Distinguishing Subcutaneous and Visceral Fat
Visceral fat can increase the risk of diabetes, heart disease and other health problems. Learn what causes it and how to reduce it safely. The “apple” body shape where fat is largely distributed around the stomach is more common in men as women are likely to experience gluteofemoral obesity than abdominal. Visceral belly fat is often a sign of a deeper organ related issue as opposed to fat stored around the buttocks and legs which is usually beneath the skin giving the appearance of cellulite.
However not all belly fat is the same, subcutaneous fat (similarly to fat on the legs) sits beneath the skin and is characterized by being able to pinch it. Whereas visceral fat surrounds the organs. A larger stomach doesn’t necessarily mean higher visceral fat, however an increasing waist circumference can be an indicator.
Health Risks of Visceral Fat
When there is more visceral fat, which is active and hormone secreting unlike subcutaneous, there is more inflammation causing a poorer insulin response. This is because the body is in survival mode due to the inflammation (meaning the body prioritizes having high blood sugar and has high cholesterol due to stress). This causes your body to be at increased risk of cardiovascular and metabolic disease. The problem is consistent, low-level inflammation (not the kind that is useful to the body in wound healing) over a long period of time.
Metabolic Impacts: Insulin and Liver Health
Insulin helps move glucose from the blood into cells where it can be used for energy. With insulin resistance, the cells do not respond effectively, so the body compensates by producing even more insulin in an effort to reduce blood sugar levels. Over time this leads to: higher fasting glucose levels, prediabetes, type 2 diabetes, stronger hunger or energy fluctuations and fat accumulation around the liver.
Fatty liver disease occurs when triglycerides are transported into the liver cells. It often shows no clear symptoms in early stages and is often discovered through blood tests, ultrasound or other health screenings.
The Limitations of BMI and Diagnosis
You can have a normal BMI or body appearance and still be at risk of carrying high levels of abdominal fat. You can be what is known as “thin outside, fat inside”. This is common with patients who have low muscle mass and physical activity or a family history of metabolic disease.
This is why doctors consider waist circumference (which has different thresholds depending on ethnicity, with Asians having a lower threshold), blood pressure and glucose levels rather than simply relying on your weight. Moreover BMI and waist circumference measure different things and are most useful when used together, but they are both screening tests and not used to conclude a diagnosis.
Cardiovascular Associations
Visceral fat is also associated with cardiovascular disease like lower levels of protective HDL cholesterol (this HDL is why you need some healthy cholesterol in your diet) as well as atherosclerosis (plaques in blood vessels) and heart failure. Body composition tests can estimate visceral fat levels but results do vary based on hydration levels.
Understanding BMI Limitations
BMI only uses height and weight so it cannot distinguish between muscle and fat (someone with high muscle mass may be incorrectly classified as obese by BMI). It also cannot distinguish between subcutaneous fat (which is normal and protective especially in middle aged women) and visceral fat. Two people can have the same BMI but completely different metabolic profiles.
The Role of Age
Visceral fat tends to increase with age due to changes in sleep quality, hormone secretion and physical activity levels. Women may notice more abdominal fat during and after menopause and men may notice it during the male menopause with the decrease in muscle mass. Although body changes in life are normal, maintaining muscle mass, staying active and reviewing nutrition are central to preventive medicine.
Management and Treatment
Visceral abdominal fat cannot be selectively targeted with core exercises. It should be treated the same as other forms of weight management as aforementioned as well as with stress management and possibly weight loss medications. Aerobic activity like swimming, resistance training and daily movement (10k steps) are crucial. With regards to diet, the goal is not to remove every carbohydrate or fat. The goal is to create a balanced eating pattern that supports fullness, nutrition and a manageable calorie intake.
For some people, nutrition and physical activity may not be enough to produce or maintain clinically meaningful weight loss. Medical weight management treatment may be considered after reviewing BMI, waist measurement, metabolic risk, medical history and previous weight loss attempts. This helps patients manage hunger and food intake but should be accompanied with side effect monitoring, realistic weight loss targets and a maintenance strategy.
Tracking Your Progress
Someone’s weight may change slowly while their waist circumference, blood sugar, blood pressure or fitness improves. Progress can therefore be measured through: clothing fit, energy and mobility, liver function markers and physical strength.