Maximal voluntary contraction (MVC) using a handgrip dynamometer was assessed in seventy-two young adult males. The subjects were divided into two groups on the basis of a BMI of 18·5 kg/m2. The subjects with a BMI < 18·5 kg/m2 (n 38) were further divided into an underweight (UW;n 20) group and a chronically energy-deficient (CED; n 18) group. The CED subjects had significantly lower MVC (30·1, SD 5·9 kg) than either the well-nourished controls (BMI > 18·5 kg/m2: 39·8, SD 5·8 kg) or the underweight group (37·6, SD 4·9 kg). The differences between the CED and UW groups persisted even after the MVC were corrected for forearm muscle area and stature. The results suggest that MVC may be a useful functional indicator of nutritional status particularly in differentiating subjects with chronic undernutrition from individuals who are underweight and not undernourished but have similar BMI.

The present study aimed to identify dietary patterns, from the frequency of consumption of food items and some semiquantitative data, in a random sample of 9003 British adults, and to examine the associations of the main dietary patterns with demographic factors, lifestyle habits, measures of self- reported health and mortality. Principal component analysis was used to identify four main dietary patterns, and analysis of variance employed to examine the characteristics associated with them. The four components explained, respectively, 10·2, 7·3, 5·1 and 4·9% of the total dietary variation. Component 1, frequent fruit, salad and vegetable consumption with infrequent consumption of high-fat foods, was associated with middle age, non-manual socio-economic groups, non- and ex-smokers, ‘sensible’ drinkers, small households, the south of the country, and self-assessed ‘excellent’ or ‘good’ health. Component 2, frequent consumption of high-starch foods, most vegetables and meat, was popular with young men, older men and women, large households, non-smokers, non-drinkers and those who viewed themselves as healthy. Component 3, frequent consumption of high-fat foods, was predominantly consumed by young people, smoking women, ‘high-risk’ drinkers, and men reporting many illness and/or malaise symptoms. Component 4, high positive loadings for sweets, biscuits and cakes, with negative weightings for vegetables, was most favoured by students, the elderly, those living alone, residents in Scotland, but not those in central England, and those who did not smoke. For women only the first component was associated with low all-cause mortality, and the third component with excess mortality

The aim of the present study was to determine the errors in the conceptualization of portion size using photographs. Male and female volunteers aged 18–90 years (n 136) from a wide variety of social and occupational backgrounds completed 602 assessments of portion size in relation to food photographs. Subjects served themselves between four and six foods at one meal (breakfast, lunch or dinner). Portion sizes were weighed by the investigators at the time of serving, and any waste was weighed at the end of the meal. Within 5 min of the end of the meal, subjects were shown photographs depicting each of the foods just consumed. For each food there were eight photographs showing portion sizes in equal increments from the 5th to the 95th centile of the distribution of portion weights observed in The Dietary and Nutritional Survey of British Adults (Gregory et al. 1990). Subjects were asked to indicate on a visual analogue scale the size of the portion consumed in relation to the eight photographs. The nutrient contents of meals were estimated from food composition tables. There were large variations in the estimation of portion sizes from photographs. Butter and margarine portion sizes tended to be substantially overestimated. In general, small portion sizes tended to be overestimated, and large portion sizes underestimated. Older subjects overestimated portion size more often than younger subjects. Excluding butter and margarine, the nutrient content of meals based on estimated portion sizes was on average within± 7% of the nutrient content based on the amounts consumed, except for vitamin C (21% overestimate), and for subjects over 65 years (15–20% overestimate for energy and fat). In subjects whose BMI was less than 25 kg/m2, the energy and fat contents of meals calculated from food composition tables and based on estimated portion size (excluding butter and margarine) were 5–10% greater than the nutrient content calculated using actual portion size, but for those with BMI 30 kg/m2or over, the calculated energy and fat contents were underestimated by 2–5% The correlation of the nutrient content of meals based on actual or estimated portion sizes ranged from 0·84 to 0·96. For energy and eight nutrients, between 69 and 89% subjects were correctly classified into thirds of the distribution of intake using estimated portion size compared with intakes based on actual portion sizes. When ‘average’ portion sizes (the average weight of each of the foods which the subjects had served themselves)were used in place of the estimates based on photographs, the number of subjects correctly classified fell to between 60 and 79%. We report for the first time the error associated with conceptualization and the nutrient content of meals when using photographs to estimate food portion size. We conclude that photographs depicting a range of portion sizes are a useful aid to the estimation of portion size. Misclassification of subjects according to their nutrient intake from one meal is reduced when photographs are used to estimate portion size, compared with the use of average portions. Age, sex, BMI and portion size are all potentially important confounders when estimating food consumptionor nutrient intake using photographs

