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Evidence of lifestyle interventions in a pregnant population with chronic hypertension and/or pre-existing diabetes: A systematic review and narrative synthesis.
Goddard, L, Patel, R, Astbury, NM, Tucker, K, McManus, RJ
Pregnancy hypertension. 2023;31:60-72
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Chronic hypertension complicates ≤5 % of pregnancies, and those entering pregnancy with a pre-existing diagnosis of diabetes has a global prevalence of between 0.5 % and 2.6 %. The aim of this study was to collate the evidence around lifestyle interventions during pregnancy for women with chronic hypertension and/or pre-existing diabetes (type 1 and type 2). This study is a systematic review and meta-analysis of nine randomised controlled trials. Results show lack of clarity and data on the effect of lifestyle interventions in pregnant women with chronic hypertension and/or pre-existing diabetes, thereby exposing key gaps in the literature. Authors conclude that there is a shortage of primary interventional studies examining the effect of lifestyle interventions in high-risk pregnant populations who enter pregnancy with chronic conditions.
Abstract
BACKGROUND Pregnant people with chronic hypertension, pre-existing diabetes or both are at high risk of developing cardiovascular disease. Lifestyle interventions play an important role in disease management in non-pregnant populations. AIM: To review the existing evidence of randomised controlled trials (RCTs) that examine lifestyle interventions in pregnant people with chronic hypertension and/or pre-existing diabetes. METHODS A systematic review and narrative synthesis was conducted. Five electronic databases were searched from inception to April 2021 for RCTs evaluating antenatal lifestyle interventions in people with chronic hypertension and/or pre-existing diabetes with outcomes to include weight or blood pressure change. RESULTS Nine randomised controlled trials including 7438 pregnant women were eligible. Eight studies were mixed pregnant populations that included women with chronic hypertension and/or pre-existing diabetes. One study included only pregnant women with pre-existing diabetes. Intervention characteristics and procedures varied and targeted diet, physical activity and/or gestational weight. All studies reported weight and one study reported blood pressure change. Outcome data were frequently unavailable for the subset of women of interest, including subgroup data on important pregnancy and birth complications. Eligibility criteria were often ambiguous and baseline data on chronic hypertension was often omitted. CONCLUSION A lack of primary interventional trials examining the effect of lifestyle interventions on weight and blood pressure outcomes in pregnant populations with chronic hypertension and/or pre-existing diabetes was evident. Lifestyle modification has the potential to alter disease progression. Future trials should address the ambiguity and frequent exclusion of these important populations.
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Short-term removal of exercise impairs glycemic control in older adults: A randomized trial.
Reynolds, LJ, Williams, TM, Harden, JE, Twiddy, HM, Kearney, ML
Physiological reports. 2023;11(2):e15591
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Advancements in glucose monitoring make assessing free-living postprandial blood glucose levels convenient and feasible. Continuous glucose monitoring systems assess blood glucose levels 24h a day and have been demonstrated to enhance diabetes management. Both acutely and chronically, physical activity and/or exercise is a powerful modulator of glycaemic control. The aim of this study was to examine if the alterations in glycaemic control in older adults who exercise were different compared to young adults who exercise, in response to short-term removal of exercise. This study was a randomised, cross-over, exploratory study design which included 20 participants (9 young, active participants and 11 older, active participants). Participants had glycaemic control assessed for 3 days while performing their normal habitual exercise and for 3 days while refraining from habitual exercise. Results show that three days of exercise removal impairs glycaemic control in older adults as well as young adults. In fact, older adults (even though they have worse glycaemic control than younger adults) do not experience a greater impairment in glycaemic control compared to young adults. Authors conclude that their findings support the overall need for regular, daily exercise in adults, particularly older adults, who have a worse glycaemic profile.
