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1.
Nutrients ; 8(4): 179, 2016 Mar 23.
Artigo em Inglês | MEDLINE | ID: mdl-27023594

RESUMO

The objective of the current study was to explore our hypothesis that average consumption of fructose and fructose containing sugars would not increase risk factors for cardiovascular disease (CVD) and the metabolic syndrome (MetS). A randomized, double blind, parallel group study was conducted where 267 individuals with BMI between 23 and 35 kg/m² consumed low fat sugar sweetened milk, daily for ten weeks as part of usual weight-maintenance diet. One group consumed 18% of calories from high fructose corn syrup (HFCS), another group consumed 18% of calories from sucrose, a third group consumed 9% of calories from fructose, and the fourth group consumed 9% of calories from glucose. There was a small change in waist circumference (80.9 ± 9.5 vs. 81.5 ± 9.5 cm) in the entire cohort, as well as in total cholesterol (4.6 ± 1.0 vs. 4.7 ± 1.0 mmol/L, p < 0.01), triglycerides (TGs) (11.5 ± 6.4 vs. 12.6 ± 8.9 mmol/L, p < 0.01), and systolic (109.2 ± 10.2 vs. 106.1 ± 10.4 mmHg, p < 0.01) and diastolic blood pressure (69.8 ± 8.7 vs. 68.1 ± 9.7 mmHg, p < 0.01). The effects of commonly consumed sugars on components of the MetS and CVD risk factors are minimal, mixed and not clinically significant.


Assuntos
Doenças Cardiovasculares/etiologia , Glucose/farmacologia , Xarope de Milho Rico em Frutose/farmacologia , Síndrome Metabólica/metabolismo , Sacarose/farmacologia , Animais , Composição Corporal , Índice de Massa Corporal , Peso Corporal , Dieta , Carboidratos da Dieta/administração & dosagem , Carboidratos da Dieta/análise , Ingestão de Energia , Análise de Alimentos , Humanos , Leite/química , Fatores de Risco
2.
Nutrients ; 7(10): 8830-45, 2015 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-26512691

RESUMO

Excess sugar consumption may promote adverse changes in hepatic and total body insulin resistance. Debate continues over the effects of sugars at more typically consumed levels and whether the identity of the sugar consumed is important. In the present study participants (20-60 years old) were randomly assigned to one of five groups, three that consumed low fat milk with added fructose containing sugars in amounts equivalent to the 50th percentile of fructose consumption (US), one which consumed low-fat milk sweetened with glucose, and one unsweetened low-fat milk control group. The intervention lasted ten weeks. In the entire study population there was less than 1 kg increase in weight (73.6 ±13.0 vs. 74.5 ± 13.3 kg, p < 0.001), but the change in weight was comparable among groups (p > 0.05). There were no changes in fasting glucose (49 ± 0.4 vs. 5.0 ± 0.5 mmol/L), insulin (56.9 ± 38.9 vs. 61.8 ± 50.0 pmol/L), or insulin resistance, as measured by the Homeostasis Model Assessment method (1.8 ± 1.3 vs. 2.0 ± 1.5, all p > 0.05). These data suggest that added sugar consumed at the median American intake level does not produce changes in measures of insulin sensitivity or glucose tolerance and that no sugar has more deleterious effects than others.


Assuntos
Comportamento Alimentar , Frutose/administração & dosagem , Intolerância à Glucose , Glucose/administração & dosagem , Resistência à Insulina , Edulcorantes/efeitos adversos , Adulto , Glicemia/metabolismo , Jejum , Feminino , Frutose/efeitos adversos , Frutose/farmacologia , Glucose/efeitos adversos , Glucose/farmacologia , Intolerância à Glucose/etiologia , Humanos , Insulina/sangue , Resistência à Insulina/fisiologia , Masculino , Pessoa de Meia-Idade , Edulcorantes/administração & dosagem , Edulcorantes/farmacologia , Aumento de Peso , Adulto Jovem
3.
J Clin Hypertens (Greenwich) ; 17(2): 87-94, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25496265

RESUMO

The impact of fructose, commonly consumed with sugars by humans, on blood pressure and uric acid has yet to be defined. A total of 267 weight-stable participants drank sugar-sweetened milk every day for 10 weeks as part of their usual, mixed-nutrient diet. Groups 1 and 2 had 9% estimated caloric intake from fructose or glucose, respectively, added to milk. Groups 3 and 4 had 18% of estimated caloric intake from high fructose corn syrup or sucrose, respectively, added to the milk. Blood pressure and uric acid were determined prior to and after the 10-week intervention. There was no effect of sugar type on either blood pressure or uric acid (interaction P>.05), and a significant time effect for blood pressure was noted (P<.05). The authors conclude that 10 weeks of consumption of fructose at the 50th percentile level, whether consumed as pure fructose or with fructose-glucose-containing sugars, does not promote hyperuricemia or increase blood pressure.