The aim of the present study was to assess, in healthy volunteers and under physiological conditions, the acceptability, clinical tolerance and effects on colonic motility of chronic supplementation of the usual diet with new dietary fibre sources. Three studies were carried out, one after a period of habitual diet, and two after randomized 3-week periods of supplementation with fibre extracted either from pea hulls or carrots, added to the meals as a fine powder. The 24 h motility was recorded on an unprepared colon at five levels to determine the initiation site and the number of high amplitude propagated contractions (HAPC) and to quantify motor activity every 30 min, particularly in the two periods following lunch and breakfast. With the habitual diet the motility pattern was an irregular alternation of quiescence and sporadic non-propagated contractions. HAPC always started from the ascending colon and occurred mainly after breakfast. With either type of fibre the 24 h motor profiles, the 24 h variations and the number of HAPC were not significantly modified but a more distal initiation of HAPC was found. The colonic postprandial motor response was more diffuse after dietary enrichment with carrot fibre than after enrichment with pea-hull fibre. In healthy volunteers the long-term addition of fibre extracted from pea hulls and carrots to the usual diet was easy and well-tolerated without clinical side-effects, but with limited colonic motor effects. However, the more distal initiation of HAPC observed could be deleterious.

A new guar-containing wheatflake product was developed to assess its effect on carbohydrate tolerance in normal-weight, healthy subjects. The extruded wheatflake breakfast cereals containing 0 (control) or approximately 90 g guar gum/kg DM were fed to ten fasting, normal-weight, healthy subjects using a repeated measures design. The meals were similar in energy (approximately 1·8 MJ), available carbohydrate (78 g), protein (15 g) and fat (5·4 g) content. The guar gum content of the test meals was 6·3 g. Venous blood samples were taken fasting and at 15, 30, 45,60, 90, 120, 150 and 240 min after commencing each breakfast and analysed for plasma glucose, insulin and C-peptide. The guar wheafflake meal produced a significant main effect for glucose and insulin at 0-60 min and 0-240 min time intervals respectively, but not for the C-peptide levels compared with the control meal. Significant reductions in postprandial glucose and insulin responses were seen following the guar wheatflake meal compared with the control meal at 15 and 60 min (glucose) and 15, 60, 90 and 120 min (insulin). The 60 and 120 min areas under the curve for glucose and insulin were significantly reduced by the guar gum meal, as was the 240 min area under the curve for insulin. Thus, it can be concluded that the use of a severe method of heat extrusion to produce guar wheatflakes does not diminish the physiological activity of the guar gum.

The aim of the present study was to determine the gastro-ileal behaviour of pea protein in humans. For this purpose, twelve healthy volunteers were intubated with an intestinal tube located either in the jejunum (n 5) or in the ileum (n 7). After fasting overnight, they ingested 195 mmol N of [15N]pea. Intestinal samples were collected for 6 h in the jejunum and for 8 h in the ileum. Before meal ingestion the basal liquid flow rate (ml/min) was 2·01 (SD 0·31) in the jejunum and 2·02 (SD 0·33) in the ileum. After meal ingestion the liquid phase of the meal peaked in the 40–60 min period in the jejunum and in the 150–180 min period in the ileum. The jejmo-ileal transit time of the liquid phase of the meal was 102 min. The basal flow rate of endogenous N (mmol N/min) was 0·22 (SD 0·15) in the jejunum and 016 (SD 0·10) in the ileum. The endogenous N flow rate peaked significantly ( P < 0·05) in the jejunum in the 40–60 min period whereas no stimulation of endogenous N could be detected in the ileum after meal ingestion. A significantly increased (P < 0·05) concentration of exogenous N was detected in the jejunum during the 20–3u)lnin period and during the 9–480 min period in the iteum. The overall true gastro-ileal absorption of pea N was 894 (SD 1·1)% with 69 (SD 14)% absorbed between the stomach and the proximal jejunum and 20·4% between the proximal jejunum and the terminal ileum. The percentage of ethanol-insoluble fraction (PN) in the exogenous N at the terminal ileum increased significantly ( P < 0·05) to 75% after 360 min. These results suggest that heat-treated pea protein has a digestibility close to that of animal protein

