The Role of Exercise in Weight Loss and Appetite Regulation

Engaging in exercise is an effective way to lose weight and protect against obesity-related diseases such as diabetes and heart disease. Researchers indicate that exercise not only burns calories but also involves mechanisms that affect appetite and weight.

Discovery of the Metabolite Lac-Phe

In a recent study, researchers discovered that Lac-Phe is the metabolite that increases the most in the blood after intense exercise, not only in mice but also in humans and racehorses. Previous studies have shown that introducing Lac-Phe to obese mice reduces their appetite and helps them lose weight without negative side effects.

Dr. Yang He, a co-researcher in the study, explained that understanding how Lac-Phe works is an important step in developing treatments that may aid in weight loss. The researchers focused on studying the effect of Lac-Phe on the brain, where it regulates appetite and eating behavior.

The Role of Neurons in Appetite Regulation

Researchers studied two types of neurons in the brains of mice. The first type is AgRP neurons, which stimulate hunger and are located in the arcuate nucleus of the hypothalamus. The second type is PVH neurons, which help suppress hunger and are located in the lateral nucleus of the hypothalamus.

AgRP and PVH neurons work together, with AgRP neurons typically sending signals that inhibit PVH neurons, making you feel hungry. However, when AgRP neurons are inhibited, PVH neurons become more active, reducing appetite.

The Effect of Lac-Phe on Neurons

Members of He’s lab and colleagues discovered that Lac-Phe directly inhibits AgRP neurons, leading to the activation of PVH neurons. This sequence of events resulted in reduced food intake in mice, while the animals’ behavior remained normal, indicating that Lac-Phe does not cause undesirable side effects.

Additionally, the team studied how Lac-Phe inhibits AgRP neurons, discovering that Lac-Phe acts on a protein called the KATP channel in AgRP neurons, which helps regulate cell activity. When these channels are activated by Lac-Phe, the neurons become less active.

Potential for Future Treatments

This research illustrates how exercise can naturally reduce appetite and improve metabolism. Dr. Yong Xu noted that the findings suggest the possibility of targeting this newly discovered mechanism for weight management.

This discovery is significant because it helps understand how a natural molecule can influence appetite by interacting with a key brain area that regulates hunger and weight.

Conclusion

Although this study focused on mice, the results are promising for humans. Future research will explore how Lac-Phe functions in different metabolic conditions, such as obesity and leanness, how it travels to the brain, and whether it can be used safely and effectively as a treatment.