Why belly fat increases with age: Breakthrough discovery
Why does belly fat increase with age? (photo: freepik)
As people age, many notice extra centimeters appearing around their waistline — and this is not just a cosmetic issue. Abdominal fat is a risk factor for many serious diseases, including diabetes, and heart problems, and it also accelerates aging and slows metabolism. Ukrainian dietitian Oleh Shvets explained why belly fat increases with age.
Why belly grows with age
For a long time, the exact reasons behind this age-related increase in belly fat remained unclear.
Now, scientists have made a breakthrough discovery. Recent research shows that stem cells responsible for fat formation play a key role in this process. It turns out that as we age, these cells begin to work excessively, producing a significantly higher number of fat cells, especially around the waist.
This important discovery was made by researchers from City of Hope, one of the leading scientific institutions in the United States. The results of their work, which shed light on the mechanism of age-related belly fat gain, were published in April 2025 in the prestigious scientific journal Science.
Traditionally, it was believed that fat cells simply increase in size with age. However, the new study showed that white adipose tissue (WAT), which accumulates around the abdomen, also grows due to the formation of new fat cells. The scientists focused on adipocyte precursor cells (APCs) — stem cells in WAT that later transform into fat cells.
In a series of experiments on mice, which were later confirmed on human cells, the researchers made a surprising discovery. They found that old adipocyte precursor cells are capable of independently, regardless of the age of the host organism, actively producing new fat cells. Unlike most other adult stem cells, whose activity decreases with age, the cells in fat tissue, on the contrary, "unlock" their growth and proliferation potential as they age. This is the first compelling evidence that belly growth with age is due to increased production of new fat cells.
The scientists also found that aging transforms these APCs into a new, age-specific type of stem cells called middle-aged preadipocytes (CP-As). These begin to appear specifically in middle age and are extremely active in generating new fat cells. A signaling pathway was also identified — the leukemia inhibitory factor receptor (LIFR) — which plays a key role in the proliferation of these cells and their transformation into fat cells.
Conclusions of study
Research on human tissue samples of different ages confirmed the presence of similar CP-A cells in humans, and their number was higher in samples from middle-aged individuals. This indicates the strong capacity of these cells to form new fat cells in the human body.
Understanding the role of these age-related stem cells (CP-As) and the LIFR pathway in belly fat formation opens new prospects for developing medical treatments. Future studies will focus on exploring ways to eliminate or block these cells to effectively combat age-related fat gain and associated metabolic disorders, thus contributing to a healthier and longer life.
Earlier, we answered how much you should weigh based on your height and what the exceptions are.
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