Why are you still hungry after a meal? If you are overweight or on a diet, you probably wonder about this on a daily basis. People often find themselves looking for something to snack on shortly after eating a full meal. Is it because your appetite is not satisfied as it should be or is there something else that’s causing these food cravings. Perhaps you grew up with a desert course after dinner. In other cases, people find themselves fighting an ongoing battle with their body chemistry.
Insulin, Leptin and Hunger
Both insulin and leptin suppress appetite when elevated blood levels of either one reach the appetite center of the brain. Insulin levels go up when you eat carbohydrate rich meals while leptin generally reflects longer term changes in body fat (energy stores).
When we eat, insulin is released. The insulin sends some tryglycerides to the fat cells, and the fat cells produce leptin in response. Once the level of leptin rises enough, the brain receives the signal that we have replenished energy stores and turns the hunger signal off. This higher level of leptin also signals the pancreas to stop making insulin. (1)
However, this mechanism does not work as it should when you are overweight or obese. As a person forms insulin and leptin resistance, the communication breaks down; the hunger signal isn’t received as and when it should, and the production of insulin does not get shut down as it should either.
The key to weight loss is to suppress your appetite and burn fat more quickly. This happens when insulin and leptin reach the brain, but both hormones don’t reach or communicate with the brain adequately when we are overweight.
When a person has insulin resistance or leptin resistance, there is an abundance of both hormones circulating in the blood, but the brain does not get the message! How is it that even though blood levels are high, the brain cannot read the levels?
The Blood-Brain Barrier
Some scientists now suspect that the blood-brain barrier is where the problem occurs. The blood-brain barrier is the doorway to the brain and it allows or blocks nutrients and signals to pass through to the brain. This might explain why elevated levels of insulin and leptin don’t signal the brain properly in individuals with insulin and leptin resistance. If insulin and leptin can’t pass through the blood-brain barrier for some reason, the message does not get delivered. (2)
How To Improve Leptin Resistance
- Reduce Fructose: fructose is converted to triglycerides when it is consumed in excess. Fructose is a part of sucrose (sugar) and high fructose corn syrup. Reduce your sugar intake and high glycemic index fruit.
- Exercise and Excitement: exercise and excitement increase epinephrine which boosts leptin transport across the blood-brain barrier by a factor of 2 to 3.
How To Improve Insulin Resistance
- Eat less free fatty acids: trans fats and omega-6 unsaturated fatty acids cause inflammation of the insulin receptors.
- Eat more omega-3 fatty acids: fish oil and coconut oil are anti-inflammatory.
- Reduce fructose: some sugars like fructose could cause inflammation
Time and Perseverance
If you are experiencing appetite control problems while dieting, it is probably your fat stores telling the brain you’ve lost some body fat that needs to be replaced. The best cure for this is simply to eat more… but make sure you eat more of the right foods.
As long as you are eating low glycemic foods you won’t trigger spikes in the release of insulin. The last thing you want to do is consume sweets or simple sugars.
As we lose weight, we always come to plateaus at various points along the journey. The only cure is time and perseverance. Stick with your diet and you will break through the plateau and shed a few more lbs. The best diet is one that puts your body into permanent fat burning mode.
(1) Byron Richards, The Leptin Diet, p. 13, 17, 23, 36.
(2) Banks WA http://www.ncbi.nlm.nih.gov/pubmed/16904139.