Belly fat is often treated as public enemy number one, but some forms of body fat play vital roles in protecting your organs, regulating hormones and storing energy
Searches for ‘belly fat’ are about to hit a five-year high; and while the world of wellness has (rightly) moved away from hardline approaches to weight loss, the concept of losing your abdominal fat — the beer belly, the pot belly, call it what you will — seems to have escaped this more forgiving reckoning.
From AI-powered calorie-counting apps to fat-scorching training plans, belly fat remains big business — but are we viewing it the wrong way?
In order to gain a more intimate understanding of belly fat — and its potential health implications — we need to start with what belly fat actually is – and the differentiation between the two types of fat that make it up: subcutaneous and visceral fat. While subcutaneous fat mostly affects appearance, excess visceral fat is metabolically active and highly linked to health risks. Let’s take a closer look.
What is visceral fat and subcutaneous fat?
Subcutaneous fat is the ‘pinchable’ fat directly under your skin that you’re probably noticing in the mirror. It sits directly beneath the skin and is distributed across the body in your thighs, hips, arms and abdomen.
While excess amounts aren’t ideal, it plays a role in hormone production, energy management and insulin resistance and inflammation.
Subcutaneous fat has also been found to synthesise and release vital hormones and metabolic substrates into your bloodstream — suggesting it can be a critical regulator of your resting metabolic rate and whole-body fat oxidation.
Visceral fat, however, is the ‘hidden’ fat stored within the abdomen that surrounds internal organs, including the liver, pancreas, and intestines. It’s often referred to as ‘active fat,’ as it can function as its own organ.
It continuously releases substances directly into the bloodstream and liver and can lead to serious health issues, including fatty liver disease, insulin resistance and type 2 diabetes.
“Excess visceral fat is known to be very damaging to health,” explains Dr Adam Staten, resident doctor for One Day Tests, “as it has the highest metabolic risk of all the different areas of body fat and it is the main determinant of insulin resistance — the precursor to diabetes.”
Both subcutaneous and visceral fat contribute to the appearance of belly fat, but its role in your body is considerably more nuanced. While visceral fat gets bad press — for good reason, mostly — Dr Staten points out that every healthy body carries some of it and it serves a genuine purpose. Here’s what it actually does:
It protects your organs
Visceral fat acts as a physical buffer, providing “a layer of protection to the vital organs to enable the body to survive trauma.” A study in the American Journal of Physiology confirmed that visceral (omental) fat functions mechanically to cushion and protect inner organs from physical injury — distinct from subcutaneous fat, however, as this primarily provides insulation and external padding.
It’s an energy reserve
An evolutionary holdover from leaner times, it functions as “an essential reserve of energy for times when food is scarce” — a function that kept our ancestors alive.
To that end, University of Edinburgh researchers traced up to 80% of visceral fat back to a single embryonic cell, suggesting the body goes to considerable lengths to establish and protect this reserve from the very earliest stages of development.
It regulates key hormones
Visceral fat is more hormonally active than most people realise, producing leptin (which governs hunger and energy balance), oestrogen (important for sexual function in both men and women), and various immune-regulating molecules.
It also releases resistin — a hormone whose full biological purpose, Dr Staten admits, “remains a bit mysterious.” A review in the European Journal of Medical Research confirmed that visceral fat functions as a fully active part of the endocrine system, with leptin, resistin and other adipokines playing documented roles in immunity and inflammation — not just energy balance.