Abstract
Postprandial glycemia (PPG) predicts cardiovascular disease, and short-term physical inactivity increases PPG in young, active adults. Whether this occurs in older, active adults who may be more prone to bouts of inactivity is unknown. This study determined if postprandial interstitial glucose (PPIG) was impaired in active older adults following the removal of exercise for 3 days (NOEX) compared to active young adults. In this randomized, crossover study, 11 older (69.1 ± 1.9 years) and 9 young (32.8 ± 1.8 years) habitually active (≥90 min/week of exercise) adults completed 3-days of NOEX and 3-days of normal habitual exercise (EX), separated by ≥1 week. Diet was standardized across phases. Glycemic control (3-day average) was assessed via continuous glucose monitoring during both phases. Significant main effects of age and phase were detected (p < 0.05), but no interaction was found for steps/day (p > 0.05) (old EX: 6283 ± 607, old NOEX 2380 ± 382 and young EX: 8798 ± 623, young NOEX 4075 ± 516 steps/day). Significant main effects of age (p = 0.002) and time (p < 0.001) existed for 1-h PPIG, but no effect of phase or interactions was found (p > 0.05). Significant main effects (p < 0.05) of age (old: 114 ± 1 mg/dl, young: 106 ± 1 mg/dl), phase (NOEX: 112 ± 1 mg/dl, EX: 108 ± 1 mg/dl), and time (0 min: 100 ± 2, 30 min: 118 ± 2, 60 min: 116 ± 2, 90 min: 111 ± 2, 120 min: 108 ± 2 mg/dl) in 2-h PPIG were detected, but no interaction was found (p > 0.05). However, only significant main effects of phase (NOEX: 14 ± 1 and EX:12 ± 1, p > 0.05) were found for 24-h blood glucose standard deviation. Older adults appear to have impaired glycemic control compared to young adults and exercise removal impairs glycemic control in both populations. Yet, the impairment in glycemic control with exercise removal is not different between old and young adults.
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The Effect of Yoga on the Lipid Profile: A Systematic Review and Meta-Analysis of Randomized Clinical Trials.
Ghazvineh, D, Daneshvar, M, Basirat, V, Daneshzad, E
Frontiers in nutrition. 2022;9:942702
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Modernisation has brought increased comforts and limited mobility in our lives at the cost of an increased prevalence of hypertension, diabetes mellitus, dyslipidaemia, and obesity, which are predecessors of major cardiovascular diseases. Prevention and control of coronary heart disease and its associated diseases are essential and can be achieved by modifying the lipid profile. The aim of this study was to systematically assess the effects of yoga on blood lipid levels. This study is a systematic review and meta-analysis of fifty-three randomised controlled studies. All studies employed a parallel design with a total of 13,191 participants whom were divided into 6,700 individuals in the control group and 6,517 in the intervention group. Results show that yoga had decreased total cholesterol, low-density lipoprotein cholesterol, triglycerides, and very low-density lipoprotein cholesterol and increased high-density lipoprotein cholesterol among yoga practitioners. Authors conclude that yoga had a striking effect on balancing lipid profiles.
Abstract
OBJECTIVES Yoga is a mind-body stress-relieving exercise that increases mental and physical health, which may have a role in the improvement of metabolic disorders. The present study has reviewed the effect of yoga on lipid profiles as a systematic review and meta-analysis. METHODS We evaluated the available randomized controlled trials on the effects of yoga-based programs, and lipid profiles by searching PubMed/Medline, Scopus, Web of Science, and the Cochrane central register of control trials up to January 2022. Both fixed and random effect analyses were used to find the relationships. Subgroup analysis was performed based on the continent, duration of the included studies, gender, and health condition of participants to discover the sources of heterogeneity. RESULT Fifty-three studies were included in the current systematic review and meta-analysis with a total sample size of 13,191. There was a striking association between yoga and total cholesterol (-10.31 mg/dl; 95% CI: -14.16, -6.45; I 2 = 82.5%, P < 0.001), low-density lipoprotein cholesterol (-8.64 mg/dl; 95% CI: -12.03, -5.25; I 2 = 75.0%, P < 0.001), high-density lipoprotein cholesterol (1.98 mg/dl; 95% CI: 0.81, 3.14; I 2 = 91.6%, P < 0.001), triglycerides (-13.50 mg/dl; 95% CI: -20.09, -6.92; I 2 = 90.7%, P < 0.001) and very low-density lipoprotein (-3.94 mg/dl; 95%CI: -6.31, -1.56; I 2 = 72.2%, P < 0.001). CONCLUSION It seems yoga interventions had a substantial effect on lipid profiles, however, more qualified trials or cohort studies are needed to conclude exactly.
