WASHINGTON – The US Department of Agriculture's Agricultural Research Service (ARS) and Ajinomoto Company are collaborating in a joint-research project to explore whether the regular inclusion of dietary sodium glutamate (MSG) used to enhance the taste of foods has beneficial effects on eating behavior and body-weight management.

To be conducted by ARS' Western Human Nutrition Research Center (WHNRC), the trial will assess in overweight women whether adding sodium glutamate to foods facilitates the control of appetite and caloric intake, and prevents body weight rebound following a period of moderate energy restriction and weight loss. The trial is expected to be completed in the next two years.

"For some people, long-term improvements in eating behavior and body weight are difficult to maintain, and the mechanisms that explain this fact are poorly understood," said Dr. Kevin Laugero of WHNRC.

Novel nutrition-based strategies might help people to improve the quality and amount of food they eat while maintaining the emotional and pleasurable qualities of eating. Foods or food ingredients that enhance these qualities of eating might also reduce the drive or motivation to eat, particularly energy dense foods.

MSG has long recognized to enhance the savory quality of foods and promote a positive emotional response (pleasantness) of eating. Regularly including MSG or foods naturally high in glutamate may help people to improve the quality and amount of their food intake, yet maintain the emotional and pleasurable qualities of eating.

The research is expected to add to the growing base of science around umami, widely accepted as the fifth basic taste in addition to sweet, sour, salty and bitter. Glutamate, an amino acid naturally found in many common foods such as tomatoes, cheese, and cured ham, is considered the purest form of umami.

Recent research has identified umami receptors on the tongue. Providing a savory taste of its own, umami also enhances and balances the sensory experience of other tastes. MSG, the sodium salt of glutamate, improves the palatability of foods and has been widely used as a flavor enhancer for more than a century, initially in Asia and later globally.

Significant research documents the potential value of MSG as an aid in reducing dietary sodium. Given the global obesity epidemic and the role of diet as part of the solution, research initiatives such as this are increasingly important for informing and creating solutions that will improve public health.

"The Western Human Nutrition Research Center's expertise in nutrition and the regulation of food intake and metabolism, combined with Ajinomoto's demonstrated knowledge and leadership related to umami and MSG, create a powerful partnership as we seek a better understanding of how to improve eating behaviors and human health," said Masatoshi Ito, president and CEO, Ajinomoto Company.

The Western Human Nutrition Research Center is one of six USDA ARS Human Nutrition Research Centers. It is located on the University of California Davis campus, and affiliated researchers have expertise in developing and conducting nutrition intervention studies.