Proportion Of Total Energy Research Articles

Ultra-processed foods and the incidence of pre-diabetes and type 2 diabetes among Iranian adults: the Tehran lipid and glucose study

BackgroundNo study has investigated the association between ultra-processed food (UPF) and pre-diabetes development. Furthermore, prior investigations on the association between UPF and the risk of type 2 diabetes (T2D) were primarily conducted in Europe and America, and studies in other regions are lacking. We investigated the association between ultra-processed foods and the risk of pre-diabetes and T2D in a cohort of Iranians.MethodsThis prospective study, with a sample size of 1954 for pre-diabetes and 2457 for T2D, was conducted among adults’ participants (aged ≥ 18 years) from the Tehran Lipid and Glucose Study (TLGS). We defined UPF intake using NOVA calcification as a proportion of total energy, and calculated its average intake during the follow-ups. The hazard ratios (HR) and 95% confidence intervals (95% CI) for pre-diabetes/T2D across tertiles of total UPF and per 10% of its increment were examined using Cox proportional hazards models. We also investigated the possibility of non-linear association using a restricted cubic spline regression.ResultsWe identified 766 and 256 cases of pre-diabetes and T2D, respectively, during a median follow-up of 7 years for pre-diabetes and 8.6 years for T2D. In the multivariable adjusted model, a 10% increase in total UPF intake was associated with a 12% higher risk of pre-diabetes (HR = 1.12; 95% 1.02, 1.23). The incidence of pre-diabetes was also higher in those in tertile 3 than those in tertile 1 (HR = 1.28; 95% CI = 1.07, 1.52). Following additional adjustment for diet quality, the results remained unchanged. Spline regression demonstrated a J-shaped association between UPF and the risk of pre-diabetes; the risk of pre-diabetes did not increase until UPF consumption exceeded about 24% of total energy intake. Of the individual UPF, hydrogenated fat/mayonnaise/ margarine group was related to an increased risk of pre-diabetes. The total UPF and its individual items were not associated with T2D.ConclusionsThis study found a positive, non-linear relationship between total UPF and the risk of pre-diabetes in Iranian adults. Our data could not show any significant association between UPF and T2D risk.

Reproductive effort of Plestiodon copei (Squamata, Scincidae), a highland viviparous lizard from Central Mexico

Female reproductive effort is defined as the proportion of total energy or resources devoted to reproduction. In reptiles, there is frequently high inter- and intra-population variation related to several factors, such as food availability, climatic conditions, age and size, all of which, in turn, also influence survival and future reproduction. The present study is the first reproductive effort analysis of a population of the high-mountain scincid lizard Plestiodon copei in central Mexico, focusing on relative litter mass (RLM), investment per capita (INV) and productivity (PROD). We also compared the reproductive efficacy of P. copei to those of other Mexican congeners. We collected 24 gravid females of P. copei over a 4-year period and recorded a total of 90 neonates born in captivity. We found significant variation in neonatal mass amongst individual females and across years. We recorded an average litter size of 3.75 and an average litter mass of 1.25 g, which were positively correlated with both the size and total mass of the reproductive females. The RLM, INV and PROD values (0.301, 0.428 g and 1.236 g × year-1, respectively) for P. copei were greater than those for other Mexican species in the P. brevirostris group (0.290, 0.412 g and 1.135 g × year-1), revealing that females of P. copei from Tenango invest a comparatively high amount of their resources in reproduction.

Carbohydrate-based diet may increase the risk of cardiovascular disease: A pooled analysis of two prospective cohort studies

According to cumulative epidemiologic studies, balancing macronutrients for energy is important to prevent metabolic diseases; however, this has not been studied extensively in Asian populations whose carbohydrate intake levels are relatively high. Therefore, we aimed to investigate the longitudinal association between carbohydrate intake and cardiovascular disease (CVD) among Korean adults in two community-based cohort studies. We included 9608 and 164,088 participants from the Korean Association Resource and Health Examinee studies, respectively, in the analysis. Carbohydrate intake was estimated using a validated semi-quantitative food frequency questionnaire. The proportion of total energy from carbohydrate (P_CARB) was calculated, and participants were divided into sex-specific quartiles based on their P_CARB values. Incident cases of CVD, including myocardial infarction, coronary artery disease, and stroke, were identified through self-reported questionnaires. Cox proportional hazards models were used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between P_CARB and CVD risk. The fixed effects model was used to pool the results. In the fully adjusted model, significant positive associations between P_CARB and CVD risk were observed in the pooled analysis, showing that the HRs (95% CIs) for CVD across increasing quartiles of P_CARB were 1.00 (reference), 1.16 (0.94-1.44), 1.25 (0.96-1.63), and 1.48 (1.08-2.03). The restricted cubic spline regression analysis confirmed a linear dose-response relationship between P_CARB and CVD risk in both cohort studies, with all p-values for nonlinearity >0.05. Our findings suggest that a carbohydrate-based diet high in proportion to total energy intake may increase the risk of CVD among middle-aged Korean adults, underscoring the importance of balanced macronutrient distribution. However, more research is needed to evaluate the sources and quality of carbohydrates in relation to CVD risk in this population.

