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Acute feeding with almonds compared to a carbohydrate-based snack improves appetite-regulating hormones with no effect on self-reported appetite sensations: a randomised controlled trial.
Carter, S, Hill, AM, Buckley, JD, Tan, SY, Rogers, GB, Coates, AM
European journal of nutrition. 2023;62(2):857-866
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Long-term regulation of body weight is controlled by balancing energy intake with energy expenditure. Understanding the role of specific food items and their impact on energy intake may assist in promoting weight reduction and weight loss maintenance for people with obesity. The aim of this study was to compare the effects of eating almonds or a carbohydrate-based snack on appetite-regulating hormones, self-reported appetite ratings, and short-term energy intake. This study is based on data obtained from a parallel arm randomised controlled trial. Participants were males and females, aged between 25 and 65 years who were randomly assigned to either the almond or the snack bar treatment groups based on age, sex and body mass index. Results show that the consumption of almonds resulted in a smaller C-peptide response and a larger glucose-dependent insulinotropic polypeptide [pancreatic hormone], glucagon-like peptide 1 [peptide hormone] (timepoint comparisons only), glucagon and pancreatic polypeptide response compared to consuming an isocaloric carbohydrate-rich snack bar. Furthermore, although not significant, the almond group consumed 300 kJ less energy in the meal challenge, 270 kJ of which came from discretionary foods, which may be a clinically important benefit in weight management. Authors conclude that foods that promote satiety help to regulate energy balance and may assist with weight management. However, future studies should consider testing food dose and composition carefully as the volume of food, its sensory qualities, and the acceptance of the food respective of usual meal patterns, may be important in eliciting a feeling of fullness and satisfaction.
Abstract
PURPOSE Early satiety has been identified as one of the mechanisms that may explain the beneficial effects of nuts for reducing obesity. This study compared postprandial changes in appetite-regulating hormones and self-reported appetite ratings after consuming almonds (AL, 15% of energy requirement) or an isocaloric carbohydrate-rich snack bar (SB). METHODS This is a sub-analysis of baseline assessments of a larger parallel-arm randomised controlled trial in overweight and obese (Body Mass Index 27.5-34.9 kg/m2) adults (25-65 years). After an overnight fast, 140 participants consumed a randomly allocated snack (AL [n = 68] or SB [n = 72]). Appetite-regulating hormones and self-reported appetite sensations, measured using visual analogue scales, were assessed immediately before snack food consumption, and at 30, 60, 90 and 120 min following snack consumption. A sub-set of participants (AL, n = 49; SB, n = 48) then consumed a meal challenge buffet ad libitum to assess subsequent energy intake. An additional appetite rating assessment was administered post buffet at 150 min. RESULTS Postprandial C-peptide area under the curve (AUC) response was 47% smaller with AL compared to SB (p < 0.001). Glucose-dependent insulinotropic polypeptide, glucagon and pancreatic polypeptide AUC responses were larger with AL compared to SB (18%, p = 0.005; 39% p < 0.001; 45% p < 0.001 respectively). Cholecystokinin, ghrelin, glucagon-like peptide-1, leptin and polypeptide YY AUCs were not different between groups. Self-reported appetite ratings and energy intake following the buffet did not differ between groups. CONCLUSION More favourable appetite-regulating hormone responses to AL did not translate into better self-reported appetite or reduced short-term energy consumption. Future studies should investigate implications for longer term appetite regulation. ANZCTR REFERENCE NUMBER ACTRN12618001861246 2018.
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Effects of acute sleep loss on leptin, ghrelin, and adiponectin in adults with healthy weight and obesity: A laboratory study.
van Egmond, LT, Meth, EMS, Engström, J, Ilemosoglou, M, Keller, JA, Vogel, H, Benedict, C
Obesity (Silver Spring, Md.). 2023;31(3):635-641
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A lack of sleep may be a risk factor for weight gain. Leptin is an adipocyte-derived hormone that activates satiety networks within the brain. Ghrelin, as opposed to leptin, is mainly produced by the stomach and it acts as a hunger hormone, signalling fuel status to the central nervous system. Some studies have found either no alterations or higher leptin and lower ghrelin blood levels following experimental sleep deprivation. The aim of this study was to investigate whether blood concentrations of leptin, ghrelin, and adiponectin are affected by acute total sleep deprivation in a sex- and weight-specific manner. This study is a laboratory study based on blood samples from 44 participants, mainly university students. Results show that: - acute total sleep deprivation is linked to lower serum levels of the adipokine leptin and higher blood levels of ghrelin. - following sleep deprivation, serum adiponectin levels were elevated. - the drop in serum leptin was larger in women after total sleep deprivation; however, there wasn’t a significant association between biological sex and experimental condition. - the increase in blood levels of adiponectin was slightly more pronounced among women, whereas there weren’t any differences in the effects of sleep loss on plasma ghrelin. Authors conclude that acute total sleep deprivation shifts the endocrine balance from the satiety hormone leptin toward the hunger-promoting hormone ghrelin. However, further investigation in larger samples focusing on their findings linked to sex- and weight-specific differences in leptin, ghrelin, and adiponectin are needed.
