The hormone leptin is the anti-starvation hormone. It signals the other fat regulating hormones how to behave.
So, if you are interested in achieving or maintaining a healthy percentage of body fat, having some understanding of how it works is very helpful.
If you have any personal experience with reducing diets, you probably understand that dieting is not the way to go if you are interested in losing fat and keeping it off.
It should be! It seems to make sense.
Yet if dieting worked, all we’d have to do is to go on a reduced calorie diet (and ramp up the exercise a bit) and we’d end up with a six-pack. That’s simply not the way it works.
Less than one-tenth of one percent of our genes have changed in the last 20,000 years. When our prehistoric ancestors had to go without food for a while, as would happen at least occasionally, their bodies attempted to keep them alive by preserving body fat. Fat is very valuable because it is good for both energy as well as warmth.
When we go on a starvation diet, which is one that averages less than 2000 calories daily, our bodies react as if we were slowly starving to death. They try to maintain as much fat as possible for as long as possible.
That’s the basic explanation for why dieting doesn’t work well. If you just go on restricting calories week after week, month after month, you are not only going to have less energy but also, after about one week, your body will begin to fight your fat loss.
Leptin plays a critical role in the starvation process.
Your leptin level is affected by both (i) your percentage of body fat and (ii) your caloric intake.
(i) With respect to body fat, the higher your percentage of body fay, the higher your leptin level; the lower your percentage, the lower the level.
This partially explains why, all other factors being equal, it is easier to go from having a high percentage of body fat to having a normal percentage of body fat than it is to go from having a normal percentage of body fat to having a low percentage of body fat. (Becoming a champion bodybuilder really is difficult!)
(ii) With respect to caloric intake, your leptin level takes about one week of dieting to be reduced by half. In other words, your fat “burning” potential gets cut in half in about 7 days!
The good news is that, if you plan a once-a-week cheat day, you can overeat carbs and fats (such as pizza!) to restore your fat burning potential.
Each of us is unique. There isn’t one formula for achieving and maintaining a healthy percentage of body fat that works best for everyone. So there are two cautions here.
First, never make major changes to your diet (or exercise program) without your physician’s approval in advance. Your physician should have a good understanding of your physical anomalies.
Second, with your physician’s blessing, experiment with a cheat day to determine if it works well for you.
In the case of testing a once-a-week cheat day, here’s a sufficient reason to get your physician’s approval in advance: leptin and insulin levels are correlated. They rise and fall together. Insulin is the fat storage hormone. If you are diabetic or pre-diabetic, you want to avoid insulin spikes, which means also avoiding leptin spikes. In general, that means usually not exceeding about 25 grams of carbohydrates from all sources per day.
Remember two facts with respect to carbohydrates: all carbohydrates, when digested, become sugars and it is not necessary to ingest any carbohydrates for excellent health. (In other words, the minimum daily requirement in grams for carbohydrates is 0.)
However, as long as you obtain your physician’s blessing in advance, I encourage you to test the once-a-week cheat day. It can be very helpful both physiologically and psychologically.
Frankly, I’m old and it doesn’t work that well for me. I think in terms of one cheat meal per week or, on my birthday, one-half of a cheat day per week!
However, it certainly has worked well for many people and it may work well for you.
Remember, though, not to confuse fat loss with weight loss. You’ll have to lose 15 or 20 pounds of weight to lose 10 pounds of fat. That’s because some of the weight loss that occurs when you lose fat is actually water loss. If you adopt a low carb diet for a few days, a considerable amount of the weight you lose will be water.
There are ways to tweak a cheat day that can maximize its effects.
For example, your body will adapt quickly to burning carbs as well as fats on your cheat day and, so, the day after the cheat day is a really good time to restrict calories and get lots of exercise. Especially when you restrict calories, it’s a good idea to use effective supplementation.
For example, the day before a cheat day is an excellent day to restrict your daily intake of carbohydrates to 20 grams or even less.
Even on your cheat day, do not stuff yourself: when you feel full, stop eating.
If you are tempted to keep eating after you are full, you probably have some emotional issues around eating that you should isolate and deal with separately. [See the book recommendation below.]
When measuring your results, remember that it’s fine to gain some weight on your cheat day if you are losing weight for the week. If you put on one-half a pound on your cheat day but end the week with a net weight loss of 1 or 2 lbs., that’s excellent! Losing one or two pounds per week is do-able for many people for months on end.
For some people, manipulating leptin levels is an effective tactic for doing that.
As always, if you know someone who might benefit from this, please pass it along.
Related resource: my How to Survive College Emotionally.