Development of an analytical platform for the affinity screening of natural extracts by SEC-MS towards PPARα and PPARγ receptors.

BACKGROUND: Peroxisome proliferator-activated receptors (PPARs) belong to the superfamily of nuclear receptors and represent the targets for the therapeutical treatment of type 2 diabetes, dyslipidemia and hyperglycemia associated with metabolic syndrome. Some medicinal plants have been traditionally used to treat this kind of metabolic diseases. Today only few drugs targeting PPARs have been approved and for this reason, the rapid identification of novel ligands and/or chemical scaffolds starting from natural extracts would benefit of a selective affinity ligand fishing assay. RESULTS: In this paper we describe the development of a new ligand fishing assay based on size exclusion chromatography (SEC) coupled to LC-MS for the analysis of complex samples such as botanical extracts. The known PPARα and PPARγ ligands, WY-14643 and rosiglitazone respectively, were used for system development and evaluation. The system has found application on an Allium lusitanicum methanolic extract, containing saponins, a class of chemical compounds which have attracted interest as PPARs ligands because of their hypolipidemic and insulin-like properties. SIGNIFICANCE: A new SEC-AS-MS method has been developed for the affinity screening of PPARα and PPARγ ligands. The system proved to be highly specific and will be used to improve the throughput for the identification of new selective metabolites from natural souces targeting PPARα and PPARγ.

Exploring potential mechanisms for zinc deficiency to impact in autism spectrum disorder: a narrative review.

Autism spectrum disorder (ASD) is a heterogeneous and complex group of life-long neurodevelopmental disorders. How this clinical condition impacts an individual's intellectual, social and emotional capacities, contributing to alterations in the proprioceptive and sensory systems and increasing their selective attitude towards food, is well described in the literature. This complex condition or status exposes individuals with ASD to an increased risk of developing overweight, obesity and non-communicable diseases compared with the neurotypical population. Moreover, individuals with ASD are characterised by higher levels of inflammation, oxidative stress markers and intestinal dysbiosis. All these clinical features may also appear in zinc deficiency (ZD) condition. In fact, zinc is an essential micronutrient for human health, serving as a structural, catalytic and regulatory component in numerous physiological processes. The aim of this narrative review is to explore role of ZD in ASD. Factors affecting zinc absorption, excretion and dietary intake in this vulnerable population are taken into consideration. Starting from this manuscript, the authors encourage future research to investigate the role of ZD in ASD. The perspective is to potentially find another missing piece in the 'ASD clinical puzzle picture' to improve the health status of these individuals.

The Effect of Crackers Enriched with Camelina Sativa Oil on Omega-3 Serum Fatty Acid Composition in Older Adults: A Randomized Placebo-Controlled Pilot Trial.

BACKGROUND: Camelina sativa oil is one of the richest dietary sources of omega-3, with polyunsaturated fatty acids amounts of over 50%, linolenic acid content of around 40-45%, and linoleic acid of about 15%. Moreover, this oil is a valuable source of antioxidants which provide oxidative stability. All those features raise interest in considering Camelina oil as an alternative and sustainable oil source providing stable omega-3-rich emulsions for functional food production. OBJECTIVES: The present study aimed to investigate the effects of Camelina oil-enriched crackers on serum omega-3 concentration, inflammatory markers and serum lipid profile. DESIGN: Randomized placebo-controlled pilot trial. SETTING: Research and Development Center (Complife Italia s.r.l.). PARTICIPANTS: Sixty-six free-living older volunteers (aged≥65 years). INTERVENTION: Older adults were enrolled and randomly assigned to one of two groups: the camelina group or the placebo group. Subjects consumed daily 35 g of crackers (Camelina enriched crackers or placebo ones) twice daily for 12 weeks. MEASUREMENTS: Serum polyunsaturated fatty acid profile, inflammatory status and serum lipid panel parameters were recorded pre and post-intervention. RESULTS: In the camelina group, alpha-linolenic acid serum concentration was significantly higher (p<0.01) compared to the placebo group at the end of the study. Concerning inflammatory plasma markers, a significant mean pro-inflammatory interleukin-18 plasma concentration decrease in the placebo group compared to the camelina one was observed (p<0.05). No significant differences in other mean inflammatory markers concentrations post-intervention were noted in either group. Lastly, examining the change in lipid profile, it is noteworthy that a higher reduction of total cholesterol, low-density lipoprotein and triglycerides in the camelina group post-intervention, despite the lack of statistical significance. CONCLUSION: Camelina oil significantly elevated the serum alpha-linolenic acid concentration with no significant changes in inflammatory markers and lipid profile.

