Belly fat gets treated as a purely cosmetic problem, but the research is clear that it's also a serious health marker — and the science on what actually reduces it is more specific than "just do more cardio."
Why Belly Fat Is Different From Other Fat
Not all body fat behaves the same way. Visceral fat — the fat packed around your abdominal organs, as opposed to the "pinchable" subcutaneous fat under your skin — is metabolically active tissue that secretes hormones and inflammatory compounds with effects throughout the body. Harvard Health reports some striking associated risks: every 2 additional inches of waist size has been linked to a 10% higher risk of cardiovascular disease, and people in their 40s with the highest abdominal fat were found to be nearly three times more likely to develop dementia by their 70s and 80s.
Belly fat is also directly tied to hormonal health: a 2026 study in the Journal of the Endocrine Society by Friedl and Potter found that men with high visceral fat had 33–36% lower testosterone than men with low visceral fat, even at the same BMI — meaning that abdominal fat specifically, not weight in general, is a major driver of low testosterone.
What Actually Reduces It: The Research
A 2025 study published in JAMA Network Open, led by researchers at the University of Cambridge's MRC Epidemiology Unit, followed 7,256 UK adults over seven years as part of the Fenland Study, using wearable sensors to track physical activity and measuring diet quality. The findings were clear:
- Improved diet quality alone and increased physical activity alone each independently reduced body fat gains and visceral fat accumulation.
- Combining both produced the best results by far: participants who improved diet and activity together gained about 1.9 kg less total body fat and 150 grams less visceral fat than those who made no changes.
- Visceral fat was especially responsive to combined lifestyle changes — more so than subcutaneous fat — reinforcing that where fat is stored, not just how much you lose, matters for health.
Does Exercise Type Matter?
According to Harvard Health's review of the research, both aerobic activity (like brisk walking) and strength training have been shown to help reduce visceral fat specifically. Importantly, doing spot exercises like sit-ups will not target visceral fat — that fat is mobilized systemically, not from the muscle underneath it (see our companion post on the myth of spot reduction).
A Practical, Research-Backed Approach
- Aim for at least 30 minutes of moderate-intensity activity most days — brisk walking counts.
- Add resistance training at least twice a week; it contributes independently to visceral fat reduction, not just muscle building.
- Focus on diet quality, not just calorie counting — the Fenland Study measured adherence to a healthy dietary pattern, not just restriction.
- Understand that combining both diet and exercise changes produces meaningfully better results than either alone — this isn't an either/or decision.
The Takeaway
Belly fat, particularly visceral fat, responds best to a genuine combination of consistent physical activity and diet quality — not to ab-specific workouts or short-term extreme diets. It also matters for more than appearance: reducing visceral fat specifically has documented links to better heart health, cognitive health, and hormonal health.
References
- Aryannezhad, S., et al. (2025). Diet, physical activity, and visceral fat changes over 7 years. JAMA Network Open, MRC Epidemiology Unit, University of Cambridge Fenland Study.
- Harvard Health Publishing. Taking Aim at Belly Fat. Harvard Medical School.
- Friedl, K. E., & Potter, A. W. (2026). Low testosterone is a phenotype of visceral adiposity. Journal of the Endocrine Society, 10(8).
Discussion