Ultra-processed foods linked to liver disease and insulin resistance in obese children

A new study links ultra-processed food consumption in obese children and adolescents to a significant rise in metabolic disorders, insulin resistance, and liver disease, highlighting the urgent need for improved dietary guidelines and public health measures.

Study: Association Between Ultraprocessed Food Consumption and Metabolic Disorders in Children and Adolescents with Obesity. Image Credit: Discover 4K World/Shutterstockc.com

In a recent study published in Nutrients, researchers examined the association between the consumption of ultra-processed foods among obese adolescents and children and the incidence of metabolic disorders such as insulin resistance, metabolic associated steatotic liver disease or MASLD, and obesity, with the aim of improving public health and dietary guidelines.

Background

Ultra-processed foods, which are made of highly synthesized and processed ingredients such as sugars, oils, and modified starches, are becoming exceedingly popular worldwide because of their long shelf-life and low preparation requirements.

However, most ultra-processed foods have very low nutritional content, such as fibers and vitamins. They are often high in unhealthy fats, sugars, and salt, which has raised concerns about their role in triggering metabolic disorders and obesity.

Studies have found that ultra-processed foods can cause insulin resistance and inflammation and could potentially contribute to MASLD. While ultra-processed foods are very common in Western diets, Asia has recently seen an increase in their consumption, especially among children.

Furthermore, the link between ultra-processed food consumption and childhood obesity has raised major concerns since it is associated with the early development of cardiovascular disease.

However, although the link between the consumption of ultra-processed foods and metabolic disorders among adults has been well-explored, the impact of such foods on pediatric health remains unclear, especially in Asian countries.

About the study

The present study aimed to understand the association between the consumption of ultra-processed foods among obese adolescents and children in Asia and the development of metabolic disorders such as MASLD.

The researchers used data from a study conducted between 2019 and 2020 by a university hospital in the Republic of Korea on nutrition and activity-based interventions for childhood obesity.

They included adolescents and children between the ages of eight and 17 years with a body mass index (BMI) greater than or equal to the 85^th percentile. After excluding participants who were using medications that could impact their body weight, the final study population consisted of 149 participants.

The caregivers of all participants were required to complete a food diary at baseline and during follow-up, which consisted of a record of all foods and beverages consumed over a two-to-five-day period.

The records were analyzed to assess nutrient intake, and the foods were categorized using established classification systems based on processing levels.

A range of anthropometric measurements were obtained from the participants using dual-energy X-ray absorptiometry, including trunk and total fat mass, fat mass index or FMI, body fat percentage, and lean mass. Bioelectrical impedance analysis was used to measure body weight.

Additionally, the study collected blood samples after 10 hours of fasting to assess the lipid profile, which included low and high-density lipoprotein (LDL and HDL) levels, as well as total cholesterol and triglyceride levels.

The levels of liver enzymes such as alanine transaminase (ALT), aspartate transaminase (AST), gamma-glutamyl transferase (γ-GT), and glucose levels were also measured. An electrochemiluminescence immunoassay was used to determine the fasting insulin levels.

Furthermore, magnetic resonance imaging proton density fat fraction or MRI-PDFF was used to measure the percentage of hepatic fat. If the liver fat percentage exceeded 5%, the participant was diagnosed with MASLD.

Results

The study found that increased consumption of ultra-processed foods in obese adolescents and children was linked to significant liver health issues and metabolic disorders.

A high intake of ultra-processed foods was associated with increased insulin levels, insulin resistance, and a high prevalence of MASLD. Surprisingly, ultra-processed food consumption was also associated with lower levels of total cholesterol and LDL cholesterol.

Participants whose ultra-processed food consumption fell in the highest tertile had a higher overall energy intake but low fiber intake.

Furthermore, they consumed lower levels of carbohydrates, as well as polyunsaturated, monounsaturated, and saturated fatty acids, and derived most of their energy from total fats. The researchers believe that the low levels of LDL-cholesterol and total cholesterol despite the high calorific intake could be due to the low levels of saturated fatty acids in the diet.

The findings also reported that a 10% increase in the consumption of ultra-processed foods resulted in a 37% increase in the odds of moderate to severe MASLD, and 30% higher odds of developing insulin resistance.

The high refined sugar and trans-fat content, the low fiber content, and the industrial additives that prolong the shelf-life of ultra-processed foods are likely to contribute to the adverse health effects.

Conclusions

Overall, the study showed that increased consumption of ultra-processed foods among obese adolescents and children significantly increased the prevalence of metabolic disorders and insulin resistance, and posed a high risk of moderate to severe MASLD.

The researchers believe that more research is required to understand the mechanisms through which ultra-processed foods impact metabolic and liver health.