Search PubMed⌕ Search

Biomedical subjects

A Ferro-Luzzi

Publications and source records attributed to A Ferro-Luzzi.

At least 37 records · Page 2Linked to original sources

Obesity and physical activity.

This paper discusses the epidemiological evidence linking obesity to physical activity. The underlying plausible hypothesis is that the feedback from energy expenditure to appetite may be weak at low levels of physical activity and that sedentary lifestyles therefore favour positive energy balance and weight gain. Obesity is widespread in developed countries and appears to have a marked secular trend. An analysis of time-budget surveys reveals that the time required for earning a living and domestic work has declined appreciably over recent decades. This negative secular trend is associated with a substantial decline in the energy spent on these activities. The contraction of work time has resulted in a converse expansion of free time, but the bulk of this is spent on passive leisure. Thus, at least for western societies, the overall energy expenditure has fallen for some decades and lifestyles have become increasingly more sedentary. The review of a large data set on energy expenditure under free-living conditions indicates that, despite their phenomenally diverse rates of obesity, there is no systematic difference between developed and developing societies. Multivariate regression analysis of body mass index on physical activity level (PAL) reveals a weak but statistically significant inverse relationship in men but not in women, and establishes that the risk of obesity increases sharply at a PAL of less than 1.80. In conclusion, a critical level of PAL has been identified, below which the chances of being overweight become substantial. The use of time is modelled contextually with its energy cost to show the extent to which energy expenditure may be modified. This has relevance from a policy standpoint, allowing a more focused approach for obesity prevention.

Body Mass Index↗

Adult malnutrition: simple assessment techniques for use in emergencies.

The recent recognition of the problem of adult malnutrition requires methods for specifying the severity of undernutrition. The measurement of mid upper arm circumference (MUAC) can now be used as a screening method for underweight (normally assessed from the BMI) or as an additional criterion with the BMI to identify the preferential loss of peripheral tissue stores of fat and protein. By analysing and extrapolating anthropometric data from nine detailed adult surveys from Asia, Africa and the Pacific a series of MUAC cut-off points have now been identified to allow the screening of individual adults under extreme conditions, e.g. during famine. Grade 4 malnutrition is now specified for those with a MUAC < 200 mm for men and < 190 mm for women since these MUAC values correspond to the loss of fat stores at BMI of < 13. Food supplementation is clearly needed in these individuals. Extreme wasting (grade 5 malnutrition) corresponds to MUAC values of < 170 and < 160 mm for men and women respectively. These adults have extremely low BMI, i.e. about 10, have lost most, if not all, of their protein stores and are at a high risk of imminent death. These individuals will need immediate special feeding regimens to ensure their survival. The sex-specific MUAC values corresponding to BMI of 16, 13 and 10 can now therefore be used for rapid screening and the choice of remedial action.

Adult↗

In vivo antioxidant effect of green and black tea in man.

OBJECTIVE: Evaluation of the vitro antioxidant activity of green and black tea, their in vivo effect on plasma antioxidant potential in man and the effect of milk addition. DESIGN: The antioxidant activity of the tea, with and without milk, was tested in vitro by measuring the length of the peroxyl radical induced lag-phase. The in vivo activity was tested on two groups of five healthy adults. Each group ingested 300 ml of either black or green tea, after overnight fast. The experiment was repeated on a separate day, adding 100 ml whole milk to the tea (ratio 1:4 ). Five subjects acted as controls. The human plasma antioxidant capacity (TRAP) was measured before and 30, 50 and 80 min from the ingestion of tea. RESULTS: Both teas inhibited the in vitro peroxidation in a dose-dependent manner. Green tea was sixfold more potent than black tea. The addition of milk to either tea did not appreciably modify their in vitro antioxidant potential. In vivo, the ingestion of tea produced a significant increase of TRAP (P <0.05), similar in both teas, which peaked at 30-50 min. When tea was consumed with milk, their in vivo activity was totally inhibited. CONCLUSIONS: The paper shows that tea possesses a strong antioxidant activity in vitro which is believed to be exerted by its polyphenols moiety. It also provides compelling evidence that tea has also a potent in vivo activity in man. The promptness of the in vivo response suggests that the absorption of the bioactive components of tea takes place in the upper part of the gastrointestinal system. The inhibition of this effect by milk is thought to be due to the complexation of tea polyphenols by milk proteins. These findings might help to clarify the putative role of dietary poly- phenols in modulating oxidative stress in vivo.

