Effect of meal size on myocardial oxygen requirements: implications for postmyocardial infarction diet

The validity of the assumption that eating a small meal places less postprandial demands on the circulatory system than eating a large meal was examined in eight healthy volunteers. Five meal sizes that ranged from 15 to 75% of daily energy requirements were fed. There was a significant correlation between meal size (in percentage of daily caloric requirements) and peak percentage change in cardiac index (p less than 0.001) and stroke volume (p less than 0.05) (echocardiography); heart rate (p less than 0.001); an index of myocardial oxygen consumption (heart rate X mean blood pressure) (p less than 0.01); and whole body oxygen consumption (p less than 0.001). There was no significant correlation between meal size and peak percentage change in systolic and diastolic blood pressure. The duration of hemodynamic and metabolic changes that followed medium and large meals (greater than or equal to 35% of daily energy needs) exceeded smaller meals (less than or equal to 25% of energy needs). These results may have implications in the management of patients with ischemic heart disease.     

Comparative review of diets for the metabolic syndrome: implications for nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a significant health problem and affects 70 million adults in the United States (30% of the adult population), and an estimated 20% of these individuals have the most severe form of NAFLD-nonalcoholic steatohepatitis (NASH). The mechanisms underlying disease development and progression are awaiting clarification. Insulin resistance and obesity-related inflammation, among other possible genetic, dietary, and lifestyle factors, are thought to play a key role. A program targeting gradual weight reduction and physical exercise continues to be the gold standard of treatment for all forms of NAFLD. Even though weight loss and dietary and lifestyle changes are recommended as primary treatment for fatty liver, little to no scientific evidence is available on diet and NAFLD. This article reviews the implications of current dietary approaches, including national guidelines and popular weight-loss diets, with a focus on determining the optimal diet to prescribe for NAFLD and NASH patients. The effects of macronutrient content (carbohydrate, fat, and protein ratios) and specific food components, such as soluble fiber, n-3 fatty acids, and fructose, are discussed. The premises, effects, barriers, and issues related to current dietary guidelines and specific diets are discussed, and the question, "Will it work for the pathogenesis of NAFLD and NASH? ", is addressed.     

Impact of maternal metabolic abnormalities in pregnancy on human milk and subsequent infant metabolic development: methodology and design

Background  

Childhood obesity is on the rise and is a major risk factor for type 2 diabetes later in life. Recent evidence indicates that abnormalities that increase risk for diabetes may be initiated early in infancy. Since the offspring of women with diabetes have an increased long-term risk for obesity and type 2 diabetes, the impact of maternal metabolic abnormalities on early nutrition and infant metabolic trajectories is of considerable interest. Human breast milk, the preferred food during infancy, contains not only nutrients but also an array of bioactive substances including metabolic hormones. Nonetheless, only a few studies have reported concentrations of metabolic hormones in human milk specifically from women with metabolic abnormalities. We aim to investigate the impact of maternal metabolic abnormalities in pregnancy on human milk hormones and subsequently on infant development over the first year of life. The objective of this report is to present the methodology and design of this study.     

Effect of diet on mucin kinetics and composition: nutrition and health implications

The mucus gel covering the gut epithelium is in dynamic balance between synthesis and secretion of mucin from goblet cells and proteolytic and physical erosion that releases mucin into the lumen. In the lumen, mucin is partially protected from proteolysis by carbohydrate chains, and it contributes to endogenous protein reaching the ileum. Dietary components modulate the contribution of mucin to endogenous protein components and their qualitative composition. In addition, mucin plays a key role in gastrointestinal protection in association with the microflora. In this review, we will attempt to evaluate the consequences of dietary manipulation of mucin on gut health.     

Retrospective versus original information on diet: implications for epidemiological studies

The aim of this study was to evaluate the use of retrospective information on diet in relation to the information originally reported. Hospital controls (n = 131) who participated in a case-control study on diet and pancreatic cancer in Stockholm, Sweden, answered a second postal questionnaire four years later about their current and previous food consumption. The food consumption was dichotomized for the purpose of the analysis. In relation to the original information, the use of retrospective information overestimated previous food consumption among subjects with increased intake, while retrospective information underestimated previous food consumption among subjects with decreased intake. These tendencies were slightly more pronounced in the age group 60-79 years than in the age group 40-59 years. For subjects with unchanged food consumption, there was a high agreement between original and retrospective information. Considerable differential misclassification could be introduced in an epidemiological study if cases and non-cases differ with regard to changes in food consumption.     

