Serum phospholipid fatty acid composition and habitual intake of marine foods registered by a semi-quantitative food frequency questionnaire

OBJECTIVE: To examine the relation between consumption of fish and fish products registered by a comprehensive food frequency questionnaire and the composition of fatty acids in serum phospholipids. DESIGN: Cross-section study. SETTING: Cardiovascular screening centre in Trondheim, Mid-Norway. SUBJECTS: Of 256 eligible women 242 agreed to participate in the present study. Altogether 234 middle-aged women (91.4%) completed the questionnaire and gave a valid blood sample. RESULTS: Total frequency consumption of fish for dinner showed only weak association with serum phospholipid fatty acid composition. In separate analyses of lean and fatty fish, consumption of fatty fish was negatively associated with n-6 and positively associated with n-3 fatty acids in serum phospholipids, while no significant associations were found for lean fish consumption. Cod liver oil consumption was strongly related to the phospholipid fatty acid composition. The associations improved moderately when adding portion size information. Spearman's correlation coefficient between dietary intake of eicosapentaenoic acid (EPA) and serum phospholipid EPA was 0.58, and Spearman's correlation coefficient between intake of docosahexaenoic acid (DHA) and serum phospholipid DHA was 0.53. CONCLUSIONS: This study suggests that in populations with a high consumption of fish and cod liver oil, habitual intake can be reflected in serum phospholipids. However, as the fat content of fish is highly variable, separate registration of lean and fatty fish consumption is needed.     

The influence of dietary fat on food intake and body weight

Excessive intake of dietary fat is associated with a number of nutrition-related disorders, including obesity, heart disease, and cancer. The over-consumption of fat may be related to its palatability, high energy density, or physiological effects. This article reviews possible reasons why fat intake is high, examines the relationship between diet composition and body weight, and explores potential fat reduction strategies. It is concluded that low-fat or fat-free products could be useful in reducing the percentage of calories derived from fat, although this assertion needs to be further tested in controlled laboratory experiments and validated on a population basis.     

Development of data-based semi-quantitative food frequency questionnaire for dietary studies in middle-aged Japanese

BACKGROUND: We designed a data-based semi-quantitative food frequency questionnaire to clarify the relationship between food intake and lifestyle-related diseases among middle-aged Japanese. METHODS: A total of 351 middle-aged individuals were recruited to a one-day weighed diet record survey in 1994. In all, 586 foods were consumed. Intake of 31 nutrients including energy, protein, fat, carbohydrate, vitamins, minerals and dietary fiber by food was computed by multiplying the weight of food consumed by its nutrient content. First, 252 foods with up to 90 cumulative % contribution to nutrient intake were selected. Of these, foods having apparently the same/similar nutrient content were combined into 206 foods by research dietitians. Next, 183 foods with up to 0.90 cumulative multiple regression coefficient and 90 cumulative % contribution were chosen. At this stage an additional food grouping was made. RESULTS: Finally, 102 foods/recipes were included in the questionnaire: rice (2 items), bread and noodles (11), eggs, milk and dairy products (10), soybean, soybean products and other beans (7), meat including beef, pork and chicken (12), fish (5), other fish, shellfish and fish products (10), green-yellow vegetables (8), other vegetables and mushrooms (7), edible roots (2), seaweeds (3), seeds (2), fruits (8), beverages (7) and confectioneries (8). The frequencies were classified into eight categories. Portion size was calculated for the respective foods largely from the one-day weighed diet record. CONCLUSIONS: The developed semi-quantitative food frequency questionnaire substantially covered the intake of 31 nutrients and may be competent to rank middle-aged Japanese efficiently.     