Adult↗

Thyroid homeostasis and retinol circulating complex relationships in a severe iodine-deficient area of Senegal.

In adult subjects living in a severely iodine-deficient area (median urinary iodine 10 microgram/L), we evaluated the biochemical parameters of protein malnutrition in relation to thyroid homeostasis. Serum transthyretine (TTR), retinol binding protein (RBP) and retinol, all components of the retinol circulating complex (RCC), as well as ceruloplasmin levels, were determined in 63 subjects (44 F/19 M). These comprised 21 controls, 31 who were euthyroid with goiter WHO stage 2 or 3 and 11 who met the criteria of hypothyroidism (i.e. FT4 < 8 pmol/L and TSH > 4.13 mU/L) with goiter stage no more than 1b. No differences in the values of TTR and RBP were found between males and females, whereas the retinol values were slightly higher in males. The mean retinol binding protein values were lower than the normal range in all three groups but were significantly lower (p < 0.01; < 0.05) in hypothyroid subjects than in the other two groups. All hypothyroid subjects exhibited reduced retinol binding protein levels and 1/3 of them showed a marked decrease. The circulating levels of transthyretine were also lower than the normal range for western countries. 45% of the hypothyroid, 26% of goitrous and 9% of control subjects exhibited a transthyretine lower than 12 mg/dl, but the mean values were not dissimilar. The mean retinol values were within the normal range in all three groups but were lower in hypothyroid as compared to the controls (< 0.01). The resulting retinol/RBP ratio was over 1 in both the whole sample and in the subgroups. Ceruloplasmin levels were in the normal range in all groups. The data indicated that hypothyroid subjects had reduced retinol binding protein and retinol circulating complex network compared to euthyroid subjects.

Adult↗

A fluorescence-based method for measuring total plasma antioxidant capability.

The Total Radical-Trapping Antioxidant Parameter (TRAP) of 10 freshly prepared human plasmas was measured by a new fluorometric assay. In this method, the rate of peroxidation induced by 2,2'-diazobis (2-amidinopropane) dihydrochloride (ABAP) was monitored through the loss of fluorescence of the protein R-Phycoerythrin (R-PE). The lag-phase induced by plasma was compared to that induced by 6-hydroxy-2,5,7,8-tetramethylchroman-2- carboxylic acid (Trolox, a water-soluble analogue of vitamin E). Proteins (but not their sulphydryl groups) interfere with the analysis, partially protecting R-PE when all plasma antioxidants are exhausted. A Trolox-induced lag-phase must therefore be measured on each plasma sample. We found that ascorbate (2.5-5.3%), alpha-tocopherol (2.9-8.5%), urate (19.6-61.0), and thiol groups (17.3-42.3%) jointly explain up to 70% of TRAP. Thus, either other compounds present in plasma are likely to exert antioxidant action, or a marked synergistic action between antioxidants should be postulated to exist. This latter hypothesis is supported by the finding that the simultaneous inactivation of ascorbate and thiol groups produces a loss in antioxidant capacity of plasma greater (26%) than the sum of the decreases produced by the separate inactivation of each of the two compounds. The proposed method appears simple, reliable, and allows the rapid handling of a reasonable number of freshly prepared plasma samples. Given the rapid loss of TRAP upon storage, the latter characteristic is crucial in studies on humans, involving a large number of subjects.

Adult↗

Accumulation of beta-carotene in normal colorectal mucosa and colonic neoplastic lesions in humans.

The quantity of beta-carotene (BC) accumulated in colonic polyps and colonic cancerous tissue in humans in situ was determined relative to the quantity accumulated in normal colon and rectal tissue. Serum concentration of BC, retinol, and alpha-tocopherol and tissue BC concentration were determined by high-performance liquid chromatography in samples obtained before and after oral supplementation with BC (30 mg/day). The serum BC and retinol concentrations significantly increased in response to supplementation in control, polyp, and cancer patients, but there was no change in serum alpha-tocopherol concentration. The BC concentration in tissue (colon, rectum, and tumor) of cancer patients was significantly less than that in tissue samples from control and polyp patients. Relative to baseline values, BC accumulated to a significant extent in tissues from all patients, including polyp and tumor tissue, during supplementation. The results indicate that BC does accumulate in colonic neoplastic tissue in humans and may potentially be utilized to augment cytotoxicity of chemotherapeutics or to prevent malignant transformation of cells.

Adenomatous Polyps↗

Mediterranean diet, Italian-style: prototype of a healthy diet.

Since Keys' first observations in the 1960s, the Mediterranean diet has been under scrutiny by researchers and public health specialists for its health-promoting qualities. Detailed analyses of food surveys carried out in Italy at that time permitted a definition of an Italian-style Mediterranean diet, characterized by low total fat (< 30% of energy), low saturated fat (< 10% of energy), high complex carbohydrates, and high dietary fiber. The importance of the plant components of this dietary pattern became increasingly recognized as a result of advances in the understanding of the pathophysiology of chronic and degenerative diseases. Thus, the Mediterranean diet was found not only to produce favorable effects on blood lipid profiles, but also to protect against oxidative stress and carcinogenesis. However, possible unwanted effects, such as those on micronutrient bioavailability, also must be taken into account. In recent years, despite an increase in consumption of animal foods, the dietary profile of southern Italy has maintained its basic features, and vital statistics still demonstrate a comparative advantage of eating behaviors in Mediterranean countries.

Antioxidants↗

Mediterranean diet pyramid: a cultural model for healthy eating.

We present a food pyramid that reflects Mediterranean dietary traditions, which historically have been associated with good health. This Mediterranean diet pyramid is based on food patterns typical of Crete, much of the rest of Greece, and southern Italy in the early 1960s, where adult life expectancy was among the highest in the world and rates of coronary heart disease, certain cancers, and other diet-related chronic diseases were among the lowest. Work in the field or kitchen resulted in a lifestyle that included regular physical activity and was associated with low rates of obesity. The diet is characterized by abundant plant foods (fruit, vegetables, breads, other forms of cereals, potatoes, beans, nuts, and seeds), fresh fruit as the typical daily dessert, olive oil as the principal source of fat, dairy products (principally cheese and yogurt), and fish and poultry consumed in low to moderate amounts, zero to four eggs consumed weekly, red meat consumed in low amounts, and wine consumed in low to moderate amounts, normally with meals. This diet is low in saturated fat (< or = 7-8% of energy), with total fat ranging from < 25% to > 35% of energy throughout the region. The pyramid describes a dietary pattern that is attractive for its famous palatability as well as for its health benefits.

Animals↗

Use of body mass index of adults in assessing individual and community nutritional status.

Adult malnutrition is much more widespread than is commonly recognized. Described in this article is the use of body mass index (BMI = weight in kg/(height in metres)2) as a measure of adult nutritional status, both of individuals and of communities. Concurrent assessment of the nutritional status of children and adults permits conclusions to be drawn about whether there is generalized undernutrition in a community or whether other factors (e.g., childhood infections or feeding practices) are more important in childhood malnutrition. Included is a tabular presentation that permits rapid assessment of both thinness or underweight (BMI values < 16, 17 and 18.5) and overweight (BMI > 25, 30 and 40). Examples of the use of BMI in both clinical and public health practice are also given.

Adult↗

Relationship between fat-free mass and urinary excretion of creatinine and 3-methylhistidine in adult humans.

The urinary excretion of endogenous creatinine (CRTN) and 3-methylhistidine (3-MH) has been proposed as a predictor of fat-free mass (FFM) in healthy subjects. In this study, we report the relationship between FFM, estimated by densitometry plus deuterium dilution, and daily urinary excretion of CRTN and 3-MH in a sample of 20 healthy adult subjects of both sexes. 3-MH and CRTN were measured in 2 days of urine collection, which followed 4 days of meat-free diet. Meat-free diet was maintained throughout the period of urine collection. The mean of 2 days of excretion of 3-MH was 237.7 +/- 87.3 (SD) and 138.9 +/- 31.2 mumol/day in men and women, respectively. The mean CRTN excretion was 1.51 +/- 0.22 and 0.98 +/- 0.15 g/day in men and women, respectively. CRTN excretion was found well associated with FFM (R2 = 0.89; P < 0.0001), whereas 3-MH was lightly associated with FFM (R2 = 0.33; P < 0.01). Residuals from the regression of 3-MH vs. FFM were found to be correlated with CRTN excretion and FFM (R2 = 0.57 and 0.67, respectively), suggesting that muscularity and the absolute amount of lean mass are relevant for the error in predicting FFM from 3-MH excretion. Data confirm that urinary CRTN excretion can be an expedient indirect method for evaluating body composition in healthy adult subjects. Data also suggest that the relationship between 3-MH and FFM is complex, limiting the possibility of predicting body composition from the excretion of this metabolite.

Adult↗

Body mass index defines the risk of seasonal energy stress in the Third World.

A method has been devised to quantify the effect of seasonal environmental stress on nutritional well-being and to estimate the proportion of Third World populations at risk of functional deterioration. An Index of Agro-Climatic Seasonality, IACS--a measure of potential agricultural biomass availability--has been developed from agro-climatic data. IACS was found to be highly correlated with the seasonal weight loss of adults in rural Third World communities. This relationship was then used to predict the existence and severity of seasonal energy stress incurred by the adult population of Third World countries at any given body mass index (BMI). The average weight loss recorded in all seasonality studies was calculated; this value was used to specify, in combination with BMI, a condition of moderate seasonal energy stress. This grade of energy stress involved a loss of about 2% fat-free mass. The risk of greater energy stress, with larger losses of lean tissue, was specified as severe when predicted weight changes exceeded the maximum losses of weight recorded--at any given BMI--in Third World rural communities. The global dimensions of seasonality were then calculated by enumerating the individuals who--by the combined criteria of the BMI and the IACS of the habitat--fell into the categories of moderate and severe seasonality risk. On this basis, 65% of the rural adult population in the Third World run the risk of at least moderate seasonal energy stress, while 45% fall into the severe stress category. Of these 25% qualify as true seasonal 'casualties' because their body weight loss shifts their BMI from the normal range of nutritional status into the category of chronic energy deficiency.

Agriculture↗

The value of arm circumference measurements in assessing chronic energy deficiency in Third World adults.

OBJECTIVE: To assess the usefulness of mid-upper arm circumference (MUAC) as a substitute for body mass index (BMI: kg/m2) or an additional measure of adult nutritional state. DESIGN: Variously sampled adults aged 18-60 years from selected regions of five African countries, India, China and Papua New Guinea were measured. SUBJECTS: 2421 men and 3248 women were measured for their heights, weights and MUAC. Of these, 1569 men and 1905 women also had their triceps skinfold thickness measured, thus allowing additional estimates of muscle area circumferences and fat areas in the arm. RESULTS: MUAC and BMI were highly correlated in each national group; each group's MUAC differed from the overall mean MUAC at any BMI value by < 10%. Women's MUACs were smaller than men's at equivalent BMIs. Increases in MUAC with age were statistically significant but trivial. Muscle and fat measurements showed similar increases with BMI; a larger muscle mass in men explained their greater MUACs but muscle differences alone did not explain national variations in MUAC. The -1 SD MUAC value, taken as an independent measure of peripheral tissue wasting, readily distinguished those with a BMI < 16.0 from those with a BMI > 18.5; intermediate grades of BMI were poorly specified by MUAC values. CONCLUSION: MUAC values of 23.0 cm in men and 22.0 cm in women are useful cut-off points for simple screening of nutritional state. In combination with BMI it may provide a more refined classification of CED. This new combined classification scheme may be a better means of discriminating the at-risk underweight adults from those who are thin but not at risk.

Adolescent↗