Association between worldwide dietary and lifestyle patterns with total cholesterol concentrations and DALYs for infectious and cardiovascular diseases: an ecological analysis.

Global dietary and lifestyle trends are primary risk factors for communicable and non-communicable diseases. An ecological analysis was conducted to examine the association of global dietary and lifestyle patterns with total cholesterol concentrations. This study also investigated whether total cholesterol modified the association between dietary and lifestyle habits with disability-adjusted-life-years-lost (DALYs) for infectious and cardiovascular diseases (CVDs). Country-specific mean total cholesterol concentrations and DALYs for infectious and CVDs were obtained. Data were then matched to country-specific food and energy availability for consumption and information on obesity, physical inactivity, urbanization, gross domestic product (GDP), life expectancy and smoking. Stepwise multiple regression models were developed to identify significant predictors of total cholesterol concentrations and DALYs for infectious and CVDs. Life expectancy and egg and meat consumption were significantly associated with cholesterol concentrations. DALYs for infectious diseases were associated with smoking, life expectancy and per capita GDP. Smoking was the only predictor of DALYs for CVDs. The improvement of socio-demographic conditions and economic growth is likely to reduce the burden of communicable diseases in developing countries. A concurring increase in non-communicable diseases is expected, and these results have, yet again, identified smoking as a primary risk factor for CVDs.

Epicardial fat thickness: threshold values and lifestyle association in male adolescents.

BACKGROUND: Obese adolescents with high proportion of visceral fat are at higher risk of developing the metabolic syndrome. OBJECTIVES: The study aims to investigate if echocardiographic epicardial fat thickness (EF) could be predictive of visceral obesity (VO) early in life and to provide EF threshold values specific for male adolescents. Further aim was to investigate the association between EF, lifestyle and metabolic disease familiarity. METHODS: Anthropometric data were collected from 102 normal weight and overweight, healthy male adolescents (mean age: 14.91 ± 1.98 years); bioelectrical impedance analysis and transthoracic echocardiogram were performed in the same sample. Each participant fulfilled a validated self-administered lifestyle questionnaire. RESULTS: We found higher EF values in sedentary adolescents (P < 0.05), in those who never eat fruit and vegetables (P < 0.05), and in those with overweight mothers (P < 0.05). The strongest independent predictor of EF was waist circumference (P < 0.0001). Using the waist to height ratio as a marker of VO, logistic regression analysis revealed that 1 mm EF gain is responsible for seven times higher VO risk (P < 0.0001). Receiver Operating Characteristic (ROC) analysis showed that the optimal cut-off for EF thickness associated to youth VO is 3.2 mm. CONCLUSION: Ultrasonography EF measurement might be a second-level assessment tool, useful to detect early cardiometabolic damage stage.

Energy balance in haemodialysis and peritoneal dialysis patients assessed by a 7-day weighed food diary and a portable armband device.