Expert Review
Conflicts of interest:
None
Take Home Message:
Sleep deprivation may shift the balance of appetite controlling hormones causing an increase in hunger and decreased satiety and therefore resulting in increased food intake. These changes may be more pronounced in biological females.
Evidence Category:
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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
Sleep deprivation may contribute to weight gain and obesity through its effect on the hormonal pathways promoting hunger and satiety. Research has also linked chronic sleep loss with an increase in the brain reward response to food, thus driving an increase in daily food intake. Leptin and ghrelin are hormones involved in the control of food intake. Some research has associated alterations in these hormones following sleep loss, whilst others have not.
This study aimed to investigate whether biological sex and weight status affect fasting serum levels of leptin, ghrelin and adiponectin following chronic sleep deprivation in a supervised laboratory setting.
Methods
This randomised crossover design study included n=44 mixed sex participants with a mean age of 24.9 years. A total of 19 of the participants were classed as obese, with the remaining n= 25 participants were considered normal weight. Participants completed 2 nights in experimental sessions under continuously supervised conditions in a laboratory. One night was spent awake and the other asleep. Fasting blood samples were taken the morning after each session to measure levels of leptin, ghrelin and adiponectin.
Results
Serum levels of leptin after one night’s sleep loss were around 7% lower than those measured after sleep (17.3 = +/-2.6 vs 18.6 +/- 2.8 ng/mL, p = 0.037). Adjustments using sex-stratified analysis showed significantly lower levels of serum leptin in women (25.8 +/_4.3 vs 28.1 +/_ 4.7 ng/mL, p = 0.030) but not for men (10.1 +/_ 2.4 vs 10.6 +/_ 2.3 ng/mL, p = 0.458). However, when comparing individual participant differences between sleep and wake sessions, the results were not significant. Additionally, no significant differences were found between normal weight and obese participants.
Higher levels of ghrelin were found following sleep deprivation in both sexes and weight sub-groups (839.4 +/-77.5 vs 741.4+/-63.2 pg/mL, p= 0.003). Adiponectin was also found to be elevated in all participants regardless of biological sex or weight status (7.5 +/- 0.6 vs 6.8 +/- 0.6ug/mL, p= 0.003). However, ghrelin was observed to increase slightly more in participants with obesity, whereas elevations in adiponectin were slightly greater in those of normal weight.
Conclusion
In this study, sleep loss was associated with lowered levels of leptin and higher levels of ghrelin. Analysis between biological sexes indicated that there may be a greater decrease in leptin in females. Serum levels of adiponectin were also found to be elevated after sleep deprivation for both sexes with a slightly larger increase in women. These changes may result in increased hunger and food intake and decreased satiety. No significant differences were found between normal weight and obese participants.
Notes: The authors reported no conflicts of interest.
Clinical practice applications:
Sleep deprivation may lead to lower levels of leptin in both sexes with a greater decrease for females. Ghrelin and adiponectin levels may be increased in both men and women after sleep loss with a slightly larger increase in adiponectin for women. This could lead to an increase in appetite, food consumption and therefore weight gain, particularly in women.
Considerations for future research:
- Larger studies are needed to investigate sex and weight status related differences in serum levels of ghrelin, leptin and adiponectin.
- It may be beneficial for blood samples to be taken at different points during the day to allow for fluctuations in hormone levels.
- Food intake should be measured to monitor any increases in food intake.
