Background Although the DASH (Dietary Approaches to Stop Hypertension) diet has been shown to lower blood pressure (BP) in short-term feeding studies, it has not been shown to lower BP among free-living individuals, nor has it been shown to alter cardiovascular biomarkers of risk. Objective To compare the DASH diet alone or combined with a weight management program with usual diet controls among participants with prehypertension or stage 1 hypertension (systolic BP, 130-159 mm Hg; or diastolic BP, 85-99 mm Hg). Design and Setting Randomized, controlled trial in a tertiary care medical center with assessments at baseline and 4 months. Enrollment began October 29, 2003, and ended July 28, 2008. Participants Overweight or obese, unmedicated outpatients with high BP (N = 144). Interventions Usual diet controls, DASH diet alone, and DASH diet plus weight management. Outcome Measures The main outcome measure is BP measured in the clinic and by ambulatory BP monitoring. Secondary outcomes included pulse wave velocity, flow-mediated dilation of the brachial artery, baroreflex sensitivity, and left ventricular mass. Results Clinic-measured BP was reduced by 16.1/9.9 mm Hg (DASH plus weight management); 11.2/7.5 mm (DASH alone); and 3.4/3.8 mm (usual diet controls) ( P P P Conclusion For overweight or obese persons with above-normal BP, the addition of exercise and weight loss to the DASH diet resulted in even larger BP reductions, greater improvements in vascular and autonomic function, and reduced left ventricular mass. Clinical Trial Registration clinicaltrials.gov Identifier:NCT00571844

https://jamanetwork.com/journals/jamainternalmedicine/articlepdf/415515/ioi90123_126_135.pdf

Effects of the DASH Diet Alone and in Combination With Exercise and Weight Loss on Blood Pressure and Cardiovascular Biomarkers in Men and Women With High Blood Pressure: The ENCORE Study

Effects of energy-restricted high-protein, low-fat compared with standard-protein, low-fat diets: a meta-analysis of randomized controlled trials

PURPOSE Cross-sectional studies show that individuals who walk more tend to be thinner than those who walk less. This does not mean, however, that the associa- tion between higher step counts and lower weight is causal or that encouraging sedentary individuals to increase step counts helps them lose weight. METHODS In this meta-analysis, we searched 6 electronic databases and contacted pedometer experts to identify pedometer-based walking studies without a dietary intervention that reported weight change as an outcome. We included randomized controlled trials and prospective cohort studies published after January 1, 1995, in either English or Japanese, with 5 or more adult participants and at least 1 cohort enrolled in a pedometer-based walking intervention lasting at least 4 weeks. RESULTS Nine studies met the study inclusion criteria. Cohort sample size ranged from 15 to 106, for a total of 307 participants, 73% of whom were women and 27% of whom were men. The duration of the intervention ranged from 4 weeks to 1 year, with a median duration of 16 weeks. The pooled estimate of mean weight change from baseline using a fi xed-effects model and combining data from all 9 cohorts was -1.27 kg (95% confi dence interval, -1.85 to -0.70 kg). Longer intervention duration was associated with greater weight change. On average, participants lost 0.05 kg per week during the interventions. CONCLUSION Pedometer-based walking programs result in a modest amount of weight loss. Longer programs lead to more weight loss than shorter programs.

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A Meta-Analysis of Pedometer-Based Walking Interventions and Weight Loss

NYBO, L., E. SUNDSTRUP, M. D. JAKOBSEN, M. MOHR, T. HORNSTRUP, L. SIMONSEN, J. BULOW, M. B. RANDERS, J. J. NIELSEN, P. AAGAARD, and P. KRUSTRUP. High-Intensity Training versus Traditional Exercise Interventions for Pro- moting Health. Med. Sci. Sports Exerc., Vol. 42, No. 10, pp. 1951-1958, 2010. Purpose: The purpose of this study was to deter- mine the effectiveness of brief intense interval training as exercise intervention for promoting health and to evaluate potential benefits about common interventions, that is, prolonged exercise and strength training. Methods: Thirty-six untrained men were divided into groups that completed 12 wk of intense interval running (INT; total training time 40 minIwk j1 ), prolonged running (E150 minIwk j1 ), and strength training (E150 minIwk j1 ) or continued their habitual lifestyle without participation in physical training. Results: The improvement in cardiorespiratory fitness was superior in the INT (14% T 2% increase in VO2max) compared with the other two exercise interventions (7% T 2% and 3% T 2% increases). The blood glucose concentration 2 h after oral ingestion of 75 g of glucose was lowered to a similar extent after training in the INT (from 6.1 T 0.6 to 5.1 T 0.4 mM, P G 0.05) and the prolonged running group (from 5.6 T 1.5 to 4.9 T 1.1 mM, P G 0.05). In contrast, INT was less efficient than prolonged running for lowering the subjects' resting HR, fat percentage, and reducing the ratio between total and HDL plasma cholesterol. Furthermore, total bone mass and lean body mass remained unchanged in the INT group, whereas both these parameters were increased by the strength-training intervention. Conclusions: INT for 12 wk is an effective training stimulus for improvement of cardiorespiratory fitness and glucose tolerance, but in relation to the treatment of hyperlipidemia and obesity, it is less effective than prolonged training. Furthermore and in contrast

