Physico-chemical properties of sobia: A traditional fermented beverage in western province of Saudi Arabia

Sobia samples (14 samples) were collected from Makkah Al-Mukarrmah (Western province) and from Riyadh (Central province). Chemical (moisture, protein, fat, ash carbohydrate, energy, sugars, and ethanol) and physical (total soluble solids, total solids, viscosity, density, refractive index (RI), and specific gravity) properties of the sobia samples were studied. The moisture, protein, ash carbohydrate, and energy contents were found to be in the range of 82.33% to 89.23%, 0.26% to 0.63%, 0.023% to 0.106%, 9.95% to 17.22%, and 41.25 kcal to 70.54 kcal, respectively, and no fat was detected. Glucose and fructose were present in all samples except sample 3. Samples 1 to 10 contained sucrose in the range of 53.93 to 130.89 g/l, while samples 11 to 14 had no sucrose. Only four samples (1, 2, 9, and 10) contained maltose. The ethanol content in fresh samples ranged from 0.00 to 1.00 g/l, and after a week of storage at refrigerator temperature (3-5 C) ethanol content increased in all samples with samples 5 and 6 having the highest ethanol content of 4.24 and 4.54 g/l, respectively. Total soluble solids (Brix ), total solids (%), viscosity (cP), density, RI, and specific gravity values of sobia were found to be in the range of 6.83 to 15.10, 7.60 to 15.40, 1.47 to 4.39, 1.033 to 1.063, 1.3429 to 1.3559, and 1.0303 to 1.0600, respectively.     

Nutritional quality of leaves of some genotypes of mulberry (Morus alba)

This study was undertaken to determine the proximate composition, vitamins, minerals and the antinutritional factor tannic acid in leaves of six genotypes of mulberry. The results showed that in fresh mulberry leaves the proximate composition values ranged from 71.13 to 76.68% for moisture, from 4.72 to 9.96% for crude protein, from 4.26 to 5.32% for total ash, from 8.15 to 11.32% for Neutral Detergent Fiber (NDF), from 0.64 to 1.51% for crude fat, from 8.01 to 13.42% for carbohydrate and from 69 to 86 kcal/100 g for energy. In dried mulberry leaf powder, moisture ranged from 5.11 to 7.24%, crude protein from 15.31 to 30.91%, total ash from 14.59 to 17.24%, NDF from 27.60 to 36.66%, crude fat from 2.09 to 4.93%, carbohydrate from 9.70 to 29.64% and energy from 113 to 224 kcal/100 g. Among vitamins ascorbic acid and β-carotene were found to range from 160 to 280 mg/100 g and from 10,000.00 to 14,688.00 µg/100 g, respectively, in fresh mulberry leaves and from 100 to 200 mg/100 g and from 8438.00 to 13,125.00 µg/100 g, respectively, in dried mulberry leaf powder. The minerals iron, zinc and calcium were observed in the ranges of 4.70–10.36 mg/100 g, 0.22–1.12 mg/100 g and 380–786 mg/100 g, respectively, for fresh mulberry leaves, and 19.00–35.72 mg/100 g, 0.72–3.65 mg/100 g and 786.66–2226.66 mg/100 g, respectively, for dried mulberry leaf powder. The tannic acid ranged from 0.04 to 0.08% in fresh leaves and from 0.13 to 0.36% in dried leaf powder.     

Nutritional quality of leaves of some genotypes of mulberry (Morus alba)