Abstract
OBJECTIVE This study investigated whether blood concentrations of leptin, ghrelin, and adiponectin are affected by acute total sleep deprivation in a sex- and weight-specific manner. METHODS A total of 44 participants (mean age 24.9 years; 20 women; 19 with obesity) participated in a crossover design, including one night of sleep deprivation and one night of sleep in the laboratory. After each night, fasting blood was collected. RESULTS After sleep deprivation, fasting levels of leptin were lower (mean [SE], vs. sleep: 17.3 [2.6] vs. 18.6 [2.8] ng/mL), whereas those of ghrelin and adiponectin were higher (839.4 [77.5] vs. 741.4 [63.2] pg/mL and 7.5 [0.6] vs. 6.8 [0.6] μg/mL, respectively; all p < 0.05). The changes in leptin and adiponectin following sleep loss were more pronounced among women. Furthermore, the ghrelin increase was stronger among those with obesity after sleep loss. Finally, the sleep loss-induced increase in adiponectin was more marked among normal-weight participants. CONCLUSIONS Acute sleep deprivation reduces blood concentrations of the satiety hormone leptin. With increased blood concentrations of ghrelin and adiponectin, such endocrine changes may facilitate weight gain if persisting over extended periods of sleep loss. The observed sex- and weight-specific differences in leptin, ghrelin, and adiponectin call for further investigation.
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Effectiveness of a minimally processed food-based nutritional counselling intervention on weight gain in overweight pregnant women: a randomized controlled trial.
Sartorelli, DS, Crivellenti, LC, Baroni, NF, de Andrade Miranda, DEG, da Silva Santos, I, Carvalho, MR, de Lima, MC, Carreira, NP, Chaves, AVL, Manochio-Pina, MG, et al
European journal of nutrition. 2023;62(1):443-454
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Excessive gestational weight gain exposes the woman and the child to a higher risk of harmful health outcomes in the short and long term. Dietary patterns based on the substitution of meals made with unprocessed or minimally processed foods for the consumption of ultra-processed items can be partly blamed for the exponential global growth in the incidence of obesity. The main aim of this study was to evaluate the effectiveness of a nutritional intervention based on encouraging the consumption of unprocessed and minimally processed foods rather than ultra-processed products. This study is a two-armed parallel randomised controlled trial conducted among overweight, pregnant women receiving prenatal care in seven primary health units. Participants (n=350) were randomly allocated into the intervention group (IG) or control group (CG). The women allocated into the IG, in addition to the usual prenatal care, were invited to participate in three individualised nutritional counselling sessions conducted by trained nutritionists. Results show that even though there were more women in the IG who had increased their daily intake of minimally processed foods and vegetables at lunch time when compared to the CG, this was not statistically significant. Additionally, there weren’t any differences between the groups in relation to physical activity. Authors conclude that their study was unprecedented in demonstrating that a nutritional counselling intervention based on the NOVA food classification system, together with the practice of physical activity, is effective in preventing excessive gestational weight gain in overweight pregnant women.
Abstract
PURPOSE This study aimed at evaluating the effectiveness of a nutritional counselling intervention based on encouraging the consumption of unprocessed and minimally processed foods, rather than ultra-processed products, and the practice of physical activities to prevent excessive gestational weight gain in overweight pregnant women. METHODS This was a two-armed, parallel, randomized controlled trial conducted in primary health units of a Brazilian municipality from 2018 to 2021. Overweight, adult pregnant women (n = 350) were randomly assigned to control (CG) or intervention groups (IG). The intervention consisted of three individualized nutritional counselling sessions based on encouraging the consumption of unprocessed and minimally processed foods rather than ultra-processed products, following the NOVA food classification system, and the practice of physical activities. The primary outcome was the proportion of women whose weekly gestational weight gain (GWG) exceeded the Institute of Medicine guidelines. Adjusted logistic regression models were employed. RESULTS Complete data on weight gain were available for 121 women of the IG and 139 of the CG. In modified intention-to-treat analysis, there was a lower chance of the IG women having excessive GWG [OR 0.56 (95% CI 0.32, 0.98), p = .04], when compared to the CG. No between-group differences were observed for the other maternal outcomes investigated. CONCLUSION The present study was unprecedented in demonstrating that nutritional counselling based on the NOVA food classification system, together with encouraging the practice of physical activity, is effective in preventing excessive weight gain in overweight pregnant women. TRIAL REGISTRATION Registered on July 30th 2018 at Brazilian Registry of Clinical Trials (RBR-2w9bhc).
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Effects of intermittent very-low calorie diet on glycemic control and cardiovascular risk factors in obese patients with type 2 diabetes mellitus: A randomized controlled trial.
