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1.
Nutr Metab Cardiovasc Dis ; 27(4): 342-349, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-28228332

RESUMEN

BACKGROUND AND AIMS: Nutritional therapy is the first line approach to treatment of hyperlipidemia in childhood. Proprotein convertase subtilisin kexin type 9 (PCSK9) is a key regulator of plasma cholesterol levels and a target of novel lipid-lowering pharmacotherapies. We examined the effects of an intensive nutritional intervention on PCSK9 levels in overweight adolescents with cardiovascular disease (CVD) risk factors. METHODS AND RESULTS: Twenty seven obese and overweight adolescents with CVD risk factors were assigned to either a low fat or low glycemic load diet. During an 8-week "Intensive Phase," assigned meals were delivered to the home, and all participants received weekly in-person home nutrition counseling and phone calls. The subjects then underwent a 4-month "Maintenance Phase" without food provision and with no in-person contact. Anthropometric measurements, laboratory data, and serum PCSK9 protein levels were measured at baseline, 8 weeks, and 6 months. PCSK9 decreased by 16.5% at 8 weeks (201.2 ± 56.3 vs 165.6 ± 58.4 ng/mL; p < 0.001); PCSK9 levels returned to baseline levels at 6 months, after the Maintenance Phase. Change in PCSK9 was associated with change in fasting insulin, HOMA-IR, and AUC insulin, independent of weight loss. CONCLUSIONS: PCSK9 decreased in youth participating in an intensive dietary intervention. Change in HOMA-IR was associated with change in PCSK9, independent of weight loss, suggesting an important relationship with insulin sensitivity. ClinicalTrials.gov Identifier: NCT01080339.


Asunto(s)
Dieta con Restricción de Grasas , Ingestión de Energía , Carga Glucémica , Obesidad Infantil/dietoterapia , Proproteína Convertasa 9/sangre , Adolescente , Factores de Edad , Biomarcadores/sangre , Glucemia/metabolismo , Boston , Niño , Consejo , Regulación hacia Abajo , Femenino , Humanos , Insulina/sangre , Resistencia a la Insulina , Masculino , Obesidad Infantil/diagnóstico , Obesidad Infantil/enzimología , Obesidad Infantil/fisiopatología , Factores de Tiempo , Resultado del Tratamiento , Pérdida de Peso
2.
Obes Rev ; 19(11): 1504-1524, 2018 11.
Artículo en Inglés | MEDLINE | ID: mdl-30019442

RESUMEN

OBJECTIVE: The objective of this study is to summarize evidence for strategies designed to reduce sugar-sweetened beverage (SSB) consumption among children aged 0 to 5 years. DATA SOURCES: PubMed, Web of Science, EMBASE, CINAHL, ERIC, Cab Abstracts and the Cochrane Central Register of Controlled Trials are the electronic databases searched in this systematic review. STUDY SELECTION: Each included study evaluated an intervention to reduce SSB consumption in children aged 0 to 5 years, was conducted in a high-income country and was published between 1 January 2000 and 15 December 2017. DATA SYNTHESIS: Twenty-seven studies met the inclusion criteria. The primary intervention settings were healthcare (n = 11), preschool/daycare (n = 4), home (n = 3), community venues (n = 3) and other settings (n = 6). Overarching strategies which successfully reduced SSB consumption included (i) in-person individual education, (ii) in-person group education, (iii) passive education (e.g. pamphlets), (iv) use of technology, (v) training for childcare/healthcare providers and (vi) changes to the physical access of beverages. Studies were of moderate methodological quality (average score of 20.7/29.0 for randomized studies; 3.1/9.0 for non-randomized studies). CONCLUSIONS: Evidence suggests that interventions successful at reducing SSB consumption among 0-year to 5-year olds often focused on vulnerable populations, were conducted in preschool/daycare settings, specifically targeted only SSBs or only oral hygiene, included multiple intervention strategies and had higher intervention intensity/contact time.