Assuntos
Pressão Sanguínea/efeitos dos fármacos , Carboidratos da Dieta/farmacologia , Ingestão de Energia/fisiologia , Frutose/farmacologia , Ácido Úrico/sangue , Adulto , Pressão Sanguínea/fisiologia , Peso Corporal/efeitos dos fármacos , Carboidratos da Dieta/efeitos adversos , Feminino , Frutose/efeitos adversos , Humanos , Hipertensão/etiologia , Hipertensão/fisiopatologia , Hiperuricemia/etiologia , Hiperuricemia/fisiopatologia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Método Simples-Cego , Sacarose/farmacologia , Resultado do Tratamento
4.
Nutrients ; 6(8): 3153-68, 2014 Aug 08.
Artigo em Inglês | MEDLINE | ID: mdl-25111121

RESUMO

The American Heart Association (AHA) and World Health Organization (WHO) have recommended restricting calories from added sugars at lower levels than the Institute of Medicine (IOM) recommendations, which are incorporated in the Dietary Guidelines for Americans 2010 (DGAs 2010). Sucrose (SUC) and high fructose corn syrup (HFCS) have been singled out for particular concern, because of their fructose content, which has been specifically implicated for its atherogenic potential and possible role in elevating blood pressure through uric acid-mediated endothelial dysfunction. This study explored the effects when these sugars are consumed at typical population levels up to the 90th percentile population consumption level for fructose. Three hundred fifty five overweight or obese individuals aged 20-60 years old were placed on a eucaloric diet for 10 weeks, which incorporated SUC- or HFCS-sweetened, low-fat milk at 8%, 18% or 30% of calories. There was a slight change in body weight in the entire cohort (169.1 ± 30.6 vs. 171.6 ± 31.8 lbs, p < 0.01), a decrease in HDL (52.9 ± 12.2 vs. 52.0 ± 13.9 mg/dL, p < 0.05) and an increase in triglycerides (104.1 ± 51.8 vs. 114.1 ± 64.7 mg/dL, p < 0.001). However, total cholesterol (183.5 ± 42.8 vs. 184.4 mg/dL, p > 0.05), LDL (110.3 ± 32.0 vs. 110.5 ± 38.9 mg/dL, p > 0.05), SBP (109.4 ± 10.9 vs. 108.3 ± 10.9 mmHg, p > 0.05) and DBP (72.1 ± 8.0 vs. 71.3 ± 8.0 mmHg, p > 0.05) were all unchanged. In no instance did the amount or type of sugar consumed affect the response to the intervention (interaction p > 0.05). These data suggest that: (1) when consumed as part of a normal diet, common fructose-containing sugars do not raise blood pressure, even when consumed at the 90th percentile population consumption level for fructose (five times the upper level recommended by the AHA and three times the upper level recommended by WHO); (2) changes in the lipid profile are mixed, but modest.


Assuntos
Composição Corporal , Peso Corporal , Carboidratos da Dieta/administração & dosagem , Frutose/administração & dosagem , Tecido Adiposo/metabolismo , Adulto , Glicemia/metabolismo , Pressão Sanguínea , Índice de Massa Corporal , Proteína C-Reativa/metabolismo , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/epidemiologia , Colesterol/sangue , Dieta , Carboidratos da Dieta/efeitos adversos , Gorduras na Dieta/administração & dosagem , Proteínas Alimentares/administração & dosagem , Ingestão de Energia , Feminino , Frutose/efeitos adversos , Humanos , Masculino , Síndrome Metabólica/sangue , Síndrome Metabólica/epidemiologia , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Risco , Triglicerídeos/sangue , Circunferência da Cintura , Adulto Jovem
5.
Nutrients ; 6(3): 1128-44, 2014 Mar 17.
Artigo em Inglês | MEDLINE | ID: mdl-24642950