This study was undertaken to determine the proximate composition, vitamins, minerals and the antinutritional factor tannic acid in leaves of six genotypes of mulberry. The results showed that in fresh mulberry leaves the proximate composition values ranged from 71.13 to 76.68% for moisture, from 4.72 to 9.96% for crude protein, from 4.26 to 5.32% for total ash, from 8.15 to 11.32% for Neutral Detergent Fiber (NDF), from 0.64 to 1.51% for crude fat, from 8.01 to 13.42% for carbohydrate and from 69 to 86 kcal/100 g for energy. In dried mulberry leaf powder, moisture ranged from 5.11 to 7.24%, crude protein from 15.31 to 30.91%, total ash from 14.59 to 17.24%, NDF from 27.60 to 36.66%, crude fat from 2.09 to 4.93%, carbohydrate from 9.70 to 29.64% and energy from 113 to 224 kcal/100 g. Among vitamins ascorbic acid and beta-carotene were found to range from 160 to 280 mg/100 g and from 10,000.00 to 14,688.00 microg/100 g, respectively, in fresh mulberry leaves and from 100 to 200 mg/100 g and from 8438.00 to 13,125.00 microg/100 g, respectively, in dried mulberry leaf powder. The minerals iron, zinc and calcium were observed in the ranges of 4.70-10.36 mg/100 g, 0.22-1.12 mg/100 g and 380-786 mg/100 g, respectively, for fresh mulberry leaves, and 19.00-35.72 mg/100 g, 0.72-3.65 mg/100 g and 786.66-2226.66 mg/100 g, respectively, for dried mulberry leaf powder. The tannic acid ranged from 0.04 to 0.08% in fresh leaves and from 0.13 to 0.36% in dried leaf powder.     

The effects of particle size and moisture content on the emanation of Rn from coal ash

Measurements of the emanation coefficients of 222Rn from coal ash were performed. Samples of coal ash from a stoker-fired furnace were mechanically sized into four categories. The mean 226Ra concentration of these categories ranged from 11.82-16.77 dpm g-1 and increased as a function of decreasing particle size. The mean bulk density and mean specific gravity of these categories ranged from 0.488-0.944 g cm-3 and 2.017-2.390 g cm-3, respectively, and both increased as a function of decreasing particle size. Samples of coal ash from four pulverized coal-fired furnaces were obtained, and demonstrated mean 226Ra concentrations ranging from 6.44-7.59 dpm g-1. The mean bulk density and mean specific gravity of these samples ranged from 1.254-1.520 g cm-3 and 2.357-2.588 g cm-3, respectively. Construction of chambers and methods for measuring 222Rn emanation coefficients are described. The measured emanation coefficient is shown to be insensitive to ingrowth time at times greater than three days. Measurements of emanation coefficients from ash samples were conducted at moisture contents of 0, 1.0, 10, 20 and 40% moisture by weight, and showed an increase in the emanation coefficient as a function of moisture content up to about 20% moisture by weight. Above 20% moisture content, most samples showed a trend toward decreasing emanation coefficients. The fractionated ash samples showed an increase in the emanation coefficient as a function of decreasing particle size. An experiment was also conducted which confirmed that sample depth was insignificant in explaining the observed emanation coefficient over the range of depths used in the other experiments.     

Proximate and mineral compositions of cooked and uncooked Solanum melongena

The proximate and mineral compositions of four different varieties of cooked and uncooked Solanum melongena were determined. Except for the percentage moisture, the levels of crude protein, crude fat, total ash and carbohydrate content were generally higher in uncooked samples than in cooked samples. Solanum macrocarpum (uncooked) has the highest moisture content with an average value of 73.9% and 84.5% for coat and flesh respectively, while the coat of Solanum sessiliflorum and flesh of Solanum aethiopicum have the least moisture content with average values of 60.0% and 69.5% respectively. The mineral components in the uncooked samples were generally found to be higher than those observed in the cooked samples. Solanum sessiliflorum has the highest value for nearly all the minerals for both the cooked and uncooked samples, while Solanum aethiopicum has the lowest value. The mineral contents were found to be higher in the coat than the flesh in most of the samples. Sodium and potassium were found to be the most abundant cations in both the coat and the flesh of cooked and uncooked fruits.     