Asunto(s)
Bebidas , Azúcares de la Dieta , Edulcorantes , Preescolar , Promoción de la Salud , Humanos , Lactante
3.
Pediatr Obes ; 12(6): 494-501, 2017 12.
Artículo en Inglés | MEDLINE | ID: mdl-27492865

RESUMEN

BACKGROUND: Telehealth offers opportunities to extend clinical and research interventions for paediatric obesity. OBJECTIVES: To assess utility of a telephone intervention, implemented through a national primary care paediatric research network, for promoting differentiation in dietary intake, consistent with either a low-glycemic load (Low GL) or Low Fat prescription, among overweight/obese school-age children. METHODS: Five-week telephone dietary counselling intervention for parents of overweight/obese school-age children recruited through the Slone Center Office-based Research Network. Parent-child dyads were randomized to Low GL or Low Fat diet. Primary outcomes were dietary GL and dietary fat, adjusted for energy intake and assessed by 24-h dietary recall. RESULTS: Subjects were randomized to Low GL (n = 11, 8.1 ± 1.7 years, 45.5% male) or Low Fat (n = 11, 8.2 ± 2.0 years, 36.4% male), with no baseline differences. Overall, 86% of subjects attended at least four of five counselling sessions, and study completion rate was 91% (based on completion of the final dietary recalls). Reported satisfaction was high. In adjusted analyses limited to 'recall completers,' reduction in dietary GL (g/1000 kcal) achieved within the Low GL group was significant (p = 0.01) and greater than the change in dietary GL in the Low Fat group (mean ± SE; -12.9 ± 4.4 vs. 5.1 ± 4.9, p = 0.03). Similarly, reduction in dietary fat (% of total energy) within the Low Fat group was significant (-5.6 ± 2.5, p = 0.046) but with no difference between groups (p = 0.25). CONCLUSION: A telephone-based dietary intervention for overweight/obese children, implemented through a national paediatric research network, fostered prescribed dietary changes. ClinicalTrials.gov registration: NCT00620152.


Asunto(s)
Dieta Baja en Carbohidratos/métodos , Dieta con Restricción de Grasas/métodos , Sobrepeso/dietoterapia , Obesidad Infantil/dietoterapia , Atención Primaria de Salud/métodos , Niño , Preescolar , Femenino , Humanos , Masculino , Telemedicina , Teléfono , Resultado del Tratamiento
4.
Pediatr Obes ; 11(3): 210-20, 2016 06.
Artículo en Inglés | MEDLINE | ID: mdl-26132306

RESUMEN

BACKGROUND: Evidence is lacking to recommend one diet over another when treating polycystic ovary syndrome (PCOS). OBJECTIVES: To obtain preliminary data, comparing the impact of a low-glycaemic load (LGL) vs. low-fat (LF) diet on biochemical hyperandrogenism in overweight and obese adolescents with PCOS. To ascertain feasibility of recruiting study participants, in partnership with an adolescent clinic, and implementing dietary interventions. METHODS: Randomized controlled trial of 19 overweight and obese adolescents with PCOS and not using hormonal contraceptives (HCs). Interventions comprised nutrition education, dietary counselling and cooking workshops to foster adherence to a LGL (45% carbohydrate, 35% fat, 20% protein) or LF (55% carbohydrate, 25% fat, 20% protein) diet over 6 months. Serum bioavailable testosterone was the primary outcome. RESULTS: Sixteen (LGL, n = 7; LF, n = 9) participants completed the study. Body fat percentage decreased (P < 0.05) in response to the interventions, with no difference between the LGL and LF groups (-1.2% vs. -2.2%; P = 0.16). Bioavailable testosterone did not change for either group (-0.4 vs. -1.8 ng dL(-1) ; P = 0.35). Regarding feasibility, recruiting adolescents posed a challenge, and use of HCs was a main reason for ineligibility. Participants attended 5.9 of 6 in-person visits and 2.6 of 3 cooking workshops, completed 4.9 of 6 telephone counselling calls, and reported high satisfaction with the diets and cooking workshops (≥8 on a 10-cm scale). CONCLUSIONS: Dietary interventions were beneficial for weight control but did not attenuate biochemical hyperandrogenism. Innovative strategies are needed to recruit adolescents for studies aimed at assessing independent effects of diet on features of PCOS.


