
Anyone who has dieted for an extended period has experienced "hitting the wall": the dreaded slowing, and even complete stoppage, of fat loss.
This is leptin.
Just as noticeable is the increase in appetite that comes with it, often showing up as true, almost uncontrollable cravings for food.
This is also leptin.
Then there is the increased loss of muscle. And the susceptibility to illness. And the fatigue.
Yep. That is leptin too.
It might be time to school yourself on this one hormone.
Fat loss is normally rapid at the start of a diet, with up to 1 kilo a week being common, even for someone who is already fairly lean. But that exciting start soon falls victim to the wonderful world of evolution. In times of scarcity, your body is a smart cookie.
If you starve yourself long enough and your body had a voice, this is what it would say:
"We are not getting many calories. I had better slow down how many calories I burn, or the fire will go out."
This is not a random idea. It is backed by science. Low leptin levels are correlated with decreases in resting energy expenditure [6][7][8], and studies that experiment with leptin in animals that have defects in leptin production back this up clearly [9].
Key findings from the study referenced here [9]:
Decreases in leptin are strongly associated with increased voluntary food intake in animals, and with hunger and the desire to eat in humans. The research found this hunger response happens regardless of changes in fat stores and food intake [10][11]. And the lower leptin goes, the greater the hunger.
In other words, this is not just a matter of willpower. It is a PHYSIOLOGICAL STARVATION RESPONSE, shaped by millions of years of evolution in a world without supermarkets. It is your body commanding you to find food, right now.
It has long been common practice, when low leptin symptoms start to appear, for the dieter (hopefully not you) to cut calories even further, add more cardio, start munching on carrots, or all of the above, to create a larger deficit and force fat loss back on track. This might work for a very short period, but it also drives leptin even lower, making things worse.
At this point the dieter usually does one of two things:
But hope is not lost.
What I am about to suggest sounds absolutely crazy and, at first, makes no sense. To keep fat loss going, the dieter needs to eat MORE, not less, for a short amount of time.
I do not mean a slice of pizza or eating at maintenance for a day. I am talking about what is essentially pigging out for 12 to 48 hours. And to top it off, most of those calories will come from the evil "carbohydrate".
I do not like the term "cheat day", because it implies you are doing something wrong. What I am describing are REFEED days. They are PURPOSEFUL and they are PLANNED. That is why we call them refeeds. "Cheat days" just make you feel bad, and that is not a healthy choice of words for self-love.
Refeeds are ideally done on a regular basis, BEFORE all of the low leptin symptoms set in. Deliberate, planned overfeeding on carbohydrates is the lever that pulls leptin back up.
If you have been stuck in a dieting rut for a while, run through this quick questionnaire:
If your honest answers point to a long, unbroken deficit with no planned high carb days and stalled fat loss, a planned refeed is very likely the lever you are missing.