I used a glucose monitor along with my smartwatch for 2 weeks to see how certain foods affected sleeping patterns and stress levels. There is a correlation between glucose levels and sleep/stress for me. I used the data and determined eating certain foods such as pasta and rice in the evening does affect my sleep. So changing what/when I eat did help me. Fluctuations are normal but there are healthier parameters and certain foods (rice sand pasta) will spike your sugar levels way more which in the long term may lead to insulin resistance. I eat anything and everything but nowadays I’m adjusting portions accordingly to improve my health and lifestyle. I learned a bit of information about myself and it has helped me tremendously. I don’t recommend spending $200 for such a device. I was lucky I had access to one for two weeks.