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Relationship between Ketones, Ghrelin, and, Appetite on Isocaloric Diets with Varying Carbohydrate Quality and Amount: Results from a Randomized Controlled Trial in People with Obesity (CARBFUNC).
Sommersten, CH, Gjerde, ES, Laupsa-Borge, J, Andersen, AI, Lawrence-Archer, L, McCann, A, Hansson, P, Raza, GS, Herzig, KH, Lied, GA, et al
The Journal of nutrition. 2023;153(2):459-469
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Diet induced fat loss can result in an increase in appetite, contributing to weight loss regression and reduced diet adherence after successful weight loss. Certain diets such as those very high in fat and low in carbohydrates, which switches the body’s main fuel source to fat instead of sugar, have been shown to suppress feelings of hunger after weight loss. When this occurs it is known as ketosis and these diets may suppress a hormone, which is responsible for feelings of hunger, known as ghrelin. Diets which focus on the quality of the carbohydrate being consumed have also been shown to affect appetite. This randomised control trial of 193 individuals aimed to determine the effect of ketosis and the quality of carbohydrates on ghrelin and feelings of hunger. The results showed that ketosis during a low carbohydrate high fat diet was insufficient to decrease levels of the hunger hormone ghrelin and increased feelings of hunger. Carbohydrate quality also failed to decrease feelings of hunger or the hunger hormone ghrelin. It was concluded that regardless of the diet, fat loss resulted in feelings of hunger, which could not be supressed by a high-quality carbohydrate diet or a low carbohydrate high fat diet. This study could be used by health care professionals to understand that weight loss may be hindered by an increase in appetite. If this occurs, strategies to limit the hunger hormone ghrelin may be successful in maintaining weight loss.
Abstract
BACKGROUND Low-carbohydrate high-fat (LCHF) diets may suppress the increase in appetite otherwise seen after diet-induced fat loss. However, studies of diets without severe energy restriction are lacking, and the effects of carbohydrate quality relative to quantity have not been directly compared. OBJECTIVES To evaluated short- (3 mo) and long-term (12 mo) changes in fasting plasma concentrations of total ghrelin, β-hydroxybutyrate (βHB), and subjective feelings of appetite on 3 isocaloric eating patterns within a moderate caloric range (2000-2500 kcal/d) and with varying carbohydrate quality or quantity. METHODS We performed a randomized controlled trial of 193 adults with obesity, comparing eating patterns based on "acellular" carbohydrate sources (e.g., flour-based whole-grain products; comparator arm), "cellular" carbohydrate sources (minimally processed foods with intact cellular structures), or LCHF principles. Outcomes were compared by an intention-to-treat analysis using constrained linear mixed modeling. This trial was registered at clinicaltrials.gov as NCT03401970. RESULTS Of the 193 adults, 118 (61%) and 57 (30%) completed 3 and 12 mo of follow-up. Throughout the intervention, intakes of protein and energy were similar with all 3 eating patterns, with comparable reductions in body weight (5%-7%) and visceral fat volume (12%-17%) after 12 mo. After 3 mo, ghrelin increased significantly with the acellular (mean: 46 pg/mL; 95% CI: 11, 81) and cellular (mean: 54 pg/mL; 95% CI: 21, 88) diets but not with the LCHF diet (mean: 11 pg/mL; 95% CI: -16, 38). Although βHB increased significantly more with the LCHF diet than with the acellular diet after 3 m (mean: 0.16 mmol/L; 95% CI: 0.09, 0.24), this did not correspond to a significant group difference in ghrelin (unless the 2 high-carbohydrate groups were combined [mean: -39.6 pg/mL; 95% CI: -76, -3.3]). No significant between-group differences were seen in feelings of hunger. CONCLUSIONS Modestly energy-restricted isocaloric diets differing in carbohydrate cellularity and amount showed no significant differences in fasting total ghrelin or subjective hunger feelings. An increase in ketones with the LCHF diet to 0.3-0.4 mmol/L was insufficient to substantially curb increases in fasting ghrelin during fat loss.
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An Energy-Reduced Mediterranean Diet, Physical Activity, and Body Composition: An Interim Subgroup Analysis of the PREDIMED-Plus Randomized Clinical Trial.