A Fourier Transform-Based Calculation Method of Wilting Index for Soybean Canopy Using Multispectral Image

The growth process of soybean plants needs a lot of water. The rapid detection of canopy wilting of soybean under drought stress is of great significance for soybean variety breeding, cultivation regulation and fine management. Aiming at the problems of cumbersome and time-consuming when the traditional chemical technology was used to determine soybean wilting index, a calculation method of wilting index for soybean canopy was proposed in this study based on multispectral images’ Fourier transform. Suinong 26, a northeast soybean variety, was taken as the object. First, four kinds of soybean multispectral images of green, red, red-edge and near-infrared channels were acquired by a Sequoia multispectral camera. Second, based on the multispectral reflection image preprocessed by median filter and mean filter, the target area of a multispectral image of the soybean canopy was extracted by the iterative threshold method and affine transformation algorithm, and the effective segmentation rate was 97.02%. In addition, Fourier transform was used to analyze the spectrum characteristics of the soybean canopy’s multispectral image. When the spectrum radius of each channel was 50, the energy reached more than 98% and was concentrated in the low-frequency region of the spectrum center. Finally, according to the difference between the low-frequency DC component and the proportion of total energy in the spectral radius of the multispectral images under normal and drought treatment, a calculation model of the soybean wilting index was constructed based on the energy spectrum of Fourier transform. The results showed that the difference of the wilting index between normal and drought treatment for the four channels (green, near-infrared, red and red-edge) was 2.38, 3.11, 3.56 and 4.11, respectively. The effectiveness of the wilting index was verified and analyzed by using the average leaf inclination angle. The determination coefficient R2 of the four channels between the calculated wilting index and the average leaf inclination angle was more than 0.85. This calculation method can provide a quantitative basis and technical support for the scientific regulation of ecological and morphological phenotypic traits of soybean plants under drought stress.

A high-carbohydrate diet lowers the rate of adipose tissue mitochondrial respiration

Adipocyte mitochondrial respiration may influence metabolic fuel partitioning into oxidation versus storage, with implications for whole-body energy expenditure. Although insulin has been shown to influence mitochondrial respiration, the effects of dietary macronutrient composition have not been well characterized. The aim of this exploratory study was to test the hypothesis that a high-carbohydrate diet lowers the oxygen flux of adipocyte mitochondria ex vivo. Among participants in a randomized-controlled weight-loss maintenance feeding trial, those consuming a high-carbohydrate diet (60% carbohydrate as a proportion of total energy, n = 10) had lower rates of maximal adipose tissue mitochondrial respiration than those consuming a moderate-carbohydrate diet (40%, n = 8, p = 0.039) or a low-carbohydrate diet (20%, n = 9, p = 0.005) after 10 to 15 weeks. This preliminary finding may provide a mechanism for postulated calorie-independent effects of dietary composition on energy expenditure and fat deposition, potentially through the actions of insulin on fuel partitioning.

Adjustment for energy intake in nutritional research: a causal inference perspective

ABSTRACTBackgroundFour models are commonly used to adjust for energy intake when estimating the causal effect of a dietary component on an outcome: 1) the “standard model” adjusts for total energy intake, 2) the “energy partition model” adjusts for remaining energy intake, 3) the “nutrient density model” rescales the exposure as a proportion of total energy, and 4) the “residual model” indirectly adjusts for total energy by using a residual. It remains underappreciated that each approach evaluates a different estimand and only partially accounts for confounding by common dietary causes.ObjectivesWe aimed to clarify the implied causal estimand and interpretation of each model and evaluate their performance in reducing dietary confounding.MethodsSemiparametric directed acyclic graphs and Monte Carlo simulations were used to identify the estimands and interpretations implied by each model and explore their performance in the absence or presence of dietary confounding.ResultsThe “standard model” and the mathematically identical “residual model” estimate the average relative causal effect (i.e., a “substitution” effect) but provide biased estimates even in the absence of confounding. The “energy partition model” estimates the total causal effect but only provides unbiased estimates in the absence of confounding or when all other nutrients have equal effects on the outcome. The “nutrient density model” has an obscure interpretation but attempts to estimate the average relative causal effect rescaled as a proportion of total energy. Accurate estimates of both the total and average relative causal effects may instead be derived by simultaneously adjusting for all dietary components, an approach we term the “all-components model.”ConclusionsLack of awareness of the estimand differences and accuracy of the 4 modeling approaches may explain some of the apparent heterogeneity among existing nutritional studies. This raises serious questions regarding the validity of meta-analyses where different estimands have been inappropriately pooled.