RESUMO

The American Heart Association (AHA) has advocated that women and men not consume more than 100 and 150 kcal/day, respectively, from added sugars. These levels are currently exceeded by over 90% of the adult population in the United States. Few data exist on longer-term metabolic effects when sucrose and High Fructose Corn Syrup (HFCS), the principal sources of added dietary sugars, are consumed at levels typical of the general population. Sixty five overweight and obese individuals were placed on a eucaloric (weight stable) diet for 10-weeks, which incorporated sucrose- or HFCS-sweetened, low-fat milk at 10% or 20% of calories in a randomized, double-blinded study. All groups responded similarly (interaction p > 0.05). There was no change in body weight in any of the groups over the 10-week study, or in systolic or diastolic blood pressure. Likewise, there were no changes in total cholesterol, triglycerides, low-density lipoprotein (LDL), or apolipoprotein B (Apo B). We conclude that (1) when consumed as part of a eucaloric diet fructose--when given with glucose (as normally consumed) does not promote weight gain or an atherogenic lipid profile even when consumed at two to four times the level recently recommended by the AHA. (2) There were no differences between HFCS and sucrose on these parameters.


Assuntos
Colesterol/sangue , Sacarose Alimentar/administração & dosagem , Frutose/administração & dosagem , Obesidade/metabolismo , Sobrepeso/metabolismo , Triglicerídeos/sangue , Adulto , Composição Corporal , Índice de Massa Corporal , Dieta , Método Duplo-Cego , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Aumento de Peso
6.
Int J Sport Nutr Exerc Metab ; 24(5): 524-31, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24458142

RESUMO

The purpose of this study was to examine whether leptin levels affect the response of leptin to exercise training (ET) and whether this is also affected by C-reactive protein (CRP) or the three common Apolipoprotein E genotypes (APOE). Ninety-seven (male = 45, female = 52) sedentary individuals underwent 6 months of supervised ET. Blood was sampled before the initiation of ET, and again 24 and 72 hr after completion of the final training session. ET resulted in a small reduction in body mass (80.47 ± 18.03 vs 79.42 ± 17.34 kg, p < .01). Leptin was reduced 24 hr after the final exercise session (p < .01), but returned to normal after 72 hr (p > .05)--Pre: 13.51 ± 12.27, 24hr: 12.14 ± 12.34, 72 hr: 12.98 ± 11.40 ng/ml. The most hyperleptinemic individuals had a greater initial response, which was sustained through to 72 hr after the final session in the pooled study population (p < .01), and in both males (p < .05) and females (p < .05) separately. CRP was related to leptin independently of body weight and positively related to the reductions in leptin. APOE genotype was not related to leptin levels and did not affect the response to ET. Leptin levels may only be reduced by ET in those with hyperleptinemia. In addition, both the initial extent of hyperleptinemia and the subsequent reduction in leptin may be related to low grade chronic systemic inflammation.


Assuntos
Apolipoproteínas E/genética , Proteína C-Reativa/metabolismo , Inflamação/sangue , Leptina/sangue , Condicionamento Físico Humano/fisiologia , Adulto , Peso Corporal/fisiologia , Exercício Físico/fisiologia , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Comportamento Sedentário
7.
Nutr Res ; 33(12): 1043-52, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24267044

RESUMO

Intake of high-fructose corn syrup (HFCS) has been suggested to contribute to the increased prevalence of obesity, whereas a number of studies and organizations have reported metabolic equivalence between HFCS and sucrose. We hypothesized that HFCS and sucrose would have similar effects on energy-regulating hormones and metabolic substrates at normal levels of human consumption and that these values would not change over a 10-week, free-living period at these consumption levels. This was a randomized, prospective, double-blind, parallel group study in which 138 adult men and women consumed 10 weeks of low-fat milk sweetened with either HFCS or sucrose at levels of the 25th, 50th, and 90th percentile population consumption of fructose (the equivalent of 40, 90, or 150 g of sugar per day in a 2000-kcal diet). Before and after the 10-week intervention, 24-hour blood samples were collected. The area under the curve (AUC) for glucose, insulin, leptin, active ghrelin, triglyceride, and uric acid was measured. There were no group differences at baseline or posttesting for all outcomes (interaction, P > .05). The AUC response of glucose, active ghrelin, and uric acid did not change between baseline and posttesting (P > .05), whereas the AUC response of insulin (P < .05), leptin (P < .001), and triglyceride (P < .01) increased over the course of the intervention when the 6 groups were averaged. We conclude that there are no differences in the metabolic effects of HFCS and sucrose when compared at low, medium, and high levels of consumption.