Asunto(s)
Síndrome del Ovario Poliquístico/dietoterapia , Adolescente , Adulto , Composición Corporal , Culinaria/métodos , Consejo , Dieta , Dieta con Restricción de Grasas , Femenino , Carga Glucémica , Humanos , Resistencia a la Insulina , Obesidad/complicaciones , Obesidad/dietoterapia , Sobrepeso/complicaciones , Sobrepeso/dietoterapia , Educación del Paciente como Asunto , Proyectos Piloto
5.
Pediatr Obes ; 11(5): e12-5, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-26317968

RESUMEN

This study evaluated the feasibility of a home-based intervention to reduce sugar-sweetened beverage intake and television viewing among children. Lower income parents of overweight children aged 5-12 years (n = 40) were randomized to a home environment intervention to reduce television viewing with locking devices and displace availability of sugar-sweetened beverages with home delivery of non-caloric beverages (n = 25), or to a no-intervention control group (n = 15) for 6 months. Data were collected at baseline and 6 months. After 6 months, television viewing hours per day was significantly lower in the intervention group compared with the control group (1.7 [SE = .02] vs. 2.6 [SE = .25] hours/day, respectively, P < .01). Sugar-sweetened beverage intake was marginally significantly lower among intervention group compared to control group children (0.21 [SE = .09] vs. 0.45 [SE = .10], respectively, P < .09). Body mass index (BMI) z-score was not significantly lower among intervention compared to control children. Among a lower income sample of children, a home-based intervention reduced television viewing, but not sugar-sweetened beverage intake or BMI z-score.


Asunto(s)
Conducta Infantil , Conducta Alimentaria , Sobrepeso/terapia , Obesidad Infantil/prevención & control , Bebidas/estadística & datos numéricos , Índice de Masa Corporal , Niño , Preescolar , Ingestión de Energía , Ambiente , Femenino , Humanos , Masculino , Proyectos Piloto , Recreación , Edulcorantes/efectos adversos , Televisión/estadística & datos numéricos
6.
Clin Obes ; 6(6): 380-388, 2016 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-27863024

RESUMEN

In an integrated care model, involving primary care providers (PCPs) and obesity specialists, telehealth may be useful for overcoming barriers to treating childhood obesity. We conducted a pilot study comparing body mass index (BMI) changes between two arms (i) PCP in-person clinic visits plus obesity specialist tele-visits ( PCP visits + specialist tele-visits) and (ii) PCP in-person clinic visits only ( PCP visits only), with ongoing tele-consultation between PCPs and obesity specialists for both arms. Patients (N = 40, 10-17 years, BMI ≥ 95th percentile) were randomized to Group 1 or 2. Both groups had PCP visits every 3 months for 12 months. Using a cross-over protocol, Group 1 had PCP visits + specialist tele-visits during the first 6 months and PCP visits only during the second 6 months, and Group 2 followed the opposite sequence. Each of 12 tele-visits was conducted by a dietitian or psychologist with a patient and parent. Retention rates were 90% at 6 months and 80% at 12 months. BMI (z-score) decreased more for Group 1 (started with PCP visits + specialist tele-visits) vs. Group 2 (started with PCP visits only) at 3 months (-0.11 vs. -0.05, P = 0.049) following frequent tele-visits. At 6 months (primary outcome), BMI was lower than baseline within Group 1 (-0.11, P = 0.0006) but not Group 2 (-0.06, P = 0.08); however, decrease in BMI at 6 months did not differ between groups. After crossover, BMI remained lower than baseline for Group 1 and dropped below baseline for Group 2. An integrated care model utilizing telehealth holds promise for treating children with obesity.