Non-Milk Extrinsic Sugars Intake and Food and Nutrient Consumption Patterns among Adolescents in the UK National Diet and Nutrition Survey, Years 2008-16.

The revised guidelines from the Department of Health (DoH) in the UK state that mean population intakes of free sugars should be below 5% of the total energy (TE) consumption of the British population. However, very few studies have assessed the impact of this recommendation on diet quality in the UK. We explored the dietary patterns and intakes of micronutrients of British adolescents with low intakes of non-milk extrinsic sugars (NMES) (similar to free sugars but not equal, with slight differences in the categorisation of fruit sugars from dried, stewed or canned fruit and smoothies), using the National Diet and Nutrition Survey Rolling Programme, years 1–8 (NDNS RP). The sample included 2587 adolescents aged 11–18 years. Four percent (112) of adolescents reported consuming 5% or lower NMES as a proportion of TE. The odds of being categorised as a low-sugar consumer in adolescents (≤5% TE from NMES) were significantly lower with higher intakes of sweetened drinks, fruit juice, cakes, biscuits, sugar and sweet spreads, chocolate confectionery and sugar confectionery, and significantly higher with higher intakes of pasta and rice, wholemeal and brown bread, and fish. Across the five categories of NMES intakes, micronutrient intakes were lowest for those consuming either ≤5% TE or more than 20% TE from NMES, and optimal for those consuming between 10–15% of energy from NMES. These findings confirm the difficulties of meeting the free sugars recommended intake for adolescents. Care needs to be taken to ensure that an adequate consumption of micronutrients is achieved in those adhering to the revised guidelines on free sugars.

Investigation on aerodynamic characteristics of tailing vehicle hood in a two-vehicle platoon

Experimental and numerical methods were performed to study the hood aerodynamics of a 1:18 scale vehicle model in a two-vehicle platoon under different fixed intra spacing and dynamic intra spacing at the Reynolds number of 4.9 × 105 and 4.08 × 105 in a 1:15 scale wind tunnel. Blockage ratio was calculated to be 5.6% for experiments. The averaged and fluctuating pressures of the hood of the tailing vehicle are much higher than that of single vehicle, and stronger fluctuation occurs at the front and rear edges of hood. Pressure fluctuation over the tailing vehicle hood increases as the intra spacing diminishes but sharply declines within intra spacing of 0.2 L. The energy of fluctuation is concentrated in frequency bands from 50 to 110 Hz at wind speed of 30 m/s and 40–90 Hz at wind speed of 25 m/s. Energy at the main frequency bands and peak frequencies take up nearly 25% of total energy, respectively. The results of proper orthogonal decomposition show that total energy proportion is 49.6% for the first 11 modes and 67.0% for the first 30 modes, respectively. Relative motion at low speed has no discernible effect on hood behavior and peak frequencies have inclination to decline during the process of vehicle approaching.

Declining consumption of added sugars and sugar-sweetened beverages in Australia: a challenge for obesity prevention

