Objectives: The objectives of this scoping review are to estimate the prevalence of obesity and overweight in the Saudi community and in different age groups, genders, and geographical location, in addition to the change in prevalence over time. Methods: This scoping review of evidence was conducted in accordance with the Joanna Briggs Institute methodology for scoping reviews and was reported following the Preferred Reporting Items for Systematic reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines. The population of this review was categorized into four age groups: young adults (18–25 years), adults (26–45), (mid-life adults) (46–60) and old people (60+). Each group was then categorized by gender into males and females. We included studies of adults aged 18 years and above. The pooled prevalence of obesity and overweight of the population, based on BMI, was estimated after stratification based on the age, gender, and geographical area. In addition, the change in the prevalence of obesity/overweight over time from 2011 to 2021 was investigated from the pooled data. The Metaprop program in Stata was used for statistical analysis. Results: A total of 39 studies with 640,952 participants were included in this review. The pooled prevalence of obesity and overweight in the age group of ≤25 years old, including both genders, was 30%. However, it was higher in young males (40%) compared to young females (25%). The prevalence of obesity and overweight among young adults has dropped by over 40% between 2012 and 2021. The overall pooled prevalence rate of obesity and overweight in the age groups >25 years old (adults, mid-life, and old people), including both genders, was 66%, with similar prevalence among males (68%) and females (71%). In addition, a similar prevalence was observed among both adult and old people (62% and 65%, respectively), but was higher in the mid-life group (76%). Furthermore, mid-life women had the highest prevalence among all groups (87%), compared to 77% among males in the same age group. The same difference in prevalence between the gender persisted in older females compared to older males (79% vs. 65%, respectively). There is a noticeable drop in the pooled prevalence of overweight and obesity among adults > 25 years old of over 28% between 2011 and 2021. There was no difference in the prevalence of obesity/overweight by geographical region. Conclusions: Despite the noticeable drop in the prevalence of obesity in the Saudi community, the prevalence of high BMI is high in Saudi Arabia irrespective of age, gender, or geographical location. Mid-life women have the highest prevalence of high BMI, which makes them the focus of a tailored strategy for intervention. Further research is needed to investigate which are the most effective interventions to address obesity in the country.

Although the burden of diphtheria has declined greatly since the introduction of vaccines, sporadic outbreaks continue to be reported. WHO recommends booster doses after a primary series, but questions remain about the optimal interval between these doses. We conducted a systematic review and quantitative data analysis to quantify the duration of protective immunity after different numbers of doses. Fifteen cross-sectional seroprevalence studies provided data on geometric mean concentration (GMC). Single-year age-stratified GMCs were analyzed using a mixed-effect linear regression model with a random intercept incorporating the between-country variability. GMC was estimated to decline to 0.1 IU/ml in 2.5 years (95% CI: 0.9–4.0), 10.3 years (95% CI: 7.1–13.6), and 25.1 years (95% CI: 7.6–42.6) after receiving three, four and five doses, respectively. The results drawn from cross-sectional data collected in countries with different epidemiologies, vaccines, and schedules had several limitations. However, these analyses contribute to the discussion of optimal timing between booster doses of diphtheria toxoid-containing vaccine.