Asunto(s)
Servicios de Salud Comunitaria , Obesidad Infantil/terapia , Atención Primaria de Salud , Telemedicina , Adolescente , Índice de Masa Corporal , Niño , Servicios de Salud Comunitaria/organización & administración , Femenino , Humanos , Comunicación Interdisciplinaria , Masculino , Proyectos Piloto , Atención Primaria de Salud/organización & administración , Derivación y Consulta , Telemedicina/organización & administración
7.
Obes Rev ; 16(4): 282-94, 2015 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-25645009

RESUMEN

Excess adiposity is the main phenotypic feature that defines human obesity and that plays a pathophysiological role in most chronic diseases. Measuring the amount of fat mass present is thus a central aspect of studying obesity at the individual and population levels. Nevertheless, a consensus is lacking among investigators on a single accepted 'reference' approach for quantifying fat mass in vivo. While the research community generally relies on the multi-component body volume class of 'reference' models for quantifying fat mass, no definable guide discerns among different applied equations for partitioning the four (fat, water, protein and mineral mass) or more quantified components, standardizes 'adjustment' or measurement system approaches for model-required labelled water dilution volumes and bone mineral mass estimates, or firmly establishes the body temperature at which model physical properties are assumed. The resulting differing reference strategies for quantifying body composition in vivo leads to small, but under some circumstances, important differences in the amount of measured body fat. Recent technological advances highlight opportunities to expand model applications to new subject groups and measured components such as total body protein. The current report reviews the historical evolution of multi-component body volume-based methods in the context of prevailing uncertainties and future potential.


Asunto(s)
Absorciometría de Fotón , Composición Corporal , Agua Corporal , Obesidad/patología , Índice de Masa Corporal , Cadáver , Humanos , Modelos Biológicos , Valores de Referencia
8.
Obes Rev ; 3(4): 235-43, 2002 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-12458970

RESUMEN

A reduction in dietary fat has been widely advocated for the prevention and treatment of obesity and related complications. However, the efficacy of low-fat diets has been questioned in recent years. One potential adverse effect of reduced dietary fat is a compensatory increase in the consumption of high glycaemic index (GI) carbohydrate, principally refined starchy foods and concentrated sugar. Such foods can be rapidly digested or transformed into glucose, causing a large increase in post-prandial blood glucose and insulin. Short-term feeding studies have generally found an inverse association between GI and satiety. Medium-term clinical trials have found less weight loss on high GI or high glycaemic load diets compared to low GI or low glycaemic load diets. Epidemiological analyses link GI to multiple cardiovascular disease risk factors and to the development of cardiovascular disease and type 2 diabetes. Physiologically orientated studies in humans and animal models provide support for a role of GI in disease prevention and treatment. This review examines the mechanisms underlying the potential benefits of a low GI diet, and whether such diets should be recommended in the clinical setting.


Asunto(s)
Enfermedades Cardiovasculares/etiología , Consejo , Diabetes Mellitus/etiología , Índice Glucémico/fisiología , Obesidad/dietoterapia , Humanos
9.
Metabolism ; 47(12): 1434-9, 1998 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9867070

RESUMEN

Dietary treatment of pediatric obesity is a challenge given the need for adequate nutrients to support the maintenance of lean tissue and growth. The primary purpose of this investigation was to assess the effects of reduced energy intake on protein turnover in obese children aged 8 to 10 years. Following a 2-week baseline period, 16 subjects reduced energy intake during a 6-week intervention period. At baseline and following the intervention, 15N-glycine methodology was used to measure nitrogen flux (Q), protein synthesis (PS), protein breakdown (PB), and net turnover ([NET] PS - PB). Other criterion measures included resting metabolic rate (RMR), fat mass (FM), fat-free mass (FFM), urinary creatinine to height ratio (Cr:Ht), and nitrogen balance (NB). On average, subjects lost 2.2 +/- 0.3 kg, of which greater than 85% was FM. Decreased Q (P = .03) indicated downregulation of protein turnover in response to diet-induced weight loss. While PB did not change, NET declined slightly (P = .06) as a consequence of reduced PS (P = .03). Reductions in FFM (P = .09), Cr:Ht (P = .02), and NB (P = .03) accompanied alterations in protein turnover, but there was no change in the RMR. In conclusion, while short-term therapy promoted the loss of FM and did not compromise RMR, practitioners must be cautious when prescribing diets, given the observed changes in protein utilization and somatic protein status. Longitudinal studies are needed to further characterize the metabolic responses of obese children to long-term diet therapy.