Effect of diet manipulation on metabolic changes and performance in competitive cyclists

Thirteen highly trained subjects were studied for the effect of consuming a normal carbohydrate-rich diet (N) on energy exchanged, substrate metabolism and performance. Six of these subjects performed the same protocol receiving N supplemented with a high maltodextrin-low fructose beverage (Mf). The studies were performed in random order. The subjects performed two days of sustained exhausting cycling, proceeded and followed by a standardized resting day, in a respiration chamber allowing for continuous gas analysis, weighed food and fluid intake, collection of excreta and drawing of blood samples at 07.00 hours, 12.00 hours (halfway exercise) and 15.00 hours at exhaustion. Muscle biopsies were taken prior to, 45 min after and 24 h after exercise (energy expenditure 25.2–26.6 MJ/day).
The results showed that while consuming a normal diet, the cyclists develop a negative energy balance (-9 MJ/day) and regulate their hormone levels in such a way that fat oxidation and protein breakdown are increased and CHO oxidation becomes depressed.
When supplemented with Mf the subjects showed increased blood glucose, insulin and decreased glucagon levels. Fat metabolism was significantly depressed as indicated by the levels of blood fatty acids, glycerol and ketones.
A significant glycogen sparing, as well as supercompensation within 24 h of recovery, was observed after Mf supplementation. The normal ad libitum available CHO-rich diet was insufficient fully to restore glycogen within 24 h. The changes in substrate availability and glycogen depletion were accompanied by a significant performance improvement, 126% when cycling a final 90% Wmax bout, when supplemented with Mf compared to N.     

The global burden of disease attributable to low consumption of fruit and vegetables: implications for the global strategy on diet

OBJECTIVE: We estimated the global burden of disease attributable to low consumption of fruit and vegetables, an increasingly recognized risk factor for cardiovascular disease and cancer, and compared its impact with that of other major risk factors for disease. METHODS: The burden of disease attributable to suboptimal intake of fruit and vegetables was estimated using information on fruit and vegetable consumption in the population, and on its association with six health outcomes (ischaemic heart disease, stroke, stomach, oesophageal, colorectal and lung cancer). Data from both sources were stratified by sex, age and by 14 geographical regions. FINDINGS: The total worldwide mortality currently attributable to inadequate consumption of fruit and vegetables is estimated to be up to 2.635 million deaths per year. Increasing individual fruit and vegetable consumption to up to 600 g per day (the baseline of choice) could reduce the total worldwide burden of disease by 1.8%, and reduce the burden of ischaemic heart disease and ischaemic stroke by 31% and 19% respectively. For stomach, oesophageal, lung and colorectal cancer, the potential reductions were 19%, 20%, 12% and 2%, respectively. CONCLUSION: This study shows the potentially large impact that increasing fruit and vegetable intake could have in reducing many noncommunicable diseases. It highlights the need for much greater emphasis on dietary risk factors in public health policy in order to tackle the rise in noncommunicable diseases worldwide, and suggests that the proposed intersectoral WHO/FAO fruit and vegetable promotion initiative is a crucial component in any global diet strategy.     

Dietary whey protein lowers the risk for metabolic disease in mice fed a high-fat diet

Consuming a high-fat (HF) diet produces excessive weight gain, adiposity, and metabolic complications associated with risk for developing type 2 diabetes and fatty liver disease. This study evaluated the influence of whey protein isolate (WPI) on systemic energy balance and metabolic changes in mice fed a HF diet. Female C57BL/6J mice received for 11 wk a HF diet, with or without 100 g WPI/L drinking water. Energy consumption and glucose and lipid metabolism were examined. WPI mice had lower rates of body weight gain and percent body fat and greater lean body mass, although energy consumption was unchanged. These results were consistent with WPI mice having higher basal metabolic rates, respiratory quotients, and hepatic mitochondrial respiration. Health implications for WPI were reflected in early biomarkers for fatty liver disease and type 2 diabetes. Livers from WPI mice had significantly fewer hepatic lipid droplet numbers and less deposition of nonpolar lipids. Furthermore, WPI improved glucose tolerance and insulin sensitivity. We conclude that in mice receiving a HF diet, consumption of WPI results in higher basal metabolic rates and altered metabolism of dietary lipids. Because WPI mice had less hepatosteatosis and insulin resistance, WPI dietary supplements may be effective in slowing the development of fatty liver disease and type 2 diabetes.     