High-intensity training versus traditional exercise interventions for promoting health.

Resolvins, Specialized Proresolving Lipid Mediators, and Their Potential Roles in Metabolic Diseases

The incidence of obesity is increasing rapidly. Research efforts for effective treatment strategies still focus on diet and exercise programmes, the individual components of which have been investigated in intervention trials in order to determine the most effective recommendations for sustained changes in bodyweight. The foremost objective of a weight-loss trial has to be the reduction in body fat leading to a decrease in risk factors for metabolic syndrome. However, a concomitant decline in lean tissue can frequently be observed. Given that fat-free mass (FFM) represents a key determinant of the magnitude of resting metabolic rate (RMR), it follows that a decrease in lean tissue could hinder the progress of weight loss. Therefore, with respect to long-term effectiveness of weight-loss programmes, the loss of fat mass while maintaining FFM and RMR seems desirable. Diet intervention studies suggest spontaneous losses in bodyweight following low-fat diets, and current data on a reduction of the carbohydrate-to-protein ratio of the diet show promising outcomes. Exercise training is associated with an increase in energy expenditure, thus promoting changes in body composition and bodyweight while keeping dietary intake constant. The advantages of strength training may have greater implications than initially proposed with respect to decreasing percentage body fat and sustaining FFM. Research to date suggests that the addition of exercise programmes to dietary restriction can promote more favourable changes in body composition than diet or physical activity on its own. Moreover, recent research indicates that the macronutrient content of the energy-restricted diet may influence body compositional alterations following exercise regimens. Protein emerges as an important factor for the maintenance of or increase in FFM induced by exercise training. Changes in RMR can only partly be accounted for by alterations in respiring tissues, and other yet-undefined mechanisms have to be explored. These outcomes provide the scientific rationale to justify further randomised intervention trials on the synergies between diet and exercise approaches to yield favourable modifications in body composition.

/pdf/the-role-of-diet-and-exercise-for-the-maintenance-of-fat-5cmsxw17ue.pdf

The role of diet and exercise for the maintenance of fat-free mass and resting metabolic rate during weight loss.

High-intensity exercise leads to reductions in muscle substrates (ATP, PCr6, and glycogen) and a subsequent accumulation of metabolites (ADP, P, H(+), and Mg(+)) with a possible increase in free radical production. These factors independently and collectively have deleterious effects on muscle, with significant repercussions on high-intensity performance or training sessions. The effect of carnosine on overcoming muscle fatigue appears to be related to its ability to buffer the increased H(+) concentration following high-intensity work. Carnosine, however, has other roles such as an antioxidant, a metal chelator, a Ca(2+) and enzyme regulator, an inhibitor of protein glycosylation and protein-protein cross-linking. To date7comma; only 1 study has investigated the effects of carnosine supplementation (not in pure form) on exercise performance in human subjects and found no improvement in repetitive high-intensity work. Much data has come from in vitro work on animal skeletal muscle fibers or other components of muscle contractile mechanisms. Thus further research needs to be carried out on humans to provide additional understanding on the effects of carnosine in vivo.

Physiological role of carnosine in contracting muscle.