Indian River male broiler chickens growing from 7 to 28 d of age were fed on diets containing 120,210 and 300 g crude protein/kg diet and 0, 1–67 or 16·7 g added tryptophan (TRP)/kg diet. The hypothesis tested was that crude protein levels and TRP would affect both growth and neurotransmitter metabolism. Heart, brain and pancreatic neurotransmitter (noradrenaline (NA), dopamine(DA), serotonin (5-HT) and 5-hydroxy-indole-3-acetic acid (5-HIAA) concentrations were determined by HPLC separation and electrochemical detection. Malate dehydrogenase (2-oxoglntarate decarboxylating) (NADP+) (MDH(NADP+); EC 1.1.1.40), isocitrate dehydrogenase (NADP+) (ICD(NADP+); EC 1.1.1.42) and aspartate aminotransferase (AAT; EC 2.6.1.1) activities were also measured. Supplemental TRP decreased growth and feed intake. Increasing dietary crude protein decreased MDH(NADP+), but increased (ICD(NADP+) and AAT activities. Additional dietary TRP decreased MDH(NADP+) activity, but had no effect on other enzyme activities. Cardiac NA concentrations were directly related to dietary crude protein levels while pancreatic levels were inversely related. An increase in dietary crude protein decreased both brain NA and DA. Supplemental dietary TRP increased both 5- HIAA and 5-HT. Changes in feed intake caused by different levels of botb dietary crude protein and TRP are accompanied by altered levels of neurotransmitters. The present study indicates that much arger amounts of TRP are required to make simultaneous changes in feed intake and neurotransmitters.

Differences in the nutritive value of four grades of stackburned yellow maize, obtained from a single storage unit in Mozambique, were examined. Samples were analysed for chemical composition, and subjected to the following in vitro assays for estimating digestibility: total dietary fibre and pancreatin for non-ruminants, and gas production using sheep rumen fluid for ruminant livestock. Samples were also fed to broiler chicks at 600 g/kg diet in a growth trial. There were no significant differences in crude protein contents of the maize samples, but there was evidence for the development of Maillard reaction products. Detectable amino acids were lower in discoloured maize, with decreases of 52% in lysine, 35% in arginine, and 15% in glycine concentration in the most severely discoloured sample compared with control. Total starch, reducing sugar, acid-detergent fibre a d amylase-neutral-detergent fibre values increased, while total non-reducing sugar content decreased with increased discolouration. Total dietary fibre and pancreatin assays indicated a lowering in digestibility of maize with increasing discolouration. Weight gain of chicks (P=0·0228), efficiency of feed utilization (P=0·0009) and the metabolizable energy value of diets decreased (P<0·0001) with increasing stackburn discolouration. There were no significant effects on N retention of diets. In vitro fermentation using sheep rumen fluid showed a linear decrease in gas production with increasing maize discolouration, indicating a reduction in rumen degradability with stackburn

Dietary fatty acids modify phospholipid fatty acids in brain and liver of growing chickens post-hatching.The effect of vitamin E deficiency on this process is unknown and may be relevant to the pathogenesis of chick nutritional encephalomalacia (NE). Therefore laying hens received a diet low in vitamin E (10 mg α-tocopherol/kg feed). Resulting chicks were assigned to nine dietary groups each fed with either oleic (18:ln-9, 58 g/kg), linoleic (18:2n-6, 57 g/kg) or linolenic (18:3n-3, 56 g/kg) acid together with 5, 25 or 125 mg α-tocopherol/kg feed. NE affecting the cerebellum only occurred in the group given linoleic acid and 5 mg α-tocopherol/kg.In l-d-old chicks and after 1 and 2 weeks the phospholipid fatty acid composition of liver, cerebrum and cerebellum (additionally after 3 weeks) was determined. The feed fatty acids were incorporated into the liver very efficiently during the first week of life. Unsaturation of liver membranes decreased in the orderdietary linolenic >linoleic >oleic acid. In liver, also, the effect of α-tocopherol supplementation on phospholipid fatty acids was most pronounced. Theunsaturation index increased during deficiency, whereas n-9 fatty acids decreased. In the chicken brain the alterations were delayed and less distinct. The cerebellum phospholipids were rich in n-9 fatty acids and as a whole more saturated in comparison with the cerebrum. Cerebellar unsaturation increased when linolenic or linoleic acid was given. However, NE-producing dietary conditions were not accompanied by specific alterations in cerebellar phospholipid fatty acids due to the α-tocopherol content of the diet. Rather the alterations of membrane fatty acids in the liver seem to play a role in the pathogenesis of NE.

