Hunger can make you happy

In contrast to the many dieters' laments, hunger can make you happy. Or at least it can be an evolutionary motivation to help you find meals instead of becoming meals.

When our bodies realize that we need more calories, the concentration of hormones called ghrelin increases . Ghrelin is known to promote hunger, but new research suggests it is only a side effect. Its main task is to reduce stress.

Researchers control gherlin levels in mice with a variety of methods, including long-term calorie restriction, gherlin injections and genetic alterations that make mice numb to gherlin's effects.

Mice with limited gherlin activity seem depressed. If they are pushed into deep water, they do not try to swim. When taken into a maze, they cling to the entrance. When placed with other mice, they tend to isolate themselves. (These behaviors are reversed when these mice are given a mild anti-stress dose commonly used for humans).

In contrast, mice with high levels of ghrelin swam energetically in deep water, finding their way out. They eagerly explore new environments. They are also more lively in the community.

Mice are considered to be suitable for humans in the above experiments. The study, funded by the National Institutes of Health and other organizations, is detailed in the journal Nature Neuroscience on July 2008.

In the wild

(Photo: thestockmasters)

Researchers believe that the state of excitement caused by hunger is an adaptation . Looking for food, especially in the wild, requires concentration, awareness, and work.

If hunger makes us afraid, we can easily become someone's dinner. Instead, gherlin promotes and makes us focus on finding food!

Hunger is not the only factor that causes gherlin levels to rise. Social anxiety can also stimulate this hormone . When mice are locked up with an older and "bully" mouse (like an authoritarian boss), gherlin levels rise and remain the same for weeks.

High Gherlin may be the reason some people eat a lot when stressed. If this action can be avoided, the researchers believe that ghrelin levels will remain high and help us face stress in a calm and effective manner.

The ability to become addicted

So when they are really hungry? Of course, there is nothing interesting about that!

Researcher Michael Lutter at the University of Texas Medical Center in Southwest said: 'You will not see the effect [of anti-stress hormone] when you reduce 10 to 15% of your body weight' . But when you feel familiar with gherlin's effects, it can be addictive - this may explain why people with anorexia are difficult to recover.

This is also the cause of Calorie Limiting (CR). Encouraged CR pursuers from animal studies suggest that eating less than 20 to 30% is enough to last a lifetime (even if this is true, according to American Medical Association monthly report). In 2007, eating less led to bone and muscle wear, fatigue, constipation, dizziness, and other poor health signs.

Although CR's anti-aging effects work according to another mechanism, Lutter is not surprised if long-term dieting gives people pursuing CR excitement.