Konieczna, J, Ruiz-Canela, M, Galmes-Panades, AM, Abete, I, Babio, N, Fiol, M, Martín-Sánchez, V, Estruch, R, Vidal, J, Buil-Cosiales, P, et al
JAMA network open. 2023;6(10):e2337994
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The Mediterranean diet (MedDiet), which focuses on whole grains, lean meat, fruits, vegetables, and low amounts of minimally processed foods has been shown in previous research to improve body composition and decrease fat storage around the middle. This randomised control trial of 1556 older adults aimed to determine the effects of combining a 30% lower energy version of the MedDiet in combination with physical exercise on body composition. After 3 years, the results showed that compared to a normal MedDiet without exercise, the lower energy version in combination with exercise improved body composition by decreasing total fat, and the fat stored around the organs and increasing muscle mass. However, benefits were more pronounced after 1 year and decreased slightly at 3 years. It was concluded that a low energy MedDiet in combination with physical activity may be able to improve the body composition of overweight and older adults with obesity. This study could be used by healthcare professionals to recommend a low energy MedDiet to older adults to promote weight loss, whilst attenuating muscle loss associated with ageing.
Expert Review
Conflicts of interest:
None
Take Home Message:
- The addition of exercise to an energy-reduced diet, which focuses on whole grains, healthy fats, lean protein, and fruits and vegetables can emphasise positive effects on body composition in older adults.
- However, there is a loss of lean mass associated with this type of diet (contrary to author conclusions) and measures should be taken to monitor and increase protein intake to prevent or limit this loss.
Evidence Category:
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X
A: Meta-analyses, position-stands, randomized-controlled trials (RCTs)
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B: Systematic reviews including RCTs of limited number
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C: Non-randomized trials, observational studies, narrative reviews
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D: Case-reports, evidence-based clinical findings
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E: Opinion piece, other
Summary Review:
Introduction
This study aimed to determine the long-term effects of an energy reduced MedDiet in combination with physical activity on body composition.
Methods
- This is a predetermined 3-year interim analysis of a 6-year single-blind, randomised control trial of 1556 individuals aged 55-75 who are overweight or obese with metabolic syndrome.
- 760 individuals on 30% energy reduced MedDiet with limited processed foods, plus 45 minutes walking 6 days per week and behavioural and motivational support. [Intervention group]
- 761 on standard MedDiet without physical activity. [Control]
Results
Within group comparisons showed that individuals in the intervention group lost (P value represents baseline vs year 3):
- Total fat mass percentage (1-year vs baseline, −1.14%; 95% CI, −1.32% to −0.96%; 3-year vs baseline, −0.52%; 95% CI, −0.71% to −0.33% P=<0.001)
- Absolute visceral fat (1-year vs baseline, −154 g; 95% CI, −191 to −116 g; 3-year vs baseline, −75.1 g, 95% CI, −115 to −35.3 g P=<0.001)
- Absolute total fat after 1 year (mean change at 1 year vs baseline, −1677 g; 95% CI, −1930 to −1424 g) but regained some at year 3 (mean change at 3 years vs baseline, −1018 g; 95% CI, −1280 to −756 g P=<0.001)
- Absolute lean mass (mean change at 1 year vs baseline −300 g; 95% CI, −439 to −162 g) with further losses at year 3 (−626 g; 95% CI, −770 to −483 g P=0.001).
Within group comparisons also showed significantly increased:
- Total lean mass percentage, which was greater at year 1 than year 3 (1-year vs baseline, 1.07%; 95%CI, 0.90%-1.25%; 3-year vs baseline, 0.47%; 95% CI, 0.29%-0.65% P=<0.001).
As a result of total fat loss and some lean mass in the intervention group, the lean:fat mass ratio improved and was unchanged in the control group (between group differences (P=<0.001).
Compared to women, men may find the MedDiet + exercise more beneficial as it was shown that body composition changes were slightly more pronounced in men.
Conclusion
An energy-reduced MedDiet plus exercise emphasised positive changes to body composition compared to standard MedDiet in older adults who are overweight or have obesity.
Clinical practice applications:
- The recommendation of a reduced energy MedDiet in combination with physical activity to older people who are overweight or obese may improve body composition.
- Although lean mass loss slowed between years 1 and 3, other practices should be employed to attenuate the loss of lean mass associated with an energy-reduced MedDiet and ageing.
Considerations for future research:
- The research has not yet concluded but when it does, it will address the incidence of cardiovascular disease along with body composition changes.
- It will also look at long-term effects of the diet to determine longevity.
- Future research could focus on how to limit lean mass loss through the possibility of changing the type of exercise that accompanies the MedDiet.