Umphonsathien, M, Rattanasian, P, Lokattachariya, S, Suansawang, W, Boonyasuppayakorn, K, Khovidhunkit, W
Journal of diabetes investigation. 2022;13(1):156-166
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Various studies have shown that intermittent low-calorie diets are effective in reducing weight and improving glycaemic control. In this randomized controlled trial, two intermittent very-low calorie diets (2 days per week and 4 days per week) were evaluated against a control group with respect to achieving diabetes remission, improving glycemic control, metabolic parameters, and quality of life in Type 2 diabetic patients. There was a significant reduction in HbA1c and insulin resistance in the 2 days/week and 4 days/week intermittent very-low calorie groups at week 20. Both the intervention groups achieved diabetes remission with 29% of participants not requiring glucose-lowering medications at week 20. Both intervention groups also showed a significant reduction in serum triglycerides, body weight, body mass index, and fat mass. Aspartate transaminase and alanine aminotransferase levels, as well as blood pressure, decreased significantly with a 4 day/week intermittent low-calorie diet. Both intervention groups experienced improved quality of life at week 10 and the interventions were generally well tolerated. To generalise the results, longer-term, robust studies are required. These results can help healthcare providers understand the clinical relevance of intermittent very-low calorie diets in managing Type 2 diabetes and obesity.
Abstract
AIMS/INTRODUCTION Very few studies assess the effectiveness of different protocols of intermittent very-low calorie diet (VLCD) in patients with diabetes. This study was designed to compare the effects of 2 days/week and 4 days/week of intermittent VLCD on glycemic control, diabetes remission, metabolic parameters and quality of life in patients with type 2 diabetes and obesity. MATERIALS AND METHODS Participants with obesity and type 2 diabetes were recruited and randomly assigned to three groups, consisting of control, 2 days/week and 4 days/week of intermittent VLCD. In the intermittent VLCD groups, participants received a 600-kcal diet per day on restricted days and ad libitum food consumption on non-restricted days. Glycemic control, rate of diabetes remission, metabolic parameters and quality of life were evaluated at baseline, weeks 2, 10 and 20. RESULTS A total of 40 participants were enrolled. The mean body mass index was 30.1 ± 5.9 kg/m2 , and the mean glycated hemoglobin was 7.4 ± 1.2%. At week 20, there was an improvement in glycemic control in both intermittent VLCD groups with significant decreases in glycated hemoglobin levels and insulin resistance index throughout the study periods. Diabetes remission without the need for medications was equally found in 29% of participants in both intermittent VLCD groups. Serum triglyceride, bodyweight, body mass index and fat mass were also significantly decreased in both VLCD groups. No serious adverse events were encountered. CONCLUSION Intermittent VLCD was highly effective in achieving optimal glycemic control. The effects of 2 days/week and 4 days/week of intermittent VLCD on diabetes remission were relatively similar.
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The effect of periodic ketogenic diet on newly diagnosed overweight or obese patients with type 2 diabetes.
Li, S, Lin, G, Chen, J, Chen, Z, Xu, F, Zhu, F, Zhang, J, Yuan, S
BMC endocrine disorders. 2022;22(1):34
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Currently, the ketogenic diet is gaining popularity in managing Type 2 diabetes (T2D). Ketogenic diets replace carbohydrates with fat and include limited carbohydrates and adequate protein. This randomised controlled trial evaluated the effects of the 12-week ketogenic diet on sixty overweight or obese T2D patients. Both the ketogenic and control diabetes diet groups achieved significant reductions in weight, body mass index, waist circumference, triglycerides, total cholesterol, low-density lipoprotein, high-density lipoprotein, fasting blood glucose, fasting insulin, and HbA1c. However, the ketogenic group showed significantly greater reductions in body mass, blood lipids, and blood glucose than the control group. In the ketogenic diet group, serum uric acid levels were higher than those in the control diet group. It was found that the control diet group adhered to the diet for a longer period than the ketogenic diet group, whose willingness to adhere to the diet long-term was weaker. More robust long-term studies are needed to evaluate the long-term effects of a ketogenic diet. In this study, more patients who followed the ketogenic diet experienced hypoglycaemic events during the first four weeks. Healthcare providers should exercise caution when recommending a short term therapeutic ketogenic diet.
