MEXICO CITY — Researchers presented findings on adipose tissue at the 2026 International Congress on Obesity (ICO), held by the World Obesity Federation.

By studying adipose tissue as an endocrine organ, research shows that the risk for metabolic disorders depends not only on the amount of body fat but also on factors such as sex, where that fat is stored, how it communicates with other organs, and the tissue’s ability to store or use energy.

Adipose tissue is distributed throughout the body — under the skin (subcutaneous fat), between internal organs (visceral fat), and even inside the bones (bone marrow adipose tissue). This tissue is essential for metabolism because it serves as the body’s primary energy reservoir and performs a highly active endocrine function.

“It releases adipokines in the form of hormones and cytokines, as well as extracellular vesicles containing lipids, proteins, and other components, which can reach distant organs and modulate their function. Healthy adipose tissue is essential for maintaining metabolic homeostasis throughout the body,” explained Yazmín Macotela, PhD, researcher at the National Autonomous University of Mexico’s Institute of Neurobiology in Juriquilla, Mexico.

In addition to storing energy, adipose tissue acts as an endocrine organ that releases hormones, cytokines, proteins, and microRNA. These signals modulate insulin sensitivity, inflammation, and cardiovascular activity; as a result, its dysfunction can contribute to type 2 diabetes, fatty liver disease, and cardiovascular disease.

The researchers emphasized the need for further studies to understand the complexity of adipose tissue and its relationship to both obesity and metabolic disorders.

Sex Also Shapes Metabolic Risk

Macotela said there are differences between visceral and subcutaneous fat in their characteristics and metabolic effects in men and women.

She noted that visceral fat surrounds the internal organs, and when it accumulates in excess, it is linked to insulin resistance, type 2 diabetes, fatty liver disease, and cardiovascular disease. Subcutaneous fat, by contrast, is typically associated with a lower cardiometabolic risk and may even serve as a safe lipid reservoir.

The distribution of these fat deposits differs by sex. Men tend to accumulate more visceral fat, whereas before menopause women have proportionally more subcutaneous fat. Although women tend to have more total body fat, they do not necessarily have a higher cardiometabolic risk.

“Total body fat alone does not explain metabolic risk: the location and function of adipose tissue are decisive factors,” Macotela noted.

Her team studied biopsies of omental visceral fat and abdominal subcutaneous fat from 21 women and 20 men aged 18-77 years. Using RNA sequencing and bioinformatic analyses, they identified profiles of dysfunction associated with insulin resistance that varied by sex and fat depot.

In male visceral fat, cell cycle activation and senescence predominated, accompanied by inflammation, extracellular matrix remodeling, and vascular alterations. Subcutaneous fat primarily showed alterations in adipocyte function and cellular stress pathways.

In contrast, in women’s visceral fat, impaired adipocyte function, cellular stress, and vascular alterations stood out. In subcutaneous fat, immune, vascular, stromal, and extracellular matrix remodeling predominated.

“There are phenotypes of adipose tissue dysfunction associated with insulin resistance that are specific to the fat depot and sex. This supports the idea that adipose tissue dysfunction associated with insulin resistance does not constitute a single phenotype. The characteristics are not the same in every case. There are specific remodeling programs that may help explain the heterogeneity of cardiometabolic risk,” Macotela said.

She also highlighted the need to replicate these analyses in different populations and age groups as the observed patterns may not be the same in young people, older adults, or individuals from different population backgrounds.

How Adipose Tissue Communicates With the Heart

Adipose tissue has the ability to communicate with the rest of the body via microRNA, which regulates gene expression, explained Marcelo Mori, PhD, a molecular biologist and researcher at the University of Campinas in São Paulo, Brazil. In addition to the role of adipose tissue in metabolic abnormalities, he emphasized that this tissue’s ability to communicate with other organs may help researchers better understand conditions such as insulin resistance.

Mori explained that his research group studied the enzyme DICER, which is necessary for processing microRNAs — a type of RNA found in cells and in the blood. In mouse models, the researchers found that a reduction in this enzyme in adipocytes led to partial lipodystrophy, insulin resistance, accelerated senescence, and the bleaching of brown fat.

The researchers found that brown adipose tissue is a major source of circulating microRNAs capable of reaching other organs and modulating gene activity. When they analyzed the hearts of animals lacking DICER in their adipocytes, they observed alterations in pathways related to circadian rhythm, insulin signaling, adrenergic response, calcium homeostasis, and cardiac contraction; among the microRNAs studied, miR-92a and miR-222 stood out.

Through cellular experiments and specific labeling, the team confirmed that these microRNAs could be produced in brown fat and reach cardiomyocytes. Reduced transfer of these microRNAs was associated with changes in the cardiac clock and functional defects.

“Adipose tissue communicates with the heart, in part via miR-92a. Adipose tissue dysfunction, as seen in lipodystrophy or obesity, reduces this microRNA and may contribute to the development of cardiometabolic dysfunction,” Mori said.

He also noted that while these results do not yet prove that modifying microRNAs can treat cardiovascular disease, they underscore the importance of studying adipose tissue as part of a communication network between organs. He added that his team is investigating possible interactions with the immune system and the brain.

The specialist added that understanding these communication mechanisms will reveal how adipose tissue dysfunction affects distant organs, even before obvious clinical manifestations appear.

Adipose Tissue and Energy Expenditure

The relationship between adipose tissue and energy expenditure is another line of research in obesity treatment. Armando Tovar, PhD, a nutritional biochemist and researcher at the Salvador Zubirán National Institute of Medical Sciences and Nutrition in Mexico City, addressed the possibility of modulating thermogenesis through diet.

He explained that brown adipose tissue, whose function is to convert energy from food into heat, expresses the UCP1 gene, which encodes a protein that allows the energy generated in the mitochondria to be dissipated as heat.

Tovar said that thermogenesis, whether induced by cold or diet, can increase energy expenditure by 5%-10%. Although this increase does not replace other strategies for combating obesity, it could help maintain or reduce weight by limiting the continuous storage of energy.

“An important strategy against obesity is to take advantage of the benefits of foods with functional properties and bioactive compounds, which can induce browning of adipose tissue and increase thermogenesis,” he emphasized.

The specialist explained that a bioactive compound “is a substance present in a food that possesses biological activity and provides health benefits in addition to its nutritional value.”

One such food containing bioactive compounds is soy; therefore, his research team studied soy protein and one of its isoflavones, genistein, in animal models. In animals fed a high-fat diet, soy protein was associated with less weight gain, lower body fat, and smaller adipocytes compared with a casein-based diet.

Genistein increased the expression of UCP1, oxygen consumption, and energy expenditure. Even under thermoneutral conditions, it reduced body weight and adipocyte size in animals. In isolated human adipocytes, it also increased mitochondria and UCP1, although the response was lower in cells from  individuals with overweight or obesity, Tovar added.

“We must continue to study the effect of diet as a first-line strategy against obesity and its relationship with beige and brown adipose tissue,” he emphasized.

These results show that nutrition can modify the biology of adipose tissue and offer a pathway for developing complementary interventions against obesity.

Macotela, Mori, and Tovar disclosed having no relevant financial relationships. 

This story was translated from Medscape’s Spanish edition.