Effects of Visceral Fat on the Body
Visceral fat is a major driver of cardiometabolic disease, causing insulin resistance, type 2 diabetes, cardiovascular disease, and increased mortality through multiple pathophysiological mechanisms including portal free fatty acid release, inflammatory cytokine production, and ectopic fat deposition. 1, 2
What is Visceral Fat?
Visceral adipose tissue (VAT) refers to fat stored within the abdominal cavity around internal organs, including:
- Omental fat
- Mesenteric fat
- Retroperitoneal fat
Unlike subcutaneous adipose tissue (SAT) that lies just under the skin, visceral fat is metabolically active and has direct access to the portal circulation.
Pathophysiological Effects of Visceral Fat
1. Metabolic Dysfunction
Insulin Resistance: Visceral fat causes insulin resistance through multiple mechanisms 2:
- Release of free fatty acids directly into portal circulation
- Impaired hepatic insulin extraction and degradation
- Increased hepatic glucose production
- Reduced insulin sensitivity in peripheral tissues
Dyslipidemia: Visceral fat contributes to 1, 3:
- Hypertriglyceridemia
- Elevated apolipoprotein B levels
- Reduced HDL cholesterol
- Increased small, dense LDL particles
2. Inflammatory Effects
- Acts as an endocrine organ producing pro-inflammatory cytokines 2, 4:
- Tumor necrosis factor-alpha (TNF-α)
- Interleukin-6 (IL-6)
- Other inflammatory mediators that impair insulin signaling
3. Ectopic Fat Deposition
- Visceral obesity is strongly associated with fat accumulation in other tissues 1, 3:
- Liver fat: Strongly linked to insulin resistance and metabolic syndrome
- Epicardial fat: Associated with coronary artery disease
- Pancreatic fat: May impair beta-cell function
- Skeletal muscle fat: Contributes to insulin resistance
4. Cardiovascular Effects
- Visceral fat independently increases risk of 4, 3:
- Hypertension
- Coronary heart disease
- Heart attack and angina
- Atherosclerosis
- Cardiovascular mortality
5. Age-Related Effects
- Visceral fat increases dramatically with age 5, 6:
- 200% increase in men between 3rd and 7th decades
- 400% increase in women between 3rd and 7th decades
- Contributes to age-related metabolic decline and disease risk
Sex Differences in Visceral Fat Effects
- Premenopausal women have approximately 50% less visceral fat than men 1
- Women have more protective gluteal-femoral fat, which may be metabolically protective 1
- Causal effect of visceral fat on type 2 diabetes is stronger in females (OR 7.34) than males (OR 2.50) 7
- After menopause, women experience accelerated visceral fat accumulation 5
Genetic Factors
- Genome-wide association studies have identified over 100 genetic loci associated with visceral adiposity 7
- Family history of visceral obesity predicts age-related visceral fat accumulation 1
- Genetic factors influence both the distribution of body fat and its metabolic consequences 7
Clinical Implications
- Visceral fat is a stronger predictor of metabolic and cardiovascular disease than overall obesity 1, 3
- "Normal-weight obesity" (normal BMI but high body fat percentage) increases metabolic syndrome risk 4-fold in men and 7-fold in women 1
- Reduction of visceral fat through diet, exercise, or other interventions improves metabolic parameters and reduces disease risk 2, 6
- Surgical removal of visceral fat in animal models has been shown to improve lifespan 6
Measurement and Assessment
- Advanced imaging techniques (CT, MRI) provide accurate measurement of visceral fat 1
- Waist circumference and waist-to-hip ratio serve as clinical proxies for visceral adiposity 1, 3
- Body mass index (BMI) alone fails to capture the metabolic risks associated with visceral fat accumulation 1, 3
Visceral fat should be considered a key therapeutic target in preventive medicine, as its reduction directly improves insulin sensitivity, lipid profiles, and inflammatory markers, ultimately reducing cardiometabolic disease risk.