Abstract
BACKGROUND The ketogenic diet (KD) is characterized by fat as a substitute of carbohydrates for the primary energy source. There is a large number of overweight or obese people with type 2 diabetes mellitus (T2DM), while this study aims to observe periodic ketogenic diet for effect on overweight or obese patients newly diagnosed as T2DM. METHODS A total of 60 overweight or obese patients newly diagnosed as T2DM were randomized into two groups: KD group, which was given ketogenic diet, and control group, which was given routine diet for diabetes, 30 cases in each group. Both dietary patterns lasted 12 weeks, and during the period, the blood glucose, blood lipid, body weight, insulin, and uric acid before and after intervention, as well as the significance for relevant changes, were observed. RESULTS For both groups, the weight, BMI(body mass index), Waist, TG (triglyceride), TC(cholesterol), LDL (low-density lipoprotein cholesterol), HDL (high-density lipoprotein cholesterol), FBG (fasting glucose), FINS (fasting insulin), HbA1c (glycosylated hemoglobin) were decreased after intervention (P < 0.05), while the decrease rates in the KD group was more significant than the control group. However, UA(serum uric acid) in the KD group showed an upward trend, while in the control group was not changed significantly (P > 0.05).The willingness to adhere to the ketogenic diet over the long term was weaker than to the routine diet for diabetes. CONCLUSION Among the overweight or obese patients newly diagnosed as type 2 diabetes mellitus, periodic ketogenic diet can not only control the body weight, but also control blood glucose and lipid, but long-term persistence is difficult.
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The potential prolonged effect at one-year follow-up after 18-month randomized controlled trial of a 90 g/day low-carbohydrate diet in patients with type 2 diabetes.
Chen, CY, Huang, WS, Ho, MH, Chang, CH, Lee, LT, Chen, HS, Kang, YD, Chie, WC, Jan, CF, Wang, WD, et al
Nutrition & diabetes. 2022;12(1):17
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A low carbohydrate diet (LCD) could be an effective dietary strategy for managing Type 2 Diabetes and body weight. This follow-up of a randomised controlled study evaluated the effect of moderate LCD after 18 months of 90 g/day LCD in 85 poorly controlled Type 2 Diabetic patients and compared it with Traditional Diabetic Diet (TDD). Those who followed the LCD diet ate significantly fewer carbohydrates and more protein and fat at the follow up between 18 and 30 months compared to those who followed the TDD group. The LCD group also showed significant improvements in serum HbA1C, two-hour serum glucose, serum alanine aminotransferase and Medication Effect Score in comparison with the TDD group. However, the level of triglycerides increased, and HDL levels decreased significantly in the LCD group from 18 to 30 months. There was however no significant difference between the groups in the improvement of HbA1C, fasting serum glucose, 2 h serum glucose, as well as serum cholesterol, triglycerides, low-density lipoprotein, ALT, creatinine, and urine microalbumin. To confirm the benefits of LCD on glycaemic control, further robust studies are needed. Results of this study can help healthcare professionals gain a better understanding of the prolonged effects of LCD on glycaemic control, liver function, and medication effect scores.
Abstract
OBJECTIVES To evaluate the effect at a one-year follow-up after an 18-month randomized controlled trial (RCT) of 90 gm/day low-carbohydrate diet (LCD) in type 2 diabetes. RESEARCH DESIGN AND METHODS Eighty-five poorly controlled type 2 diabetic patients with an initial HbA1c ≥ 7.5% who have completed an 18-month randomized controlled trial (RCT) on 90 g/day low-carbohydrate diet (LCD) were recruited and followed for one year. A three-day weighted food record, relevant laboratory tests, and medication effect score (MES) were obtained at the end of the previous trial and one year after for a total of 30 months period on specific diet. RESULTS 71 (83.5%) patients completed the study, 35 were in TDD group and 36 were in LCD group. Although the mean of percentage changes in daily carbohydrate intake was significantly lower for those in TDD group than those in LCD group (30.51 ± 11.06% vs. 55.16 ± 21.79%, p = 0.0455) in the period between 18 months and 30 months, patients in LCD group consumed significantly less amount of daily carbohydrate than patients in TDD group (131.8 ± 53.9 g vs. 195.1 ± 50.2 g, p < 0.001). The serum HbA1C, two-hour serum glucose, serum alanine aminotransferase (ALT), and MES were also significantly lower for the LCD group patients than those in the TDD group (p = 0.017, p < 0.001, p = 0.017, and p = 0.008 respectively). The mean of percentage changes of HbA1C, fasting serum glucose, 2 h serum glucose, as well as serum cholesterol, triglyceride, low-density lipoprotein, ALT, creatinine, and urine microalbumin, however, were not significantly different between the two groups (p > 0.05). CONCLUSIONS The one-year follow-up for patients on 90 g/d LCD showed potential prolonged and better outcome on glycaemic control, liver function and MES than those on TDD for poorly controlled diabetic patients.
