We know there are certain things we can do to lose weight. But I wanted to know what actually happens to those fat cells at a molecular level, so I spoke with Mackenzie Blakey, program and research lead for Body Fit Training.
Sophie Hanson spends a lot of time thinking about weird things. And she’s pretty sure you do, too. In her new column, Serious Question, Soph will explore the health questions you’ve always wanted to know the answer to, but never knew how to ask.
Excess fat, particularly around our vital organs, can cause a myriad of health problems. Diabetes, heart disease, high blood pressure, increased risk of stroke. The list is a long one and it’s why there are those of us who are looking to shed fat.
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But when we lose weight, when we drop dress sizes, where does the fat go? We first need to understand how fat loss works.
“As the old saying goes, to lose weight, calories in need to be less than calories out. Therefore, increasing calorie output through exercise is a great way to accelerate fat loss,” says Mackenzie Blakey, program and research lead at Body Fit Training, who also has a master’s degree in applied sports science.
At the most basic level, muscles sit closest to our bones, while fat sits on top of that closer to the surface of the skin. When a calorie deficit is paired with strength and weight training, we’re encouraging the building of muscle cells while shrinking fat cells.
It’s a common misconception, but fat does not turn into muscle, nor muscle into fat, and yes, we do require both in healthy amounts to ensure proper bodily function.
“When we build muscle, we are increasing the cross-sectional area of the muscle tissue, creating a larger muscle mass and size,” explains Blakey.
“When we ‘lose’ fat, we are essentially shrinking our fat cells into more compact tissue structures, accounting for a smaller area. We do not, however, reduce the total number of fat cells, as they are still required for storage of lipids and triglycerides (the building blocks of fat and protein).
She adds: “Fat cells do not ever exit our body; they just get smaller.”
Therefore, if your exercise levels dwindle, you will notice the opposite occurring: muscle cells will shrink while fat cells will increase in size.