Dietary management of malnourished children with a new enteral feeding

Balance (nitrogen, fat, carbohydrate) and growth studies were carried out in nine children (6 to 26 months old) recovering from protein-energy malnutrition (PEM) using a concentrated (1 kcal/mL) formula designed specifically for 1- to 6-year-olds. The formula provided 12% of energy as protein (18% whey, 82% casein), 44% of energy as carbohydrate (69% corn syrup solids, 31% sucrose), and 44% of energy as fat (50% high-oleic safflower oil, 30% soy oil, 20% medium-chain triglycerides). Means +/- standard deviations of apparent nitrogen retention and absorption were 90 +/- 3% and 39 +/- 13%, respectively. Mean fecal fat excretion was 1.3 +/- 1.0 g/day. Length-age increased 3.0 +/- 0.8 months and weight-age increased 8.3 +/- 3.8 months during the 2.4 +/- 0.3 months of the study. (Length-age and weight-age were defined as the age (in months) to which the child's length or weight corresponded at the 50th percentile of the National Center for Health Statistics reference data). Thirteen additional 40- to 30-month-old children with kwashiorkor were fed the formula for 8 to 35 days as part of the initial management of PEM. The result was prompt weight gain and increases in serum proteins. Its formulation and the findings of our study indicate that this new formula offers a notable advantage over products designed for infants or adults in the enteral alimentation of young children.     

三例慢性放射病患者的氮平衡观察

选择三例慢性放射病患者进行了两期氮平衡实验,每期三日。第一期:当膳食中蛋白质摄入量为75.4～77.2g,热量为1586～1669kcal时,氮平衡为-0.01～-0.50g,第二期:当膳食中蛋白质和热量分别增加至97.2g和2467～2483kcal时,氮平衡为+2.37～+2.93g。两期的蛋白质、脂肪、糖的表观消化率基本相似,显然第一期出现的负氮平衡与蛋白质和热量摄取量不足有关。文中指出,在治疗慢性放射病患者时,应注意供给高热量和高蛋白质的膳食。     

Food glycemic index, as given in glycemic index tables, is a significant determinant of glycemic responses elicited by composite breakfast meals

BACKGROUND: Recent studies have concluded that the carbohydrate content and glycemic index (GI) of individual foods do not predict the glycemic and insulinemic effects of mixed meals. We hypothesized that these conclusions may be unwarranted because of methodologic considerations. OBJECTIVE: The aim was to ascertain whether the GI and carbohydrate content of individual foods influence glucose and insulin responses elicited by realistic mixed meals in normal subjects. DESIGN: With the use of a crossover design, we determined the glucose and insulin responses of 6 test meals in 16 subjects in Sydney and the glucose responses of 8 test meals in 10 subjects in Toronto and then the results were pooled. The 14 different test meals varied in energy (220-450 kcal), protein (0-18 g), fat (0-18 g), and available carbohydrate (16-79 g) content and in GI (35-100; values were rounded). RESULTS: The glucose and insulin responses of the Sydney test meals varied over a 3-fold range (P < 0.001), and the glucose responses of the Toronto test meals varied over a 2.4-fold range (P < 0.001). The glucose responses were not related to the fat or protein content of the test meal. Carbohydrate content (P = 0.002) and GI (P = 0.022) alone were related to glucose responses; together they accounted for 88% of the variation in the glycemic response (P < 0.0001). The insulin response was significantly related to the glucose response (r = 0.94, P = 0.005). CONCLUSIONS: When properly applied in realistic settings, GI is a significant determinant of the glycemic effect of mixed meals in normal subjects. For mixed meals within the broad range of nutrient composition that we tested, carbohydrate content and GI together explained approximately 90% of the variation in the mean glycemic response, with protein and fat having negligible effects.     