BACKGROUND: Energy balance (EB) is important when assessing nutritional status. EB has never been assessed in haemodialysis (HD) and peritoneal dialysis (PD) patients. The present study aimed to assess weekly EB in these patients. METHODS: This clinical cross-sectional study was conducted for 7 days in eight HD and eight PD patients. Nutritional status was assessed by anthropometry, bioelectrical impedance analysis and biochemical markers. Energy intake (EI per day) and total energy expenditure (TEE per day) were determined by a 7-day weighed food diary and a portable armband device, respectively. RESULTS: No significant differences in age, body mass index, fat free mass (FFM), parathyroid hormone were found between the two groups. EB was calculated by subtracting TEE per day from EI per day. EB was negative in HD {-1347 (1276) kJ day(-1) [-322 (305) kcal day(-1) ]}, as well as in PD patients {-427 (5338) kJ day(-1) [-102 (395) kcal day(-1) ]}. TEE per day was positively correlated with EI per day, prealbumin, FFM. EI per day was positively correlated with prealbumin. C-reactive protein was negatively correlated with TEE and FFM (P < 0.05). EB showed a positive correlation with EI per day (P = 0.012) and a negative trend with TEE. CONCLUSIONS: HD and PD patients have a negative EB and are at risk of malnutrition. Inflammatory status determines a lower EI per day and a reduction in TEE per day. The most important parameter in determining EB in HD and PD patients is EI per day. This topic deserves further investigation to better understand the mechanisms of impaired EB with respect to preserving patients' nutritional status.

Dietary attitudes and diseases of comfort.

This article reviews Western dietary attitudes and lifestyle choices by identifying the environmental, social and personal factors that determine said attitudes and choices. Environmental factors exert a major influence on, and complicate, dietary behavior, primarily by facilitating the consumption of meals away from home and by minimizing time dedicated to meal preparation and consumption. Social factors, from mass media to advertising and cultural traditions, also influence food intake, to an extent that is still underestimated. Ignorance of the real influence of environment and society on food choices could well blind consumers to the real significance of such choices. Accordingly, this review discusses differing aspects of emerging dietary trends and/or philosophies, and underlines their potentially harmful influence on health. Western countries are increasingly witnessing a dichotomy between the findings of nutritional science and the choices that dietary trends propose and impose. Coinciding with the obesity epidemic and the spread of other food-related diseases, this dichotomy calls for the development of effective preventive strategies.

Changes in nutritional status and body composition during enzyme replacement therapy in adult-onset type II glycogenosis.

BACKGROUND: In adult glycogen storage disease type II (GSDII), a single-gene mutation causes reduction of the lysosomal enzyme acid alpha-glucosidse. This produces a chronic proximal myopathy with respiratory involvement. Enzyme replacement treatment (ERT) has recently become available and is expected to improve muscle strength. This should result in increased lean body mass. In this study we evaluate body composition and nutritional status in GSDII, and assess whether these parameters changed during treatment. METHODS: Seventeen patients with late-onset GSDII, aged 52.6 +/- 16.8 years, received ERT for >18 months. Dietary habits and metabolic profiles of glucids, lipids, and proteins were assessed. Body composition was calculated using anthropometry and bioelectrical impedence analysis. RESULTS: On inclusion, we found increased fat mass (FM) in five patients in severe disease stage; all had normal body mass index (BMI). FM correlated inversely, and lean mass (LM) directly, with creatine kinase, prealbumin and albumin levels. After treatment, BMI and FM significantly increased, while LM only showed a trend toward increase. Prealbumin and albumin levels increased as early as after the first months of ERT. DISCUSSION: Body mass index value may underestimate FM in patients in severe stage of disease, due to altered body composition. In severely affected patients, laboratory parameters revealed a relative protein malnutrition, that was reversed by ERT, this reflecting restoration of normal muscle metabolic pathways. Increased BMI may indicate a reduction in energy consumption during exercise or respiration, along with clinical improvement.

Effect of dietary glycemic index on food intake, adiposity, and fasting plasma ghrelin levels in animals.