Background: Reduced intakes of added sugars and sugar-sweetened beverages (SSBs) have been the main focus of efforts to stall obesity. Although obesity has risen steeply in Australia, some evidence suggests that added-sugars and SSB intakes have declined over the same time frame.Objective: We investigated recent trends in the availability of sugars and sweeteners and changes in intakes of total sugars, added sugars, and SSBs in Australia by using multiple, independent data sources.Design: The study was designed to compare relevant data published by the Food and Agriculture Organization of the United Nations [FAO Statistics Division Database (FAOSTAT)], the Australian government, academia, and the food industry.Results: With the use of the FAOSTAT food balance sheets for Australia, the per capita availability of added or refined sugars and sweeteners was shown to have fallen 16% from 152 g/d in 1980 to 127 g/d in 2011 (P-trend = 0.001). In national dietary surveys in 1995 and 2011–2012, added-sugars intake declined markedly in adult men (from 72 to 59 g/d; −18%) but not in women (44–42 g/d; NS). As a proportion of total energy, added-sugars intake fell 10% in adult men but nonsignificantly in adult women. Between 1995 and 2011–2012, the proportion of energy from SSBs (including 100% juice) declined 10% in adult men and 20% in women. More marked changes were observed in children aged 2–18 y. Data from national grocery sales indicated that per capita added-sugars intakes derived from carbonated soft drinks fell 26% between 1997 and 2011 (from 23 to 17 g/d) with similar trends for noncarbonated beverages.Conclusions: In Australia, 4 independent data sets confirmed shorter- and longer-term declines in the availability and intake of added sugars, including those contributed by SSBs. The findings challenge the widespread belief that energy from added sugars or sugars in solution are uniquely linked to the prevalence of obesity.

The effects of feeding increasing concentrations of corn oil on energy metabolism and nutrient balance in finishing beef steers1

The use of an added lipid is common in high-concentrate finishing diets. The objective of our experiment was to determine if feeding increasing concentrations of added dietary corn oil would decrease enteric methane production, increase the ME:DE ratio, and improve recovered energy (RE) in finishing beef steers. Four treatments were used in a replicated 4 × 4 Latin square ( = 8; initial BW = 397 kg ± 3.8). Data were analyzed using a Mixed model with the fixed effects of period and dietary treatment and random effects of square and steer within square. Treatments consisted of: (1) 0% added corn oil (Fat-0); (2) 2% added corn oil (Fat-2); (3) 4% added corn oil (Fat-4); (4) 6% added corn oil (Fat-6). Dry matter intake or GE intake did not differ across diets ( ≥ 0.39). As a proportion of GE intake, fecal energy loss, DE, and urinary energy loss did not differ by treatment ( ≥ 0.27). Additionally, methane energy produced decreased linearly as corn oil increased in the diet ( < 0.01). No differences were detected in ME loss as a proportion of GE intake ( ≥ 0.98). However, the ME:DE ratio increased linearly ( < 0.01; 93.06, 94.10, 94.64, and 95.20 for Fat-0, Fat-2, Fat-4, and Fat-6, respectively) as corn oil inclusion increased in the diet. No differences in RE or heat production as a proportion of GE intake were noted ( ≥ 0.59) and dry matter digestibility did not differ across diets ( ≥ 0.36). Digestibility of NDF as a proportion of intake responded quadratically increasing from 0% corn to 4% corn oil and decreasing thereafter ( = 0.02). Furthermore, ether extract digestibility as a proportion of intake responded quadratically, increasing from 0% to 4% corn oil inclusion before reaching a plateau ( < 0.01). As a proportion of GE intake, RE as protein decreased linearly as corn oil was increased in the diet ( < 0.01). As a proportion of total energy retained, RE as protein decreased when corn oil increased from 0% to 6% of diet DM ( < 0.01). Similarly, RE as fat and carbohydrate as a proportion of GE intake increased linearly as corn oil increased in the diet ( = 0.05). From these data, we interpret that adding dietary fat decreases enteric methane production and increases the ME:DE ratio, in addition to increasing the amount of energy retained as fat and carbohydrate.

Protein Intake and Weight Loss in Obese Men and Women with Cardiometabolic Risk Factors

Protein Intake and Weight Loss in Obese Men and Women with Cardiometabolic Risk Factors Background Despite its popularity, increasing dietary protein appears to have modest effects on weight loss. Furthermore, the proportion of total energy from protein that facilitates weight loss in nutritionist-recommended moderately energy-restricted diets is not clarified. We studied the association between protein intake and weight loss in obese men and women with cardiometabolic risk factors.

