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.

The study below compared HIIT cardio to regular cardio. Subcutaneous fat loss was 9 times larger in the HIIT cardio group.

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.

Conclusion

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.

I’ve always been skeptical of Low Carb Diets for the average bodybuilder, unless they are getting ready for a competition. Low carb diets are needed for competition condition so they come in very dry. It’s almost been accepted as fact in the bodybuilding community for years that low carb diet was the quickest way to lose muscle, especially if you are a hardgainer. Recent bodybuilding authors like Lyle Mcdonald, who is making low carb diets very popular and new studies released, may prove that high carbs are not the best after all.

Low carb diets vs. high carb diet metabolism

In high carb diets you generally eat around 40 percent of your calories from carbohydrates. There are different Low Carb Diets usually called keto diets for bodybuilders, but most like the TKD (Targeted Keto Diet) has you eat about 10 percent of your calories as carbs and you cycle carbs at certain times and days. Instead low carb diets eat a lot more protein and fat to make up for the loss in carbs.

During High carb diets your body continues to metabolize macronutrients as usual, using glucose from carbs mainly for energy. With very Low Carb Diets your glycogen levels would get very depleted extremely fast with the lack of carbs shuttling glucose into your muscles. Your body has to come up with an alternative energy source to preserve some of that glycogen in your muscle for your brain, which needs glucose from the bloodstream. It does this by entering ketosis, where fat sources are used to make ketone bodies. Your brain tends to prefer glucose so that is mainly reserved for brain, while ketone bodies are burned for energy for other activities. Glycogen in the muscles won’t be completely depleted either, especially when carb load up days are utilized like in the TKD diet. Therefore during your weight training days you can use glycogen from your muscles for short term energy.

Studies on Low carb and muscle preservation and fat loss

There seems to be studies supporting both sides of the argument when it comes to muscle preservation. Many studies show low carbs preserving muscle better during diet than high carb diets and many studies say the complete opposite too. Here is just 3 studies I want to go over.

The study below shows a simultaneous fat loss and significant muscle gain while dieting low carbs. There was also lower insulin levels in the low carb diet. No other hormonal changes between the two groups such as testosterone or cortisol.

The study below shows that most of the loss in weight was due to fat and not muscle on a low carb diet.

The study below measured protein breakdown at the site and found no difference between low carb and high carb.

The following study showed that the higher carb diet lost less total fat and lost more muscle (ie. a larger percentage of their weight gains lost were muscle instead of fat)

These are just some of the studies supporting low carb diets are better at preserving muscle. There are many others out there. There is also many studies out there that show high carbs preserved muscle better.

Final conclusion on low carb vs. high carb

One common denominator from most of the studies I have come across is that Low Carb Diets are a better fat burner. Regardless if one preserves muscle better than the other, if fat loss is your number one concern than low carb diet is the best way to go. That has been the general consensus among bodybuilders for years anyways. The muscle preservation part is more controversial theory I believe. If you’re a hardgainer or your muscle genetics aren’t that good then it matters a lot more whether or not low carb diets or high carb diets are better in regards to preserving muscle. From all the studies I’ve seen its really hard to tell which side is right if you don’t do some further digging. Even Lyle Mcdonald in his book on keto diets the biggest advocate of low carb diets for bodybuilders, suggests that the results vary and that some lose muscle on low carb and for some its the opposite. Not exactly the most assuring assessment from the number one advocate in the industry.

The other thing I’ve noticed is most of these studies weren’t done on people who weight train. I believe that when someone is working out hard with weights 3+ times a week, the lack of carbs could be a game changer. Carbs give you plenty of energy and strength by keeping your glycogen levels full. When they get depleted more in low carb diets, its much harder to maintain strength and endurance. As you lose strength and do less reps week after week as you get fatigued easier its much harder to hold onto your muscle since they aren’t getting the same stimulation so your muscles are going to shrink.

The other reason I’m skeptical that Low Carb Diets hold onto muscle better than high carb diets is insulin is the most potent anabolic hormone in the body. Most people don’t realize this, they usually think of Testosterone first. Insulin increases protein synthesis and stops muscle breakdown by up to 50 % (University College London 2006 (2006) Proc Physiol Soc 3, C46) and helps shuttle nutrients into the muscles. Its hard for me to believe that when your eating mainly protein and fat which have very little impact on insulin compared to carbs, you can hold onto your muscle to the same degree. Insulin also counteracts cortisol the main culprit for muscle breakdown.

Could both sides be right?

Lower insulin levels have been shown in these studies for those on Low Carb Diets. They also show no changes in cortisol or other hormones between the two groups that may have an effect. Insulin resistance does lead to poor nutrient partitioning (higher bodyfat percent). Your body doesn’t burn fat as effectively or build muscle as well when you don’t respond to insulin and become resistant. As said earlier insulin is a potent anabolic hormone and if your body becomes resistant to it your fat loss should be less and your more likely to burn muscle instead.