BACKGROUND: An increase in lipid storage as a consequence of feeding animals with high-glycemic index (GI) diets has been observed by many authors. Ghrelin is one of the most important orexigenic hormones, and curiously, its fasting plasma levels are decreased in human obesity. AIM: As ghrelin secretion is affected by insulin concentration, we hypothesized that carbohydrates with different glycemic responses might influence fasting plasma ghrelin levels. MATERIAL AND METHODS: Twenty rats were divided into two groups and fed ad libitum a low-GI or a high-GI diet for 21 days. RESULTS: In rats fed a high- vs low-GI diet we observed: increased food intake (18.9+/-0.6 vs 16.4+/-2.0 g/day; p<0.01), increased weight gain (28.8+/-6.6 vs 16.4+/-6% of initial weight; p<0.01), higher relative weight of epididymal fat pads (1.7+/-0.4 vs 1.4+/-0.3%; p=0.05), but lower total fasting ghrelin levels (41.1+/-10.7 vs 59.5+/-9.8 pg/ml; p=0.05). CONCLUSIONS: Ghrelin appeared to be downregulated in rats fed a high-GI diet; this observation could be related to the higher food intake and fat mass observed in these rats and to the effects of insulin response on ghrelin levels.

Assessment of weight gain during pregnancy: an Italian practical approach.

AIM: Weight increase during pregnancy is an extremely useful parameter since adequate weight gain is associated with better outcomes for the health of both the mother and the baby. On the other hand, if there is an inappropriate change in weight, either too much or too little, both mother and fetus are more greatly exposed to numerous complications with different degrees of seriousness. Therefore it is necessary to rely on appropriate guidelines that provide medical and obstetric personnel with clear directions regarding correct weight gain. Since the recommendations of the guidelines must be adapted to the patient's specific profile, establishing the ideal weight gain in numerical terms is not immediate. METHODS: The authors developed an instrument for estimating the ideal weight gain during pregnancy, which is quick and easy to use and takes the specific subject's characteristics into account, in order to allow a personalized evaluation. RESULTS: A pocket instrument was developed, with a circular shape and two sides (A and B). On side A, two concentric disks contain weight and height, which allow pre-pregnancy Body Mass Index (BMI) to be calculated. On side B, three concentric disks contain respectively: a solar calendar, a calendar calculating the week of pregnancy and a window behind which the desired weight gain values scroll, divided by weight category. CONCLUSIONS: The authors believe that the instrument may be an additional helpful tool to control weight gain during pregnancy.

Nutritional assessment of elderly people.

Since today's society is characterised by an increase in the number of elderly persons, who are subject more than any other group to an alteration in their state of nutrition, in this review we propose the possible methods that can be used for an accurate nutritional diagnosis in this age group. Considering that malnutrition, sarcopenia and motor disability are factors that are more likely to occur with aging, it is extremely important for certain clinical anamnestic parameters, such as biohumoral and anthropometric indicators, but also specific tables and questionnaires, to become standard routine practice in health care in order to facilitate the diagnosis of these possible events.

Quality of life (QoL) and motivation for treatment: a female issue?

OBJECTIVE: The Quality of Life (QoL) of overweight and obese subjects is a widely discussed topic. From numerous studies, it emerges that obese persons suffer significant damage as result of their overweight in terms of QoL with regard to their physical and psychosocial well-being, with greater incidence associated with the degree of obesity. Our study aims at evaluating the usefulness of specific psychometric tests on the "obese population" that may be effective for the overall evaluation of the patient and in identifying specific subgroups on the basis of psychometric characteristics relating to QoL and of motivation for treatment. METHODS: The study was carried out on a sample of 150 obese subjects who approached the Section of Human Nutrition of the University of Pavia requesting treatment for weight loss. The persons in the selected sample were subjected to a specialized examination during which, as well as collecting all the anamnestic information on each individual patient, they were also asked to fill out the obesity-specific ORWELL 97 (Obesity Related Well- Being) questionnaire and the DBI (Decisional Balance Inventory) questionnaire. RESULTS: An analysis of the results indicates that the female group is strongly characterized by a lower QoL, as well as by a clearly larger number of failed dieting attempts and by a strong motivation to undergo treatment. CONCLUSIONS: The evaluation of QoL and motivation for treatment in overweight and obese individuals appears to be an effective tool for better identification of the subjects and for planning the most appropriate diagnostic approach.