The Malm? Food Study: the relative validity of a modified diet history method and an extensive food frequency questionnaire for measuring food intake

OBJECTIVE: To assess the relative validity of two diet assessment methods, an extensive quantitative food frequency questionnaire (method A) and a novel shorter quantitative food frequency questionnaire with a 14 day food record (method B). DESIGN: A randomized prospective cohort study. SETTING: General community. SUBJECTS: 206 residents of the town of Malm?, aged between 50-69 years, 101 men and 105 women who completed the methods during one year. METHODS: Both diet methods were designed to cover the whole diet and portion sizes were estimated using a booklet with 120 photographs; method A comprised 250 items and method B combined a two-week food record measuring lunch and dinner meals and a shorter 130 item quantitative food frequency questionnaire for average consumption of foods, snacks and beverages during the past year. An 18 day dietary record comprising six 3-day weighed records evenly distributed over one year served as a reference method. RESULTS: Pearson's correlation coefficients varied from 0.25 for fat intake to 0.84 for milk products for method A and from 0.32 for fish to 0.88 for meat for method B. Correlations for most food groups ranged between 0.50-0.80, and were higher for method B. Only small changes were noted after adjustment for energy intake. On average for most food groups categorization of subjects into quartiles, 55% of subjects belonging to the lowest quartile, and 57-59% of those belonging to the highest quartile for method A and B were correctly classified. CONCLUSION: A combined food record with a quantitative food frequency questionnaire is a better tool for food assessment than an extensive food frequency questionnaire.     

A methodological approach for estimating turbidity in a river

During the operations of purging and disposal of sediments of a reservoir it is necessary to know the values of turbidity in the river downstream in natural condition, in the absence of dams or river training works. The paper shows that under these conditions the ratio of the average values of sediment discharge to the annual maximum value of water discharge is a function of the average annual turbidity. Turbidity can be considered as representative synthetic index of the climatic conditions, the lithological features and the land cover of the basin, and the geometric characteristics of the river network. The proposed relationship of sediment discharge as a function of water discharge were validated on the basis of data collected from different Italian regions that have very different morphological, geo-lithological and rainfall features and that are characterised by a basin area changing between a few dozen and thousands of square kilometres. The results can be considered satisfying.     

Assessment of trans-fatty acid intake with a food frequency questionnaire and validation with adipose tissue levels of trans-fatty acids

Past studies of the association of trans-fatty acid intake with coronary heart disease have been hindered by the lack of a database on the trans-fatty acid content of various foods. The authors used new data from the US Department of Agriculture to estimate trans-fatty acid intake using a self-administered food frequency questionnaire (FFQ), and they assessed the validity of the FFQ by comparing the dietary estimates with trans-fatty acid concentrations in adipose tissue. The 1996 study included 27 women and 24 men aged 51-78 years. The mean consumption of total trans-fatty acids estimated from the FFQ was 2.24 g per day and 5% of total dietary fat. The mean concentration of total trans-fatty acids in buttock adipose tissue was 4.7% of total fatty acids. Pearson correlations between total dietary intake of trans-fatty acids and total trans-fatty acid levels in adipose tissue were 0.67 (95% confidence interval (CI) 0.36-0.84) among men and 0.58 (95% CI 0.26-0.79) among women. After adjustment for energy intake, age, and body mass index, the correlation coefficients were 0.76 (95% CI 0.51-0.89) among men and 0.52 (95% CI 0.17-0.75) among women. The FFQ validated in this study is an important new tool for assessing usual intake of trans-fatty acids.     

Lactational exposure and neonatal kinetics of methylmercury and inorganic mercury in mice

The concentration of mercury in milk and the distribution pattern in the sucking pup was followed over time after administration of a single iv injection of 0.5 mg/kg body wt of 203Hg-labeled methylmercuric chloride or mercuric chloride to lactating mice on Day 10 of lactation. Mercury concentrations in milk of the dams and in whole body, blood, plasma, GI-tract, liver, kidneys, and brain of the offspring were followed up to 11 days after dosing (until lactational Day 21). Following the inorganic mercury dose to the dams, most of the mercury in milk was delivered to the pups during the first 24 h, but the maximum mercury concentration in plasma and tissues of pups was not reached until 7 days after dosing, indicating a prolonged absorption of inorganic mercury in the sucking pup. Pups of dams given methylmercury were exposed to a much lower and constant mercury concentration in milk. The estimated accumulated mercury dose via milk per pup of dams given methylmercury was less than half of that estimated after the inorganic mercury dose. When the accumulated dose via milk from methylmercury-exposed dams was compared to the amount of mercury in pup's carcass (whole body minus GI-tract including content), it was revealed that almost all mercury delivered via milk was absorbed, and that the suckling pups had a very low elimination of mercury until lactational Day 17. Lactational exposure following a maternal methylmercury or inorganic mercury dose resulted in almost similar mercury concentrations in liver, kidneys, and plasma of the suckling, but higher concentrations in brain (as most 14 times) and also twice as high mercury body burden in the methylmercury group. Thus, differences in kinetics indicate that lactational exposure of methylmercury is a greater hazard for the breast-fed infant than inorganic mercury.     