Effect of diet on progression of chronic renal disease

Changes in renal function induced by protein intake are thought to reflect evolutionary adaptation of the kidney. Excess dietary proteins over long periods may increase normal blood flow and glomerular filtration rate, requiring the continuous use of outer cortex's reserve glomeruli. According to the hyperfiltration theory, pressures and flows in outer cortical glomeruli contribute to continuous intrarenal capillary hypertension and predispose healthy people to progressive glomerular sclerosis and deterioration of renal function. Pressures and flows associated with the response to renal disease in turn may accelerate the development of sclerosis, leading to even more rapid loss of renal function. Restriction of dietary protein (less than or equal to 0.6 g/kg per day) and/or phosphorus seems to slow the rate of loss of renal function in patients with chronic renal insufficiency. Evidence for the role of lipids in the progression of renal disease is not clear. All of these dietary factors possibly play a role in the progression of renal disease; the relative importance of each factor varies, depending on the pathogenesis, stage, and mechanism of progression of the disease. Findings indicate that nutrition therapy can decrease rate of deterioration of renal function in patients with chronic renal diseases.     

Electrostatic potential on human leukocyte antigen: implications for putative mechanism of chronic beryllium disease

The pathobiology of chronic beryllium disease (CBD) involves the major histocompatibility complex class II human leukocyte antigen (HLA). Although occupational exposure to beryllium is the cause of CBD, molecular epidemiologic studies suggest that specific (Italic)HLA-DPB1(/Italic) alleles may be genetic susceptibility factors. We have studied three-dimensional structural models of HLA-DP proteins encoded by these genes. The extracellular domains of HLA-DPA1*0103/B1*1701, *1901, *0201, and *0401, and HLA-DPA1*0201/B1*1701, *1901, *0201, and *0401 were modeled from the X-ray coordinates of an HLA-DR template. Using these models, the electrostatic potential at the molecular surface of each HLA-DP was calculated and compared. These comparisons identify specific characteristics in the vicinity of the antigen-binding pocket that distinguish the different HLA-DP allotypes. Differences in electrostatics originate from the shape, specific disposition, and variation in the negatively charged groups around the pocket. The more negative the pocket potential, the greater the odds of developing CBD estimated from reported epidemiologic studies. Adverse impact is caused by charged substitutions in positions 55, 56, 69, 84, and 85, namely, the exact same loci identified as genetic markers of CBD susceptibility as well as cobalt-lung hard metal disease. These findings suggest that certain substitutions may promote an involuntary cation-binding site within a putatively metal-free peptide-binding pocket and therefore change the innate specificity of antigen recognition.     

Trans fatty acids in human milk lipids: influence of maternal diet and weight loss

Geometric and positional isomers of octadecanoic acid in milk expressed during the first 9 weeks of lactation were determined for mothers delivering prematurely (PT) and at term (FT). Total C18:1 concentration was lower in PT than FT milk. C18:1 trans (elaidic acid) content was higher in PT and FT colostrum compared with subsequent milk samples. No relationship was observed between C18:1 trans level in milk and oleic acid, linoleic acid, total fatty acid levels, or volume of milk expressed. While gestational age and lactational stage appeared to affect the trans fatty acid pattern, the overriding influence was rate of maternal postpartum weight loss. Effect of weight loss on milk trans fatty acid levels was independent of maternal diet. Trans fatty acid content of milk as a function of recent maternal fat intake was also demonstrated. This study indicates that infants receiving human milk ingest levels of trans fatty acids reflecting short and long term maternal diet.     

