Leptin:  the Scoop on this Hunger Suppressing Hormone!  

Leptin plays an important part with your weight and any goals you have related to it.  It's a hormone released by the fat cells to tell the body when it is satiated.  The more adipose tissue (fat) you have, the more leptin your body makes.  Exercise and food also affect leptin production.  The more calories you burn in a workout, lowers the level and the more carbohydrates you eat, raises it.  Also, woman produce more than men with the same body fat percentage.   

When you eat, your body releases leptin.  This is received by the receptors in the hypothalamus--part of the brain responsible for hormone production and management.  The purpose is to tell the stomach, energy stores are replaced, so hunger is no longer needed.  According to WebMD, "starvation triggers several processes within the body that drive leptin levels back up. One includes stimulation of the vagus nerve - regarded as your energy storage nerve - which runs between the brain and the abdomen".  Any deficit will drop leptin, including exercise.  Research from Wake Forest University found burning 900 calories raised levels more than a 200 calorie workout.  Also, carbohydrates raised it more than eating fat. Why then does obesity exist if this hormone is controlling hunger?  Aside from it not being the only hunger controlling hormone, bodies develop leptin resistance.   

Like most anything we introduce our bodies to, it adapts or in this case, builds a resistance.  The reason behind this particular resistance isn't fully known, one theory is, receptors it binds with don't function properly.   According to Muscle Evo, "It appears that leptin isn't active in the part of the brain that controls eating behavior. When leptin is constantly elevated, which it will be in most overweight or obese people, the transporters that help leptin to cross from the blood into the brain become saturated. There may also be genetic causes that contribute to leptin resistance", such as with women. 

Leptin is linked to fertility in women and theorized to protect the reproductive system.  Which is why women produce more than men and when women experience a deficit, the levels drop but don't change in men, based on a 1997 study.  A lot of energy (calories) is needed for reproduction.  Harvard Medical School gave eight women, with "40% less fat than average women their age"--do to overexercising--and who had lost their periods, leptin injections.   Once levels were restored to normal, six of the women's menstrual cycles returned.   

This doesn't mean if you're a woman having trouble losing weight, you should throw up your hands and say, "I quit!"  Authority Nutrition suggests avoid processed food, eat soluble fiber, exercise, get restful sleep, eat protein, and lower triglycerides because they can "prevent the transport of leptin from the blood into the brain".  Don't let your body go into starvation mode, like we discussed last month.  Eat a high protein breakfast and reduce or eliminate refined carbohydrates.  Stick to whole grains, starchy vegetables, and  fruits. 

Shimmy Away the Inches in BellyFIT!