The feeling of satiety (fullness) does not come only from a “full” stomach, in fact it is only a minor contributor. Hunger, fullness and the desire to start eating and stop eating is a complicated process controlled by a delicate dance of hormones, neurotransmitters (chemical messengers) and other body chemistry, the majority of which are controlled by the primary brain in the skull and the secondary brain in the gut … yes we do have a brain in the gut.
Reason one – insulin resistance
If you are hungry (desire to keep eating) after eating, it may be time to look at the quality and composition of food being consumed. According to one researcher (Lustig, 2012) humans release double the insulin as we did 30 years ago. The research seems to point to a poor diet that can include excessive amounts of calorie dense nutrient deficient foods. This can lead to excess production of the hormone insulin. According to the research, insulin, which is a fat storage hormone, builds up in the blood. The body can reacts to this hyperinsulemia by developing insulin resistance. This insulin resistance reduces the function of insulin to get needed fuel into the cells for energy … the cells hunger for energy.
This excess insulin then performs it’s other primary function of fat storage. The accumulation of body fat can also disrupt the hormone leptin. Leptin, along with insulin, controls energy balance by signaling the brain to stop eating. Disrupt leptin and the brain does not receive the message … the desire to eat continues.
Consuming a nutritional dense diet, low in concentrated carbohydrates with calories equivalent to meet our needs is one strategy to combat insulin resistance. It is also important to have an annual physical to rule out any disease or deficiencies that already may exist.
Reason two – brain’s reward system
There are 2 systems in the brain that control hunger. The first is the Homeostatic System and it is vital to our survival. Our brain is the command center for regulating our appetite which includes a complex dance between hormones, neurotransmitters, neuropeptides, and macronutrients such as carbohydrates, proteins and fats. Our bodies are designed to maintain a balance between our needs for energy derived from foods and our intake of the food. Without this drive for “homeostasis” we wouldn’t have survived all these eons. However, in the past 30 years something has interrupted this homeostasis resulting in the obesity epidemic.
The second system at work is called the Hedonic System or pleasure-reward system. Our brains are hardwired to respond and seek rewards that are essential for survival through the hedonic system. This system drives the homeostatic system to encourage us to eat and to store sufficient calories to protect us from the potential of future starvation or famine, based on how agreeable the food and liquid is to the “palate”. This palatability varies … it is lower after consumption of food and liquid and higher when deprived. The pleasure-reward system is activated when we eat food that is pleasurable thus making us more likely to seek out that food again. The more pleasurable, the more addictive the food becomes, the more we seek it and we learn the more we eat the better is seems to make us feel, physically and often mentally. This can create a hedonic hunger, that is driven by a need for pleasure-reward that is independent of basic homeostatic needs.
The Hedonic System places a higher value … higher reward and satisfaction … on some foods more than others, especially those containing high amounts of fat, sugar, salt and flavorings. Consuming 2 slices of pizza and a sweetened beverage, or a burger and high fat fries with sweet and salty condiments and a sweetened beverage, could drive you to want more of the same or something of equal value on the reward and satisfaction scale. A salad on the other hand may not evoke such a strong reward, but one that rewards the brain sufficiently enough to satisfy the appetite without driving you to seek more. This takes us to reason three, highly palatable food.
It is possible to rewire the brain. Click this link to learn more about rewiring the brain http://yeahstub.com/article/rewiring-your-brain-to-stop-food-addiction-and-obesity
Reason three – highly palatabile food
Food that is palatable prompts us … drives us … to seek out and eat more, even when we’re not physically hungry. So what makes food palatable? What makes foods so palatable that they can make us overeat to the point of feeling “Thanksgiving stuffed” at any time of the year?
In a previous Examiner article the 7 factors noted that influence palatability included:
1. Processed foods. No surprise here. The mixture of foods refined by industrial processes, such as sugar, flour, salt and certain fats are typically mixed with flavor enhancers and chemical additives. These food-like products are ingested in a form that triggers an excessive release of neurotransmitters, similar to recreational drugs, which can promote compulsive intake and loss of control.
2. High sugar / high glycemic load carbohydrates. Sugar, a type of a carbohydrate known as a disaccharide, is classified as addictive based on animal models. When sugar is found in fruits and vegetables it’s found in smaller concentrations and coexists with other natural substances like fiber, vitamins and trace minerals that have numerous beneficial benefits.
Highly refined carbohydrates have a rapid absorption rate causing a spike in the blood glucose level, followed by a surge of neurotransmitters. The body responds to this increase in blood glucose by a sudden drop resulting in increased hunger.
Human studies have shown that a high glycemic load shakes triggered the Hedonic System resulting in increased hunger resulting in overeating in spite of adequate caloric intake. Take home message: avoiding highly processed/refined/high glycemic load carbohydrates can help people avoid overeating.
3. High fat. Many people crave fatty foods, like melted cheese, full fat ice cream, and cream of broccoli soup. Eating foods high in fat have not shown to trigger the same circuitry followed by drug abusers but animal studies have shown that another mechanism may be involved in cravings for high fat foods. This may be why you can’t just eat 12 almonds!
4. Salt. Some researchers believe that salty food might be an addictive substance that stimulates the reward-pleasure system. Research to date has been on animal models yet shows once again, that salty foods encourages more salt binging. This may be why “you can’t just eat one” of your favorite chips. The food industry uses salt as the answer to making cheap, unpalatable food edible at a very low cost.
5. The combination of sugar and fat. Animal models show that rats will work hardest for a food that combines sugar and fat. The combination of these two food components promoted weight gain in rats vs. a diet only high in sugar or a diet only high in fat. Fast food scientist have taken this combination to create “food” with super addictive palatability. Add to this clever and constant marketing; enticing food-eating restaurant environments, and a stressful day, enough for the primitive human brain to be easily hijacked to overeat.
6. High fructose corn syrup (HFCS). The controversy over HFCS still continues yet some facts cannot be overlooked. Fructose follows a different pathway than glucose. Breaking down fructose results in an increase in hunger and creates a strong desire for food. Interesting side note; the special properties of fructose resemble that of alcohol. Just like alcohol, when fructose is taken in large quantities, it can result in neurobiological changes (the brain begins to change the way it responds and even looks!)
7. Food availability, it’s visual appeal, incentives (i.e. Value Meal); social situations revolving around eating, and advertising and marketing are other factors that influence the potential for food addictive-like behaviors.
There may be many reasons for excessive hunger including medical conditions like, but not limited to, reactive hypoglycemia, per-diabetes and diabetes. If you are experiencing excessive hunger see your medical care provider for a strategy that matches your specific circumstances.
This information is not intended to replace a one-on-one relationship with a qualified health care professional and is not intended as medical/nutritional/fitness advice. Information presented is subject to change as additional discoveries are made or additional research is published. Links to various sites are provided for your convenience only and we are not responsible or liable for the content, accuracy of information provided or privacy practices of linked sites or for products or services described on these sites.
Additional information: Dash Eating Plan, http://www.B3Nutrition.com
Sources: http://yeahstub.com/article/scottsdale-food-addiction-obesity-and-diabetes, National Institute of Drug Abuse, The Free Dictionary, wikipedia.org/wiki, Institute of National Resources, Merck Manuals, http://en.wikipedia.org/wiki/, http://www.webmd.com/, http://yeahstub.com/article/rewiring-your-brain-to-stop-food-addiction-and-obesity,