Effect of fast-food Mediterranean-type diet on human plasma oxidation

Oxidation of lipoproteins, particularly of low-density lipoprotein (LDL), is of prime importance in the initiation and progression of atherosclerosis. The Mediterranean diet has been associated with an unexpectedly low rate of cardiovascular events. Type 2 diabetic patients are at high risk of developing atherosclerosis. Functional alterations in the endothelium, which lead to atherosclerosis, are stimulated by oxidized lipoproteins, particularly oxidized LDL. The present study investigated the effect of Greek quick casual Mediterranean-type diet (fast food Mediterranean-type diet) consumption on the resistance to oxidation in plasma from type 2 diabetic patients and healthy human subjects. Lipids from fast food Mediterranean-type foodstuffs were extracted and tested in vitro for their ability to inhibit copper (Cu2+)-induced LDL oxidation. Foodstuffs that exerted the most potent in vitro antioxidative activity were chosen for the diet of study groups. Eighteen type 2 diabetic patients (group A) and 10 healthy subjects (group B) were fed a 4-week diet contained the chosen foodstuffs, while 17 type 2 diabetic patients (group C) were kept on their regular diet that they were following before the study. Type 2 diabetic patients were treated with sulfonylureas or metformin and were under good glycemic control (hemoglobin A1C < 7%). Serum lipoproteins, triglycerides, glucose, body mass index (BMI), and plasma resistance to Cu2+-induced oxidation before and after the 4-week diet were monitored. At the beginning of the study, no statistical difference was detected in plasma resistance to Cu2+-induced oxidation between type 2 diabetic patients (groups A and C) and healthy human subjects (group B), as this was detected at a time before the oxidation products become detectable, namely, lag time. After the 4-week period on the chosen diet the lag time in groups A and B significantly increased, while it was not changed in group C. In type 2 diabetic patients lag time was increased from 57.3 +/- 13.3 minutes (mean +/- SD) to 103.8 +/- 21.8 minutes (mean +/- SD) (P < .000), while in healthy human subjects there was an increase from 58.0 +/- 8.5 minutes (mean +/- SD) to 85.7 +/- 21.8 minutes (mean +/- SD) (P < .004). In all groups, total cholesterol, high-density lipoprotein-cholesterol, LDL-cholesterol, triglycerides, glucose, and BMI were not changed. Fast food Mediterranean foodstuffs exerted antioxidant activities both in vitro and in vivo after consumption in type 2 diabetic patients and healthy human subjects. Therefore consumption of a fast food Mediterranean-type diet should contribute to prevention against cardiovascular diseases.     

孕期高中链脂肪膳食对后代UCP3基因的影响

目的:探讨孕期膳食对子代肥胖和肥胖相关基因解偶联蛋白3(UCP3)表达的影响,寻找肥胖预防和治疗的靶标。方法:W istar孕鼠分别食用标准膳食和高中链脂肪膳食,所产雄性子鼠分别为对照组和高中链脂肪酸组(HMCFA),3周断乳后大鼠均食用标准膳食至成年,将对照组的大鼠随机分为两组:一组继续食用标准膳食;另一组为高脂对照组(HFCON),HFCON和HMCFA组的大鼠均高脂膳食诱导肥胖6周。分别在大鼠出生、断乳、成年、高脂诱导肥胖后各处死一批大鼠,取褐色脂肪检测UCP3 mRNA的表达。结果:与孕期标准膳食的子代相比,孕期高中链脂肪膳食可持续降低子代大鼠的体重和肥胖率(P<0.05),同时也可持续升高UCP3 mRNA的表达。结论:孕期高中链脂肪膳食可降低子代成年高脂诱导肥胖的发生;其机制为通过程序性升高子代UCP3基因的表达增加脂肪氧化和热能散失。     

孕期膳食结构对妊娠结局的影响研究

目的探讨孕期膳食结构对妊娠结局的影响,为指导孕期合理膳食提供科学依据。方法选择950例晚期妊娠妇女,对28~39周的膳食结构进行调查,将600例膳食不均的孕产妇为观察组,350例膳食均衡的孕产妇为对照组,采用妊娠妇女健康问卷、膳食调查及营养评定,追踪随访两组孕妇的妊娠结局,比较两组孕妇的膳食结构对母儿影响情况。结果观察组妊娠妇女的膳食结构存在总能量摄入量、蛋白质量、脂肪量不平衡。观察组的剖宫产率、妊娠期合并症(贫血、糖尿病、糖耐量异常、高血压)的发生率、早产、流产、产后出血、胎儿窘迫、胎膜早破、巨大儿、低体重儿、死胎及畸胎发生率均显著高于对照组(P0.05)。结论应重视和改善孕妇孕期营养状况,并根据孕期产妇的个体情况,指导其饮食多样化,合理调节各项营养素的摄入比例,平衡膳食,保证胎儿生命早期的良好营养状况,降低妊娠合并症的发生率。