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Changes in physical activity and sedentary behaviours from before to during the COVID-19 pandemic lockdown: a systematic review.
Stockwell, S, Trott, M, Tully, M, Shin, J, Barnett, Y, Butler, L, McDermott, D, Schuch, F, Smith, L
BMJ open sport & exercise medicine. 2021;7(1):e000960
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COVID-19 has led several countries to enforce social distancing in order to reduce the rate of transmission, commonly called ‘lockdown’. These lockdowns have impacted people’s work, education, travel and recreation, and subsequent levels of physical activity (PA) and sedentary behaviours (SB). The aim of this study was to review and compare the changes in all reported PA and SB behaviours during versus before the COVID-19 pandemic lockdown, stratifying between adults and children, and special populations. This study is a systemic review of 66 studies which yielded a total of 86981 participants with an age range between 13 and 86 years. Results demonstrated that the majority of studies found that PA declined and SB increased during the COVID-19 pandemic lockdown, regardless of the subpopulation. In healthy adults and children, PA during lockdown decreased compared with pre-lockdown, despite various government organisations and health or exercise practitioners providing guidance on how to stay active during the pandemic and in self-quarantine. Authors conclude that the public health officials should promote ways of increasing PA and reducing SB should further lockdowns occur, especially in populations with medical conditions that are improved by PA.
Abstract
OBJECTIVE In March 2020, several countries banned unnecessary outdoor activities during COVID-19, commonly called 'lockdowns. These lockdowns have the potential to impact associated levels of physical activity and sedentary behaviour. Given the numerous health outcomes associated with physical activity and sedentary behaviour, the aim of this review was to summarise literature that investigated differences in physical activity and sedentary behaviour before vs during the COVID-19 lockdown. DESIGN DATA SOURCES AND ELIGIBILITY CRITERIA Electronic databases were searched from November 2019 to October 2020 using terms and synonyms relating to physical activity, sedentary behaviour and COVID-19. The coprimary outcomes were changes in physical activity and/or sedentary behaviour captured via device-based measures or self-report tools. Risk of bias was measured using the Newcastle-Ottawa Scale. RESULTS Sixty six articles met the inclusion criteria and were included in the review (total n=86 981). Changes in physical activity were reported in 64 studies, with the majority of studies reporting decreases in physical activity and increases in sedentary behaviours during their respective lockdowns across several populations, including children and patients with a variety of medical conditions. CONCLUSION Given the numerous physical and mental benefits of increased physical activity and decreased sedentary behaviour, public health strategies should include the creation and implementation of interventions that promote safe physical activity and reduce sedentary behaviour should other lockdowns occur.
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The Kids Obesity Prevention Program: Cluster Randomized Controlled Trial to Evaluate a Serious Game for the Prevention and Treatment of Childhood Obesity.
