Visceral fat and subcutaneous are very different anatomically and physiologically. Both have their pros and cons in wanting to get rid of first. I had to really dig deep to find the information on subcutaneous and visceral and how diet and cardio effects each.
Differences between visceral fat and subcutaneous
When people think of fat, they usually only think of subcutaneous. That’s the fat right below your skin that you can grab as flab. There is another type of fat called visceral fat, which makes up about 10 to 20 percent of your total fat. Its buried deep inside your body, especially around your abdomen area. Men tend to have more visceral fat than women, which is why they tend to carry more of a protruding gut.
Visceral fat is the most unhealthy and effects your entire body. It leads to insulin resistance, high cortisol levels, sleeping problems like sleep apnea and snoring, diabetes, and other chronic degenerative diseases. Generally fat people with a large gut and thick neck have a lot of visceral fat, but even sometimes skinny people can have a lot of visceral fat. Genetics plays a role if skinny people have a lot of visceral fat naturally. If they have a poor diet and other factors like lack of excercise and smoking and drinking that can increase the risk of visceral fat. The high levels of visceral fat even in skinny people was shown in recent studies that made major headlines in the news a few years ago. Just because you are skinny doesn’t always mean you are healthy.
Losing subcutaneous fat doesn’t really have much of an impact on your health according to the studies done on patients who went through liposuction, which just removes subcutaneous fat. Therefore, getting rid of visceral is to feel better and be healthier vs. subcutaneous is mainly for just looking physically better.
Factors that affect how visceral vs. subcutaneous fat is lost
After looking at all the evidence in studies of different factors affecting visceral fat is mainly sensitive to hormones; insulin, testosterone, and cortisol. Genetics also play a role, as some people just naturally lose and gain more visceral fat than others. Thats why some guys tend to get big beer guts when they get fat and others store it more evenly. Visceral fat is very easy to lose and gain compared to subcutaneous, which seems more stubborn. A higher percentage of your fat loss in the beginning of a diet will be visceral because it’s easier to lose. This is supported in studies and I have observed it myself.
Insulin sensitivity plays a crucial role in visceral fat loss. When you restrict calories, your insulin sensitivity goes up. This is probably why visceral fat comes off the easiest when first starting a diet. People who went on low carb diets tended to lose even more visceral fat and I believe this is because low carb diets increase insulin sensitivity moreso than high carb diets do. Lowering saturated fat intake and replacing it with mono-unsaturated and polyunsaturated fats, also helped lower visceral fat in studies. Saturated fats increases insulin resistance.
Subcutaneous fat seems more correlated with cardio. When people increased the amount of cardio and the intensity they lost more subcutaneous according to studies. The intensity is also important, HIIT cardio seems to really melt the subcutaneous compared to regular cardio.
Older people tend to have more visceral fat too. That’s why on body fat measurement scales, they have different adjustments based on age. They assume that as you get older more of your fat is visceral instead of subcutaneous. I believe as you get older you become more insulin resistance naturally, which may explain the change in visceral fat.
Women and men also have different levels of visceral fat. Hence why big beer guts are rarely seen on fat women. I believe this has to do with differences in estrogen and testosterone. Testosterone causes more of your fat to be gained as visceral fat. Subcutaneous is correlated with estrogen. There is even Aromatase enzyme in subcutaneous fat that convert testosterone to estrogen. The more subcutaneous fat you have the more estrogen you will produce. There may be an ancestral reason for this. Visceral is a source of quick energy and men generally had to use fat quickly while away looking for food and the women stayed home.
Alcohol and smoking may also increase visceral fat. Hence why they tend to have beer guts. Stress and depression have been shown in studies to cause visceral. This isn’t surprising since visceral has a lot of cortisol receptors and more visceral fat leads to more cortisol released. If someone is stressed or depressed they have chronic high levels of cortisol, which leads to visceral fat storage in an endless cycle. You might want to read one of my other articles where I discuss how to naturally lower cortisol levels
Lets just review a few studies I have come across.