Asunto(s)
Metabolismo Energético/fisiología , Obesidad/fisiopatología , Proteínas/farmacocinética , Aminoácidos/sangre , Metabolismo Basal/fisiología , Peso Corporal/fisiología , Niño , Creatinina/sangre , Dieta , Femenino , Glicina/farmacocinética , Humanos , Masculino , Obesidad/terapia
10.
Sports Med ; 7(4): 207-34, 1989 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-2657962

RESUMEN

Novel, unaccustomed exercise has been shown to result in temporary, repairable skeletal muscle damage. After exhaustive endurance exercise, muscle damage can be produced by metabolic disturbances associated with ischaemia. Extensive disruption of muscle fibres also occurs after relatively short term eccentric exercise where high mechanical forces are generated. Biopsies taken after repetitive eccentric muscle actions have revealed broadening, streaming and, at times, total disruption of Z-discs. Muscles that develop active tension eccentrically also become sore, lose inherent force-producing capability, and show a marked release of muscle proteins into the circulation. Because creatine kinase (CK) is found almost exclusively in muscle tissue, it is the most common plasma marker of muscle damage. Despite the universal use of CK as a marker, several factors with regard to efflux and clearance remain unexplained. Also the large intersubject variability in response to exercise complicates its interpretation. Damage progresses in the postexercise period before tissues are repaired. However, the mechanism to explain exercise-induced muscle damage and repair is not well defined. Among the factors that may influence the damage and repair processes are calcium, lysosomes, connective tissue, free radicals, energy sources, and cytoskeletal and myofibrillar proteins. Physical conditioning results in an adaptation such that all indicators of damage are reduced following repeated bouts of exercise. Recently, investigators have suggested that the prophylactic effect of training may be due to performance of a single initial exercise bout. Following a second bout of exercise performed 1 to 6 weeks after the first bout, there is a reduction in morphological alterations and performance decrements and a profoundly reduced elevation in plasma CK levels. Several hypotheses have been presented to explain the repeated bout or rapid training effect. Stress-susceptible fibres may be eliminated or susceptible areas within a fibre may undergo necrosis and then regenerate. These regenerated fibres, along with adaptations in the connective tissue, may provide greater resistance to further insult.


Asunto(s)
Adaptación Fisiológica , Ejercicio Físico , Músculos/fisiología , Humanos , Esfuerzo Físico
11.
J Am Diet Assoc ; 99(5): 544-52, 1999 May.
Artículo en Inglés | MEDLINE | ID: mdl-10333775

RESUMEN

OBJECTIVE: To assess the effectiveness of a dietitian-based nutrition counseling and education program for patients with hyperlipidemia. DESIGN: A 4-session program implemented as a complement to a randomized physician-delivered intervention. SUBJECTS/SETTING: From 12 practice sites of the Fallon Clinic, 1,162 subjects with hyperlipidemia were recruited, 645 of whom had data sufficient for our primary analyses. INTERVENTION: Two individual and 2 group sessions conducted over 6 weeks. MAIN OUTCOME MEASURES: Total and saturated fat levels; serum low-density lipoprotein cholesterol levels; and body weight, measured at baseline and after 1 year. STATISTICAL ANALYSES: Multiple linear regression was used to evaluate changes in outcome measures. RESULTS: After 1 year, there were significant reductions in outcome measures for subjects attending 3 or 4 nutrition sessions vs subjects attending fewer than 3 sessions or those never referred to a nutrition session. Reductions (mean +/- standard error) in saturated fat (measured as percent of energy) were 2.7 +/- 0.5%, 2.1 +/- 0.5%, and 0.3 +/- 0.1%, respectively. These reductions correspond to roughly a 22% relative change from baseline in those attending 3 or 4 sessions. Corollary reductions were observed for total fat (measured as percent of energy): 8.2 +/- 1.4%, 5.0 +/- 1.4%, and 0.7 +/- 0.4%; low-density lipoprotein cholesterol: 0.48 +/- 0.11 mmol/L, 0.13 +/- 0.11 mmol/L, and 0.02 +/- 0.03 mmol/L; and body weight: 4.5 +/- 0.9 kg, 2.1 +/- 0.8 kg, and 1.1 +/- 0.2 kg. The specified changes were additive to those of the physician-delivered intervention. APPLICATIONS/CONCLUSIONS: This investigation provides empirical data demonstrating the effectiveness of a dietitian-delivered intervention in the care of patients with hyperlipidemia.