Mack, I, Reiband, N, Etges, C, Eichhorn, S, Schaeffeler, N, Zurstiege, G, Gawrilow, C, Weimer, K, Peeraully, R, Teufel, M, et al
Journal of medical Internet research. 2020;22(4):e15725
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Authors developed a motion-controlled serious game for children, the Kids Obesity Prevention (KOP) program, addressing the areas of nutrition, physical activity, and stress coping. The aim of the KOP study was to evaluate the game in a cluster randomized controlled trial with two parallel groups in a primary school setting in children aged 9 to 12 years. The main aim of this study was to gain knowledge about important lifestyle factors with the focus on nutrition, especially the dietary energy density (DED) principle. Five fourth grade classes in a single school were randomly allocated to an intervention group or a control group. Results showed that: - children gained sustainable knowledge about the food pyramid concept, the DED concept (including the topic of liquids), and about stress and stress-coping strategies after game play. In fact, 4 weeks after the intervention, the knowledge level was similar to the level directly after intervention. - the children were able to apply their DED knowledge by transferring it to unknown foods. - physical activity decreased in roughly 30-40% of children, whereas it increased in 10% of the cohort. Authors conclude that the game was highly accepted by children, sustainably increased their knowledge of the topics addressed, and could be a useful tool for further studies and education.
Abstract
BACKGROUND Health games provide opportunities for the treatment and prevention of childhood obesity. We developed a motion-controlled serious game for children that addresses 3 core topics of nutrition, physical activity, and stress coping. It is the first serious game that extensively targets the dietary energy density principle (DED-P) in relation to nutrition. The game is intended to provide an additional educational component for the prevention and treatment of obesity in children. OBJECTIVE The Kids Obesity Prevention study aimed to evaluate the newly developed game and to evaluate how well children are able to understand and apply the DED-P. METHODS This cluster randomized controlled trial collected data from 82 primary school children aged 9 to 12 years and their parents at baseline (T0), at 2 weeks after study commencement (T1), and at the 4-week follow-up (T2). The dropout rate was 3.6%. The intervention group (IG) played the game within 2 weeks (2 sessions with different game modules). One part of the game involves selection of food with the lower energy density when presented with a pair of foods. This allows assessment of whether the children have understood the DED-P and whether they can apply it to unknown foods under time pressure. The control group (CG) received a brochure about the food pyramid concept and physical activity. The primary outcome was the gain in knowledge (nutrition and stress coping) and measured with a pretested questionnaire. The secondary outcomes were the maintenance of knowledge, application of the DED-P, feelings during game play, game acceptance, and behavioral measures (physical activity, media consumption, and dietary intake). RESULTS The knowledge score ranging from 0 to 100 increased from T0 (IG: 53 [SD 10], CG: 50 [SD 11]) to T1 (IG: 69 [SD 11], CG: 52 [SD 12]) in IG versus CG (P<.001). At T2, the knowledge score of IG remained at the same level as that of T1. Game data showed that after DED-P education, the classification under time pressure of unknown versus known food pairs according to their DED category was similar (hit rate around 70%). Overall, 95% of the children liked the game very much or much. No group changes were observed at the behavioral level. CONCLUSIONS The Kids Obesity Prevention program sustainably increased knowledge in the areas of nutrition and stress coping, and children were able to apply the DED-P. TRIAL REGISTRATION ClinicalTrials.gov NCT02551978; https://clinicaltrials.gov/ct2/show/NCT02551978.
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Social isolation during the COVID-19 pandemic can increase physical inactivity and the global burden of cardiovascular disease.
Peçanha, T, Goessler, KF, Roschel, H, Gualano, B
American journal of physiology. Heart and circulatory physiology. 2020;318(6):H1441-H1446
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Home isolation, adopted worldwide to contain the spread of the coronavirus disease 2019 (COVID-19), is likely to result in a profound decrease in moderate-to-vigorous physical activity levels and increase in sedentary behaviour. Literature shows that the potential increase in physical inactivity induced by the pandemic may have substantial repercussions for cardiovascular health. Achieving minimum physical activity levels and reducing sedentary behaviour in times of social isolation have become a challenge and, at the same time, a necessity for everyone. In fact, remotely supervised home-based interventions have been shown to significantly improve physical fitness in coronary artery disease and heart failure patients and to be equally effective in centre-based interventions for secondary prevention. Authors conclude that the recognition of the impact of physical inactivity on the burden of cardiovascular disease and the evidence-based interventions to counteract it is of paramount relevance to inform coordinated public health actions aimed at tackling both COVID-19 and inactivity pandemics simultaneously.