Abstract
IMPORTANCE Strategies targeting body composition may help prevent chronic diseases in persons with excess weight, but randomized clinical trials evaluating lifestyle interventions have rarely reported effects on directly quantified body composition. OBJECTIVE To evaluate the effects of a lifestyle weight-loss intervention on changes in overall and regional body composition. DESIGN, SETTING, AND PARTICIPANTS The ongoing Prevención con Dieta Mediterránea-Plus (PREDIMED-Plus) randomized clinical trial is designed to test the effect of the intervention on cardiovascular disease prevention after 8 years of follow-up. The trial is being conducted in 23 Spanish research centers and includes men and women (age 55-75 years) with body mass index between 27 and 40 and metabolic syndrome. The trial reported herein is an interim subgroup analysis of the intermediate outcome body composition after 3-year follow-up, and data analysis was conducted from February 1 to November 30, 2022. Of 6874 total PREDIMED-Plus participants, a subsample of 1521 individuals, coming from centers with access to a dual energy x-ray absorptiometry device, underwent body composition measurements at 3 time points. INTERVENTION Participants were randomly allocated to a multifactorial intervention based on an energy-reduced Mediterranean diet (MedDiet) and increased physical activity (PA) or to a control group based on usual care, with advice to follow an ad libitum MedDiet, but no physical activity promotion. MAIN OUTCOMES AND MEASURES The outcomes (continuous) were 3-year changes in total fat and lean mass (expressed as percentages of body mass) and visceral fat (in grams), tested using multivariable linear mixed-effects models. Clinical relevance of changes in body components (dichotomous) was assessed based on 5% or more improvements in baseline values, using logistic regression. Main analyses were performed in the evaluable population (completers only) and in sensitivity analyses, multiple imputation was performed to include data of participants lost to follow-up (intention-to-treat analyses). RESULTS A total of 1521 individuals were included (mean [SD] age, 65.3 [5.0] years; 52.1% men). In comparison with the control group (n=761), participants in the intervention arm (n=760) showed greater reductions in the percentage of total fat (between group differences after 1-year, -0.94% [95% CI, -1.19 to -0.69]; 3 years, -0.38% [95% CI, -0.64 to -0.12] and visceral fat storage after 1 year, -126 g [95% CI, -179 to -73.3 g]; 3 years, -70.4 g [95% CI, -126 to -15.2 g] and greater increases in the percentage of total lean mass at 1 year, 0.88% [95% CI, 0.63%-1.12%]; 3-years 0.34% [95% CI, 0.09%-0.60%]). The intervention group was more likely to show improvements of 5% or more in baseline body components (absolute risk reduction after 1 year, 13% for total fat mass, 11% for total lean mass, and 14% for visceral fat mass; after 3-years: 6% for total fat mass, 6% for total lean mass, and 8% for visceral fat mass). The number of participants needed to treat was between 12 and 17 to attain at least 1 individual with possibly clinically meaningful improvements in body composition. CONCLUSIONS AND RELEVANCE The findings of this trial suggest a weight-loss lifestyle intervention based on an energy-reduced MedDiet and physical activity significantly reduced total and visceral fat and attenuated age-related losses of lean mass in older adults with overweight or obesity and metabolic syndrome. Continued follow-up is warranted to confirm the long-term consequences of these changes on cardiovascular clinical end points. TRIAL REGISTRATION isrctn.org Identifier: ISRCTN89898870.
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The effect of weight loss following 18 months of lifestyle intervention on brain age assessed with resting-state functional connectivity.
Levakov, G, Kaplan, A, Yaskolka Meir, A, Rinott, E, Tsaban, G, Zelicha, H, Blüher, M, Ceglarek, U, Stumvoll, M, Shelef, I, et al
eLife. 2023;12
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Obesity is linked to premature brain ageing and subsequent development of diseases such as dementia and Alzheimer’s disease. Weight loss through lifestyle modifications may be able to attenuate brain ageing. This sub-study of 102 individuals from a randomised control trial known as the Dietary Intervention Randomised Controlled Trial Polyphenols Unprocessed Study (DIRECT-PLUS), aimed to determine the effect of 18 months lifestyle modifications and weight loss on brain age. The results showed that a decrease in BMI attenuated brain ageing and that 1% body weight loss reduced brain ageing by 8.9 months. Reduced brain age was also associated with decreased waist circumference and fat mass. Interestingly, reduced consumption of processed foods was also associated with reduced brain age. It was concluded that weight loss can be of benefit to brain health. This study could be used by healthcare professionals to understand that people with obesity are at a higher risk of brain related diseases, and that weight loss may be an effective way to prevent their development.