Assuntos
Dieta , Sacarose Alimentar/farmacologia , Metabolismo Energético/efeitos dos fármacos , Frutose/farmacologia , Obesidade , Hormônios Peptídicos/sangue , Zea mays , Adulto , Área Sob a Curva , Glicemia/metabolismo , Método Duplo-Cego , Feminino , Grelina/sangue , Humanos , Insulina/sangue , Leptina/sangue , Masculino , Pessoa de Meia-Idade , Obesidade/sangue , Obesidade/etiologia , Período Pós-Prandial , Estudos Prospectivos , Edulcorantes/farmacologia , Triglicerídeos/sangue , Ácido Úrico/sangue , Adulto Jovem
8.
Appl Physiol Nutr Metab ; 38(6): 681-8, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23724887

RESUMO

It has been postulated that fructose-induced triglyceride synthesis is augmented when accompanied by glucose. Chronic elevations could lead to excess fat accumulation in the liver and ectopic fat deposition in muscles, which in turn could contribute to the induction of abnormalities in glucose homeostasis, insulin resistance, and the subsequent development of type 2 diabetes. Our objective was to evaluate the effect of the addition of commonly consumed fructose- and (or) glucose-containing sugars in the usual diet on liver fat content and intramuscular adipose tissue. For 10 weeks, 64 individuals (mean age, 42.16 ± 11.66 years) consumed low-fat milk sweetened with either high-fructose corn syrup (HFCS) or sucrose; the added sugar matched consumption levels of fructose in the 25th, 50th, and 90th percentiles of the population. The fat content of the liver was measured with unenhanced computed tomography imaging, and the fat content of muscle was assessed with magnetic resonance imaging. When the 6 HFCS and sucrose groups were averaged, there was no change over the course of 10 weeks in the fat content of the liver (13.32% ± 10.49% vs. 13.21% ± 10.75%; p > 0.05), vastus lateralis muscle (3.07 ± 0.74 g per 100 mL vs. 3.15 ± 0.84 g per 100 mL; p > 0.05), or gluteus maximus muscle (4.08 ± 1.50 g per 100 mL vs. 4.24 ± 1.42 g per 100 mL; p > 0.05). Group assignment did not affect the result (interaction > 0.05). These data suggest that when fructose is consumed as part of a typical diet in normally consumed sweeteners, such as sucrose or HFCS, ectopic fat storage in the liver or muscles is not promoted.


Assuntos
Frutose , Xarope de Milho Rico em Frutose , Diabetes Mellitus Tipo 2 , Frutose/farmacologia , Humanos , Fígado/efeitos dos fármacos , Obesidade , Sacarose , Edulcorantes , Zea mays
9.
Nutr J ; 11: 71, 2012 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-22978828

RESUMO

BACKGROUND: Strategies that may increase compliance to reduced energy intakes are needed to reduce the health burden of obesity. Conflicting evidence exists regarding the effects of snacking on satiety and energy intake. METHODS: This study compared short-term satiety from two common snack foods, low fat popcorn or potato chips. Using a counterbalanced within-subject design, 35 normal weight non-smoking participants (17 men, 18 women) ages 20-50 years (mean age 33 ± 11, BMI 23 ± 2 kg/m²) consumed four conditions each: 200 mL of water (control), one cup (4 g, 15 kcal) popcorn, 6 cups (27 g, 100 kcal) popcorn, and one cup (28 g, 150 kcal) potato chips, each with 200 mL water. Participants rated their hunger, satisfaction, prospective consumption, and thirst on 100 mm visual analogue scales 30 minutes after commencement of snack consumption. In addition, post-snack energy intake from an ad libitum meal (amount served less amount remaining) was measured, and the test food and meal combined energy intake and energy compensation were calculated. RESULTS: Participants expressed less hunger, more satisfaction, and lower estimates of prospective food consumption after six cups of popcorn compared to all other treatments (P < 0.05). Energy compensation was 220% ± 967%, 76% ± 143% and 42% ± 75% after one cup popcorn, six cups popcorn and one cup potato chips, respectively. Combined energy intake was significantly greater (P < 0.01) during the potato chips condition (803 ± 277 kcal) compared to control (716 ± 279 kcal) or popcorn conditions (698 ± 286 kcal for one cup and 739 ± 294 kcal for six cups). Combined energy intakes from both popcorn conditions were not significantly different than control (p > 0.05). CONCLUSION: Popcorn exerted a stronger effect on short-term satiety than did potato chips as measured by subjective ratings and energy intake at a subsequent meal. This, combined with its relatively low calorie load, suggests that whole grain popcorn is a prudent choice for those wanting to reduce feelings of hunger while managing energy intake and ultimately, body weight.