Abstract
Emerging data indicate a substantial decrease in global physical activity levels during the period of social isolation adopted worldwide to contain the spread of the coronavirus disease 2019 (COVID-19). Confinement-induced decreases in physical activity levels and increases in sedentary behavior may provoke a rapid deterioration of cardiovascular health and premature deaths among populations with increased cardiovascular risk. Even short-term (1-4 wk) inactivity has been linked with detrimental effects in cardiovascular function and structure and increased cardiovascular risk factors. In this unprecedented and critical scenario, home-based physical activity programs arise as a clinically relevant intervention to promote health benefits to cardiac patients. Many studies have demonstrated the feasibility, safety, and efficacy of different models of home-based exercise programs in the primary and secondary prevention of cardiovascular diseases and major cardiovascular events among different populations. This body of knowledge can inform evidence-based policies to be urgently implemented to counteract the impact of increased physical inactivity and sedentary behavior during the COVID-19 outbreak, thereby alleviating the global burden of cardiovascular disease.
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Systematic review of the prospective association of daily step counts with risk of mortality, cardiovascular disease, and dysglycemia.
Hall, KS, Hyde, ET, Bassett, DR, Carlson, SA, Carnethon, MR, Ekelund, U, Evenson, KR, Galuska, DA, Kraus, WE, Lee, IM, et al
The international journal of behavioral nutrition and physical activity. 2020;17(1):78
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The health benefits of physical activity for people of all ages, fitness levels, and sociodemographic backgrounds are well-documented. The main aim of this study was to provide an updated description of the association between daily step counts and subsequent cardiovascular disease (CVD) morbidity or mortality, dysglycaemia, and all-cause mortality in adults and the patterns of these associations. This study is a systemic review of 17 studies from 13 different cohorts. Participants’ mean age ranged from 49.7 to 78.9 years with samples comprised of 46.9% female participants on average. Results showed that increasing steps per day is beneficial for health: taking more steps per day was associated with lower risk of all-cause mortality, and lower risk of CVD morbidity or mortality. These associations appear to hold across age, gender, and weight status. Authors conclude that this additional evidence will help guide meaningful volume targets that can be used for health care, education, and behavioural interventions, and potentially inform the development of public health guidelines for steps and health.
Abstract
BACKGROUND Daily step counts is an intuitive metric that has demonstrated success in motivating physical activity in adults and may hold potential for future public health physical activity recommendations. This review seeks to clarify the pattern of the associations between daily steps and subsequent all-cause mortality, cardiovascular disease (CVD) morbidity and mortality, and dysglycemia, as well as the number of daily steps needed for health outcomes. METHODS A systematic review was conducted to identify prospective studies assessing daily step count measured by pedometer or accelerometer and their associations with all-cause mortality, CVD morbidity or mortality, and dysglycemia (dysglycemia or diabetes incidence, insulin sensitivity, fasting glucose, HbA1c). The search was performed across the Medline, Embase, CINAHL, and the Cochrane Library databases from inception to August 1, 2019. Eligibility criteria included longitudinal design with health outcomes assessed at baseline and subsequent timepoints; defining steps per day as the exposure; reporting all-cause mortality, CVD morbidity or mortality, and/or dysglycemia outcomes; adults ≥18 years old; and non-patient populations. RESULTS Seventeen prospective studies involving over 30,000 adults were identified. Five studies reported on all-cause mortality (follow-up time 4-10 years), four on cardiovascular risk or events (6 months to 6 years), and eight on dysglycemia outcomes (3 months to 5 years). For each 1000 daily step count increase at baseline, risk reductions in all-cause mortality (6-36%) and CVD (5-21%) at follow-up were estimated across a subsample of included studies. There was no evidence of significant interaction by age, sex, health conditions or behaviors (e.g., alcohol use, smoking status, diet) among studies that tested for interactions. Studies examining dysglycemia outcomes report inconsistent findings, partially due to heterogeneity across studies of glycemia-related biomarker outcomes, analytic approaches, and sample characteristics. CONCLUSIONS Evidence from longitudinal data consistently demonstrated that walking an additional 1000 steps per day can help lower the risk of all-cause mortality, and CVD morbidity and mortality in adults, and that health benefits are present below 10,000 steps per day. However, the shape of the dose-response relation is not yet clear. Data are currently lacking to identify a specific minimum threshold of daily step counts needed to obtain overall health benefit.
