Leptin is a hormone. It is extremely important in the regulation of appetite, food intake and body weight. An absence of leptin in the body can lead to uncontrolled feeding and weight gain.
What it does. Leptin acts as a hormone that regulates the size of the fatty tissues in the body. It controls food intake and body weight. It also acts to inhibit appetite. When fat mass decreases, the level of leptin falls so that appetite is stimulated until the fat mass is recovered. There is also a decrease in body temperature and energy expenditure. In comparison when fat mass increases, so do leptin levels and appetite is suppressed until weight loss starts up again. This is how leptin regulates energy intake and fat stores so that weight is maintained within a healthy range.
To simplify (if that’s possible) the hypothalamus in the brain controls leptin. When leptin levels increase, leptin attaches to leptin receptors in the hypothalamus, and your brain sends a signal that you are “full”. Your metabolic rate will increase as a result of this signal. When leptin levels decrease, the brain thinks you are no longer fueled. Consequently, your brain sends a message that you are hungry, and your metabolic rate decreases. Leptin receptors are mainly in the hypothalamus, but they are also located throughout the rest of the body.
What Does This Mean?
What it means is you need leptin levels to be in order if you want to be or stay lean, think clearly, be in a good mood, etc. The longer your body is in a calorie deficit, then the lower your leptin levels and metabolic rate become. What this means is your metabolism slows, and it will be extremely hard to lose that last bit of fat. I see this all the time in the gym.
On the flipside, leptin can also be your enemy. If you constantly eat excessively above maintenance levels, then the body can become leptin resistant. What this means is your body cannot distinguish that your body fat levels are too high, and leptin receptors are desensitized. The more leptin resistant the body becomes, then the more the body tends to sway towards staying fat compared to lean.
Also, toxins or other stressors can result in leptin resistance. These can range from anything from our diet to lack of sleep.
What can I do to control leptin levels?
A good way to control leptin is to stay lean! Don’t go on large bulks and/or get too far over target weight.
When you feel that your metabolism slows or that you have been in a deficit for too long, you may periodically include a re-feed day. When prepping for a show, bodybuilders will have a re-feed day. Usually, a re-feed day consists of a day with a 20-50% increase above maintenance calorie level. A general rule for a re-feed day is to increase carbohydrates 100-150% than normal, keep protein at about 1g/lb. of bodyweight, and keep fat intake as low as possible. A re-feed day is a sure way to kickstart your metabolism and to normalize your leptin levels. This does not mean you should start shoving pop-tarts and skittles down your throat. When you do as much cellular damage in the gym as most serious lifters do, the smart thing would be to try and make those healthy carbs if possible.
Speaking of cellular damage and the like…
Vitamin C is very important as an antioxidant in relation to obesity. This is because most mammals synthesize vitamin C from sugar, but humans have an abnormal genetic mutation that prevents this (dammit). This will cause cravings for sugar when what you really need is vitamin C. Some scientists believe it is helping to cause the obesity epidemic.
Overweight people must have more antioxidants in order to get a good response to exercise. This is due to poor oxygen usage in cells, which is common in overweight people. Ironically, simply boosting exercise without supporting antioxidant needs can actually worsen free radical damage and induce greater levels of inflammation – the opposite of what any person would like to have happen. unsure emoticon
I recommend a variety of antioxidants for maintaining a healthy weight, including:
Vitamin D Low vitamin D has now been conclusively linked to obesity and the metabolic syndrome. It is clear that vitamin D helps to slow down the increase in the number of fat cells that accompany gaining weight. Vitamin D is the key nutrient that enables your body to tolerate inflammation, especially important for lifters and those with arthritis etc. Vitamin D and magnesium deficiency have been clearly established as mutual deficiencies in highly dysfunctional fat. Lower levels of vitamin D are associated with leptin resistance. A half hour of sun exposure gives you 10,000 IU of vitamin D. Overweight individuals should get at least 2,000 IU per day and likely need doses ranging from 4,000 IU – 8,000 IU per day to support healthy metabolism. Especially in the winter.
Calcium A lack of calcium can cause an elevation of neuropeptide in your brain, which causes you to have cravings for carbohydrates. It also stimulates the production of new fat cells. Calcium also helps regulate energy.
B Vitamins B vitamins are integral to how your body prepares any type of calorie to be burned as fuel. B6, B12, and folic acid are required for protein metabolism to work properly. When you increase protein intake to assist weight management you need an adequate supply of B vitamins for best results. Vitamin B12, folic acid, and B6 are needed to lower a natural byproduct of protein metabolism called homocysteine. Elevated levels of homocysteine are linked to obesity.
So, as you can see it’s not just about less food and more work to lose body fat and gain muscle. There are a lot of other things that together have a huge effect on the outcome. My advice to you is if you are going to put all that work into lifting heavy stuff and putting it down, put just as much work into understanding the science behind it. There are a lot of very unhealthy “fit” people out there. I’d love it if you were not one of them ☺