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The Effect of Dietary Carbohydrate and Fat Manipulation on the Metabolome and Markers of Glucose and Insulin Metabolism: A Randomised Parallel Trial.
McCullough, D, Harrison, T, Boddy, LM, Enright, KJ, Amirabdollahian, F, Schmidt, MA, Doenges, K, Quinn, K, Reisdorph, N, Mazidi, M, et al
Nutrients. 2022;14(18)
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Insulin resistance is a complex metabolic disorder that increases the risk of type 2 diabetes (T2D) and is integral to cardiometabolic disease. The aim of this study was to investigate the impact of an ad libitum 8-week low-carbohydrate high fat (LCHF) diet compared with a high-carbohydrate low-fat (HCLF) diet (current UK guidelines) on cardiometabolic risk factors, the plasma metabolome, and markers of glucose and insulin metabolism in adults with a slightly elevated cardiometabolic risk. This is a parallel randomised design study where participants were randomly assigned to either a HCLF (n = 8), or a LCHF (n = 8) diet for 8 weeks. Results show that both the LCHF and HCLF diets exerted benefits on markers of insulin resistance and metabolic risk. Both diets had no effect on fasting glucose levels, but insulin concentrations significantly decreased comparably with both diets. Authors conclude that following either a LCHF or HCLF diet may reduce the risk of developing T2D by reducing markers of insulin resistance.
Abstract
High carbohydrate, lower fat (HCLF) diets are recommended to reduce cardiometabolic disease (CMD) but low carbohydrate high fat (LCHF) diets can be just as effective. The effect of LCHF on novel insulin resistance biomarkers and the metabolome has not been fully explored. The aim of this study was to investigate the impact of an ad libitum 8-week LCHF diet compared with a HCLF diet on CMD markers, the metabolome, and insulin resistance markers. n = 16 adults were randomly assigned to either LCHF (n = 8, <50 g CHO p/day) or HCLF diet (n = 8) for 8 weeks. At weeks 0, 4 and 8, participants provided fasted blood samples, measures of body composition, blood pressure and dietary intake. Samples were analysed for markers of cardiometabolic disease and underwent non-targeted metabolomic profiling. Both a LCHF and HCLF diet significantly (p < 0.01) improved fasting insulin, HOMA IR, rQUICKI and leptin/adiponectin ratio (p < 0.05) levels. Metabolomic profiling detected 3489 metabolites with 78 metabolites being differentially regulated, for example, an upregulation in lipid metabolites following the LCHF diet may indicate an increase in lipid transport and oxidation, improving insulin sensitivity. In conclusion, both diets may reduce type 2 diabetes risk albeit, a LCHF diet may enhance insulin sensitivity by increasing lipid oxidation.
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The effectiveness of diet intervention in improving the metabolism of overweight and obese women: a systematic review and meta-analysis.
Chen, M, Chen, Q, Liu, W, Tong, H, Wu, Y
American journal of translational research. 2022;14(5):2926-2938
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At present, the treatment for obesity includes regular physical activity, diet intervention, medication and bariatric surgery. The aim of this study was to summarise the current literature and investigate whether different dietary interventions influence the metabolic indicators of overweight or obesity. This study is a systematic review and meta-analysis of twelve papers, eight of which were of medium quality. The duration of dietary therapy was usually an average of 19 weeks, from 4 weeks to 24 weeks. Dietary interventions included a calorie-restricted diet, a Mediterranean diet, a low-carb diet, a low-fat diet, and a ketogenic diet. Results show that dietary intervention had a significant effect on changes in fasting insulin, fasting glucose and insulin resistance changes in women. Additionally, dietary intervention also had a positive effect on triglycerides, total cholesterol, low-density lipoprotein cholesterol and high-density lipoprotein cholesterol. Authors conclude that obese women should follow dietary interventions to improve their metabolic index. Furthermore, future large-scale randomised controlled trial experiments should be performed on specific diet therapies.
Abstract
OBJECTIVES Dietary therapy may improve glucose and lipid metabolism function in women. However, there is no systematic review to investigate the association between metabolic effects and different dietary interventions in obese women. The main purpose of this study is to summarize the current literature and investigate whether different dietary interventions have an effect on glucose and metabolic indicators of overweight or obese women. METHODS We conducted a scoping review of randomized controlled trial (RCT) studies from 1991 to 2022 by adopting a systematic review and meta-analysis. The database includes Google Scholar, PubMed, Embase and Web of Science. Literature screening, data extraction, and quality assessment were independently completed by 2 researchers. Meta-analysis was performed with RevMan. RESULTS Twelve articles were extracted and the meta-analysis results showed that the mean difference of metabolic indexes of obese women before and after dietary intervention, including fasting glucose, fasting insulin, HOMA-IR (Homeostasis model assessment-insulin resistance), TG (triglyceride), TC (total cholesterol), LDL-C (low-density lipoprotein cholesterol), HDL-C (high-density lipoprotein cholesterol) are -0.13 [-0.15, -0.10], -2.41 [-3.44, -1.38], -0.13 [-0.15, -0.10], -21.71 [-24.19, -19.22], -21.71 [-24.19, -19.22], -13.29 [-17.86, -8.72], 3.31 [2.22, 4.40], respectively. CONCLUSIONS Different dietary interventions benefit glucose and lipid metabolism of overweight or obese women. Further study is needed to determine which specific dietary effects have the greatest effect on improving metabolic indicators.
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Therapeutic Effects of Butyrate on Pediatric Obesity: A Randomized Clinical Trial.
Coppola, S, Nocerino, R, Paparo, L, Bedogni, G, Calignano, A, Di Scala, C, de Giovanni di Santa Severina, AF, De Filippis, F, Ercolini, D, Berni Canani, R
JAMA network open. 2022;5(12):e2244912
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Gut microbiome (GM) could play a role in obesity. A metabolically healthy GM is maintained by a diet rich in fibre. Plant foods are fermented by the gut microbiome to produce the antiobesogenic short-chain fatty acid butyrate. The aim of this study was to evaluate whether butyrate supplementation can be effective in paediatric obesity treatment. This study was a randomised, quadruple-blind, parallel-group, placebo-controlled trial. Children were randomly assigned to the treatment group or placebo in a 1:1 ratio. Results showed that in children with obesity, oral butyrate supplementation produced a reduction of body mass index and exerted beneficial effects on glucose metabolism and inflammation. In fact, butyrate supplementation decreased homeostatic model assessment of insulin resistance [HOMA-IR] and fasting insulin levels in children with obesity. Additionally, the GM analysis supported the role of butyrate in glucose metabolism, as suggested by a more positive response in children with a higher abundance of butyrate-producing bacteria at baseline. Authors conclude that their findings support the importance of the GM-derived metabolite butyrate as a protective factor against obesity, highlighting the central role of a healthy diet and GM function to achieve an optimal endogenous production of butyrate.
Abstract
IMPORTANCE The pediatric obesity disease burden imposes the necessity of new effective strategies. OBJECTIVE To determine whether oral butyrate supplementation as an adjunct to standard care is effective in the treatment of pediatric obesity. DESIGN, SETTING, AND PARTICIPANTS A randomized, quadruple-blind, placebo-controlled trial was performed from November 1, 2020, to December 31, 2021, at the Tertiary Center for Pediatric Nutrition, Department of Translational Medical Science, University of Naples Federico II, Naples, Italy. Participants included children aged 5 to 17 years with body mass index (BMI) greater than the 95th percentile. INTERVENTIONS Standard care for pediatric obesity supplemented with oral sodium butyrate, 20 mg/kg body weight per day, or placebo for 6 months was administered. MAIN OUTCOMES AND MEASURES The main outcome was the decrease of at least 0.25 BMI SD scores at 6 months. The secondary outcomes were changes in waist circumference; fasting glucose, insulin, total cholesterol, low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, triglyceride, ghrelin, microRNA-221, and interleukin-6 levels; homeostatic model assessment of insulin resistance (HOMA-IR); dietary and lifestyle habits; and gut microbiome structure. Intention-to-treat analysis was conducted. RESULTS Fifty-four children with obesity (31 girls [57%], mean [SD] age, 11 [2.91] years) were randomized into the butyrate and placebo groups; 4 were lost to follow-up after receiving the intervention in the butyrate group and 2 in the placebo group. At intention-to-treat analysis (n = 54), children treated with butyrate had a higher rate of BMI decrease greater than or equal to 0.25 SD scores at 6 months (96% vs 56%, absolute benefit increase, 40%; 95% CI, 21% to 61%; P < .01). At per-protocol analysis (n = 48), the butyrate group showed the following changes as compared with the placebo group: waist circumference, -5.07 cm (95% CI, -7.68 to -2.46 cm; P < .001); insulin level, -5.41 μU/mL (95% CI, -10.49 to -0.34 μU/mL; P = .03); HOMA-IR, -1.14 (95% CI, -2.13 to -0.15; P = .02); ghrelin level, -47.89 μg/mL (95% CI, -91.80 to -3.98 μg/mL; P < .001); microRNA221 relative expression, -2.17 (95% CI, -3.35 to -0.99; P < .001); and IL-6 level, -4.81 pg/mL (95% CI, -7.74 to -1.88 pg/mL; P < .001). Similar patterns of adherence to standard care were observed in the 2 groups. Baseline gut microbiome signatures predictable of the therapeutic response were identified. Adverse effects included transient mild nausea and headache reported by 2 patients during the first month of butyrate intervention. CONCLUSIONS AND RELEVANCE Oral butyrate supplementation may be effective in the treatment of pediatric obesity. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT04620057.