Abstract
BACKGROUND Obesity negatively impacts multiple bodily systems, including the central nervous system. Retrospective studies that estimated chronological age from neuroimaging have found accelerated brain aging in obesity, but it is unclear how this estimation would be affected by weight loss following a lifestyle intervention. METHODS In a sub-study of 102 participants of the Dietary Intervention Randomized Controlled Trial Polyphenols Unprocessed Study (DIRECT-PLUS) trial, we tested the effect of weight loss following 18 months of lifestyle intervention on predicted brain age based on magnetic resonance imaging (MRI)-assessed resting-state functional connectivity (RSFC). We further examined how dynamics in multiple health factors, including anthropometric measurements, blood biomarkers, and fat deposition, can account for changes in brain age. RESULTS To establish our method, we first demonstrated that our model could successfully predict chronological age from RSFC in three cohorts (n=291;358;102). We then found that among the DIRECT-PLUS participants, 1% of body weight loss resulted in an 8.9 months' attenuation of brain age. Attenuation of brain age was significantly associated with improved liver biomarkers, decreased liver fat, and visceral and deep subcutaneous adipose tissues after 18 months of intervention. Finally, we showed that lower consumption of processed food, sweets and beverages were associated with attenuated brain age. CONCLUSIONS Successful weight loss following lifestyle intervention might have a beneficial effect on the trajectory of brain aging. FUNDING The German Research Foundation (DFG), German Research Foundation - project number 209933838 - SFB 1052; B11, Israel Ministry of Health grant 87472511 (to I Shai); Israel Ministry of Science and Technology grant 3-13604 (to I Shai); and the California Walnuts Commission 09933838 SFB 105 (to I Shai). Obesity is linked with the brain aging faster than would normally be expected. Researchers are able to capture this process by calculating a person’s ‘brain age’ – how old their brain appears on detailed scans, regardless of chronological age. This approach also helps to monitor how certain factors, such as lifestyle, can influence brain aging over relatively short time scales. It is not clear whether lifestyle interventions that promote weight loss can help to slow obesity-driven brain aging. To answer this question, Levakov et al. studied 102 individuals who met the criteria for obesity and took part in a lifestyle intervention aimed to improve diet and physical activity levels over 18 months. The participants received a brain scan at the beginning and the end of the program; additional tests and measurements were also conducted at these times to capture other biological processes impacted by obesity, such as liver health. Levakov et al. used the brain scans taken at the start and end of the study to examine the impact of the lifestyle intervention on the aging trajectory. The results revealed that a reduction in body weight of 1% led to the participants’ brain age being nearly 9 months younger than the expected brain age after 18 months. This attenuated aging was associated with changes in other biological measures, such as decreased liver fat and liver enzymes. Increases in liver fat and production of specific liver enzymes were previously shown to negatively impact brain health in Alzheimer’s disease. Finally, examining more closely the food consumption reports completed by participants showed that reduced consumption of processed food, sweets and beverages were linked to attenuated brain aging. The findings show that lifestyle interventions which promote weight loss can have a beneficial impact on the aging trajectory of the brain observed with obesity. The next steps will include determining whether slowing down obesity-driven brain aging results in better clinical outcomes for patients. In addition, the work by Levakov et al. demonstrates a potential strategy to evaluate the success of lifestyle changes on brain health. With global rates of obesity rising, identifying interventions that have a positive impact on brain health could have important clinical, educational and social impacts.
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Novel nutraceutical supplements with yeast β-glucan, prebiotics, minerals, and Silybum marianum (silymarin) ameliorate obesity-related metabolic and clinical parameters: A double-blind randomized trial.
Nehmi-Filho, V, Santamarina, AB, de Freitas, JA, Trarbach, EB, de Oliveira, DR, Palace-Berl, F, de Souza, E, de Miranda, DA, Escamilla-Garcia, A, Otoch, JP, et al
Frontiers in endocrinology. 2022;13:1089938
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Obesity is a growing concern around the world and. There are several factors that contribute to its development such as genetics, lack of exercise and poor diet. Interest in food supplements and nutraceuticals is growing as a strategy to treat and prevent obesity. This randomised control trial of 59 individuals aimed to determine whether a nutritional supplement containing yeast beta-glucan, prebiotics, minerals, and S. marianum (Silymarin) had any effect on obesity related body biochemistry and metabolism. The results showed that body morphology and enzymes associated with non-alcoholic fatty liver disease, which is a disease associated with obesity, were improved with supplementation. In addition, levels of stress hormones and hormones associated with metabolism were improved. It was concluded that supplementation with yeast beta-glucan, prebiotics, minerals, and Silymarin may be of benefit to individuals with obesity to improve associated diseases and metabolism. This study could be used by healthcare professionals to understand that supplementation may be of benefit to individuals with obesity.