Asunto(s)
Colesterol/sangre , Dieta con Restricción de Grasas , Dietética , Hiperlipidemias/dietoterapia , Fenómenos Fisiológicos de la Nutrición , Educación del Paciente como Asunto , Pérdida de Peso , Adulto , Anciano , Peso Corporal , LDL-Colesterol/sangre , Consejo , Ejercicio Físico , Femenino , Estudios de Seguimiento , Humanos , Masculino , Massachusetts , Persona de Mediana Edad , Motivación , Selección de Paciente , Apoyo Social
12.
J Am Diet Assoc ; 101(3): 332-41, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11269614

RESUMEN

Recent data indicate that the patient-centered counseling model enhances long-term dietary adherence. This model facilitates change by assessing patient needs and subsequently tailoring the intervention to the patient's stage in the process of change, personal goals, and unique challenges. This article describes this model, including its theoretical foundations, a 4-step counseling process, and applications. This behavioral counseling model can help nutrition professionals enhance patient adherence to nutrition care plans and dietary guidelines.


Asunto(s)
Consejo/métodos , Conducta Alimentaria/psicología , Modelos Psicológicos , Cooperación del Paciente , Atención Dirigida al Paciente/métodos , Terapia Conductista , Dietética , Promoción de la Salud , Humanos
13.
J Am Diet Assoc ; 101(4): 421-31, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11320947

RESUMEN

OBJECTIVE: To determine the effectiveness of an intensive dietary intervention on diet and body mass in women with breast cancer. DESIGN: Randomized clinical trial. SUBJECTS: 172 women aged 20 to 65 years with stage I or II breast cancer. INTERVENTION: A 15-session, mainly group-based and dietitian-led nutrition education program (NEP) was compared to a mindfulness-based stress reduction clinic program (SRC); or usual supportive care (UC). MAIN OUTCOME MEASURES: Dietary fat, complex carbohydrates, fiber, and body mass were measured. STATISTICAL ANALYSIS: In addition to descriptive statistics, analysis of variance was conducted to test for differences according to intervention group. RESULTS: Of the 157 women with complete dietary data at baseline, 149 had complete data immediately postintervention (at 4 months) and 146 had complete data at 1 year. Women randomized to NEP (n = 50) experienced a large reduction in fat consumption (5.8% of energy as fat) at 4 months and much of this reduction was preserved at 1 year (4.1% of energy) (both P < .0002) vs no change in either SRC (n = 51) or UC (n = 56). A 1.3-kg reduction in body mass was evident at 4 months in the NEP group (P = .003) vs no change in the SRC and UC groups. Women who had higher-than-average expectations of a beneficial effect of the intervention experienced larger changes. APPLICATIONS: Dietitians' use of group nutrition interventions appear to be warranted. Increasing their effectiveness and maintaining high levels of adherence may require additional support, including the involvement of significant others, periodic individual meetings, or group booster sessions.


Asunto(s)
Neoplasias de la Mama/dietoterapia , Dieta , Carbohidratos de la Dieta/administración & dosificación , Grasas de la Dieta/administración & dosificación , Fibras de la Dieta/administración & dosificación , Adulto , Análisis de Varianza , Índice de Masa Corporal , Femenino , Humanos , Persona de Mediana Edad , Ciencias de la Nutrición/educación , Cooperación del Paciente/psicología , Educación del Paciente como Asunto , Estrés Fisiológico/prevención & control
14.
Med Sci Sports Exerc ; 31(3): 378-85, 1999 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10188741