[Nutritional management of patients suffering of chronic renal failure]. / La terapia nutrizionale nel nefropatico non dializzato.

Nutritional support constitutes a fundamental approach to favour the management of chronic renal failure and to postpone the need of kidney dialysis. The specific goals of the nutrition intervention are: control of protein intake, control of phosphate and of calcium intake, control of potassium intake, control of energy intake, control of lipid intake with clear identification of the polyunsaturated vs monounsaturated vs saturated fatty acid rate, control of vitamin intake, prevention of malnutrition and intervention with oral supplements or artificial nutrition (even if for short time) if malnutrition occurs. The proper management of the nutritional problems of patients with chronic renal failure slows the disease progression, prevents or controls symptoms associated with uremia and postpones the beginning of substitutive treatment that is of hemodialysis or of peritoneal dialysis, thus allowing a better quality of life either in the short or long term for patients suffering of chronic renal failure.

Validation of the Dutch Eating Behaviour Questionnaire parent version (DEBQ-P) in the Italian population: a screening tool to detect differences in eating behaviour among obese, overweight and normal-weight preadolescents.

OBJECTIVE: To validate the Dutch Eating Behaviour Questionnaire Parent version (DEBQ-P) in the Italian population and investigate the differences in eating behaviour among Italian normal-weight, overweight and obese preadolescents. DESIGN: A cross-sectional validation study. Participants were measured and the approved translation of the questionnaire was administered to their parents. SETTING: : Three school communities in the province of Bergamo, Northern Italy. SUBJECTS: A total of 312 preadolescents (mean age 12.9 y; s.d. 0.8, both sexes) from three secondary schools of the province of Bergamo, Northern Italy, and their parents were invited to participate to the study. Informed written consent was obtained from each subject and their parents. Students were measured and their parents filled in the approved translation of the DEBQ-P. Recruitment was opportunistic and school based. RESULTS: Factor and internal consistency analysis confirmed the factor structure of the DEBQ-P and the high internal consistency of its three scales. Variance analysis showed that eating behaviour of Italian normal-weight, overweight and obese preadolescents differs significantly only in regards to the 'restrained eating' scale (F 19.29, P < 0.001), with overweight and obese scoring higher. CONCLUSIONS: The DEBQ-P can be used for screening projects regarding eating behaviour in the Italian population. The association between restrained eating and weight status was confirmed for both sexes, but the relationship between external eating and emotional overeating and overweight requires further exploration.

Is a modest weight loss significant in the improvement of dyslipidemic patients lipid profile.

AIM: The aim of the present study was to evaluate serum lipid abnormalities and the relationship with various factors in overweight and obese patients and to assess lipid profile modifications subsequent to weight loss in a subgroup of patients. METHODS: A sample of 110 obese out-patients first and a subgroup of 34 subjects afterwards, was selected at the Human Nutrition Research Centre of the University of Pavia for a retrospective analysis. The subjects recruited were all dyslipidemic, according to the American Clinical Guidelines for the assessment of cardiovascular risk. Differences in lipid profiles in subjects with different life habits were evaluated and in a subgroup of 34 subjects compared before and after a short-term moderate hypocaloric diet. RESULTS: Sample's mean age was 46.8+/-12.6 with a mean body mass index (BMI) of 32.1+/-4.8 kg/m2 (no difference with gender). The correlation analyses showed that total cholesterol (TC) concentrations were highly correlated with age (p<0.001); no correlation was found between TC and BMI, waist hip ratio (WHR), % body fat (BF%). Triglycerides (TG) concentrations were not related to age or BMI, however there was a significant correlation between TG and WHR and with waist circumference (WC) (p<0.001). The 34 subjects selected to take part in a dietary regimen, without significant changes in life habits, lost 5.1% of their initial weight and presented a significant improvement (p<0.001) in lipid profile. CONCLUSIONS: The high correlation between lipid profile and anthropometric measurements implies further longitudinal evaluation of the validity of the anthropometric indexes in the dyslipidemic patient management. Indeed, the results suggest that modest weight loss is sufficient to obtain a significant improvement in fasting serum lipid profile of dyslipidemic overweight patients.