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Links between metabolic syndrome and the microbiome.
Gildner, TE
Evolution, medicine, and public health. 2020;2020(1):45-46
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Metabolic syndrome (MetS) is a cluster of co-occurring pathological conditions, characterised by insulin resistance, abdominal obesity, hypertension and dyslipidaemia One possible factor contributing to MetS risk is change in microbiome composition. Diets high in processed foods appear to alter microbiome composition in ways that promote higher fat mass and insulin resistance. Additionally, a sedentary lifestyle decreases microbiome diversity, elevating inflammation and metabolic disease risk. Research on how the microbiome responds to modest, attainable changes in diet and physical activity will help identify which dietary adjustments and exercise types have the greatest potential to protect patients from MetS.
Abstract
Metabolic syndrome (MetS) is a cluster of harmful conditions which occur together, such as insulin resistance, abdominal obesity, and hypertension. The global prevalence of MetS is growing rapidly, with some estimates suggesting over one billion people worldwide experience increased morality and disease rates linked with this syndrome. One possible factor contributing to MetS risk is changes in microbiome composition. Approximately 100 trillion bacteria and other microbes reside in the human intestinal tract, collectively termed the gut microbiome. Humans and microbes share a long evolutionary history, with many of these microbes influencing human health outcomes. However, environmental conditions have changed dramatically with human technological innovations; many of these changes (e.g., diets high in processed foods and sedentary lifestyles) appear to impact human-microbe relationships. In general, recent changes in diet and activity patterns have been linked to decreased microbiome diversity, elevating inflammation and metabolic disease risk and likely promoting the development of MetS. Targeting patient diet or exercise patterns may therefore help doctors better treat patients suffering from MetS. Still, additional work is needed to determine how the microbiome responds to changes in patient activity and diet patterns across culturally and biologically diverse human populations.
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Comparison of the Effectiveness of Lifestyle Modification with Other Treatments on the Incidence of Type 2 Diabetes in People at High Risk: A Network Meta-Analysis.
Yamaoka, K, Nemoto, A, Tango, T
Nutrients. 2019;11(6)
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The prevalence of diabetes has been increasing worldwide. The accompanying increase in the prevalence of diabetes-related complications and the occurrence of diabetes are likely to have a substantial impact on healthcare costs. The aim of the study was to compare the effectiveness of lifestyle modifications to other treatments for patients at high risk of type 2 diabetes. The study design is a systemic review of published literature and a network meta-analysis of data from each selected study. Forty-seven interventions were used for the analyses. The results of the meta-analysis highlight the efficacy of lifestyle modification in preventing the onset of type 2 diabetes in high-risk patients in comparison with standard treatment or placebo as well as other treatments. The proportion of patients with onset of type 2 diabetes in the intervention (lifestyle modification) group was approximately twice as low as compared to the control (standard intervention) group. Authors conclude that lifestyle modification is the superior treatment intervention among 12 treatments for the prevention of type 2 diabetes in high-risk individuals.