RESUMEN

PURPOSE: Hypocaloric therapy may adversely affect protein utilization in obese children given that metabolic reactions involving protein, a nutrient essential for growth, are energy-dependent. Because physical activity influences nutrient utilization and may modulate the effects of reduced energy intake, exercise combined with diet therapy may be beneficial with regard to protein metabolism. The primary purpose of this study was to evaluate changes in protein utilization in response to sequential addition of an exercise program to dietary intervention in obese children. METHODS: After a 2-wk baseline period, five subjects aged 8-10 yr reduced energy intake [-2092 to -2510 kJ.d(-1)(-500 to -600 kcal.d(-1))] for 12 wk. A walking program [5 d.wk(-1), 3.2-4.8 km.d(-1) (2-3 miles.d(-1))] was implemented during the final 6 wk of diet therapy. At baseline and after phases I (diet only) and II (exercise and diet) of intervention, 15N-glycine was used to assess protein synthesis (PS), protein breakdown (PB), net turnover (NET = PS - PB), and nitrogen flux (Q). RESULTS: Subjects lost 4.2+/-0.4 kg during the 12-wk intervention period (P < or = 0.05). With diet only, NET decreased (P < or = 0.05) due to a reduction in PS (P < or = 0.05) accompanied by no change in PB. Although PS increased with walking (P < or = 0.05), NET did not return to baseline levels due to a concurrent increase in PB (P < or = 0.05). Changes in PS and PB yielded an increase in Q (P < or = 0.05), a measure of amino acid cycling between protein and free amino acid pools. CONCLUSIONS: These results suggest that exercise offers metabolic benefits for obese children during diet-induced weight loss. Longitudinal studies are needed to assess long-term health outcomes associated with the observed changes in protein utilization.


Asunto(s)
Terapia por Ejercicio , Obesidad/metabolismo , Obesidad/terapia , Proteínas/metabolismo , Composición Corporal , Niño , Creatinina/orina , Metabolismo Energético , Femenino , Humanos , Masculino , Nitrógeno/orina , Obesidad/dietoterapia , Obesidad/orina
15.
Med Sci Sports Exerc ; 23(8): 966-73, 1991 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-1956273

RESUMEN

An equation was developed to estimate maximal oxygen uptake (VO2max, ml.kg-1.min-1) based on a single submaximal stage of a treadmill walking test. Subjects (67 males, 72 females) aged 20-59 yr completed 4-min stages at 0, 5, and 10% grades walking at a constant speed (2.0-4.5 mph) and then performed a VO2max test. Heart rate and respiratory gas exchange variables were measured during the test. Multiple regression analysis (N = 117) to estimate VO2max from the 4-min stage at 5% grade yielded the following model (R2 = 0.86; SEE = 4.85 ml.kg-1.min-1): VO2max = 15.1 + 21.8*SPEED (mph) -0.327*HEART RATE (bpm) -0.263*SPEED*AGE (yr) + 0.00504*HEART RATE*AGE + 5.98*GENDER (0 = Female; 1 = Male). The constant and all coefficients were highly significant (P less than 0.01). To assess the accuracy of the model in a cross-validation group (N = 22), an estimated VO2max value was obtained using the above model. Estimated VO2max then was regressed on observed VO2max yielding the following equation (R2 = 0.92): ESTIMATED VO2max = 0.15 + 1.03*OBSERVED VO2max. The intercept and slope of this equation were not significantly different from 0 and 1, respectively. For 90.9% of the subjects in the cross-validation group, residual scores were within the range of +/- 5 ml.kg-1.min-1. In conclusion, this submaximal walking test based on a single stage of a treadmill protocol provides a valid and time-efficient method for estimating VO2max.


Asunto(s)
Prueba de Esfuerzo/métodos , Consumo de Oxígeno , Adulto , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Persona de Mediana Edad , Esfuerzo Físico , Distribución Aleatoria , Análisis de Regresión
16.
Med Sci Sports Exerc ; 27(5): 765-75, 1995 May.
Artículo en Inglés | MEDLINE | ID: mdl-7674883

