A recent study says it has discovered another way in which the body controls its food intake and this could help understand obesity. US researchers say that poor or lacking diets could trigger a signaling system which goads the body to eat more by throwing critical potions out of sync. The signals involved a protein linked to inflammation and when it was blocked in mice they came back to normal weight 

The study in the October 3rd issue of the journal Cell, a Cell Press publication was conducted on mice and it found that the response in the brain's hypothalamus, the "headquarters" for maintaining energy balance, can happen even in the absence of any weight gain. The key role is carried out by a molecular player, called IKKß/NF-κB, which is known to drive metabolic inflammation in other body tissues. Experts feel this discovery could mean that treatments that were designed to block this pathway of the brain could help in controlling obesity and related diseases like diabetes, and heart disease. 

Dongsheng Cai of the University of Wisconsin-Madison who led the study said, "This pathway is usually present but inactive in the brain." He says why IKKß/NF-κB is present is not clear but speculates that it may have been an important element for innate immunity, the body's first line of defense against pathogenic invaders, at some time in the distant past. "In today's society, this pathway is mobilized by a different environmental challenge—overnutrition," he said. Once activated, "the pathway leads to a number of dysfunctions, including resistance to insulin and leptin," both important metabolic hormones.

In the study the researchers discovered that when mice were given a high fat, high sugar diet, a protein connected to inflammatory reactions was switched on. This led the mice to eat more which led them to believe this was part of a pathway which regulated food intake. When the hypothalamus, which is known to be involved in energy regulation, was examined it revealed the presence of the protein there as well. 

"Our work marks an initial attempt to study whether inhibiting an innate immune pathway in the hypothalamus could help to calibrate the set point of nutritional balance and therefore aid in counteracting energy imbalance and diseases induced by overnutrition," the researchers said. "We recognize that the significance of this strategy has yet to be realized in clinical practice; currently, most anti-inflammatory therapies have limited direct effects on IKKß/NF-κB and limited capacity to be concentrated in the central nervous system. Nonetheless, our discoveries offer potential for treating these serious diseases."

Professor Fran Ebling, from the University of Nottingham, said this new finding may not result in an effective anti obesity drug. "It's certainly interesting, but if we have some drugs that target this pathway, they may well interfere with some other part of the immune system."

Cai feels that inflammation and obesity are "quite intertwined” and an abundance of calories tends to promote inflammation, as does obesity in a vicious cycle by feeding back to the neurons. These findings could help discover treatments that could stop this cycle before it starts and if it does succeed, such a strategy would likely offer a safe approach given that the critical pathway appears to be unnecessary in the hypothalamus under normal circumstances, they noted.

Cai said, "The ultimate goal will certainly be to identify a selective and effective suppressor of the pathway to target related neurons."