Background: Obesity is a growing public health concern worldwide, significantly contributing to premature mortality and noncommunicable diseases. Weight reduction through lifestyle interventions, including diet and physical activity, is the primary approach to combating obesity, with studies showing that a 5% to 10% reduction in body weight can notably reduce obesity-related complications. Recently, smartphone apps have emerged as popular tools to aid in weight loss. However, the effectiveness of smartphone-only apps for weight management in people with overweight or obesity without comorbidities remains unclear. Objective: This meta-analysis aims to evaluate the efficacy of these apps in supporting weight loss and improving body composition in such populations. Methods: A systematic review and meta-analysis were conducted following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines, with a search across databases including PubMed, Scopus, Cochrane Library, and others. The inclusion criteria were randomized controlled trials involving adults (aged ≥18 years) with overweight or obesity (BMI≥25 kg/m2) and assessing the use of smartphone-only apps for weight loss. Studies using additional devices or involving participants with comorbidities were excluded. Data extraction focused on weight loss, BMI, waist circumference, and body fat percentage, and the risk of bias was assessed using the Revised Cochrane Risk-of-Bias tool. Results: A total of 11 randomized controlled trials with 1717 participants were included in the meta-analysis. The interventions, lasting between 60 days and 12 months, involved diet and exercise monitoring via smartphone apps. At 4-6 months of follow-up, app-based interventions significantly reduced body weight (standardized mean difference –0.33, 95% CI –0.48 to –0.17; P<.001; I2=49%) and BMI (mean difference [MD] –0.76, 95% CI –1.42 to –0.10; P=.02). Reductions in body fat percentage were also observed at 3 months (MD –0.79, 95% CI –1.38 to –0.20; P=.009) and between 4 and 6 months (MD –0.46, 95% CI –0.71 to –0.20; P<.001). However, no significant effects on waist circumference were noted (P=.07). Conclusions: Smartphone apps demonstrate a modest but statistically significant effect on weight loss and BMI reduction over a 4- to 6-month period in individuals with overweight or obesity. The effectiveness of these interventions appears limited beyond 6 months, with a tendency for weight regain. Many apps lack the personalized support necessary to sustain long-term weight loss, contributing to high dropout rates. Future development of weight loss apps should focus on enhanced customization to improve user adherence and long-term outcomes. Trial Registration: PROSPERO CRD42024570999; https://tinyurl.com/2xw6j4fy

Background: Magnesium (Mg²⁺) plays a fundamental role in various physiological processes, including neuromuscular function, glucose metabolism, cardiovascular regulation, and bone health. Despite its significance, the influence of sex on magnesium metabolism, requirements, and health outcomes remains unexplored. The aim of this review is to analyze sex-based differences in magnesium homeostasis, with a particular focus on hormonal regulation, body composition, and disease susceptibility. Methods: This narrative review, based on a non-systematic MEDLINE search conducted in January 2025, prioritized clinical trials from the past 15 years on human subjects and explored gender-specific aspects of magnesium intake, status, metabolism, and supplementation. Results: Hormonal fluctuations, particularly variations in estrogen levels, affect magnesium absorption, distribution, and retention, thereby influencing magnesium balance across different life stages such as puberty, pregnancy, and menopause. Additionally, dietary intake and lifestyle factors often differ between men and women, further impacting magnesium status. Emerging evidence suggests that suboptimal magnesium levels may differentially contribute to conditions such as osteoporosis, cardiovascular disease, and metabolic disorders in each sex. Conclusions: In conclusion, acknowledging sex-specific differences in magnesium metabolism is essential for developing personalized dietary guidelines and therapeutic strategies. Tailored nutritional approaches could significantly improve magnesium status, enhance overall health, and reduce the burden of chronic diseases linked to magnesium imbalance.