The influence of dietary protein intake on milk production and blood composition of high-yielding dairy cows

Isolated rat adipocytes were incubated with serum lipoproteins or lymphchylomicrons which contained 14c-labeled cholesterol. The specific activity of lipoprotein free cholesterol decreased and that of cellular free cholesterol increased linearly up to 7 h. At this time the cell cholesterol specific activity was only 11% of that of medium cholesterol indicating that the rate of exchange was slow. The specific activity of lipoprotein esterified cholesterol remained unchanged while that of cells showed a slight increase suggesting esterification of incorporated free cholesterol. No detectable change of the lipoprotein or cellular cholesterol concentration occurred indicating that the uptake of radioactive free cholesterol was due to exchange without net movement of sterol. The radioactive cholesterol was incorporated into both membrane fraction and the fat droplet of the adipocytes. The rate of cholesterol exchange was temperature-dependent but it was not influenced by the metabolic state of the cells and not by addition of metabolic inhibitors. Trypsin or pronase treatment of the cells were without influence on the rate of the exchange and denaturation of the plasma lipoproteins with formalin increased the rate of exchange. These results indicate that the exchange of cholesterol is a physical chemical process, which is not linked to energy metabolism of the cells, and which is not mediated by either specific lipoprotein receptors on fat cell membranes or pinocytic uptake of lipoproteins. The rate of free cholesterol exchange showed a linear correlation with the concentration of lipoprotein particles in the medium. The relative transfer rate was highest for chylomicrons and decreased in order chylomicron remnants greater than very low density lipoprotein greater than low density lipoprotein greater than high density lipoprotein. A saturation of the system could be obtained only with high density lipoprotein.     

Responses in growth, food intake and food conversion efficiency to different dietary protein concentrations in meat-type lines of Japanese quail

1. A total of 360 Japanese quail of 4 commercial meat-type lines and two diet treatments (260 and 216 g/kg or 238 and 195 g/kg of crude protein (CP) in the starter and grower diet, respectively) were used. 2. The positive effect of a high CP diet on body weight was significant only for the first 4 weeks after hatching. 3. The mean age at inflection point of the growth curve (t+) across lines and sexes was 1.4 d (0.6 to 2.8 d within line/sex groups) earlier for quail fed on a high CP diet than in quail receiving a low CP diet. The inflection (y+) and asymptotic (A) weights were similar under both dietary protein concentrations. Nevertheless, the shape of the growth curve, characterised by the ratio y+/A and parameter of the maturing rate k, was significantly influenced by diet. 4. A higher food intake and less efficient food conversion were found for quail fed on a high CP diet in the period from 15 to 28 d of age. 5. The fattening traits such as body weight, cumulative food intake and food conversion, were not affected by dietary CP content at the age of 5 weeks. 6. The effects of line on body weight, food intake and food conversion are discussed.     

Implications of fat replacement for nutrition and food intake

This article provides specifics on the development of a clinical track for faculty appointments at the University of Pittsburgh. The criteria to be used for appointment and promotion on the clinical track are discussed along with the practice requirements of 60 hours per term of participation in and responsibility for direct care of patients. The purposes of faculty practice are set forth along with the formation and functioning of a Faculty Practice Council which handles decisions related to faculty practice. Results of the first year after implementation of a clinical track showed that 64 per cent (18) of the faculty had met all of their faculty practice obligations; of the remaining 36 percent (10) who had not, a variety of circumstances were cited. The Income to the School of Nursing for faculty practice, although modest, has helped to highlight that practice is valued and an integral part of the faculty role.     

