Global obesity has tripled since 1975, now affecting about 30% of the population, approximately 2.1 billion people, and continues to increase. While the Body Mass Index (BMI) is a common but flawed obesity measure, the Waist-to-Height Ratio (WHtR) offers a more accurate assessment by considering waist circumference.

Pacific island nations dominate the top obese countries, with Nauru leading at 61% obesity; factors include dietary changes, fast food prevalence, and possible genetic predispositions. The least obese countries, like Madagascar, Eritrea, Ethiopia, and Japan, have low average BMIs due to healthy diets or, conversely, issues like famine and poverty.

European Obesity Rates by Country 2024 Listed rates define obesity as individuals with a body mass index (BMI) greater than or equal to 30 kilograms per square meter of body area (BMI ≥30kg/m²) 44 countries

World Obesity Atlas 2023 - World Obesity Federation; Overweight prevalence among children under 5 years of age - WHO; Prevalence of overweight among children and adolescents - WHO; Share of children who are overweight or obese, 2010 to 2020 - Our World In Data

West Virginia is the most obese U.S. state, with an obesity rate of 40.6%. West Virginia also has the highest rate of type 2 diabetes in the U.S. at 15.7%. Severe Obesity Has Also Increased in Recent Years

Eight of the ten most obese countries in the world are Pacific Island nations, a problem attribute to the influence of Western settlers, who taught them to fry their foods and import more process, less healthy food products.

Most Obese Countries: Detailed data of the most obese countries, detailing the prevalence of obesity in various nations, highlighting the top countries with the highest rates of obesity. Neonatal Mortality Rate by Country

Developed countries often rank as the healthiest due to better quality of life, lower pollution, and access to health care and education. Unhealthy countries typically lack sufficient education, good jobs, and infrastructure, leading to higher pollution, illness, and lower life expectancy.

The country with the highest rate of malnutrition in the world is Somalia. In 2019, it was estimated that close to 60 percent of everyone in Somalia suffered from some degree of malnutrition.

Diet and exercise are particularly important: according to the Global Health Data Exchange, cardiovascular disease—which is typically caused by obesity stemming from unhealthy eating habits—was the leading cause of death worldwide from 1990-2019. Diabetes, which is also diet-related, ranked 9th.