Osteoporosis and chronic conditions such as type 2 diabetes mellitus, cardiovascular disease, heart failure, and chronic kidney disease share several common biological mechanisms, including chronic inflammation, oxidative stress, hormonal dysregulation, and metabolic alterations. In this context, multimorbidity presents an increasing clinical challenge, particularly in older populations, where osteoporosis remains frequently underdiagnosed and undertreated. This review aims to explore the complex interplay between skeletal fragility and cardiometabolic diseases, emphasizing the role of nutritional deficiencies (such as iron and vitamin C), shared molecular pathways (advanced glycation end-products, Renin–Angiotensin–Aldosterone System, RANK Ligand, RANK), and the systemic impact of chronic inflammation and tissue hypoperfusion. The review also addresses the effects of various drug classes—antidiabetics, antihypertensives, anticoagulants, and anti-osteoporotic agents—on bone metabolism and cardiovascular risk. Special focus is given to the implementation of integrated and personalized care models, particularly multidisciplinary team-based approaches, which have demonstrated significant reductions in mortality and refracture rates, despite their still limited adoption in clinical practice. In conclusion, this review highlights the shared mechanisms between osteoporosis and cardiometabolic conditions in the context of multimorbidity, underscoring persistent clinical challenges related to diagnosis, drug interactions, and care fragmentation that warrant further research into integrated care models.

Background: Apple cider vinegar (ACV) is a naturally fermented beverage with potential metabolic health benefits; however, its effects on weight loss remain controversial. This systematic review and meta-analysis of randomized controlled trials (RCTs) was conducted to assess the effect of ACV on anthropometric measurements in adults. Methods: We performed a systematic search of PubMed, Web of Science, Scopus, and CENTRAL up to March 2025 for randomized controlled trials (RCTs) in adults (≥18 years) evaluating the effects of ACV for ≥4 weeks on body composition parameters. Primary outcomes included changes in body weight, BMI, waist circumference, and other anthropometric measures. Risk of bias was assessed using the Revised Cochrane Risk-of-bias tool. Results: Out of 2961 reports screened, 10 RCTs comprising a total of 789 participants were eligible for inclusion in this meta-analysis. The pooled results using a random-effects model showed that daily ACV intake significantly reduced body weight [SMD: −0.39; 95% CI: −0.63, −0.15; p = 0.001; I² = 62%], BMI [SMD: −0.65; 95% CI: −1.05, −0.26; p = 0.001; I² = 83%], and WC [SMD: −0.34; 95% CI: −0.67, −0.02; p = 0.04; I² = 61%]. However, no significant effects of ACV were observed on the other body composition parameters analyzed. Sensitivity analyses excluding high-risk-of-bias studies confirmed the robustness of ACV’s beneficial effects on body weight and BMI. Subgroup analyses suggested that ACV consumption significantly improved anthropometric parameters when administered for up to 12 weeks, at a dose of 30 mL/day, and in adults who were overweight, obese, or had type 2 diabetes. Conclusions: Overall, this meta-analysis suggests that ACV supplementation may be a promising and accessible adjunctive strategy for short-term weight management in adults with excess body weight or metabolic complications.

Accurate dietary assessment is essential in nutritional research and epidemiology. Food Frequency Questionnaires (FFQs) are widely used to estimate habitual intake; however, their performance may vary according to questionnaire design, administration procedures, and the dietary components being assessed. This systematic review and meta‐analysis evaluated the relative validity of FFQs designed to assess overall dietary intake in adults and explored methodological characteristics associated with their performance. A meta‐analysis was conducted on studies validating FFQs against reference methods, including 24‐h recalls and food records. A comprehensive search of the PubMed, Web of Science, and Scopus databases was conducted for publications from January 2000 to February 1, 2026. Pooled estimates were calculated for correlation coefficients and mean differences for energy and nutrients between FFQs and reference methods. The literature search identified 43 articles that included 8467 participants. Subgroup analyses according to the sample size, administration methods, FFQ items, quality of the studies, and regions were also performed. Overall, FFQs showed moderate‐to‐good relative validity for most nutrients. Performance was relatively consistent for energy and macronutrients, particularly carbohydrates, whereas greater variability was observed for micronutrients, although some, including magnesium and riboflavin, showed high correlations. Systematic overestimation of certain nutrient intakes was observed, particularly when FFQs were compared with 24HRs. Interviewer‐administered FFQs and questionnaires with a greater number of items tended to yield slightly higher correlations, while studies of higher methodological quality also tended to report stronger correlations. These findings support the use of FFQs primarily for ranking individuals according to habitual dietary intake and suggest that administration mode, questionnaire comprehensiveness, and methodological quality should be carefully considered in future FFQ development and validation. Greater caution may be warranted when overall‐diet FFQs are used to estimate specific micronutrient intakes.