free article in JAMA about wearables and weight loss: “Devices that monitor and provide feedback on physical activity may not offer an advantage over standard behavioral weight loss approaches.”

Martin Daumer September 22, 2016

Effect of Wearable Technology Combined With a Lifestyle Intervention on Long-term Weight LossThe IDEA Randomized Clinical Trial

http://jama.jamanetwork.com/article.aspx?articleid=2553448

http://www.heilpraxisnet.de/naturheilpraxis/studie-fitnessarmbaender-fuehren-doch-nicht-zu-einem-zusaetzlichen-gewichtsverlust-20160922203238