Abstract
BACKGROUND Many clinical trials have been conducted to verify the effects of interventions for prevention of type 2 diabetes (T2D) using different treatments and outcomes. The aim of this study was to compare the effectiveness of lifestyle modifications (LM) with other treatments in persons at high risk of T2D by a network meta-analysis (NMA). METHODS Searches were performed of PUBMED up to January 2018 to identify randomized controlled trials. The odds ratio (OR) with onset of T2D at 1 year in the intervention group (LM, dietary, exercise, or medication) versus a control group (standard treatments or placebo) were the effect sizes. Frequentist and Bayesian NMAs were conducted. RESULTS Forty-seven interventions and 12 treatments (20,113 participants) were used for the analyses. The OR in the LM was approximately 0.46 (95% CI: 0.33 to 0.61) times lower compared to the standard intervention by the Bayesian approach. The effects of LM compared to other treatments by indirect comparisons were not significant. CONCLUSIONS This meta-analysis further strengthened the evidence that LM reduces the onset of T2D compared to standard and placebo interventions and appears to be at least as effective as nine other treatments in preventing T2D.
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Fat Quantity and Quality, as Part of a Low-Fat, Vegan Diet, Are Associated with Changes in Body Composition, Insulin Resistance, and Insulin Secretion. A 16-Week Randomized Controlled Trial.
Kahleova, H, Hlozkova, A, Fleeman, R, Fletcher, K, Holubkov, R, Barnard, ND
Nutrients. 2019;11(3)
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Dietary macronutrients play an important role in the risk of obesity and type 2 diabetes. The aim of this study was to assess the effect of diet changes on body weight and metabolism. This study is a 16-week randomized clinical trial. Adult men and women, with a body-mass index between 28 and 40 kg/m2, were enrolled. Participants were randomly assigned to the vegan or the control group and examined at baseline and 16 weeks. Results show that: - in overweight individuals, both fat quantity and quality were associated with changes in body weight, body composition, insulin resistance and insulin secretion. - decreased intake of saturated, trans, or total fat was linked to decreased fat mass. - changes in the fatty acid composition of the diet were associated with changes in insulin resistance and insulin secretion. Authors conclude that selecting foods so as to limit the intake of saturated and trans fats and increase the relative content of polyunsaturated fatty acids, may be a useful strategy for metabolic health.
Abstract
Macronutrient composition of the diet influences the development of obesity and insulin resistance. The aim of this study was to assess the role of dietary fat quantity and fatty acid composition in body composition, insulin resistance, and insulin secretion. An open parallel randomized trial design was used. Overweight participants (n = 75) were randomized to follow a low-fat vegan (n = 38) or control diet (n = 37) for 16 weeks. Dual X-ray absorptiometry was used to measure body composition. Insulin resistance was assessed with the Homeostasis Model Assessment (HOMA-IR) index. Insulin secretion was assessed after stimulation with a liquid breakfast (Boost Plus, Nestle, Vevey, Switzerland). Self-reported 3-day diet records were used to assess dietary intake. A linear regression model was used to test the relationship between fat intake and body composition, insulin resistance, and insulin secretion. Changes in fat intake expressed as percent of total energy consumed correlated positively with changes in fat mass (r = 0.52; p < 0.001; and 0.347; p = 0.006, respectively), even after adjustment for changes in body-mass index (BMI) and energy intake (0.33; p = 0.01). Decreased intakes of C18:0 (r = 0.37, p = 0.004) and CLA-trans-10-cis12 (r = 0.40, p = 0.002), but increased intake of C18:2 (r = -0.40, p = 0.002) and C18:3 (p = -0.36, p = 0.006), were associated with a decrease in HOMA-IR, independent on changes in BMI and energy intake. The main fatty acids associated with changes in fasting insulin secretion were C12:0 (r = -0.31, p = 0.03), and TRANS 16:1 (r = -0.33, p = 0.02), both independent on changes in BMI and energy intake. Our findings demonstrate that, in the context of a low-fat vegan diet, decreased intake of saturated and trans fats and increased relative content of polyunsaturated fatty acids, particularly linoleic and α-linolenic acids, are associated with decreased fat mass and insulin resistance, and enhanced insulin secretion.