Two types of fat
‘It’s important to remember that not all fat is created equal,’ says Dr Blom. ‘Subcutaneous and visceral fats behave very differently.’ Subcutaneous fat is located just below your skin, giving it a soft, rounded appearance. It is also responsible for dimpling and cellulite. Subcutaneous fat functions as an energy storage system and, although unattractive in excess amounts, it is regarded as relatively harmless.
Visceral fat, on the other hand, is located deep inside the body in the abdominal area. It is visceral fat which causes the infamous beer boep which is particularly common among men. Visceral fat is also associated with elevated cholesterol levels, high blood pressure, diabetes and heart disease.
The only way to accurately measure your level of visceral fat is by a CT (computed tomography) or magnetic resonance imaging (MRI) scan. However, the most obvious indication that you have excess visceral fat is weight gain around your waist. In general, waist circumference should be below 102cm for men and below 88cm for women.
An obese person
may have up to
100 billion fats cells
Why are high levels of visceral fat so dangerous?
Subcutaneous fat is the best place to store triglycerides but in some people visceral fat cells are used more readily. Visceral fat cells behave differently from subcutaneous fat cells. For example, they secrete more inflammatory substances and high levels of visceral fat are linked to low levels of the beneficial hormone adiponectin. ‘The result is that excess visceral fat is associated with many of the factors known to cause damaged and blocked arteries such as hypertension, elevated blood cholesterol and high blood sugar,’ says Dr Blom.
In addition, when subcutaneous fat cells can no longer cope with the amount of triglycerides that need to be stored, the triglycerides are deposited in inappropriate cells like those of the muscles and the liver, causing them to become insulin resistant.
How can I target visceral fat?
1. Exercise. ‘Visceral fat is used more quickly than subcutaneous fat when undergoing regular exercise due to the fact that it is more metabolically active,’ says Dr Wasserfall.
2. Avoid eating trans fats. In a study at Wake Forest University in North Carolina, two groups of male vervet monkeys were fed the same amount of calories for six years. One group was fed mono-unsaturated fats and the other group was fed trans fats. Those who were fed trans fats accumulated substantial fat deposits in their abdominal area and showed signs of insulin resistance.
What causes the middle-age spread?
Dr Blom believes that a wide range of factors are to blame for the weight that suddenly seems to ‘pile on’ when you reach your 40s. As you get older, your metabolism slows down, which means that your body doesn’t burn energy as quickly. ‘But I think a huge part of middle age spread is due to lifestyle changes – we go from being active and playing sports at school and university to becoming highly stressed workaholics with no time to exercise, who tend to sit in front of the TV and eat. It’s no wonder we pick up weight,’ says Dr Blom.
What is insulin resistance?
The body’s main source of energy is glucose. When you eat food, your levels of blood glucose (also known as blood sugar) rise and the pancreas secretes insulin in response, to help cells take in and use the glucose and stop producing glucose themselves. But when your liver and muscles are being misused to store triglycerides, they become insulin resistant and so don’t absorb the blood sugar or switch off sugar production. In order to compensate for this, the pancreas has to secrete more insulin. When the pancreas is unable to keep secreting such large amounts of insulin, the blood sugar will start rising and may eventually become so high that diabetes is diagnosed. Insulin resistance increases the risk of developing type 2 diabetes and heart disease