Visceral fat & subcutaneous loss studies
The study below showed that visceral fat only responded to calorie deficits (either from diet or more excercise). Whereas subcutaneous was correlated to amount of cardio.
Med Sci Sports Exerc. 1997 Dec;29(12):1549-53.
Twenty-six sedentary young women (27.9% body fat) were randomized into three groups: nonexercising control (C, N = 8); 1-2 sessions/wk plus a 240 kcal caloric restriction (1-2SW, N = 9); and 3-4 sessions/wk without caloric restriction (3-4SW, N = 9). There was a equivalent decrease in the percentage of body fat and total fat mass in both exercise groups compared with that in C. Reduction in SFM was significant in 3-4SW, but not in 1-2SW or C. A negative correlation was observed between training frequency and changes in SFM (r = -0.65). In contrast, VFM decreased significantly and equivalently in both 1-2SW and 3-4SW, but there was no correlation between training frequency and changes in VFM (r = 0.20). It is suggested that the decrease in SFM, but not VFM, is proportional to the amount of aerobic exercise training. A change in VFM appears to be related to an deficit in caloric balance either by dietary restriction (decrease caloric intake) or by increased caloric expenditure.
The study below compared HIIT cardio to regular cardio. Subcutaneous fat loss was 9 times larger in the HIIT cardio group.
Metabolism. 1994 Jul;43(7):814-8.
The impact of two different modes of training on body fatness and skeletal muscle metabolism was investigated in young adults who were subjected to either a 20-week endurance-training (ET) program (eight men and nine women) or a 15-week high-intensity intermittent-training (HIIT) program (five men and five women). When corrected for the energy cost of training, the decrease in the sum of six subcutaneous skinfolds induced by the HIIT program was ninefold greater than by the ET program.
The study showed that high carb diet increased visceral fat and insulin resistance, but switching to a low saturated fat with plenty of mono-unsaturated fats lowered visceral fat storage and increased insulin sensitivity. Even the saturated fat diet did a better job of keeping off visceral fat than the high carb diet.
Monounsaturated Fat–Rich Diet Prevents Central Body Fat Distribution and Decreases Postprandial Adiponectin Expression Induced by a Carbohydrate-Rich Diet in Insulin-Resistant Subjects
Published ahead of print at http://care.diabetesjournals.org on 6 April 2007. DOI: 10.2337/dc06-2220.
All subjects underwent three dietary periods of 28 days each in a crossover design: 1) diet enriched in saturated fat (SAT), 2) diet rich in monounsaturated fat (MUFA) (Mediterranean diet), and 3) diet rich in carbohydrates (CHOs).
RESULTS— Weight, body composition, and resting energy expenditure remained unchanged during the three sequential dietary periods. Using dual-energy X-ray absorptiometry we observed that when patients were fed a CHO-enriched diet, their fat mass was redistributed toward the abdominal depot, whereas periphery fat accumulation decreased compared with isocaloric MUFA-rich and high-SAT diets (ANOVA P < 0.05). Changes in fat deposition were associated with decreased postprandial mRNA adiponectin levels in peripheral adipose tissue and lower insulin sensitivity index values from a frequently sampled insulin-assisted intravenous glucose tolerance test in patients fed a CHO-rich diet compared with a MUFA-rich diet (ANOVA P < 0.05).
An isocaloric MUFA-rich diet prevents central fat redistribution and the postprandial decrease in peripheral adiponectin gene expression and insulin resistance induced by a CHO-rich diet in insulin-resistant subjects.
Any diet or cardio plan will lose both types of fat simultaneously, no matter what. However, depending on diet and lifestyle changes you will change how much you will lose more of each type up to a certain extent. Depending on your goal of vanity vs. health, you may want to target visceral or subcutaneous more. If your stomach width is at least half the size around the belly button as your height in inches, than visceral fat is a major health concern. Anything less and visceral may or may not be a concern depending on your genetics and lifestyle choices effect on if you store a lot of visceral fat.