Assuntos
Raízes de Plantas/química , Resposta de Saciedade , Sementes/química , Lanches , Solanum tuberosum/química , Zea mays/química , Adulto , Dieta com Restrição de Gorduras , Fibras na Dieta/administração & dosagem , Ingestão de Energia , Feminino , Humanos , Fome , Hiperfagia/prevenção & controle , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Sede , Estados Unidos , Adulto Jovem
10.
Nutr J ; 11: 55, 2012 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-22866961

RESUMO

BACKGROUND: The replacement of sucrose with HFCS in food products has been suggested as playing a role in the development of obesity as a public health issue. The objective of this study was to examine the effects of four equally hypocaloric diets containing different levels of sucrose or high fructose corn syrup (HFCS). METHODS: This was a randomized, prospective, double blind trial, with overweight/obese participants measured for body composition and blood chemistry before and after the completion of 12 weeks following a hypocaloric diet. The average caloric deficit achieved on the hypocaloric diets was 309 kcal. RESULTS: Reductions were observed in all measures of adiposity including body mass, BMI,% body fat, waist circumference and fat mass for all four hypocaloric groups, as well as reductions in the exercise only group for body mass, BMI and waist circumference. CONCLUSIONS: Similar decreases in weight and indices of adiposity are observed when overweight or obese individuals are fed hypocaloric diets containing levels of sucrose or high fructose corn syrup typically consumed by adults in the United States.


Assuntos
Dieta Redutora , Sacarose Alimentar/efeitos adversos , Frutose/efeitos adversos , Obesidade/dietoterapia , Sobrepeso/dietoterapia , Edulcorantes/efeitos adversos , Redução de Peso , Adiposidade , Adulto , Índice de Massa Corporal , Estudos de Coortes , Sacarose Alimentar/administração & dosagem , Método Duplo-Cego , Feminino , Florida , Frutose/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , Sementes/química , Edulcorantes/administração & dosagem , Circunferência da Cintura , Zea mays/química
11.
Nutr J ; 11: 57, 2012 Aug 27.
Artigo em Inglês | MEDLINE | ID: mdl-22925169

RESUMO

BACKGROUND: Given the rise in obesity and associated chronic diseases, it is critical to determine optimal weight management approaches that will also improve dietary composition and chronic disease risk factors. Few studies have examined all these weight, diet, and disease risk variables in subjects participating in recommended multi-disciplinary weight loss programs using different dietary strategies. METHODS: This study compared effects of three dietary approaches to weight loss on body composition, dietary composition and risk factors for metabolic syndrome (MetS). In a 12-week trial, sedentary but otherwise healthy overweight and obese adults (19 M & 138 F; 38.7±6.7 y; BMI 31.8±2.2) who were attending weekly group sessions for weight loss followed either portion control, low energy density, or low glycemic index diet plans. At baseline and 12 weeks, measures included anthropometrics, body composition, 3-day food diaries, blood pressure, total lipid profile, HOMA, C-reactive protein, and fasting blood glucose and insulin. Data were analyzed by repeated measures analysis of variance. RESULTS: All groups significantly reduced body weight and showed significant improvements in body composition (p<0.001), and components of metabolic syndrome (p<0.027 to 0.002), although HDL decreased (p<0.001). Dietary energy, %fat and %saturated fat decreased while protein intake increased significantly (p<0.001). There were no significant differences among the three groups in any variable related to body composition, dietary composition, or MetS components. CONCLUSION: Different dietary approaches based on portion control, low energy density, or low glycemic index produced similar, significant short-term improvements in body composition, diet compositin, and MetS components in overweight and obese adults undergoing weekly weight loss meetings. This may allow for flexibility in options for dietary counseling based on patient preference.


