It slows down.
“Low energy intake and minimal body fat are perceived as indicators of energy unavailability, resulting in homeostatic endocrine responses aimed at conserving energy and promoting energy intake.” (Trexler, Smith-Ryan, & Norton, 2014)
Translation- our body adjusts endocrine responses when we are consuming low calorie diets and when our body fat percentage drops.
I think where people tend to struggle with dieting is coming off of the diet.
Think about it- we’ve been consuming a low amount of food, our body fat percentage is down, we’ve likely been in a restrictive mindset, etc- maybe we didn’t properly plan our dieting phase, so at a certain point, we’re like fuck it- I’m over it- and we stop our diet and go back to our previous dietary habits- whatever they happen to be.
So now, we likely have a steep increase in energy intake along with a metabolism that is down regulated (or slowed down) from a period of low energy intake.
What do we think is going to happen? We are probably going to have some fat gain- and because our body is smart and wants to keep us safe- we might even overshoot the level of body fat that we had prior to our diet.
Gaining weight after a diet does not make you a bad person. It does not make you a failure.
It does make you a human. Lols.
I feel like I say this all the time, but we just can’t diet forever.
Periodization is key. Absolutely.
So what are the implications of this idea? How do we go about changing our body composition for good?
You guys freaking know the answer to this!
Put on muscle!
Remember our basal metabolic rate (BMR) makes up 60-70% of our energy expenditure- and guess what the main predictor of BMR is? Fat free mass- aka muscle mass!!
This also means that you likely won’t be able to achieve (AND MAINTAIN) the body composition you want after one 12-week dieting cycle- it will likely take multiple cycles of dieting and eating in a surplus to GAIN MUSCLE in order to get the physique you want.
There are no short-cuts. We simply can’t outsmart our physiology- but we can learn to work with it.
Trexler, Smith-Ryan & Norton (2014). Metabolic adaptation to weight loss: implications for the athlete. Journal for the International Society of Sports Nutrition, 11(7).