Abstract
PURPOSE It is known that obesity has a multifactorial etiology that involves genetic and environmental factors. The WHO estimates the worldwide prevalence of 1.9 billion overweight adults and more than 650 million people with obesity. These alarming data highlight the high and growing prevalence of obesity and represent a risk factor for the development and aggravation of other chronic diseases, such as nonalcoholic fatty liver disease (NAFLD) that is frequently considered the hepatic outcome of type 2 diabetes. The use of non-pharmacological therapies such as food supplements, nutraceuticals, and natural integrative therapies has grown as an alternative tool for obesity-related diseases compared to conventional medications. However, it is a still little explored research field and lacks scientific evidence of therapeutic effectiveness. Considering this, the aim is to evaluate whether a new nutraceutical supplement composition can improve and supply essential mineral nutrients, providing an improvement of obesity-related metabolic and endocrine parameters. METHODS Sedentary volunteers (women and men) with body mass index (BMI) ≤34.9 kg/m2 were divided into two groups: Novel Nutraceutical Supplement_(S) (n = 30) and Novel Nutraceutical Supplement (n = 29), differing in the absence (S) or presence of silymarin, respectively. Volunteers were instructed to take two capsules in the morning and two capsules in the evening. No nutritional intervention was performed during the study period. The data (anthropometrics and anamneses) and harvest blood (biochemistry and hormonal exams) were collected at three different time points: baseline time [day 0 (T0)], day 90 (T90), and day 180 (T180) post-supplementation. RESULTS In the anthropometric analysis, the waist circumference in middle abdomen (WC-mid) and waist circumference in iliac crest (WC-IC) were reduced. Also, the waist-to-height ratio (WHt R) and waist-to-hip ratio (WHR) seem to slightly decrease alongside the supplementation period with both nutraceutical supplements tested as well as transaminase enzyme ratio [aspartate aminotransferase (AST)/alanine aminotransferase (ALT) ratio (AAR)], a known as a biomarker of NAFLD, and endocrine hormones cortisol and thyroid-stimulating hormone (TSH) at 90 and 180 days post-supplementation. CONCLUSIONS In a condition associated with sedentary and no nutritional intervention, the new nutraceutical supplement composition demonstrated the ability to be a strong and newfangled tool to improve important biomarkers associated with obesity and its comorbidities.
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The Effects of Low-Energy Moderate-Carbohydrate (MCD) and Mixed (MixD) Diets on Serum Lipid Profiles and Body Composition in Middle-Aged Men: A Randomized Controlled Parallel-Group Clinical Trial.
Michalczyk, MM, Maszczyk, A, Stastny, P
International journal of environmental research and public health. 2020;17(4)
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Diets high in poor quality carbohydrates and fats and low in fibre are believed to play an integral role in the formation of many different chronic diseases. Calorie restricted diets have previously shown to have health benefits, but these are stringent and hard to maintain. More recently low-carbohydrate diets have shown that they may be better tolerated. This randomised control trial aimed to compare a calorie restricted diet (MixD) with a calorie restricted moderate-carbohydrate diet (MCD) on indicators for chronic disease in 60 overweight and obese men over four weeks. The results showed that MCD resulted in significant loss of body fat without loss of muscle mass compared to MixD and significantly decreased markers for heart disease risk. It was concluded that the amount of body fat can be attributed to the amount and quality of carbohydrates consumed and that consumption of a MCD is more effective for weight loss without compromising muscle mass than a MixD. This study could be used by health professionals to recommend a MCD to middle aged obese men in order to lose body fat, retain muscle mass and reduce their risk of heart disease.
Abstract
Carbohydrate-restricted diets have become very popular due to their numerous health benefits. The aim of this study was to determine the influence of 4 weeks of a well-planned, low-energy moderate-carbohydrate diet (MCD) and a low-energy mixed diet (MixD) on the lipoprotein profile, glucose and C-reactive protein concentrations, body mass, and body composition in middle-aged males. Sixty middle-aged males were randomly assigned to the following groups: hypocaloric MCD (32% carbohydrates, 28% proteins, and 40% fat), hypocaloric MixD (50% carbohydrates, 20% proteins, and 30% fat), and a conventional (control) diet (CD; 48% carbohydrates, 15% proteins, and 37% fat). The participants who were classified into the MCD and MixD groups consumed 20% fewer calories daily than the total daily energy expenditure (TDEE). Baseline and postintervention fasting triacylglycerol (TG), LDL (low-density lipoprotein) cholesterol (LDL-C), HDL (high-density lipoprotein) cholesterol (HDL-C), total cholesterol (tCh), glucose (Gl), and C-reactive protein were evaluated. Body mass (BM) and body composition changes, including body fat (BF), % body fat (PBF), and muscle mass (MM), were monitored. Compared with MixD and CD, MCD significantly changed the fasting serum concentrations of TG (p < 0.05), HDL-C (p < 0.05), LDL-C (p < 0.05), tCh (p < 0.05), and glucose (p < 0.01). Additionally, body fat content (kg and %) was significantly reduced (p < 0.05) after MCD compared with MixD and CD. After the MixD intervention, BM and MM decreased (p < 0.05) compared with baseline values. Compared with baseline, after the MixD, BM, MM, tCh, LDL-C, and TG changed significantly. The 4 week low-energy MCD intervention changed lipoproteins, glucose, and body fat to a greater extent than the low-energy MixD. A hypocaloric MCD may be suggested for middle-aged male subjects who want to lose weight by reducing body fat content without compromising muscle mass.