Serum fatty acid composition in primary school children is associated with serum cholesterol levels and dietary fat intake

To examine the serum fatty acid composition, serum cholesterol levels, and dietary fat intake associated with body composition in primary school children of both urban and rural regions in Taiwan. Subjects were randomly stratified by region and primary school. The sample consisted of 870 children aged 10 and 11 y old. The sample was equally distributed between an urban region (Kaohsiung City) and a rural region (Yunlin County). The gender ratio of samples from each area was matched. Food record-assisted 24-h dietary recalls and serum lipid measurements were collected for each child, and associations between serum total cholesterol (TC) and fatty acids composition as well as between body mass index (BMI) and triceps skinfold (TSF) were evaluated for both urban and rural regions. Compared with students in the urban region, those in the rural region had significantly lower total fat intake, BMI, TSF, TC, and LDL cholesterol (LDL-C) and higher HDL-cholesterol (HDL-C) (P<0.05). Increased total fat (P<0.05) as a proportion of total energy was associated with increased TC and LDL-C. Lauric, myristic, and oleic acid levels in the serum of urban boys were significantly higher (P=0.0001, 0.0003, and 0.0398, respectively) than those of rural boys. In girls, the different fatty acid compositions affected TC concentrations, and palmitic and stearic acids of serum in the high-TC group were significantly lower (P=0.0179 and 0.0001, respectively) than those in the low-TC group. Urban children had a dietary fat intake that both quantitatively and qualitatively differed from the traditional rural Chinese diet in Taiwan as reflected in rural children. Consumption of total fat was positively associated with BMI, TSF, TC, and LDL-C levels in Taiwanese children aged 10 and 11 y. This study was partly sponsored by a research grant from the Department of Health, Taiwan, ROC.

Breakfast cereal consumption in young children: associations with non-milk extrinsic sugars and caries experience: further analysis of data from the UK National Diet and Nutrition Survey of children aged 1.5-4.5 years.

This study examined the relationship between breakfast cereal consumption and non-milk extrinsic sugars (NMES) intake and the possible implications of this for caries in preschool children. Data from the 1995 UK National Diet and Nutrition Survey (NDNS) of children aged 1.5-4.5 years were reanalysed. Four-day weighed food records and dental examinations were available on 1450 children living in private households in Britain. Children were classified by tertiles (age-adjusted) according to the proportion of energy derived from breakfast cereals, and the amount of NME sugar from cereals. There were no significant differences in social class background between any of the groups. Children with diets high in breakfast cereals as a proportion of total energy (top third) had lower proportional intakes of NMES, compared with low consumers of cereals (lowest third). Consumption of sweetened cereals was positively associated with NMES intake. However, caries experience was unrelated to breakfast cereal consumption, whether presweetened or not. Although presweetened cereals are relatively high in NMES, their cariogenic potential is probably minimal in the circumstances in which they are normally consumed.

Dietary patterns in six European populations: results from EURALIM, a collaborative European data harmonization and information campaign

To determine and describe the extent to which European dietary data collected in disparate surveys can be meaningfully compared. Seven independent population-based surveys from six European countries were initially included. Differences in study designs and methodological approaches were examined. Risk factor data for 31,289 adults aged 40-59 y were harmonized and pooled in a common, centralized database. Direct comparisons of dietary measures across studies were not deemed appropriate due to methodological heterogeneity. Nonetheless, comparisons of intra-population contrasts by gender across sites were considered valid. Women consumed fruit and vegetables more often than men. Age-standardized gender differences in the prevalence of low fruit and vegetable consumption ranged from 7 to 18% and 5 to 15%, respectively. Data on energy intake showed good agreement across study populations. The proportion of total energy from macronutrients was similar for women and men. Gender differences for relative intakes of saturated fatty acids (percentage energy) were small and only in France were they significant. Dietary fibre density was significantly higher in women than in men. Overall, the participating Southern European populations from Italy and Spain exhibited more healthful food composition patterns. Contrasts in dietary patterns by gender across populations may provide the basis for health promotion campaigns. The most favourable patterns observed may serve as attainable goals for other populations. An international risk factor surveillance programme based upon locally run, good quality studies has the potential to provide the needed data. European Community (DG V), project 96CVVF3-446-0; Swiss Federal Office for Education and Science, OFES 96.0089.

Energetic costs of activity by lizards in the field

1. The available data related to the activity energetics of lizards in the field were collated with respect to three indices of activity energetics: the ecological cost of transport (ECT) expressed as a percentage of the total energy, the proportion of total energy used in all forms of activity (%AR), and the sustained metabolic scope (SusMS), defined as the ratio of the total energy expenditure to the total resting metabolism. 2. The ECT values of lizards ranged from 3 to 36% with five of 11 species having values &gt;20%. The percentage AR ranged from 23 to 80% for lizards during active seasons, with most species having values &gt; 50%. The SusMS ranged from 1·1 to 5·1. 3. Values of ECT are higher for lizards than for mammals, in part because the costs of maintenance metabolism are higher in mammals. 4. The percentage AR and SusMS values of mammals are higher than those of lizards. 5. It follows from the previous two points that the proportion of the total daily energy that is expended in non‐locomotory activities is disproportionately higher in mammals compared with lizards. 6. The energy expended in locomotion is a significant portion of the energy budget of lizards. This is generally true for all seasons in which there is activity.