Assuntos
Composição Corporal , Dieta , Síndrome Metabólica/dietoterapia , Obesidade/dietoterapia , Sobrepeso/dietoterapia , Adulto , Glicemia , Pressão Sanguínea , Proteína C-Reativa , Ingestão de Energia , Feminino , Índice Glicêmico , Humanos , Insulina/sangue , Masculino , Síndrome Metabólica/complicações , Síndrome Metabólica/fisiopatologia , Pessoa de Meia-Idade , Obesidade/complicações , Obesidade/fisiopatologia , Sobrepeso/complicações , Sobrepeso/fisiopatologia , Estudos Prospectivos , Fatores de Risco , Redução de Peso , Adulto Jovem
13.
J Strength Cond Res ; 23(7): 1915-20, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19749605

RESUMO

The purpose of this study was to assess the association of age with muscle mass and strength in a group of young adults before and after 12 weeks of progressive resistance training. Eight hundred twenty-six young males and females (age 24.34 +/- 5.69 yr, range 18-39 yr) completed a strictly supervised 12-week unilateral resistance training program of the nondominant arm. Isometric (maximal voluntary contraction [MVC]) and dynamic strength (1 repetition maximum [1RM]) of the elbow flexors and cross-sectional area (CSA) of the biceps-brachii using magnetic resonance imaging (MRI) scans were measured before and after training. Pearson correlation coefficients were calculated for size and strength variables and age. In addition, the cohort was divided into groups according to decade of life and differences assessed by analysis of variance. Age correlated significantly and positively with all pretraining measures of muscle size and strength (CSA: r = 0.191, p < 0.001; MVC: r = 0.109, p = 0.002; 1RM: r = 0.109, p = 0.002). Age was not related to the training-induced changes in CSA or MVC but was negatively associated with the change in 1RM (r = -0.217, p < 0.001). The study indicates that age does have a significant positive relationship with muscle size and strength in untrained young adults. Although age was negatively associated with improvements in 1RM, the effect of age was small relative to the improvements induced through resistance training, thus suggesting age does not limit response to training in any practical way during early adulthood.


Assuntos
Envelhecimento/fisiologia , Força Muscular , Músculo Esquelético/anatomia & histologia , Treinamento Resistido , Adolescente , Adulto , Braço , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
14.
J Nutr ; 139(6): 1242S-1245S, 2009 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-19403709

RESUMO

Rates of overweight and obesity have been on a steady rise for decades, and the problems society faces from this and associated metabolic diseases are many. As a result, the need to understand the contributing factors is great. A very compelling case can be made that excess sugar consumption has played a significant role. In addition, fructose, as a component of the vast majority of caloric sweeteners, is seen to be particularly insidious. Evidence shows that fructose bypasses many of the body's satiating signals, thus potentially promoting overconsumption of energy, weight gain, and the development on insulin resistance. It has also been shown to increase uric acid levels, which in turn promotes many of the abnormalities seen in the metabolic syndrome including hypertriglyceridemia. However, the main source of fructose in the diet is high-fructose corn syrup (HFCS), an artificially manufactured disaccharide that is only 55% fructose. This review highlights the fact that limited data are available about the metabolic effects of HFCS compared with other caloric sweeteners. The data suggest that HFCS yields similar metabolic responses to other caloric sweeteners such as sucrose.


Assuntos
Dieta , Frutose/farmacologia , Triglicerídeos/sangue , Ácido Úrico/sangue , Zea mays/química , Frutose/administração & dosagem , Frutose/química , Humanos
15.
Am J Clin Nutr ; 88(6): 1738S-1744S, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19064539

RESUMO

High-fructose corn syrup (HFCS) has been implicated in excess weight gain through mechanisms seen in some acute feeding studies and by virtue of its abundance in the food supply during years of increasing obesity. Compared with pure glucose, fructose is thought to be associated with insufficient secretion of insulin and leptin and suppression of ghrelin. However, when HFCS is compared with sucrose, the more commonly consumed sweetener, such differences are not apparent, and appetite and energy intake do not differ in the short-term. Longer-term studies on connections between HFCS, potential mechanisms, and body weight have not been conducted. The main objective of this review was to examine collective data on associations between consumption of HFCS and energy balance, with particular focus on energy intake and its regulation.