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Effects of green tea extract combined with brisk walking on lipid profiles and the liver function in overweight and obese men: A randomized, double-blinded, placebo-control trial.
Zhang, T, Li, N, Chen, SI, Hou, Z, Saito, A
Anais da Academia Brasileira de Ciencias. 2020;92(4):e20191594
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Studies have shown that green tea extract (GTE) and exercise may help manage obesity. This randomised double-blind placebo-controlled trial study aimed to assess the role of GTE plus exercise on the amount of cholesterol in the blood and in the treatment of chronic diseases in 24 overweight and obese men over 12 weeks. The results showed that although cholesterol levels did not improve with GTE, they were maintained, whereas the placebo groups increased. There was an improvement in liver function in the GTE group, which was not observed with placebo. It was concluded that GTE plus exercise maintained but did not improve cholesterol levels in overweight and obese men contrary to previous study results. This could be due to a lower dose of GTE in the present study. GTE plus exercise did improve liver function. This study could be used by practitioners to recommend GTE supplementation and exercise in the management of cholesterol and to improve liver function in overweight and obese patients.
Abstract
This study was aimed to investigate the effect of green tea extract (GTE) combined with brisk walking on lipid profiles and the liver function in overweight and obese men. Twenty-four participants were randomized to either the GTE group or the placebo group for 12 weeks with a 4-week follow-up. The walking program consisted of four 60-min-sessions/week and all participants were asked to consume two GTE (150mg) or placebo tablets daily. After 12-week intervention, GTE group resulted in a significant difference in the low-density lipoprotein cholesterol (LDL-C) and total cholesterol (TC) levels when compared to placebo group (P < 0.01). There was also a significant reduction in the aspartate aminotransferase levels (P < 0.01) in the GTE group, but no change in the placebo group (P >0.05). There was no change in the triglyceride or high-density lipoprotein cholesterol (HDL-C) levels in the placebo group, but a significant reduction was noted in the HDL-C levels in the GTE group (P < 0.05). GTE combined with brisk walking resulted in a significant change in the LDL-C and TC levels, however, a significant reduce in HDL-C in the GTE group. The study has a more positive effect on the liver function than brisk walking alone.
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Efficacy of a 2-Month Very Low-Calorie Ketogenic Diet (VLCKD) Compared to a Standard Low-Calorie Diet in Reducing Visceral and Liver Fat Accumulation in Patients With Obesity.
Cunha, GM, Guzman, G, Correa De Mello, LL, Trein, B, Spina, L, Bussade, I, Marques Prata, J, Sajoux, I, Countinho, W
Frontiers in endocrinology. 2020;11:607
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Excess fat in the liver, known as non-alcoholic fatty liver disease (NAFLD), has been shown to increase the risk of chronic diseases such as type 2 diabetes. Standard treatment regimens consist of low-calorie (LC) diets and exercise, however these may be ineffective at reversing fat accumulation in the liver. A very low-calorie ketogenic diet (VLCKD) has been proposed as an alternative treatment for NAFLD. This randomised control pilot study of 39 individuals with obesity aimed to compare LC diet and VLCKD on fat accumulation and indicators for NAFLD for two months. The results showed greater weight loss, abdominal fat reduction, liver fat reduction and improvements in liver function with VLCKD compared to the LC diet. Cholesterol was significantly reduced by both diets. However liver stiffness remained unchanged. The authors concluded that VLCKD was more successful at reducing liver fat and abdominal fat accumulation than current standard therapy and has the potential to improve NAFLD. Health care professionals could use this study to improve liver and abdominal fat loss in patients with obesity to improve NAFLD, when standard therapy has been inadequate.
Abstract
Background: Currently the treatment of non-alcoholic fatty liver disease (NAFLD) is based on weight loss through lifestyle changes, such as exercise combined with calorie-restricted dieting. Objectives: To assess the effects of a commercially available weight loss program based on a very low-calorie ketogenic diet (VLCKD) on visceral adipose tissue (VAT) and liver fat content compared to a standard low-calorie (LC) diet. As a secondary aim, we evaluated the effect on liver stiffness measurements. Methods: Open, randomized controlled, prospective pilot study. Patients were randomized and treated either with an LC or a VLCKD and received orientation and encouragement to physical activity equally for both groups. VAT, liver fat fraction, and liver stiffness were measured at baseline and after 2 months of treatment using magnetic resonance imaging. Paired t-tests were used for comparison of continuous variables between visits and unpaired test between groups. Categorical variables were compared using the χ2-test. Pearson correlation was used to assess the association between VAT, anthropometric measures, and hepatic fat fraction. A significance level of the results was established at p < 0.05. Results: Thirty-nine patients (20 with VLCKD and 19 with LC) were evaluated at baseline and 2 months of intervention. Relative weight loss at 2 months was -9.59 ± 2.87% in the VLCKD group and -1.87 ± 2.4% in the LC group (p < 0.001). Mean reductions in VAT were -32.0 cm2 for VLCKD group and -12.58 cm2 for LC group (p < 0.05). Reductions in liver fat fraction were significantly more pronounced in the VLCKD group than in the LC group (4.77 vs. 0.79%; p < 0.005). Conclusion: Patients undergoing a VLCKD achieved superior weight loss, with significant VAT and liver fat fraction reductions when compared to the standard LC diet. The weight loss and rapid mobilization of liver fat demonstrated with VLCKD could serve as an effective alternative for the treatment of NAFLD. Clinical Trial Registration: ClinicalTrials.gov, identifier: NCT04322110.