Determination of the optimum dietary proportions of lysine and tryptophan for growing rats based on growth, food intake and plasma metabolites

Weanling crossbred pigs were divided into 24 groups and fed one of three levels of lysine and one of eight levels of tryptophan in a 3 X 8 factorial design to determine the optimum dietary proportions of these two amino acids. Weight gain and feed efficiency, and changes in plasma levels of lysine, tryptophan and urea were the response criteria. The tryptophan "requirement" and the optimum lysine:tryptophan ratio were estimated for each of the three lysine levels. The data indicate a tryptophan requirement of 0.19% to 0.23% for the 3-week-old pig when the lysine level is adequate. For pigs of this age a lysine:tryptophan ratio of from 4 to 5 was about optimum.     

Frequency of food intake and natural dietary components are potent modulators of bone resorption and bone mass in rats

Prevention of low bone mass is important to reduce the incidence of osteoporotic fractures. In this report evidence is provided that feeding habits per se, that is, increased frequency of food intake as well as a diet containing soy and other raw components, decrease bone resorption and increase bone mass in growing rats. Interim results after 6 weeks indicate that food fractionation and natural dietary components are both capable of inhibiting trabecular bone loss in aged rats. These interim results indicate that the effect of both dietary interventions are additive and together are capable of nearly completely blunting the age-dependent loss of trabecular bone mineral density. These dietary manipulations are, however, only partially effective in inhibiting the strongly increased loss of trabecular bone mineral density induced by estrogen deprivation. The fact that the natural dietary components are not more effective in ovariectomized rats as compared to intact females confirms our contention that these components may not operate by mimicking the effect of estradiol. Whether bone mass in humans is also under the control of dietary habits is not known. If so, an increased frequency of meals of appropriate composition may be used to prevent osteoporosis.     

Changes in body composition and dietary intake induced by tumor necrosis factor alpha and corticosterone--individually and in combination

Previous studies have shown that anorexia and reduced food intake are the main causes of weight loss in rats infused with tumor necrosis factor alpha (TNF-alpha), with no influence on corticosterone concentrations. In contrast, in clinical sepsis, muscle wasting due to increased catabolism is associated with increased corticosteroid concentrations. We hypothesized that in the rat model, corticosterone potentiates the catabolic effect of TNF-alpha in amounts that by itself does not influence muscle catabolism. Orally fed rats were divided into 3 treatment groups: continuous infusion of TNF-alpha (TNF; 100 microg x kg(-1) x d(-1)), corticosterone (Cort; 50 microg x g(-1) x d(-1)), or both (TNF+Cort). Each group was compared with a respective pair-fed (PF) group. In addition an ad libitum (AL)-fed group receiving an infusion of physiologic saline was studied to observe unrestricted food intake and weight gain. After 4 d of infusion, dietary intake and weight gain were significantly higher in the Cort and AL groups than in the TNF and TNF+Cort groups. Although wet liver weights and protein contents were significantly higher in the Cort, TNF, and TNF+Cort groups than in their respective PF group, the TNF and TNF+Cort groups had lower relative carcass weights. The weight and protein content of the diaphragm were lower and nitrogen excretion was higher in the TNF+Cort group than in the respective PF group. The results suggest that TNF-alpha plus corticosterone had a specific catabolic effect on the diaphragm. In addition, together they increased overall nitrogen excretion.     

Leptin is a physiologically important regulator of food intake

OBJECTIVE: These studies were designed to test the hypothesis that endogenous leptin, acting within the brain plays a physiologically important role in the control of food intake in lean rats. DESIGN: Antibodies directed against mouse leptin were raised in rabbits. The purified IgG fractions prepared from pre-immune and immune sera were injected into the right lateral ventricle of lean Sprague-Dawley rats and obese Zucker fatty fa/fa rats. Changes in food intake were measured over the following 20 h period. RESULTS: The anti-leptin antibodies recognized a major epitope in the C-terminal region of the leptin molecule. The antibodies bound both mouse and rat leptin with high affinity, but did not bind human leptin, or a selected range of other hormones and neurotransmitters known to affect food intake. In competition studies, the binding of mouse, but not human leptin to the human Ob-Rb receptor was prevented by the antibodies. This indicates that the antibodies can block the action of leptin by preventing its binding to the ob-Rb receptor. Injection of the anti-leptin antibodies into the brain of lean rats led to an increase in food intake during the first hour after injection which was not compensated during the following 19 h period. Injection of the anti-leptin antibodies did not affect food intake in Zucker fatty fa/fa rats which express an abnormal ob-Rb receptor. CONCLUSION: Endogenous leptin acting within the brain plays a physiologically important role in the control of food intake in lean rats.     