Assuntos
Regulação do Apetite/efeitos dos fármacos , Ingestão de Energia/efeitos dos fármacos , Frutose/farmacologia , Edulcorantes/farmacologia , Regulação do Apetite/fisiologia , Peso Corporal/efeitos dos fármacos , Peso Corporal/fisiologia , Ingestão de Energia/fisiologia , Metabolismo Energético/efeitos dos fármacos , Metabolismo Energético/fisiologia , Frutose/administração & dosagem , Frutose/metabolismo , Humanos , Edulcorantes/administração & dosagem , Edulcorantes/metabolismo
17.
Metabolism ; 57(9): 1204-10, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18702945

RESUMO

C-reactive protein (CRP) is a marker for systemic inflammation and increased cardiovascular disease risk. Regular exercise may decrease CRP. Apolipoprotein E (apo E) has 3 common genotype variants--E2/3, 3/3, and 3/4--that modulate lipid metabolism and may have other metabolic physiologic roles, including some evidence that the genotype affects CRP levels. We assessed fasting serum CRP in 117 (male = 51, female = 66) healthy adults who volunteered for a 6-month aerobic exercise program. Both pre- and posttraining measurements were available in 71 (male = 31, female = 40) subjects. At baseline and follow-up, the numbers of subjects in the 3 groups were approximately equal: 2/3, n = 33 and 20; 3/3, n = 41 and 26; and 3/4, n = 43 and 25. At baseline, CRP levels differed by apo E genotype: means +/- SD were 2.84 +/- 2.18, 2.59 +/- 2.34, and 1.90 +/- 2.13 mg/L for E2/3, 3/3, and 3/4 subjects, respectively (3/4 vs 2/3, P < .05). In women, CRP was higher than that in men (3.14 +/- 2.49 vs 2.12 +/- 2.13 mg/L, P < .006). Exercise failed to affect CRP in the entire cohort (2.68 +/- 2.38 vs 2.52 +/- 2.48 mg/L) or in any apo E genotype group, and the apo E genotype effect observed at baseline persisted after training. In a largely white study cohort, CRP is higher in apo E3/3 than in 3/4 subjects and in women compared with men, but remains unchanged by 6 months of standard aerobic exercise training of the volume and higher intensity promoted by national organizations to reduce cardiovascular disease risk. How apo E genotype affects CRP is not known.


Assuntos
Apolipoproteínas E/genética , Proteína C-Reativa/metabolismo , Educação Física e Treinamento , Aptidão Física , Fatores Sexuais , Adulto , Antropometria , Fenômenos Fisiológicos Cardiovasculares , Estudos de Coortes , Jejum/sangue , Feminino , Genótipo , Humanos , Estilo de Vida , Masculino , Pessoa de Meia-Idade , Fatores de Tempo
18.
Eur J Appl Physiol ; 101(5): 621-8, 2007 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-17701049

RESUMO

Apolipoprotein B (apoB) concentration and age are independently associated with an increased risk for cardiovascular disease. Age is also associated with increased apoB concentration. The purpose of this study was to determine the effects of exercise on apoB and examine the association between age and lipoproteins. Forty-one sedentary individuals exercised for 6 months, four times/week for 40 min between 60 and 85% of their maximal heart rate. Lipids were determined three times: before training, 24 and 72 h after the last training session. Exercise did not alter apoB (1.2+/-0.05 g/l vs. 1.2+/-0.05 g/l; P>0.05), or other lipids or lipoproteins. When participants were sequestered by baseline low density lipoprotein cholesterol (LDLc), total cholesterol (TC) was decreased at 24 h post (6.3+/-0.2 mmol/l vs. 6.0+/-0.2 mmol/l, P<0.05) and LDLc after 24 and 48 h post (4.3+/-0.1 mg/dl vs. 3.9+/-0.1 and 4.1+/-0.2 mg/dl, P<0.05) in the high LDLc group. In the low LDLc group both TC (4.4+/-0.2 mmol/l vs. 4.6+/-0.2 and 4.6+/-0.2 mmol/l, P>0.05) and LDLc (2.6+/-0.1 mmol/l vs. 2.8+/-0.1 and 2.8+/-0.2 mmol/l, P<0.05) were elevated at 24 h and remained elevated at 72 h post compared to baseline. Age does not affect apoB or lipoproteins in response to exercise. Individuals with high baseline LDLc experienced acute reduction in TC and LDLc produced by each exercise session.