Feeding a liquid diet increases energy intake, weight gain and body fat in rats

Studies were undertaken to analyze the role of moisture content of foods in producing dietary obesity. Female CD rats consumed more energy when offered a sucrose solution and plain water to drink than when they were only given plain water, regardless of the sugar content of their diet (0-65%). This suggested that the overeating that commonly occurs when sucrose solutions are offered may not be due to sucrose per se. In subsequent experiments, rats were fed modified AIN-76 diets high in sucrose, starch or fat for 28-42 d. For some rats, the diet was liquefied by adding water to make a 32% suspension. Plain drinking water was always available. Rats fed high carbohydrate liquid diets, with or without solid diet, consumed 8-15% more energy than rats fed solid diet only. Rats fed liquid diets also gained 43-206% more weight than did rats fed solid diets. Analysis of carcass composition revealed that the liquid diets increased body fat. For high fat diets, the results were more complicated. Addition of water to a low cellulose, high fat diet did not increase adiposity, whereas addition of water to a high cellulose, high fat diet did increase adiposity. These results suggest that the obesity-inducing effects of feeding sugar solutions or cafeteria diets may be due, in part, to the high water content of these foods.     

Nutrition evaluation and mutagenicity testing of freeze-dried distiller's grains with solubles

Distiller's grains with solubles (DGS) was obtained from a commercial fermentation of 90% corn and 10% wheat for ethanol production. The DGS was freeze-dried and proximate analysis resulted in 17.6% protein, 5.5% fat, 3.0% ash, 17.3% moisture, 21.6% neutral detergent fiber, and 35% carbohydrate by difference. Fatty acid analysis and amino acid analysis were similar to those of corn. Tryptophan was the limiting amino acid with a chemical score of 47. Protein Efficiency Ratio (PER) was 1.49. Mutagenicity testing of lipid and aqueous extracts of DGS in the Ames Salmonella mammalian microsome assay were negative.     

黄鳍马面魨肌肉主要营养成分分析与评价

目的分析测定南海海区黄鳍马面魨的肌肉营养成分,对其营养价值进行综合评价。方法采用现时的国家标准方法测定粗蛋白质、粗脂肪、灰分、氨基酸和脂肪酸含量。结果黄鳍马面魨肌肉鲜肉的粗蛋白质含量(17.01±0.12)%;粗脂肪含量(0.67±0.23)%;水分含量(79.81±0.36)%;灰分含量(1.88±0.27)%;18种氨基酸总量为67.70%,其中8种必需氨基酸含量占氨基酸总量的44.43%,必需氨基酸与非必需氨基酸比值79.96%,氨基酸得分(AAS)2435;粗脂肪中含28种脂肪酸,以油酸的含量最高,二十碳五烯酸EPA与二十二碳六烯酸DHA之和占总脂肪酸含量的17.03%;鱼肉富含Ca、Fe、Zn等必需金属元素,有害元素含量均在允许范围之内。结论黄鳍马面魨肌肉蛋白质含量较高,必需氨基酸含量较丰富,粗脂肪含量较低,是营养价值较高的鱼类。     

北京市城乡乳母的营养状况、乳成分和婴儿摄入母乳量及生长发育的关系——Ⅲ母乳的脂质分析

本文报导了1983～1984年北京市城区(宣武区),近郊区(西红门)和远郊区(大皮营)母乳脂质成分的测定结果,并结合乳母营养状况给予评价。 共测定了207例母乳比重,平均范围在1.018～1.023之间;测定了216例母乳的脂肪含量(g/100g乳),城区平均值为3.78,近郊区为3.31,远郊区为3.08,城区的显著较高;测定了194例母乳胆固醇含量,初乳的最高(23.4mg/100g乳),以后逐渐减低,到第三个月后达稳定水平(约10mg/100g乳),三个调查点的情况相同,测定了221例母乳的脂肪酸组成,其主要成分为油酸(29～37％),棕榈酸(17～25％)和亚油酸(12～25％),远郊区母乳中所含的必需脂肪酸显著较高。 统计分析证明三个地区的乳脂含量(％)与乳胆固醇含量(mg/100g乳)间有显著性相关(P<0.01);188例乳母的膳食脂肪摄入量(g/日或％kcal)与乳脂含量间也有显著性相关(P<0.05),此结果表明,北京城乡母乳的乳脂含量可能受膳食脂质与量的影响,其脂肪酸组成的特点是亚油酸含量高,反映了我国人民以素食为主的饮食习惯。乳中的必需脂肪酸供给量可满足婴儿所需,胆固醇供给量为70～85mg/d,可作为同龄婴儿自母乳摄入量的参考。     