Obesity-related metabolic disorders are characterized by mild chronic inflammation, leukocyte infiltration, and tissue fibrosis as a result of adipocytokine production from the expanding white adipose tissue. Annexin A1 (AnxA1) is an endogenous glucocorticoid regulated protein, which modulates systemic anti-inflammatory processes and, therefore, may be altered with increasing adiposity in humans. Paradoxically, we found that plasma AnxA1 concentrations inversely correlated with BMI, total percentage body fat, and waist-to-hip ratio in human subjects. Plasma AnxA1 was also inversely correlated with plasma concentrations of the acute-phase protein, C-reactive protein (CRP), and the adipocytokine leptin, suggesting that as systemic inflammation increases, anti-inflammatory AnxA1 is reduced. In addition, AnxA1 gene expression and protein were significantly up-regulated during adipogenesis in a human adipocyte cell line compared to vehicle alone, demonstrating for the first time that AnxA1 is expressed and excreted from human adipocytes. These data demonstrate a failure in the endogenous anti-inflammatory system to respond to increasing systemic inflammation resulting from expanding adipose tissue, a condition strongly linked to the development of type 2 diabetes and cardiovascular disease. These data raise the possibility that a reduction in plasma AnxA1 may contribute to the chronic inflammatory phenotype observed in human obesity.

https://faseb.onlinelibrary.wiley.com/doi/pdf/10.1096/fj.12-213728

Attenuation of plasma annexin A1 in human obesity

Melanin concentrating hormone (MCH) is an anabolic neuropeptide with multiple and diverse physiologic functions including a key role in energy homeostasis. Rodent studies have shown that ablation of functional MCH results in a lean phenotype, increased energy expenditure and resistance to diet-induced obesity. These findings have generated interest amongst pharmaceutical companies vigilant for potential anti-obesity agents. Nutritional status impacts on reproductive physiology and behaviours thereby optimising reproductive success and the ability to meet energetic demands. This complex control system entails integration of direct or indirect peripheral stimuli with central effector systems and involves numerous mediators. A role for MCH in the reproductive axis has emerged giving rise to the premise that MCH may serve as an integratory mediator between those discrete systems which regulate energy balance and reproductive function. Hence this review focuses on published evidence concerning a) the role of MCH in energy homeostasis and b) the regulatory role of MCH in the reproductive axis. The question as to whether the MCH system mediates the integration of energy homeostasis with the neuroendocrine reproductive axis and if so by what means has received limited coverage in the literature; evidence to date and current theories are summarised here.

/pdf/the-roles-of-melanin-concentrating-hormone-in-energy-balance-586694beu6.pdf

The roles of melanin-concentrating hormone in energy balance and reproductive function: Are they connected?

Maximizing postprandial energy expenditure and fat oxidation could be of clinical relevance for the treatment of obesity. This study investigated the effect of prior exercise on energy expenditure and substrate utilization after meals containing varying amounts of macronutrients. Eight lean (11.6% ± 4.0% body fat, M ± SD) and 12 obese (35.9% ± 5.3% body fat) men were randomly assigned to a protein (43% protein, 30% carbohydrate) or a carbohydrate (10% protein, 63% carbohydrate) meal. The metabolic responses to the meals were investigated during 2 trials, when meals were ingested after a resting period (D) or cycling exercise (Ex+D; 65% of oxygen consumption reserve, 200 kcal). Energy expenditure, substrate utilization, and glucose and insulin responses were measured for 4 hr during the postprandial phase. Although postprandial energy expenditure was not affected by prior exercise, the total amount of fat oxidized was higher during Ex+D than during D (170.8 ± 60.1 g vs. 137.8 ± 50.8 g, p < .05), and, accordingly, the use of carbohydrate as substrate was decreased (136.4 ± 45.2 g vs. 164.0 ± 42.9 g, p < .05).After the protein meal fat-oxidation rates were higher than after carbohydrate intake (p < .05), an effect independent of prior exercise. Plasma insulin tended to be lower during Ex+D (p = .072) and after the protein meal (p = .066). No statistically significant change in postprandial blood glucose was induced by prior exercise. Exercising before meal consumption can result in a marked increase in fat oxidation, which is independent of the type of meal consumed.

Adam Cunliffe

Papers

The role of diet and exercise for the maintenance of fat-free mass and resting metabolic rate during weight loss.

Physiological role of carnosine in contracting muscle.

Attenuation of plasma annexin A1 in human obesity

The roles of melanin-concentrating hormone in energy balance and reproductive function: Are they connected?

Moderate exercise, postprandial energy expenditure, and substrate use in varying meals in lean and obese men.