Body uneasiness in overweight and obese Italian women seeking weight-loss treatment.

OBJECTIVE: It is known that the psychopathology of eating disorders is associated with body image disturbances, but little is known concerning the body image of obese subjects. The aim of this study was to assess body uneasiness in overweight and obese women in relation to their age, degree of obesity, the percentage and distribution of body fat mass, and eating disordered behaviours. METHOD: The study population consisted of 99 overweight and obese women with a mean age of 34.3 +/- 10.1 years and a mean body mass index (BMI) of 31.3 +/- 5.4 kg/m2, who completed two self-report questionnaires: the Bulimic Investigation Test Edinburgh (BITE) to assess disordered eating behaviours and the Body Uneasiness Test (BUT) to assess body image uneasiness. Pearson correlations were used to determine the associations between the BUT scores and age, anthropometric measures (BMI, waist and hip circumferences, waist/hip ratio, percentage of body fat mass) and the BITE scores. The most significant determinants of the BUT scores were also determined using a multiple linear regression model. RESULTS: Disordered eating behaviours were found in 7.1% of the patients. Neither BUT nor BITE scores correlated with age, but BITE scores correlated with BMI and hip circumference (p < 0.05). The overall BUT score increased with increasing BITE scores and higher indices of all of the anthropometric measures (p < 0.001) except for the percentage of body fat mass. Multiple linear regression analyses showed that, among the considered parameters, the only significant determinants of body uneasiness were disordered eating behaviours. CONCLUSIONS: Our results confirm that body uneasiness in an obese clinical population is closely associated with disordered eating behaviours, and suggest that it is not dependent on age, the degree of obesity, or the percentage or distribution of body fat mass.

[Adolescent Body Mass Index data: what differences result using different reference standard curves?]. / Indice di Massa Corporea e adolescenti: quali le differenze utilizzando diversi standard di riferimento?

Childhood and adolescent obesity prevalence rates have steadily increased both in industrialised and developing countries in the last years. Data from literature show that BMI is an acceptable indicator to assess overweight and obesity also in children and adolescents. Different reference standard curves for BMI exist: the percentiles of Rolland-Chacherà, Luciano, the National Center for Health Statistics, Cole and Cacciari. Nevertheless, different cut off points are used by the authors to identify underweight, overweight and obesity. The aim of the present study was to investigate what differences can emerge when comparing adolescent BMI using different references standard curves. Five hundreds and thirty-five adolescent subjects, aged 15.4 +/- 0.7 years, were recruited in Aosta Valley (Northen Italy). BMI was calculated according to the following equation: BMI = weight/height2 (kg/m2). The data obtained were distributed according to BMI percentiles and than compared with references standard curves. The comparison shows different results especially when underweight, overweight and obesity are identified. In conclusion, it can be asserted that BMI is an useful indicator to assess adiposity (overweight and obesity) in adolescent, but one should be cautious when comparing results based on different references.

[Obesity etiology: role of leptin]. / Eziologia dell'obesità: il ruolo della leptina.

