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Endogenous Ghrelin Levels and Perception of Hunger: A Systematic Review and Meta-Analysis

2024-09-25T03:40:10Z

Title: Endogenous Ghrelin Levels and Perception of Hunger: A Systematic Review and Meta-Analysis Authors: Anderson, Kara C. Faten Hasan; Grammer, Emily E.; Kranz, Sibylle Abstract: ABSTRACT Background: Ghrelin is an orexigenic hormone primarily released by the stomach and has 2 isoforms: acylated ghrelin (AG) and de-acylated ghrelin (DAG), that appear to have different functions in humans. Objectives: To perform a systematic review and meta-analysis of the association between plasma concentrations of total ghrelin (TG), AG, and DAG and perceptions of hunger in healthy adults. Methods: The following criteria were used for inclusion: 1) sample contained adults 18 y of age, 2) body mass index [BMI kg/m2 ] was 18.5, 3) ghrelin was sampled through blood, 4) subjective hunger was measured on a validated scale, 5) study reported a Pearson product correlation of ghrelin or had relevant figure(s) for data extraction, 6) participants were healthy with no overt disease, 7) protocols contained no physical activity or weight loss medication that suppressed appetite, 8) interventions were conducted without environmental manipulations. Moderators assessed were age, BMI, percentage of body fat (%BF), macronutrient content of test meals, energy intake (kcals), sex, and ghrelin isoform (AG, DAG, or TG). Results: The analysis included 47 studies (110 trials, n ¼ 1799, age: 31.4 12.0 y, BMI: 26.0 4.75 kg/m2 ) and measured AG (n ¼ 47 trials), DAG (n ¼ 12 trials), and TG (n ¼ 51 trials). The overall model indicated that ghrelin concentrations and perceptions of hunger were moderately correlated (r ¼ 0.43, P < 0.001), and ghrelin isoform significantly moderated this relationship (AG: r ¼ 0.60, P < 0.001; TG: r ¼ 0.215, P ¼ 0.01; DAG: r ¼ 0.53, P ¼ 0.695). Other significant moderators included age (b ¼ –0.02, P ¼ 0.01), BMI (b ¼ –0.03, P ¼ 0.05), % BF (b ¼ –0.03, P ¼ 0.05), energy intake (b ¼ 0.0003, P ¼ 0.04), and percentage of carbohydrates of test meals (b ¼ 0.008, P ¼ 0.05). Conclusions: Ghrelin is associated with perceptions of hunger in humans, and this relationship is strengthened when AG is isolated; thus, AG may have a large impact on hunger signals in various populations. Future research should attempt to understand the role of DAG in hunger sensations. Keywords: hunger, appetite, ghrelin, gut hormones

The Beneficial and Adverse Effects of Autophagic Response to Caloric Restriction and Fasting

2024-09-25T03:36:13Z

Title: The Beneficial and Adverse Effects of Autophagic Response to Caloric Restriction and Fasting Authors: Shabkhizan, Roya; Haiaty, Sanya; Sadat Moslehian, Marziyeh; Bazmani, Ahad; Sadeghsoltani, Fatemeh; Saghaei Bagheri, Hesam; Rahbarghazi, Reza; Sakhinia, Ebrahim Abstract: ABSTRACT Each cell is equipped with a conserved housekeeping mechanism, known as autophagy, to recycle exhausted materials and dispose of injured organelles via lysosomal degradation. Autophagy is an early-stage cellular response to stress stimuli in both physiological and pathological situations. It is thought that the promotion of autophagy flux prevents host cells from subsequent injuries by removing damaged organelles and misfolded proteins. As a correlate, the modulation of autophagy is suggested as a therapeutic approach in diverse pathological conditions. Accumulated evidence suggests that intermittent fasting or calorie restriction can lead to the induction of adaptive autophagy and increase longevity of eukaryotic cells. However, prolonged calorie restriction with excessive autophagy response is harmful and can stimulate a type II autophagic cell death. Despite the existence of a close relationship between calorie deprivation and autophagic response in different cell types, the precise molecular mechanisms associated with this phenomenon remain unclear. Here, we aimed to highlight the possible effects of prolonged and short-term calorie restriction on autophagic response and cell homeostasis. Keywords: short-term and long-term, calorie restriction, autophagy, cellular homeostasis, therapeutic effects

Global Coverage of Mandatory Large-Scale Food Fortification Programs: A Systematic Review and Meta-Analysis