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Weight Loss and Exercise Differentially Affect Insulin Sensitivity, Body Composition, Cardiorespiratory Fitness, and Muscle Strength in Older Adults With Obesity: A Randomized Controlled Trial.
Brennan, AM, Standley, RA, Anthony, SJ, Grench, KE, Helbling, NL, DeLany, JP, Cornnell, HH, Yi, F, Stefanovic-Racic, M, Toledo, FGS, et al
The journals of gerontology. Series A, Biological sciences and medical sciences. 2022;77(5):1088-1097
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Aging is marked by increased risk for type 2 diabetes, reduced muscle mass and strength (ie, sarcopenia), decreased physical function and cardiorespiratory fitness, ectopic fat deposition, and insulin resistance all of which increase the risk for physical disability, morbidity, and mortality. These adverse health consequences associated with advanced age are exacerbated with obesity and physical inactivity. The aim of this study was to investigate the effects of weight loss with or without exercise on skeletal muscle insulin sensitivity, exclusively in obese older adults. This study is a 2-site, 6-month randomized controlled trial with a parallel group design. Eighty-six older (60–80 years of age), physically inactive men and women with obesity were randomised into one of the 3 treatments (1:1:1 allocation ratio): control (health education), calorie restriction-induced weight loss, and weight loss with exercise. Results suggest that weight loss via calorie restriction alone is insufficient to significantly improve skeletal muscle insulin sensitivity and requires the addition of exercise to incur benefit, which was also true for clinical measures of insulin resistance including haemoglobin A1C [a blood test that measures the average blood sugar levels over a period of 3 months] and fasting insulin. Authors conclude that regular exercise should be considered as a useful and manageable adjunct to traditional weight loss therapies for older adults with obesity to mitigate risk for chronic disease and maintain functional independence and quality of life.
Abstract
BACKGROUND Aging-related disease risk is exacerbated by obesity and physical inactivity. It is unclear how weight loss and increased activity improve risk in older adults. We aimed to determine the effects of diet-induced weight loss with and without exercise on insulin sensitivity, VO2peak, body composition, and physical function in older obese adults. METHODS Physically inactive older (68.6 ± 4.5 years) obese (body mass index 37.4 ± 4.9 kg/m2) adults were randomized to health education control (HEC; n = 25); diet-induced weight loss (WL; n = 31); or weight loss and exercise (WLEX; n = 28) for 6 months. Insulin sensitivity was measured by hyperinsulinemic-euglycemic clamp, body composition by dual-energy X-ray absorptiometry and MRI, strength by isokinetic dynamometry, and VO2peak by graded exercise test. RESULTS WLEX improved (p < .05) peripheral insulin sensitivity (+75 ± 103%) versus HEC (+12 ± 67%); WL (+36 ± 47%) versus HEC did not reach statistical significance. WLEX increased VO2peak (+7 ± 12%) versus WL (-2 ± 24%) and prevented reductions in strength and lean mass induced by WL (p < .05). WLEX decreased abdominal adipose tissue (-16 ± 9%) versus HEC (-3 ± 8%) and intermuscular adipose tissue (-15 ± 13%) versus both HEC (+9 ± 15%) and WL (+2 ± 11%; p < .01). CONCLUSIONS Exercise with weight loss improved insulin sensitivity and VO2peak, decreased ectopic fat, and preserved lean mass and strength. Weight loss alone decreased lean mass and strength. Older adults intending to lose weight should perform regular exercise to promote cardiometabolic and functional benefits, which may not occur with calorie restriction-induced weight loss alone.