Tolerance of pouch young kangaroos (Macropodidae) for cows&amp;apos; milk and milk replacers containing different amounts of glucose or lactose.

Young Red (Macropus rufus) and Eastern Grey (M. giganteus) Kangaroos, aged between 150-190 days and between 200-250 days of age respectively at the start of the experiments, were obtained after their mothers had been shot by commercial shooters. A system of housing was developed so that they could be fed continuously by stomach tube and balance experiments performed. Experiment 1: Three joeys were each given six diets which contained (expressed as a proportion of total energy) either 6.6%, 13.3% or 20.0% of glucose or lactose. Measurements of dry matter excretion in faeces plus urine showed a decrease in dry matter utilisation at the two highest levels of lactose. Diarrhoea occurred in all joeys given the highest levels of lactose. No diarrhoea occurred in the joeys given equivalent amounts of glucose. Volatile fatty acid excretion was positively correlated with lactose intake. Experiment 2: Four joeys were given reconstituted dried whole cows&amp;apos; milk to provide a lactose intake similar to that given in experiment I at the intermediate level. Since cows&amp;apos; milk contains approximately 26% energy as lactose, the intake of milk had to be restricted severely. One joey developed diarrhoea. Experiment 3: Four joeys were given a carbohydrate-free milk replacer to provide control data for experiments I and 2. The chance occurrence of spontaneous bone fractures in two joeys after 5 weeks on the experiment necessitated an investigation of mineral utilisation. It was concluded that mineral requirements are very high in later pouch life and that tolerance for cows&amp;apos; milk and for lactose is limited to an intake of &lt; 6.5 g lactose kg-1 d-1, or &lt; 11-12 g d-1 for kangaroo joeys between 1.4-3.0 kg live weight.

Energy Efficiency and the Domestic Consumer

Domestic energy consumption represents a sizable proportion of total energy delivered in the U.K. The major source of variance between households lies in the behaviour of the occupants rather than the physical parameters of the buildings. The behaviour of the consumer, and particularly its cognitive aspects, needs to be understood. Simply attempting to change attitudes is not sufficient; if a person is motivated to save energy/money he still needs to know how this can be acheived. More efficient use of energy will follow from human factors studies that lead to the redesign of controls, tariffs, bills. These issues will become more, not less, acute with the advent of new technology in energy controls and metering.

Dietary standards for the postponement of coronary heart disease: their practical application in Britain and Ireland.

Acomparison is made of the role of fat in the average diets of Britain and Ireland and following implementation of 5 dietary modifications: (i) the consumption of lean meat only; (ii) the substitution of a soft margarine for butter; (iii) the substitution of a soft margarine for shortening; (iv) the substitution of a vegetable oil for lard and (v) the exclusion of cream, ice-cream and sausagemeat from the diet. Fat intake would be reduced by about 18% by modification (i) and by only 5% by modification (v). The implementation of modification (ii) would have the greatest effect on the fatty acid composition of the diet. The total effect of the five modifications would be to reduce the proportion of total energy derived from fat from 42% to 33% in Britain, and from 37% to 28% in Ireland. The P/S ratio of the dietary fat would increase from 0.23 on the normal diet to 0.53 on the modified diet and 0.68 on a diet that had linoleic acid rich ruminant foods substituted for conventional ruminant foods. Dairy produce is the most significant source of saturated fatty acids on both normal and modified diets while cereals and margarine account for most of the intake of polyunsaturated fatty acids. It is concluded that while the proportion of dietary energy derived from fat can be maintained at or below 30%, it would be extremely difficult to partition the energy derived from fat equally among saturated, monounsaturated and polyunsaturated fatty acids or to achieve a P/S ratio of 1.0.

Studies on energy metabolism of germinating wheat seeds

The amount of energy dissipated in the form of heat in the metabolic processes carried on during the initial period of the germination of wheat seeds was determined directy by means of an adiabatic microcalorimeter. The total energy simultaneously liberated in the respiration of the investigated seeds was calculated from the carbon-dioxide production. The proportion of total energy released in respiration to the amount of energy dissipated as heat indicates that about 5 per cent of respiratory energy is retained in the tissues of growing seedlings. The percentual rate of energy dissipated is not dependent on the temperature or the age of seedlings.