Leptin was Kat James’ topic during the first half of the program Saturday. It is an interesting subject, so I thought it might be helpful to review and expand a bit.
For most of man’s entire history, lack of food was the danger. Therefore, our brain wisely responds to many signals to find food, eat it and pack on body fat as a hedge against the next famine. Even our pleasure center rewards us when we eat.
In those relatively rare times of plenty when humans put on fat, those fat cells made leptin which tells the brain we are satisfied—e.g. not hungry. (Leptin is a kind of a “boss” hormone/messenger that has extremely important jobs that we’ll discuss more next week.) Fast forward to modern times when most Americans have access to too much food and are overweight. You’d think we would make a whole bunch of leptin. That should make us stop eating to provide the body “fuel” and burn our stored body fat instead. In Part 2, I’ll explain why the plan is often not working due to “leptin resistance”.
Another way to get the body to burn fat for fuel is to eat dietary fat. That tells the body we are in times of abundance and can afford to burn our fat. In contrast, when we eat carbohydrates (other than non-starchy vegetables), the message is that we better store fat. Looking at it another way, the fats we eat are temporary. However, the kind of fat that the body creates from blood-sugar-spiking carbohydrates in the diet may stick around for decades. The simplistic notion that if we eat fat, it just gets stored as fat around our middles seemed logical, but was flat wrong.
In fact, the US population started becoming obese with the “food pyramid” when we were told to avoid butter, lard, other sources of saturated fat, as well as avocados, nuts, and so on. Of course, not all fats are good. The Trans fats in margarine and other partially-hydrogenated oils are terrible. (Hah! That was another classic piece of bad advice from the so-called experts. They told us to give up butter and eat margarine.) I recommend avoiding corn oil, soy oil and the like because they are contain an excess of pro-inflammatory omega-6 fats. Olive oil, fish oil, and nut oils (especially macadamia) are excellent. The tide of expert opinion is turning in a more positive direction on saturated fat like butter. I sang its praises in last week’s blog and next week will cover ideas on how much of the diet might be fat.
Read part 2 of this blog.