The backlash against the skinny brigade might be comforting, but while it might be psychologically healthy it’s not entirely healthy for our bodies. While we all want to feel comfortable in our bodies, and not feel pressure to look like the models we see in the media, the fact is, being overweight is bad for our health and carries with it an increased risk of heart disease, diabetes, high blood pressure and other health risks.
Where does fat come from?
Fat cells (also known as adipocytes) are formed in the foetus during the third trimester of pregnancy, and then again at the beginning of puberty when the sexual hormones begin to function. It is at puberty when the distribution of fat cells begins to differ for men and women, giving rise to the typical male and female body shapes.
A healthy adult
between 10 and 20
billion fat cells
in their body
A healthy adult generally has between 10 and 20 billion fat cells in their body. Each of these fat cells is filled with fat in the form of triglycerides. Interestingly, the number of fat cells generally remains constant throughout your life. If you overeat and pick up weight, your existing fat cells will simply become enlarged to accommodate the excess fatty tissue. However, if you pick up a significant amount of weight and become obese your existing fat cells become overextended and they send out a signal to form additional fat cells. ‘Once new fat cells are formed, they remain throughout life and only a reduction in the size of the cell is possible,’ says Cape Town specialist physician Dr Marius Wasserfall. An obese person may have up to 100 billion fats cells.
What happens to fat in the body?
When you consume fatty foods the triglycerides don’t simply go straight to your fat cells. The journey from French fry to fat cell is a long process which involves your intestines, gall bladder, pancreas, lymphatic system and bloodstream. During this process the triglycerides get broken down into fatty acids and glycerol to make them small enough to move from the intestine to intestinal cells. The intestinal cells then reassemble the glycerol and fatty acids back into triglycerides which move into the lymphatic system and eventually into the bloodstream where they are absorbed by fat, muscle and liver cells.
A new perspective on fat
The medical outlook on fat has changed dramatically in the past two decades. ‘In the past, fat was viewed as an inert storage system that was only useful for insulation and energy storage, and more often a liability than an asset,’ says Dr Dirk Blom from the Groote Schuur Lipid Clinic. ‘But in recent years scientists have discovered that fat is incredibly active, releasing hormones, proteins and chemicals into the body.’
Two examples of hormones released by fat include leptin and adiponectin. Leptin helps to keep your appetite in check. ‘It has been described as the anti-obesity hormone as it sends signals to your brain relating to the amount of fat stored in the fat cells,’ says Dr Wasserfall. ‘Adiponectin also plays an important role as it suppresses inflammatory hormones (some of which are associated with atherosclerosis – a condition in which an artery wall thickens because of a build-up of fatty substances such as cholesterol). Adiponectin also improves cholesterol abnormalities and insulin resistance, and has a variety of anti-tumour effects.’