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Proteomic profiles before and during weight loss: Results from randomized trial of dietary intervention.
Figarska, SM, Rigdon, J, Ganna, A, Elmståhl, S, Lind, L, Gardner, CD, Ingelsson, E
Scientific reports. 2020;10(1):7913
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Understanding biological substances, or "biomarkers" that are present in the body of individuals with obesity, could lead to personalised dietary recommendations for weight loss. Current research on biomarkers in individuals with obesity who have undergone a weight loss intervention is lacking. This secondary analysis of a randomised control trial study of 609 healthy and obese adults over 6 months, aimed to identify biomarkers associated with obesity, determine any changes with weight loss and if these could be used to make personalised recommendations. 263 biomarkers were tested and the results showed that 102 were associated with body mass index (BMI). 88 were elevated in individuals with a higher BMI. Upon weight loss, a large number of these decreased and a small number increased. The type of diet had no influence on how these biomarkers changed and only one could be used to predict weight loss. It was concluded that many of the biomarkers were connected to BMI and many changed with weight loss, however none of the biomarkers studied could be used to individualise dietary recommendations. This study could be used by healthcare professionals to understand that the role of biomarkers in personalising recommendations is complex and more research may be needed.
Abstract
Inflammatory and cardiovascular biomarkers have been associated with obesity, but little is known about how they change upon dietary intervention and concomitant weight loss. Further, protein biomarkers might be useful for predicting weight loss in overweight and obese individuals. We performed secondary analyses in the Diet Intervention Examining The Factors Interacting with Treatment Success (DIETFITS) randomized intervention trial that included healthy 609 adults (18-50 years old) with BMI 28-40 kg/m2, to evaluate associations between circulating protein biomarkers and BMI at baseline, during a weight loss diet intervention, and to assess predictive potential of baseline blood proteins on weight loss. We analyzed 263 plasma proteins at baseline and 6 months into the intervention using the Olink Proteomics CVD II, CVD III and Inflammation arrays. BMI was assessed at baseline, after 3 and 6 months of dietary intervention. At baseline, 102 of the examined inflammatory and cardiovascular biomarkers were associated with BMI (>90% with successful replication in 1,584 overweight/obese individuals from a community-based cohort study) and 130 tracked with weight loss shedding light into the pathophysiology of obesity. However, out of 263 proteins analyzed at baseline, only fibroblast growth factor 21 (FGF-21) predicted weight loss, and none helped individualize dietary assignment.
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The Weight Optimization Revamping Lifestyle using the Dietary Guidelines (WORLD) Study: Sustained Weight Loss Over 12 Months.
Psota, TL, Tindall, AM, Lohse, B, Miller, PE, Petersen, KS, Kris-Etherton, PM
Obesity (Silver Spring, Md.). 2020;28(7):1235-1244
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Effective long-term weight loss strategies to reduce the risk of death and diseases associated with being obese or overweight are required, as restrictive programmes are difficult to sustain, and weight loss may be heavily influenced by behavioural factors. This randomised control trial of 101 premenopausal women with obesity or overweight aimed to compare a lower-fat and moderate-fat diets, both with nutrition education for 12 months. The results showed that both treatment groups lost weight. Both groups consumed the same amount of fat but increased their diet quality. Diet quality and greater attendance at nutritional education sessions were associated with greater weight loss. Cholesterol was significantly lower in both groups, but blood pressure remained unchanged. Interestingly there were a large number of women who did not complete the trial. It was concluded that irrespective of the amount of fat consumed, nutrition education can help to achieve sustained weight loss, improve diet quality and decrease heart disease risk for at least 12 months. This study could be used by healthcare professionals to understand that recommending fat-based targets for weight loss may be ineffective and the importance of emotional and behavioural support for individuals on a weight loss regime to improve their risk for heart disease.