The present study investigated the effect of the acute-phase ‘injury’ response, induced by subcutaneous injection of turpentine, on the hydration and protein content of organs and tissues of normally nourished rats receiving a diet containing 200g protein/kg, and of protein-malnourished rats receiving a diet containing 30 g protein/kg. The measurements were carried out 48 h after turpentine injection, and were compared with both saline-injected animals, and pair-fed control animals. Circulating α2-macroglobulin was also measured as an index of the acute-phase-protein response. In normally nourished rats turpentine injection caused a significant increase in the mean masses of the liver, kidney and lung (7–35% compared with saline-injected animals, and 20–44% compared with pair-fed controls), and a small reduction in the mass of extra-abdominal and extrathoracic tissues (‘carcass’). In general the protein content of tissues changed in a similar way (for liver, kidney and lung a 16–33% increase compared with saline-injected animals, and 32–49% compared with pair-fed controls). Protein deficiency produced a significant attenuation in the response to turpentine. The change in the mass and protein content of several tissues was reduced (for lung, liver and kidney, the increase in protein content was only 5–15%), and the effects on anorexia (1 v. 41% reduction infood intake) and the α2,-macroglobulin response (1·28 v. 4·28 g/l; P< 0·001) were also reduced. It is concluded that the injury response spares most central thoracic and abdominal organs, but this effect as well as the anorexia and acute-phase-protein response to injury are attenuated by protein deficiency.

The present study aimed to determine if the type of dietary fat or oil affects erythrocyte morphology and/or filterability in normal healthy rats. A feeding trial was carried out, in which nine groups of nine rats were fed on diets containing one of the following treatments (test fats or oils): anhydrous milk fat, anhydrous milk fat after passage through a column of active carbon, palm oil, MaxEPA fish oil, hydrogenated coconut oil, anhydrous tallow shortening, margarine hardstock, olive oil and soyabean oil. The test fats or oils supplemented with 10 g safflower-seed oil/kg were incorporated into otherwise nutritionally adequate diets so that the test fat or oil plus safflower- oil contributed 35% of the gross energy of the diet. The rats were fed for 10 weeks. Diet had a significant effect on five of the six classes of erythrocytes identified, and the proportion of cells in each class was shown to be dependent on diet. However, the attribute causing the dependence was not clear. There was no significant effect of diet on erythrocyte filterability index. There was no statistical correlation between erythrocyte filterability index and morphology. Although it has been observed that diet, particularly fish oil, can improve the filterability of erythrocytes once filterability is impaired, the effect of diet on erythrocyte filterability in normal healthy animals including humans is unclear. The importance of the differences in erythrocyte morphology due to diet is also unclear. Both areas deserve further investigation.

The aim of the present study was to investigate whether oat saponins (avenacosides A and B) have any effect on the permeability of the rat intestine to actively and passively transported markers in vitro and in vivo. Intestinal segments were mounted in modified Ussing chambers, and thepassage of the different marker compounds from the mucosal to the serosal side was measured for 120 min. Avenacosides (1 mg/ml) gave a significantly higher passage of the macromolecule ovalbumin and there was a tendency to increased passage of [14C]D-mannitol and [15Cr]EDTA. On the other hand, the saponins did not affect the active transport of [3H]methyl glucose. When rats were given saponins (40 mg/kg body weight)together with markers by gastric intubation, the passage of [51Cr]EDTA into blood and urine was somewhat reduced. For the macromolecule bovine serum albumin, no evident effect on the passage was observed in the presence ofsaponins. Thus, in contrast to the in vitro results, the in vivo marker passage seemed to be unaffected or even reduced in the presence of avenacosides. The study shows that saponinscan affect the permeability of the rat intestine. However, this effect needs further investigation in vivo, especially regarding proteins.