I'm a Celebrity... Get me out of here! Tziporah Malkah eats dinner from under a bed sheet amid contestant clashes, saying "I don't like to look at toxic people when I eat." Courtesy: Channel 10
Casey Donovan has dropped a massive 17kgs since entering the Im a Celeb camp. Picture: Nigel Wright
MOST of us are well aware that weight loss is hard.
You can slave away at the gym and eat barely anything and lose a kilo at most.
So why was it that on Sunday nights episode of Im a Celebrity.....Get Me Out Of Here, Casey Donovan was able to lose a massive 17kg, Dane Swan dropped 14kg, and Steve Price shed more than 10kg while Ash Pollard and Tegan Martin only managed just a tiny few kilos off on the scale over the same time frame?
Here are some of the reasons for the weight loss outcome:
The more you have, the easier it is to lose
The body works like a machine when it comes to burning energy. This means the more body fat you have, the more likely it will be burnt as there is plenty of extra.
On the other hand, when you have relatively small amounts of extra body fat, the machine will work a lot more efficiently to preserve energy.
It is for this reason that larger people can lose seemingly massive amounts of weight compared to a few kilos for those who only have a little extra to spare even though they are following the same diet and activity regime.
Casey Donovan walked into the Im a Celeb camp weighing 149kg. She has since lost 17kgs. Picture: Nigel WrightSource:Channel 10
The more you have, the more fluid you have
The actual process of burning body fat is a demanding metabolic process, which means the body has to work pretty hard to do it. This is part of the reason that losing body fat is tough for anyone.
For people who carry a lot of extra body fat, and for whose cells are packed full of extra carbohydrate in the form of glycogen, the body will also be storing a significant amount of extra fluid.
Steve Price has dropped an impressive 10 kilos on Im a Celeb. Picture: Nigel Wright/Ten.Source:Supplied
Once carb and/or calorie intake is heavily reduced, such as on Im a Celebrity, where they consume an 800 calorie diet, the body will rapidly deplete its stores of carbohydrate and fluid, resulting in rapid weight loss. This will especially be the case for those who started with plenty of extra weight on board.
This is another reason that individuals on televisions shows such as The Biggest Loser can lose 6-8 kilos or even more in a single week much of it is actually fluid, not fat.
Severe calorie restriction leads to reduced metabolic rate
When it comes to cutting back on calories, it is impossible to keep cutting back and losing weight.
As the body requires a certain number of calories just to function, when the total calorie intake is significantly reduced, the metabolic rate will also reduce to work more efficiently at keeping the body working for fewer calories.
I'm A Celebrity ... Get Me Out Here! contestants for 2017. Picture: Supplied/Nigel Wright for TenSource:Supplied
This is another reason why people may lose relatively larger amounts of weight initially but weight loss will reduce over time as metabolic rate reduces. This is also the reason why we do not necessarily lose the same amount of weight each week.
Men lose weight more easily than women
Generally speaking, men, even older non-athletic men, have significantly more muscle mass, the tissue that actually burns calories.
As such, men will always lose weight more quickly than women, when calories are reduced and /or activity levels increased, even though women may have more to lose.
Casey Donovans restricted diet while on the reality television show has lead her to shed 17kgs. Picture: Nigel WrightSource:Channel 10
The biological need for women to keep body fat with levels suitable for reproduction will also see women preserve much more body fat than men. This is why an older, 60 year old male can lose much more weight than a younger female.
Steve Price has dropped 10kg in the jungle. Picture: Supplied/Nigel Wright for Ten.Source:Supplied
Casey Donovan has dropped a whopping 17kg on Im a Celeb. Picture: Supplied/Nigel Wright for TenSource:Supplied
Muscle will be wasted
When calories are restricted, especially carbohydrates, both muscle and fat mass will be burnt down to be used as energy.
For a more muscular female, this explains why she is able to lose a lot more weight than a less muscular smaller female who only has extra body fat to lose.
Dane Swan, left, lost 14kg. Natalie Bassingthwaighte and Tegan Martin only dropped a few kilos each. Picture: Nigel WrightSource:Channel 10
Different people = different body types
When it comes to metabolism and weight loss, there is not a one size fits all model. Sure initially fatter people will lose more weight on a severe calorie restriction than less fat people, but over time the degree of leanness we can achieve is largely down to our bone mass, body fat set point and the way fat and muscle are distributed around the body.
Fit former AFL player Dane Swan dropped 14kgs. Picture: Nigel WrightSource:Channel 10
This can be seen from the range of body types and weight loss discrepancies in the contestants currently appearing on Im a Celebrity.
Basically, the small, lean people get a little leaner, while the larger muscly people maintain their larger frames with relatively small weight losses and the larger people and men lose the most weight.
That is genetics and biology, which we can manipulate but never actually change.