Body fat: the science you really need to know

Whether you’re a gold medal-winning Olympic athlete or a self-confessed couch potato, body fat is a perfectly normal and natural part of human genetics.

It’s something most of us will have battled with at some point in our lives – exacerbated by the messages in mass media which seek to continually demonise it.

 Here, we’re going to take the emotion out of the subject, bring you the facts and give you science-based suggestions how on you can best maintain a healthy level of it.

THERE ARE 3 TYPES OF BODY FAT.

Body fat is simply the layer of fat that sits in the cells underneath our skin, around our internal organs and in vitals parts of our bodies such as the brain, bone marrow and nerves.

There are 3 different types of body fat and they’re all pretty important when it comes to sustaining a healthy body.

White fat – this is the most commonly recognised type of fat and is used by the body to do the following jobs:

• Store energy that can be broken down and used later
• Regulate hormone levels
• Help control body temperature
• Support reproductive health

Brown fat – this is the fat that we mostly grow out of from birth, but still retain a small amount of as we grow up. Brown fat burns energy through a process called thermogenesis, which just means burning energy to produce heat. This is what helps us stay warm when we get too chilly.

Beige fat – this is the least known kid on the body fat block and is like a
combination of white and brown fat. Beige fat cells behave just like white cells until they go through a process called ‘browning’, when they start behaving like brown cells instead.

Scientists are still in the very early days of studying beige fat but it’s believed that certain hormones are released when we’re stressed, cold or exercising that cause our white fat cells to go through this browning process.

HOW MUCH IS TOO MUCH?

The good news is that each type of fat serves a purposeful role in the body and is beneficial. Body fat isn’t the enemy.

That said, if you have too much body fat, you run the risk of health conditions such as type 2 diabetes, heart disease and some types of cancer. That’s why it’s so important to keep your body fat percentage at a healthy level.

For a male, the recommended body fat percentage (i.e. the proportion of fat a body is made up of) is 14-24%. For a woman, the recommendation is 21-31%.

WHAT DETERMINES WHERE WE STORE FAT?

• The physical location of fat dramatically changes the disease risk associated with fat mass – higher concentrations around the organs and stomach are related to higher disease risk

• Sex hormones – premenopausal women are more likely to store fat around the buttocks and thighs, whereas men will have more (dangerous) fat around their abdomen. Post menopause the switch in hormones changes fat distribution more towards the stomach much like men. Oestrogen is therefore a key driver in fat distribution and can offer a protective effect in women.

•  Ageing – as we age we tend to gain weight as our cells become less energy efficient and we are more predisposed to storing fat, this also corresponds to a shift in storing more visceral fat rather than subcutaneous fat.

• Genetics – some studies place the heritability of body fat percentage around 40-70%, and combination gene changes can predispose obesity. There have been around 100 combinations to date associated with body fat distribution

• Epigenetic effects – epigenetics is the factor of your internal processes on genetics, ie. The effect of the environment on how genes are expressed. Evidence has found that those with high body fat start to become more disposed to gaining body fat quicker, but this is reversed in weight loss. However the data on this is very new and still up for debate.

BALANCING A HEALTHY BODY FAT PERCENTAGE

Despite what we’re sometimes sold, there is no magical quick fix when it comes to reducing excess body fat. Fact. It really all boils down to eating a healthy, balanced diet in combination with doing regular exercise.

Exercise alone isn’t enough to keep body fat at bay.

Exercise has hundreds of health benefits and is an essential part of a healthy lifestyle but won’t help you reduce body fat percentage unless it’s accompanied by a well-balanced diet.

When we consume more energy than we need (i.e. when we eat more calories than we burn) the body converts this surplus energy into fat, which is then stored.

WHEN WE GET “FATTER” WE AREN”T ACTUALLY ADDING MORE FAT TO OUR BODY,  OUR FAT CELLS JUST BECOME LARGER, EVENTUALLY BECOMING SWOLLEN AND INFLAMED.

Words of wisdom:

“It’s not about weight, it’s about fitness, and one component of being fit is to have relatively low body fat, because fat is not very efficient, whereas muscle is.” – Deborah Bull.