Assuntos
Envelhecimento/fisiologia , Apolipoproteínas B/sangue , LDL-Colesterol/sangue , Colesterol/sangue , Exercício Físico/fisiologia , Lipoproteínas/sangue , Aptidão Física/fisiologia , Adolescente , Adulto , Algoritmos , Limiar Anaeróbio/fisiologia , Estatura/fisiologia , Índice de Massa Corporal , Peso Corporal/fisiologia , Dieta , Feminino , Humanos , Lipase/sangue , Lipídeos/sangue , Lipase Lipoproteica/sangue , Fígado/enzimologia , Masculino , Pessoa de Meia-Idade
19.
Clin J Sport Med ; 17(1): 49-51, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17304006

RESUMO

OBJECTIVE: The purpose of the study was to determine whether exercise-induced increases in energy expenditure (EE) alter circulating leptin levels in obese individuals. DESIGN: Participants were randomized to an exercise intervention group (n = 8) or nonexercising control (n = 7). SETTING: All data were collected on an outpatient basis at the exercise physiology laboratory at the University of Central Florida. PATIENTS: Fifteen healthy obese males (24.9 +/- 1.4 years old, body mass index 33.4 +/- 0.7 kg . m). INTERVENTIONS: Members of the intervention group underwent a single exercise session of moderate intensity (58.4 +/- 1.3% of VO2max) for 60 minutes. MAIN OUTCOME MEASUREMENTS: Postexercise, 24 hour postexercise, and 48 hour postexercise levels of leptin, insulin, and ghrelin. RESULTS: The exercise session elicited an EE of 567 +/- 25 Kcal. No significant main effect or time-by-group interactions for leptin or ghrelin were observed immediately after the exercise bout or in the days following the intervention. CONCLUSIONS: These preliminary data suggest that a bout of acute exercise of moderate intensity and duration does not affect leptin concentration. It is possible that a higher level of EE is required to elicit substantial changes.


Assuntos
Metabolismo Energético , Exercício Físico/fisiologia , Leptina/fisiologia , Atividade Motora/fisiologia , Obesidade/fisiopatologia , Adulto , Grelina , Humanos , Leptina/sangue , Masculino , Hormônios Peptídicos/sangue , Estudos Prospectivos , Fatores Sexuais , Inquéritos e Questionários , Fatores de Tempo
20.
Nutrition ; 23(2): 103-12, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17234503

RESUMO

OBJECTIVE: Fructose has been implicated in obesity, partly due to lack of insulin-mediated leptin stimulation and ghrelin suppression. Most work has examined effects of pure fructose, rather than high-fructose corn syrup (HFCS), the most commonly consumed form of fructose. This study examined effects of beverages sweetened with HFCS or sucrose (Suc), when consumed with mixed meals, on blood glucose, insulin, leptin, ghrelin, and appetite. METHODS: Thirty lean women were studied on two randomized 2-d visits during which HFCS- and Suc-sweetened beverages were consumed as 30% of energy on isocaloric diets during day 1 while blood was sampled. On day 2, food was eaten ad libitum. Subjects rated appetite at designated times throughout visits. RESULTS: No significant differences between the two sweeteners were seen in fasting plasma glucose, insulin, leptin, and ghrelin (P > 0.05). The within-day variation in all four items was not different between the two visits (P > 0.05). Net areas under the curve were similar for glucose, insulin, and leptin (P > 0.05). There were no differences in energy or macronutrient intake on day 2. The only appetite variable that differed between sweeteners was desire to eat, which had a higher area under the curve the day after Suc compared with HFCS. CONCLUSION: These short-term results suggest that, when fructose is consumed in the form of HFCS, the measured metabolic responses do not differ from Suc in lean women. Further research is required to examine appetite responses and to determine if these findings hold true for obese individuals, males, or longer periods.


Assuntos
Apetite/efeitos dos fármacos , Metabolismo Energético/efeitos dos fármacos , Frutose/farmacologia , Obesidade/etiologia , Sacarose/farmacologia , Edulcorantes/farmacologia , Adulto , Apetite/fisiologia , Área Sob a Curva , Glicemia/metabolismo , Estudos Cross-Over , Método Duplo-Cego , Metabolismo Energético/fisiologia , Feminino , Frutose/efeitos adversos , Grelina , Humanos , Insulina/sangue , Leptina/sangue , Pessoa de Meia-Idade , Hormônios Peptídicos/sangue , Estudos Prospectivos , Sacarose/efeitos adversos , Edulcorantes/efeitos adversos
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