalence of obesity. Thus, to assess PA in this age range valid measurement instruments are essential. The aim of this study was to evaluate the validity of four easily applied questionnaires (the enKid and FITNESSGRAM questions, the Patient-Centered Assessment and Counselling [PACE] questionnaire, and an activity rating) to assess PA in Spanish adolescents by using an accelerometer as the criterion instrument. METHODS: A total of 232 adolescents (113 girls) completed the questionnaires and wore an ActiGraph accelerometer for 7 consecutive days. Spearman's correlation coefficient (rho) was used to compare the questionnaires and total PA, moderate PA, vigorous PA and moderate-to-vigorous PA (MVPA) assessed by the accelerometer. RESULTS: All the questionnaires showed moderate correlations when compared against total PA (rho=0.36-0.43) and MVPA (rho=0.34-0.46) obtained by the accelerometer in the total sample. Higher correlations were found when comparing the questionnaires against vigorous PA (rho=0.42-0.51) than against moderate PA (rho=0.15-0.17). The FITNESSGRAM question and the PACE questionnaire obtained weak correlations in girls and the enKid question and activity rating were moderately correlated for boys and girls. CONCLUSIONS: The four questionnaires evaluated showed acceptable validity in the assessment of PA in the Spanish adolescent population.