Metabolically healthy obesity (MHO) is a term to describe people with a body mass index (BMI) of 30 or higher but do not have metabolic disorders. The concept emerged from clinical observations and research findings in the 1990s and early 2000s, which led to the recognition that not all individuals with obesity share the same metabolic risks.
On the other hand, MUO is a condition whereby a person has a similar amount of excess body fat as someone with MHO, but has already developed health consequences of obesity.
According to data, the prevalence of obesity in South Korea had increased from 30.2% in 2012 to 38.4% in 2021.
Although there are many studies focusing on MUO, few have investigated the factors for MUO in the Korean population with obesity, as well as the association between metabolic health and food insecurity.
As such, a group of Korean researchers sought to elucidate these links by analysing data from the 8th Korea National Health and Nutrition Examination Survey (KNHANES) from 2019 to 2021.
Since 1998, KNHANES has been conducted periodically by the Korea Disease Control and Prevention Agency (KDCA) to assess the health and nutritional status of South Koreans. It uses a multistage sampling design to ensure that the survey results are representative of the entire population.
In this analysis, data from 5,191 adults with obesity (BMI above 25) were included.
While there is universally accepted definition of MHO or MUO, common criteria for categorisation include levels of blood pressure, fasting blood glucose, triglyceride, and high-density lipoprotein (HDL) cholesterol.
It was found that the prevalence of MUO and MHO among the participants was 85.4% and 14.6% respectively.
Participants with MUO were older, and had higher BMI, waist circumference, blood pressure, fasting glucose, total cholesterol, and liver enzyme levels than those with MHO.
In terms of dietary intake, MUO was more prevalent in the low-fat intake group than the high-fat intake group, which is contrary to previous studies.
“Lower fat intake was linked to MUO in this study, potentially because lower fat intake may conversely increase the intake of unhealthy carbohydrates. A high-carbohydrate diet can adversely affect weight, HDL cholesterol, and triglyceride profiles.
“The Korean diet is known to be carbohydrate-rich, underscoring the authenticity of this hypothesis. A well-proportioned intake of macronutrients should be encouraged to promote metabolic health in individuals with obesity,” the researchers said.
In addition, the proportion of participants with MUO was higher among those with lower educational level and household income, lesser physical activity, and who are non-manual workers.
More secure, less obese
A paradoxical association between obesity and food insecurity has been studied over the past decades.
Similar to past studies indicating that food insecurity is linked to poor metabolic health outcomes, including a higher prevalence of obesity, food insecurity was associated with MUO in this analysis.
“Food insecurity does not necessarily mean hunger. It is associated with poor diets, not lower energy intake. Unhealthy food environments may lead to poor dietary choices, such as diets that are high in calories but low in essential nutrients.
“Specifically, dietary choices in populations with food insecurity include low consumption of fruits and vegetables, lean proteins and milk products, and high consumption of energy-dense foods with low dietary diversity.”
Therefore, improving access to food that is available and affordable is an important contributor to healthy diets.
To effectively address food insecurity and its impact on metabolic health, tackling the underlying economic issues of low-income individuals is also crucial, as a lower level of national economic development has been strongly linked to severe food insecurity.
In this study, household food security status was assessed based on an 18-item questionnaire tailored for Koreans, adapted from the US Household Food Security Survey Module (HFSSM).
The results showed that participants with MUO were more likely to be in the food-insecure group, with the proportion of MUO raised as food security decreased.
“These findings imply a close relationship between food insecurity and low household income, as individuals and families with limited financial resources are more likely to struggle with consistent access to adequate and healthy foods.”
With several studies highlighting that MHO is a transient state that may progress into MUO at a later life stage, targeted interventions and policies are needed for vulnerable groups.
“Along with the development of treatment guidelines, public health strategies focusing on improving food security and encouraging physical activity, better education, and appropriate dietary fat intake should be implemented,” the researchers concluded.
Source: Nutrients
https://doi.org/10.3390/nu16223833
“Factors Associated with Metabolically Unhealthy Obesity and Its Relation to Food Insecurity in Korean Adults with Obesity”
Authors: Jimin Lee, et al