Comparison of the Block and the Willett self-administered semiquantitative food frequency questionnaires with an interviewer-administered dietary history

The performances of two commonly used diet instruments, the Block and the Willett food frequency questionnaires, were compared with a longer, interviewer-administered diet history. Participants in a case-control study on diet and colon cancer were interviewed between 1990 and 1994 in northern California, Utah, and Minnesota by trained nutritionists using a validated diet history. Two separate subsamples of participants were asked to complete either the Block or the Willett questionnaire exactly 5 days after they completed the original diet history. Data were analyzed separately by subsample comparing either the Block or the Willett questionnaire with the original diet history by using means, correlations, quintile agreement, and odds ratios for the relation between several nutrients and colon cancer. The Block and the Willett questionnaires generally provided lower absolute intake estimates than did the original diet history; however, the Block questionnaire underestimated more than did that by Willett. Both correlations and quintile agreement were slightly better for the Willett questionnaire than for that by Block when compared with the original diet history. In general, point estimates obtained from either the Block or the Willett questionnaire fell within the confidence intervals of the estimates of the odds ratios obtained from the original diet history, and no real difference in significance levels appeared. Although the Block and Willett questionnaires differed slightly from each other and from our original diet history in estimating absolute nutrients and ranking or classifying individuals, they were very similar in their ability to predict disease outcome.     

Determinants of dietary intake in a sample of white and Mexican-American children

Using a modified method consisting of chromatography on phenyl-Sepharose, Q-Sepharose, and hydroxyapatite, we isolated a highly purified heat shock protein with molecular weight 90 kD (Hsp90) from rabbit liver. The isolated protein was recognized on immunoblot by commercially available monoclonal anti-Hsp90 antibodies. The chromatographic properties, interaction with actin and calmodulin, phosphorylation in the presence of Mg-ATP, and one-dimensional peptide maps of rabbit liver Hsp90 are similar to the corresponding properties of Hsp90 isolated from other sources. In the presence of soluble carbodiimide and N-hydroxysuccinimide, rabbit liver Hsp90 can be cross-linked with calmodulin, troponin C, troponin I, and calponin. The data obtained indicate that Hsp90 may participate in the assembly of regulatory proteins of the actin filament.     

Evidence for leptin regulation of food intake in humans

The adipocyte hormone leptin regulates body weight in mice by decreasing food intake and increasing energy expenditure. Whether leptin is of physiological importance for these processes in humans is, however, not clear. We therefore studied the relation between leptin and habitual food intake in 64 healthy postmenopausal women. Dietary habits were assessed with a modified diet history method. Body fat content was measured using bioelectrical impedance. In the 64 women, aged 58.6+/-0.4 yr (mean+/-SD), serum leptin was 19.3+/-12.7 ng/mL, body mass index was 25.0+/-3.5 kg/m2, body fat content was 31.6+/-4.3%, fasting glucose was 4.6+/-0.5 mmol/L, and fasting insulin was 56+/-21 pmol/L. Leptin levels were negatively correlated to total energy intake (r=-0.34; P=0.006), carbohydrate intake (r=-0.36; P=0.004), and total (r=-0.27; P=0.034) as well as saturated fat intake (r=-0.31; P=0.014). Leptin was correlated to the absolute, but not to the percent, intake of these nutrients. When normalized for body fat content, the correlations remained significant. Our results suggest that plasma leptin is involved in the physiological regulation of food intake in humans, and that leptin is related to the quantity rather than the quality of habitual food intake.