Effects of Preloads of Differing Energy and Macronutrient Content on Eating Behavior in Bulimia Nervosa

Evidence suggests that bulimics demonstrate blunted satiety possibly due to repeated episodes of overeating. This suggestion was tested further by comparing responses to yogurt preloads differing in carbohydrate and fat relative to a lower energy control yogurt in 12 bulimics and 12 age- and weight-matched controls. Participants were tested on three occasions at lunchtime. On each occasion, appetite and mood were rated before and after receiving a lunch of raspberry yogurt (350 g). Covert manipulation of energy and nutrient content was achieved by matching the yogurts on sensory properties and formulating a control yogurt (161 kcal), a high-fat version (357 kcal: 65% calories from fat), and a high-carbohydrate version (357 kcal: 81% calories from carbohydrate). Although there were no differential effects of the preloads on intake of anad libitumtest meal given 5 hr later in either the control or bulimic groups, there were significant differences in test meal energy intake between groups. On average and with all conditions combined, bulimics ate significantly fewer calories (775±167 kcal) than controls (1182±94 kcal) and consumed a greater percentage of calories from carbohydrate than controls. Bulimics restricted their intake relative to controls, and chose foods low in fat. This study provides further evidence of restricted eating in bulimia nervosa when the opportunity to purge is not available. Furthermore, the present study suggests that intake by bulimics is not influenced by nutrient contentper sebut by consideration of the caloric value of foods and the consequences of eating certain foods for weight control.     

Impact of flour particle size on nutrient and phenolic acid composition of commercial wheat varieties

In the present study, the effect of particle size (PS) on phenolic acid content and proximate composition (moisture, ash, protein, total fat, crude fiber and total carbohydrates) of whole-wheat flour (WWF) was determined. Five different particle size fractions <1.18 to>0.43, <0.43 to>0.30, <0.30 to>0.15, < 0.15 to>0.08 mm, and < 0.08 mm (ASTM recommended), of three commercial wheat varieties (Benazir, TJ-83, Imdad) were used for the present study. Total phenolic acid was determined using HPLC-DAD detections after base hydrolysis of the samples. Proximate composition of each particle size fraction of all three wheat flours were determined by recommended AOAC methods. In all wheat varieties, maximum quantities of total phenolic acids (162.12–554.16 mg/100 g) were obtained from <1.18 to>0.43 mm PS fractions. The maximum moisture content (8.12–8.98 g/100 g) was observed in the two lower PS (<0.15 mm) fractions while ash and protein were highest in the largest PS (<1.18 to>0.43) i.e. 2.10–2.77 mg/100 g and 10.9–11.8 mg/100 g respectively. The total fat (0.24-0.53 mg/100 g) and crude fiber (0.40-0.59 mg/100 g) were highest in <0.43 to>0.30 PS fraction of all wheat varieties. The average carbohydrates (g/100 g) and energy (kilojoules) were ranged from 77.4-79.9, 1502.0-–1518.8 for Imdad; 79.7-84.3, 1518.8-–1527.2 for Benazir; and 78.4-81.1, 1506.2-–1518.8 for TJ-83 wheat varieties. Pearson correlation showed negative correlation between particle size and carbohydrate and energy content and positive correlation with phenolic acids content. This study concludes that particle size has direct influence on the distribution of phenolic acids, carbohydrate, protein, crude fiber, ash, crude fat and moisture in the three wheat varieties.     