2024-09-25T03:30:37Z

Title: Global Coverage of Mandatory Large-Scale Food Fortification Programs: A Systematic Review and Meta-Analysis Authors: Rohner, Fabian; Wirth, James P.; Zeng, Wu; Petry, Nicolai; Donkor, William E.S.; Neufeld, Lynnette M.; Mkambula, Penjani; Groll, Sydney; Mbuya, Mduduzi NN.; Friesen, Valerie M. Abstract: ABSTRACT Food fortification with micronutrients is widely implemented to reduce micronutrient deficiencies and related outcomes. Although many factors affect the success of fortification programs, high population coverage is needed to have a public health impact. We aimed to provide recent global coverage estimates of salt, wheat flour, vegetable oil, maize flour, rice, and sugar among countries with mandatory fortification legislation. The indicators were the proportion of households consuming the: food, fortifiable food (that is, industrially processed), fortified food (to any extent), and adequately fortified food (according to national or international standards). We estimated the number of individuals reached with fortified foods. We systematically retrieved and reviewed all applicable evidence from: published reports and articles from January 2010 to August 2021, survey lists/databases from key organizations, and reports/literature received from key informants. We analyzed data with R statistical package using random-effects meta-analysis models. An estimated 94.4% of households consumed salt, 78.4% consumed fortified salt (4.2 billion people), and 48.6% consumed adequately fortified salt in 64, 84, and 31 countries, respectively. Additionally, 77.4% of households consumed wheat flour, 61.6% consumed fortifiable wheat flour, and 47.1% consumed fortified wheat flour (66.2 million people) in 15, 8, and 10 countries, respectively, and 87.0% consumed vegetable oil, 86.7% consumed fortifiable oil, and 40.1% consumed fortified oil (123.9 million people) in 10, 7, and 5 countries, respectively. Data on adequately fortified wheat flour and vegetable oil and coverage indicators for maize flour, rice, and sugar were limited. There are major data gaps on fortification coverage for most foods except salt. All countries with mandatory fortification programs should generate and use more coverage data to assess program performance and adjust programs as needed to realize their potential to reduce micronutrient deficiencies (PROSPERO CRD42021269364). Keywords:

The Effects of Dairy Product Supplementation on Bone Health Indices in Children Aged 3 to 18 Years: A Meta-Analysis of Randomized Controlled Trials

2024-09-25T03:22:56Z

Title: The Effects of Dairy Product Supplementation on Bone Health Indices in Children Aged 3 to 18 Years: A Meta-Analysis of Randomized Controlled Trials Authors: Hidayat, Khemayanto; Zhang, Li-Li; Rizzoli, Rene; Guo, Ya-Xin; Zhou, Yan; Shi, Yu-Jie; -Wen Su, Hong; Liu, Biao; Qin, Li-Qiang Abstract: ABSTRACT Childhood and adolescence are critical periods for optimizing skeletal growth. Dairy products are valuable sources of bone-beneficial nutrients, particularly calcium and protein. A random-effects meta-analysis of published randomized controlled trials was performed to quantitatively assess the effects of dairy supplementation on bone health indices in children and adolescents. The PubMed and Web of Science databases were searched. Dairy supplementation increased whole-body bone mineral content (BMC) (þ25.37 g) and areal bone mineral density (aBMD) (þ0.016 g/cm2 ), total hip BMC (þ0.49 g) and aBMD (þ0.013 g/cm2 ), femoral neck BMC (þ0.06 g) and aBMD (þ0.030 g/cm2 ), lumbar spine BMC (þ0.85 g) and aBMD (þ0.019 g/cm2 ), and height (0.21 cm). When expressed as a percentage difference, whole-body BMC was increased by 3.0%, total hip BMC by 3.3%, femoral neck BMC by 4.0%, lumbar spine BMC by 4.1%, whole-body aBMD by 1.8%, total hip aBMD by 1.2%, femoral neck aBMD by 1.5%, and lumbar spine aBMD by 2.6%. Dairy supplementation increased serum insulin-like growth factor I concentrations (19.89 nmol/L) and reduced concentrations of urinary deoxypyridinoline (1.78 nmol/mmol creatinine) and serum parathyroid hormone (10.46 pg/mL) but did not significantly affect the serum concentrations of osteocalcin, bone alkaline phosphatase, and C-terminal telopeptide of type 1 collagen. Serum 25-hydroxyvitamin D concentrations (þ4.98 ng/mL) increased with vitamin D-fortified dairy supplementation. The positive effects on bone mineral mass parameters and height were generally consistent across subgroups defined by sex, geographical region, baseline calcium intake, calcium from the supplementation, trial duration, and Tanner stages. In summary, dairy supplementation during growth leads to a small but significant increase in bone mineral mass parameters, and these findings are generally supported by the changes in several biochemical parameters related to bone health. Keywords: