Visceral Fat vs Subcutaneous Fat
Subcutaneous fat lays just beneath the surface of the skin and has a tendency to accumulate around the thighs, arms and backside. The midsection may contain both subcutaneous and visceral fat.
On the other hand, you have visceral fat which is found within the midsection and wraps around your internal organs. This type of fat has been strongly linked to systemic inflammation, insulin resistance (link to insulin resistance) and metabolic disease (dyslipidemia, coronary artery disease, hypertension, etc.). Larger amounts of visceral fats may even further increase your risk breast cancer, colon cancer and Alzheimer’s. Research behind the mechanisms of disease implication is still ongoing but involves its metabolically active role as a chemical messenger triggering a chain of reactions within your cells. You don’t have to be obese to have a harmful amount of visceral fat, commonly referred to as thin-outside-fat-inside (TOFI). Visceral fat has been linked to more health problems than having an elevated BMI.
What promotes storage of visceral fat?
This is an area of continued research, but high sugar diet has been found to play a crucial role (1). In the past decade, a new hypothesis for obesity has emerged based upon insulin being a fat storage hormone. Overconsumption of sugar and carbohydrates induces high insulin levels and insulin resistance causing obesity. There is also a hypothesis for the role of overconsumption of fructose (a form of sugar) and its subsequent effect of creating inflammation in cells metabolizing it. This leads to an increase in intracellular cortisol, which pushes fatty acids out of the subcutaneous fat cells allowing more to be stored in visceral fat tissue and the liver (fatty liver disease) (1).
There may also be a genetic source of preferential accumulation of visceral fat as suggested in recent association cohort study (2) . Epigenetics and other genetic variants (such as MC4R), are also being studied for their role in fat distribution (3). More studies are needed, but for now it would be safe to limit your refined sugar and carbohydrate consumption in an effort to minimize visceral fat deposition.
Maersk M, Belza A, Stodkilde-Jorgensen H, Ringgaard S, Chabanova E, Thomsen H, Pedersen SB, Astrup A, Richelsen B. Sucrose sweetened beverages increase fat storage in the liver, muscle and visceral fat depot: a 6-mo randomized intervention study. Am J Clin Nutr. 2012 Feb;95(2):283-9
DiNicolantonio JJ, Mehta V, Onkaramurthy N, O’Keefe JH. Fructose induced Inflammation and increased cortisol: A new mechanism for how sugar induces visceral adiposity. Prog Cardiovasc Dis. 2018 May-Jun;61(1):3-9. https://www.ncbi.nlm.nih.gov/pubmed/29225114
Shin J, Syme C, Wang D, Richer L, Pike JB, Gaudet D, Paus T, Pausova Z. Novel genetic locus of visceral fat and systemic inflammation. J Clin Endocrinol Metab. 2019 Apr 3. pii: jc.2018-02656.
Adamska-Patruno E, Goscik J, Czajkowski P, Maliszewska K, Ciborowski M, Golonko A, Wawrusiewicz-Kurylonek N, Citko A, Waszczeniuk M, Kretowski A, Gorska M. Genetic variants are associated with lower visceral fat accumulation and higher postprandial relative increase in carbohydrate utilization in humans. Eur J Nutr. 019 Apr 3. https://www.ncbi.nlm.nih.gov/pubmed/30945034