Protein and energy relationships in the diet of the American alligator (Alligator mississippiensis)

First-year alligators (Alligator mississippiensis) averaging 377-857 g body weight were fed diets containing various levels of protein, fat and carbohydrate. In experiment 1, nine diets arranged in a centrally rotatable composite design contained 0-36% extruded corn and 4-20% total fat. Response surface analysis predicted maximum responses in performance criteria at 6.3-18.8% corn and 15.8-27.4% fat. Corn inclusion at up to 27-36% of diet resulted in equal or improved performance compared to carbohydrate-free diets of equal fat content. Energy digestibility averaged 84.3%. Protein digestibility averaged 86.7%. Maximum responses in performance criteria were predicted at 42.5-48.7% digestible protein and 4367-4421 kcal/kg digestible energy. In two additional experiments, alligators were either fasted or fed for various numbers of days/week. Carbohydrate-supplementation of high protein diets led to equal or significantly improved performances. Performance was maximized by feeding the alligators 5-6 d/w. Regression of body weight changes against energy and protein intake yielded estimates of daily maintenance requirements of 5.7-8.4 kcal and 0.49-0.89 g protein/kg live body weight. Dietary fat and carbohydrate in the forms and amounts fed to young alligators were well-utilized. Optimal digestible energy:crude protein ratios (8.2-10.9:1 kcal/g protein) were similar to those of other aquatic ectotherms of equal size.     

Nutritional Attributes of Improved Varieties of Cowpea (Vigna Unguiculata (L.) Walp.)

The proximate and mineral compositions of four different varieties of cooked and uncooked Solanum melongena were determined. Except for the percentage moisture, the levels of crude protein, crude fat, total ash and carbohydrate content were generally higher in uncooked samples than in cooked samples. Solanum macrocarpum (uncooked) has the highest moisture content with an average value of 73.9% and 84.5% for coat and flesh respectively, while the coat of Solanum sessiliflorum and flesh of Solanum aethiopicum have the least moisture content with average values of 60.0% and 69.5% respectively. The mineral components in the uncooked samples were generally found to be higher than those observed in the cooked samples. Solanum sessiliflorum has the highest value for nearly all the minerals for both the cooked and uncooked samples, while Solanum aethiopicum has the lowest value. The mineral contents were found to be higher in the coat than the flesh in most of the samples. Sodium and potassium were found to be the most abundant cations in both the coat and the flesh of cooked and uncooked fruits.     

Proximate Composition and Functional Properties of Mushroom Flours from Ganoderma spp., Omphalotus olearius (DC.) Sing. and Hebeloma mesophaeum (Pers.) Quél. Used in Nasarawa State, Nigeria

The proximate composition and functional properties of three edible mushroom (Ganoderma spp., Omphalotus olearius (DC.) Sing. and Hebeloma mesophaeum (Pers.) Quél.) flours used in Nasarawa state, Nigaria were investigated using standard analytical techniques. The samples contained crude protein in the range of 18.5% in Omphalotus olearius to 21.5% in Ganoderma spp. Crude fat varied with values ranging from 6.9% in Ganoderma spp. to 8.7% in Omphalotus olearius. Other proximate composition values were in the following ranges: moisture content 10.0 - 11.1%, ash 7.3 - 8.3%, crude fibre 2.8 - 3.5% and carbohydrate (by difference) 50.3 - 50.9%. The range values of functional properties were: foaming capacity 101.8 - 131.5%, foaming stability 51.0 - 54.0%, water absorption capacity 260.0 - 390.0%, oil absorption capacity 450 - 480%, oil emulsion capacity 57.3 - 61.0mLg- 1, least gelation concentration 12.0 - 14.0% and bulk density 230.0 - 410.0gmL-1. The results showed that these nutrient rich mushroom flours under investigation may prove useful in the formulation of different food products where foaming, emulsification, retention of flavour and palatability as well as gel formation are required.     

