By Brian Foley from Activate Fitness

I had a client talk to me last week about something they had seen online about 'Fat Burning' and how they had been told it can be 'flushed' out with the right teas and other potions.

Never in all of the science classes I’ve taken and in all of the years I’ve been studying human metabolism and health, have I ever heard of a ‘flush’. Turns out, the person who posted the picture - a ‘health coach’ - said that’s what happens to fat cells when we lose weight. Of course, she was selling a product.

Another person on the Internet floated the claim that the ‘flush’ happens when we lose weight.

This person said that after the cells release fat, they temporarily fill with water, making you feel ‘squishy’. She said that this water retention occurs because ‘the fat cells are hoping to fill up again with fat’.

Apparently, this person doesn’t understand science because, despite her compelling description, she’s absolutely wrong.

Our fat cells don’t fill with water after they release triglycerides during weight loss. They just sort of…wait there, like when the train takes half an hour reversing into Killarney Station and it’s baltic outside!

The question is where does it go? And maybe there isn’t a ‘flush,’ but do fat cells disappear or leave the body when they’re empty?

All very good questions, and all about to be answered in this week’s and next week's article.

Warning: People who use words like 'flush' and 'burn' about the complex human metabolic process should be ignored. But you knew that already.

What are fat cells?

Contrary to popular belief, we aren’t born with all of our fat cells. We accumulate them – at least what’s determined to be our baseline number – until well into our teens.

Most of the fat in our bodies is what we refer to as white fat, or WAT (White Adipose Tissue). White fat stores triglycerides for energy, cushions our organs, keeps us warm, and produces hormones.

When we eat fat, it gets broken down and metabolised by the liver into triglycerides. These are stored in the fat cells, liver, and to a small extent, in muscle. When your body needs energy, it releases the triglycerides into the bloodstream in a process called lipolysis.

The body tries to maintain a balance of ‘lipid turnover’, which is the name given for the process of storing and removing triglycerides in fat cells for energy. Of course, if you go into calorie deficit, this balance tips, and you lose weight.

Recent research measuring lipid turnover rates showed that lipid removal slows as we age – basically, our cells continue to take up fat, without losing as much of it. That may make it harder to lose weight as we get older.

In Part 2 next week, we'll look at macronutrients and what happens to fat when we lose weight.

In the meantime, if you would like some free advice from qualified professionals, visit www.activate.ie/nutrition.