RESUMEN

Psychological changes associated with 16-wk moderate and low intensity exercise training programs, two of which possessed a cognitive component, were evaluated. Subjects were healthy, sedentary adults, 69 women (mean age = 54.8 +/- 8.3 yr) and 66 men (mean age = 50.6 +/- 8.0 yr). Participants were randomly assigned to a control group (C), moderate intensity walking group (MW), low intensity walking group (LW), low intensity walking plus relaxation response group (LWR), or mindful exercise (ME) group-a Tai Chi type program. Women in the ME group experienced reductions in mood disturbance (tension, P < 0.01; depression, P < 0.05; anger, P < 0.008; confusion, P < 0.02; and total mood disturbance, P < 0.006) and an improvement in general mood (P < 0.04). Women in the MW group noted greater satisfaction with physical attributes (body cathexis, P < 0.03), and men in MW reported increased positive affect (P < 0.006). No other differences were observed between groups on measures of mood, self-esteem, personality, or life satisfaction. Equivocal support is provided for the hypothesis that exercise plus cognitive strategy training programs are more effective than exercise programs lacking a structured cognitive component in promoting psychological benefits.


Asunto(s)
Adaptación Psicológica , Ejercicio Físico/psicología , Adulto , Afecto , Cognición , Femenino , Humanos , Masculino , Salud Mental , Persona de Mediana Edad , Inventario de Personalidad , Autoimagen
17.
Eur J Clin Nutr ; 54(6): 479-86, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10878649

RESUMEN

OBJECTIVE: Limited inter-person variability in nutrient intake hampers epidemiologic studies of diet-disease relationships. Despite conjecture about non-traditional study bases providing large inter-person differences, virtually nothing is known about variations in nutrient intake outside of Europe and North America. The current study was conducted in India to determine sources of variability in the intakes of nutrients thought to be of public health importance. DESIGN: Adult subjects in Gujarat (North India; n=60) and in Kerala (South India, n=60) were administered 24 h diet recall interviews six and eight times, respectively, over a 1 y period. To assess subject (inter-person) and residual (intra-person) contributions to variance, regression models were fit to the data. From this, the variance ratio (VR, total within or intra-person: total between or inter-person) was computed. SETTING: Rural communities in North and South India. RESULTS: In both regions, inter-person variability was larger than that observed in the West. This was most pronounced in Gujarat, for which the VR was <1.0 for seven of the 12 energy-adjusted nutrient intakes in both men and women. In analyses of the combined data, region accounted for >20% of variance for fat, iron, copper, zinc, beta-carotene and riboflavin in both men and women. With the region term removed from this model, virtually all of the variability ascribed to region contributed to inter-person variability. CONCLUSIONS: The relatively large inter-person variability observed here could contribute to improved 'resolution' of diet-outcome relationships in epidemiologic studies. While this applies to data from each region, it was especially evident in analyses of the combined data.


Asunto(s)
Dieta , Fenómenos Fisiológicos de la Nutrición , Proyectos de Investigación , Población Rural , Adulto , Cobre/administración & dosificación , Registros de Dieta , Grasas de la Dieta/administración & dosificación , Conducta Alimentaria , Femenino , Humanos , India , Hierro de la Dieta/administración & dosificación , Masculino , Persona de Mediana Edad , Riboflavina/administración & dosificación , Zinc/administración & dosificación , beta Caroteno/administración & dosificación
19.
Adv Pediatr ; 48: 179-212, 2001.
Artículo en Inglés | MEDLINE | ID: mdl-11480757

RESUMEN

Although the adverse effects of excess adiposity on health outcomes are widely recognized, there is no consensus regarding the most appropriate dietary strategies for managing obesity in youth. Recently, a novel dietary variable termed glycemic load has been postulated to influence hunger and body weight regulation. Glycemic load, a measure of the effects of a meal on blood glucose levels, is determined by the type and the amount of carbohydrate consumed. According to a hypothetical model, ingestion of high-glycemic load meals induces a sequence of hormonal changes that alter partitioning of metabolic fuels, exacerbate hunger, and over the long-term, promote weight gain. This chapter provides an overview of the available evidence suggesting that dietary glycemic load, and its related factor, the glycemic index, should be taken into consideration in the design of weight loss interventions.


Asunto(s)
Glucemia/metabolismo , Carbohidratos de la Dieta/administración & dosificación , Obesidad/dietoterapia , Adolescente , Femenino , Guías como Asunto , Humanos , Masculino , Fenómenos Fisiológicos de la Nutrición , Obesidad/sangre
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