不同产地薏苡仁资源营养成分分析与评价

目的对我国12个薏苡主产区薏苡仁资源的营养品质进行分析与评价,为薏苡资源的合理开发利用提供基础资料。方法采用常规生化分析方法。结果13种薏苡仁营养成分的平均值为:蛋白质15.80%,脂肪5.49%,均高于米、面;碳水化合物63.05%,低于米、面;粗纤维和灰分分别为1.75%与1.68%。薏苡仁的Ca含量丰富,高于米、面;VB1、VB2、VB6、Fe、Zn、Se平均含量与米、面相当。薏苡仁的谷氨酸、亮氨酸含量丰富,均高于米、面;赖氨酸含量较低;但含硫氨基酸平均含量丰富,为6.05mg/g,均高于米、面。以AAS为标准,13个样品中,赖氨酸为第一限制性氨基酸,第二限制性氨基酸随产地不同而异,云南产等8个样品为苏氨酸,四川产等5个样品为异亮氨酸,贵州产为缬氨酸。平均EAA/TAA、EAA/NEA值分别为35.86%、55.91%,平均EAAI值58.91%。结论我国薏苡资源营养较齐全,蛋白质具有较好的氨基酸组成,属于较优质蛋白质。     

Nutrient intake and health status of vegans. Chemical analyses of diets using the duplicate portion sampling technique

A strict vegetarian diet [vegan diet (VD)] was investigated. Six middle-aged vegans (three men and three women) collected copies of 24-h diets using the duplicate portion sampling technique. By chemical analyses, the nutrient composition was determined in detail and compared with corresponding figures of a normal mixed Swedish diet. In the VD 30% of the energy originated from fat compared with 40% in normal Swedish mixed diet (MD). Linoleic acid was the dominant fatty acid (60% of total fat in VD versus 8% in MD). The VD contained 24 g protein/1000 kcal compared to 30 g/1000 kcal in MD, but the intake of essential amino acids by the vegans exceeded the recommendations. Dietary fiber was about 5 times higher in the vegan diet (29 versus 6 g/1000 kcal) and sucrose similar to MD (18 versus 21 g/1000 kcal). Among the inorganic nutrients the concentration of calcium (351 versus 391 mg/1000 kcal) and sodium (53 versus 49 mmol/1000 kcal) were similar in both types of diets but the amount of potassium (56 versus 30 mmol/1000 kcal, magnesium (300 versus 110 mg/1000 kcal), iron (9 versus 6.5 mg/1000 kcal), zinc (6.5 versus 4.7 mg/1000 kcal), and copper (2 versus 0.7 mg/1000 kcal) were nearly doubled. Iodine (39 versus 156 micrograms/1000 kcal and selenium (5 versus 17 micrograms/1000 kcal) were much lower in the VD, selenium even being undetectable in several 24-h diets. The VD was rich in folic acid (301 versus 90 micrograms/1000 kcal in MD) but the intake of vitamin B12 was only 0.3 to 0.4 microgram/day (MD: 3 to 4 micrograms/day). No clinical signs of nutritional deficiency were observed in the vegans. Serum protein levels of the vegans as well as their serum lipoproteins were near the lower range of the reference group. In addition, none of the vegans was overweight and their blood pressures were low for their age.     

Failure of dietary fat intake to promote fat oxidation: a factor favoring the development of obesity

Seven young men spent three nights and 2 d in a respiration chamber where their rates of energy expenditure and substrate oxidation were continuously measured by indirect calorimetry. During the first 24 h they ingested a mixed maintenance diet containing 35% of calories as fat. An additional amount of 106 +/- 6 g fat/24 h (means +/- SD) was added to this diet during the following 36 h. The fat supplement (987 +/- 55 kcal/d) did not alter 24-h energy expenditure (2783 +/- 232 vs 2820 +/- 284 kcal/d) and failed to promote the use of fat as a metabolic fuel (fat oxidation 1032 +/- 205 vs 1042 +/- 205 kcal/d). The overall energy balance was closely correlated with the fat balance (r = 0.96, p less than 0.001) but not with the carbohydrate balance (r = -0.12, NS). These data indicate that substantial imbalances between intake and oxidation are much more likely for fat than for carbohydrate.