A huge interest in the scientific community has been aroused since leptin's discovery (from greek leptos=thin), due to its important role in the body energetic balance regulation. This protein is synthesized from ob gene and secreted by the adipose tissue when fat mass increases, decreasing hunger and increasing energy expenditure in order to restore energetic balance. In the latest years many human genetic studies have been conducted showing that sometimes obesity may be due to mutations of genes involved in energetic balance mediated by leptin. These findings amplified the knowledge of obesity etiopathogenesis, thus arousing hopes and expectations for new therapeutic horizons in this disease. Latest researches also outlined many other functions of leptin, some of which are presented in this review. In this paper we collected the most significant data about leptin's physiology and its role in body energetic homeostasis, looking also to the effects on hypothalamus-hypophysis-endocrine axes regulation, on body thermoregulation, on the reproductive function and on foetus and child growth. A wide section is thus reserved to the most recent findings about the role of leptin in obesity and about its therapeutic applications in this field.

[Epidemiology of obesity]. / Epidemiologia del fenomeno obesità.

Overweight and obesity are conditions characterized by weight levels higher than the normal limits for age, sex, and height. Because people stratified for sex and age vary in stature and this influences weight, criteria for being overweight must take height into account: this is defined and set out in WHO guidelines on the basis of Body Mass Index (BMI): weight (kg)/height2 (m2). Obese and overweight individuals are at a greater risk of developing chronic metabolic conditions and general ill health, than those whose weights are within the recommended guidelines. Besides these chronic related conditions for which obesity is a major risk factor incur enormous expenditure. The health hazards of obesity are compounded by the influence of central fat distribution. The disease associations of central fat are present even in people who are not overweight. Waist circumference is a simple measure that gives a very reasonable estimate of the amount of central fat. Data collected in the USA and Europe show a common trend: the increase of obesity and overweight among the adult and children population. Obesity appears to be the result of several factors that interact among them such as: genetic, environment, and behaviour. Current strategies, such as reducing food intake, seem to lead to poor long term outcomes. Management has tended to neglect the unavoidable need to consider obese subjects as chronically ill patients, requiring continuous assistance for active steps to maintain weight loss. Treatments should be multidisciplinary aiming at the achievement of radical changes in the individual's lifestyle. The planning and management of preventive programs for young people such as pubertal children have been disregarded up to now. They require not only attention, but also organization, clear goals and standardized methods. Moreover, a correct education is a key-element of these issues. Our unit has designed for this purpose an observational study aimed to reach a better comprehension of the proportion of ''weight problems'' and eating behavioural patterns in a population of adolescents.

Comparative study of the relationship between multi-frequency impedence and body water compartments in two European populations.

To investigate possible differences in the relationship between multi-frequency impedance and body-water compartments (total body water (TBW) and extracellular water (ECW)) measured by dilution techniques in two European populations, we studied forty Italian (twenty male and twenty female) and forty-three Dutch (twenty-three male and twenty female) healthy subjects aged 19-41 years. The main differences in body build between the two groups were height, trunk length and the two ratios TBW/height and ECW/height. Population-specific prediction formulas for ECW (at 1 kHz) and TBW (at 100 kHz) were developed. The prediction errors for ECW and TBW were about 0.6 and 1.5 kg respectively, (CV 4%) in both groups. Cross-validation analysis showed no significant error in the prediction of TBW but a slight error (range -4.9 to +2.8%) in the ECW prediction. The biases in both TBW and ECW were correlated with ECW/TBW (r -0.44, P < 0.0005 and r +0.52, P < 0.0005 respectively) in the two groups; the biases in ECW were also related to ECW/height (r 0.51, P < 0.001), TBW/height (r 0.25, P < 0.05), trunk length (r 0.36, P < 0.001) and Z1/Z100 (r 0.32, P < 0.01). In conclusion, the water distribution between the extra- and intracellular compartments emerged in the present study as the major cause of error in the prediction of body water, and in particular of ECW from impedance measurements with a population-specific equation. Moreover, body build, expressed as TBW/height and ECW/height, had an impact on the bias.