Abstract
OBJECTIVE This study aimed to compare two energy-restricted, nutrient-dense diets at the upper or lower ends of the dietary fat recommendation range (lower fat [20% energy from fat] versus moderate fat [35%]) on weight loss using behavioral theory-based nutrition education. METHODS A total of 101 premenopausal women with overweight or obesity were randomized to an energy-restricted lower-fat or moderate-fat diet for 1 year. Interventions included 28 behavioral theory-based nutrition education sessions plus weekly exercise sessions. RESULTS Both treatment groups experienced weight loss (-5.0 kg for lower fat and -4.3 kg for moderate fat; P < 0.0001), but there was no difference in weight loss or fat intake between groups. Total and low-density lipoprotein cholesterol decreased (-3. 4 mg/dL and -3.8 mg/dL; P < 0.05), and high-density lipoprotein cholesterol increased (1.9 mg/dL; P < 0.05) in both groups at 12 months. Diet quality, assessed by the Healthy Eating Index, increased significantly at 4 months versus baseline (70.8 [0.9] vs. 77.8 [1.0]) and was maintained through 12 months. Higher Healthy Eating Index scores were associated with greater weight loss at 4 months (r = -0.2; P < 0.05). CONCLUSIONS In the context of a well-resourced, free-living weight-loss intervention, total fat intake did not change; however, theory-based nutrition education underpinned by food-based recommendations resulted in caloric deficits, improvements in diet quality, and weight loss that was sustained for 1 year.
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Lipid Metabolism Links Nutrient-Exercise Timing to Insulin Sensitivity in Men Classified as Overweight or Obese.
Edinburgh, RM, Bradley, HE, Abdullah, NF, Robinson, SL, Chrzanowski-Smith, OJ, Walhin, JP, Joanisse, S, Manolopoulos, KN, Philp, A, Hengist, A, et al
The Journal of clinical endocrinology and metabolism. 2020;105(3)
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Plain language summary
Following exercise, various metabolic changes occur which may be of benefit in fighting diseases such as type 2 diabetes and obesity. However, the degree of change may vary depending on whether the exercise has been performed pre or post meal consumption. This 6-week randomised crossover trial of 30 overweight or obese men aimed to determine the effect of exercising before or after breakfast on the use of fats and sugars by the body. The results showed that exercise before breakfast increased fat and sugar use in the body and also resulted in the alteration of eight genes associated with metabolism. Exercise before carbohydrate consumption also increased lipid use and improved insulin sensitivity, however body composition was similar regardless of when exercise was performed. It was concluded that exercising in the fasted state can optimise the body’s response without having to change intensity or effort. This study could be used by health care professionals to advise patients with obesity or overweight that exercising whilst in the fasted state could optimise their outcomes without having to increase exercise intensity or frequency.
Abstract
CONTEXT Pre-exercise nutrient availability alters acute metabolic responses to exercise, which could modulate training responsiveness. OBJECTIVE To assess acute and chronic effects of exercise performed before versus after nutrient ingestion on whole-body and intramuscular lipid utilization and postprandial glucose metabolism. DESIGN (1) Acute, randomized, crossover design (Acute Study); (2) 6-week, randomized, controlled design (Training Study). SETTING General community. PARTICIPANTS Men with overweight/obesity (mean ± standard deviation, body mass index: 30.2 ± 3.5 kg⋅m-2 for Acute Study, 30.9 ± 4.5 kg⋅m-2 for Training Study). INTERVENTIONS Moderate-intensity cycling performed before versus after mixed-macronutrient breakfast (Acute Study) or carbohydrate (Training Study) ingestion. RESULTS Acute Study-exercise before versus after breakfast consumption increased net intramuscular lipid utilization in type I (net change: -3.44 ± 2.63% versus 1.44 ± 4.18% area lipid staining, P < 0.01) and type II fibers (-1.89 ± 2.48% versus 1.83 ± 1.92% area lipid staining, P < 0.05). Training Study-postprandial glycemia was not differentially affected by 6 weeks of exercise training performed before versus after carbohydrate intake (P > 0.05). However, postprandial insulinemia was reduced with exercise training performed before but not after carbohydrate ingestion (P = 0.03). This resulted in increased oral glucose insulin sensitivity (25 ± 38 vs -21 ± 32 mL⋅min-1⋅m-2; P = 0.01), associated with increased lipid utilization during exercise (r = 0.50, P = 0.02). Regular exercise before nutrient provision also augmented remodeling of skeletal muscle phospholipids and protein content of the glucose transport protein GLUT4 (P < 0.05). CONCLUSIONS Experiments investigating exercise training and metabolic health should consider nutrient-exercise timing, and exercise performed before versus after nutrient intake (ie, in the fasted state) may exert beneficial effects on lipid utilization and reduce postprandial insulinemia.