Perhaps the insulin sensitivity changes in low carb diets are enough to overcome the other obstacles of a low carb diet and actually lead to better fat loss and muscle gains. If someone is borderline diabetic or has a lot of insulin sensitivity due to be overweight or genetics, then perhaps the switch to low carb diets puts their body into a different shift primed for not only losing fat better, but even sometimes gaining muscle. Perhaps this is why results vary between individuals. If someone is presently insulin resistant than low carb diet may be a better option.

Other possible reasons to avoid low carb diets

Whether or not Low Carb Diets works better for fat loss or muscle preservation, some choose to not do them because the risks outweigh any slight gains. I think low carb diets are much harder to stick to long term. What good is a diet if you can’t stick to it? Its very hard to come up with a diet for months or years that relies on mainly food that isn’t carbs. Also it is very hard to get enough fiber in your diet with such a low carb diet. Low fiber leads to constipation and increased risk of cancer. I also worry about the long term health effects on the body of such low carbs. Low carb diets also make you lose massive amounts of water weight which can give you the false impression of more fat lost than you really lost. You will be dissapointed when you carb back up and gain a lot of that water weight back giving you a more bloated fat appearance.

Here is a practical basic cutting guide that allows you to adjust it as you see progress (or lack of) in your fat loss phase. This will work for everyone, whether your a hardgainer or a endomorph body type.

Cutting Diet calories:

A cutting diet should start at 15 calories per lean muscle weight, unless you were previously bulking. Your lean muscle weight is calculated by first knowing your bodyfat %. If you are 12% bodyfat, subtract 100 from your bf% to get the percentage of lean muscle weight. For example, if you weigh 200 lbs at 12% bf, 100 minus 12 equals 88% lean weight. 88% of 200 lbs is 176 lbs. So this person should start at 2640 calories / dayfor cutting.

If you are currently bulking already and ready to start cutting, then ignore the 15 calculation and just lower your current total bulking calorie intake by 400 calories. If you were to lower your calorie intake to the 15 times bodyweight calculation, you would cause your body to go into starvation mode and you would lose a lot of muscle and little fat.

Monitoring progress:

Please note, that these are just starting calorie recommendations. Everyone’s metabolism and genetics are different. People with faster metabolisms may need a higher calorie starting point. You first need to start at some point though, so you can use it as a reference point for your results.

For best results, its important to measure bodyfat % weekly. That way you can see how muscle muscle mass vs. fat mass you are losing. If you are losing weight too quick, or just as much muscle as fat, your calorie intake is probably too low. If you are losing a lot of weight quickly, but it is showing as mostly fat loss, then that is perfect! What you want is most of the weight you are losing to be fat (at least 2/3).

Avoding Fat loss plateaus:

As you lose fat, you will have to slowly lower calories to continue to lose fat. You won’t keep losing fat on the same diet for weeks and weeks, just like the same workout routine and weightswon’t lead to continued muscle gains. Long term dieters, should cycle calories to help get through more stubborn plateaus. You do this by having large high carb calorie days once in a while.

These calorie spikes help maintain healthy leptin, thyroid, and testosterone levels, which help ultimately with fat loss. If you restrict calories everyday for weeks and don’t incorporate these calorie cycles, no matter what you do your fat loss will halt. All your hormones including the thyroid, which controls your metabolism, gets stunted during low calorie dieting. A large spike in calories is proven scientifically to cause a spike in all these important hormones.

You may not have heard of leptin, but you probably have felt the power of Leptin trying to keep you from losing fat during dieting. Leptin is a type of chemical hormone called a cytokine, that controls your hunger and metabolism. Leptin plays it’s biggest role during long term dieting. During a long diet, your leptin levels increase in order to slow your metabolism down and increase your cravings. This is a survival mechanism by the body, to try and keep you to hang onto as much fat as possible during times of starvation. Although, dieters are not usually “starving” when they diet, it’s the bodies way of trying to stay in balance. Leptin is mainly released through the fat cells, so people who start a diet fatter will have a harder time controlling their appetite and will hit a fat losing plateau easier.

How to diet properly to lower leptin levels:

To help ward off a potential fat loss plateau, you can manipulate lower leptin levels while dieting. To do this is simple, Leptin is dependant on your glucose levels. If you have a large meal, high in carbs, your Leptin levels will drop. Not only that, but you get an extra benefit, your Testosterone, IGF-1, Growth hormone, and thyroid levels will skyrocket. All of these hormones help in fat loss and maintain your muscle.

You may be wondering how you can get away with these kinds of meals, if your goal is to lose fat. The answer is through cycling or some kind of “cheat meal”. Every few days have one or 2 cheat meals. This will help temporarily ward off the long term trend to lower leptin levels.
Realize, this does not mean that you can diet indefinitely. While the high carb meals will give a temporary drop in Leptin levels, eventually you will plateau permanently. You can only push your body so much before it eventually stops losing fat. This is how all biological systems work as they are built to resist too much extreme change. These cheat meals are just a way to get more fat loss, before you reach the dreaded fat loss plateau.